No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Septic shock caused by Streptococcus suis: Case report and investigation of a risk group
Abstract
A case of septic shock caused by Streptococcus suis type 2 occurred in a 36-year-old truck driver who transported pigs. Here, as well as in nearly all other cases of S. suis infections reported to date, close occupational contact with pork or pigs preceded the incident. This epidemiological link may be explained by the frequent occurrence of S. suis as a commensal and opportunistic germ in pigs. In order to assess the potential risk for an infection with S. suis, 132 workers in pig slaughtering, pork dissecting and processing industries were examined in a cross sectional study for the occurrence of S. suis in their pharynx, and compared with an age and sex matched control group. The evaluation of the pharyngeal swabs showed an atypical colonisation by a variety of microorganisms in some of the employees who were so far healthy, but potentially at risk. The colonisation of the case group with S. suis amounted to 5.3%.
... Strangmann et al. published a case of septic shock from Germany caused by S. suis type 2 in a 36-year-old man, who was working as a truck driver transporting pigs preceding the incident [63]. In the same study, 132 workers were involved in pig slaughtering, pork dissecting and processing industries, to assess the potential risk for an infection with S. suis [63]. ...
... Strangmann et al. published a case of septic shock from Germany caused by S. suis type 2 in a 36-year-old man, who was working as a truck driver transporting pigs preceding the incident [63]. In the same study, 132 workers were involved in pig slaughtering, pork dissecting and processing industries, to assess the potential risk for an infection with S. suis [63]. In their cross-sectional study, the otherwise healthy workers were examined for the occurrence of S. suis in their pharynx, and compared with an age and sex matched control group. ...
... In their cross-sectional study, the otherwise healthy workers were examined for the occurrence of S. suis in their pharynx, and compared with an age and sex matched control group. The colonization rate of case group with S. suis amounted to 5.3% [63]. In a study by Gustavsson et al., two patients infected with the rare S. suis serotype 5 strains have been documented: one of them was a 65-year-old pig farmer who had cut his hand at work (while no cases were noted of severe illness among his pigs, he had a history of benign hyperplasia of the prostate gland he later developed septic arthritis in Sweden [64]. ...
Streptococcus suis is an emerging zoonotic human pathogen, which is a causative agent of invasive infections in people who are in close contact with infected pigs or contaminated pork products. It is associated with severe systemic infections, most commonly meningitis and sepsis, which may lead to high rates of morbidity and mortality. Serotype 2 is the most prevalent type in S. suis infections in humans. We have reported a case of a very rapidly proceeding fatal human S. suis infection in a splenectomized, but otherwise immunocompetent patient in Hungary. We would like to highlight the attention for this pathogen for the risk group patients, not only pig breeders, veterinarians, abattoir workers, meat processing and transport workers, butchers and cooks, that those persons who are immunocompromised including those with spleen removed, persons with diabetes mellitus, cancer and alcoholism, are also at greater risk of infection.
... Transmission in working environments. S. suis can be transmitted to workers by close contact with pigs or pig products [4], usually through contamination of minor cuts or abrasions on the skin of hands and/or arms causing a breach of skin integrity [5,7,13,41,61,[66][67][68]. Such injuries have frequently been recorded as having occurred 2-3 days prior to the onset of clinical signs [69]. ...
... Such injuries have frequently been recorded as having occurred 2-3 days prior to the onset of clinical signs [69]. It is noteworthy that both Strangmann et al. [66] in Germany and Tramontana and al. [27] in Australia noted the presence of multiple scars and cuts on the hands of the patients who developed septic shock syndrome caused by S. suis after handling pigs or animal carcasses. ...
... The respiratory route with subsequent colonization of the tonsils which is the basic way of transmission among pigs seems to be less significant among humans. Some authors, based on the relatively common presence of S. suis in tonsils of exposed workers, suggest that the workers may become infected by the inhalation of bioaerosols emitted by swine [3,35,66,74], while others regard the airborne transmission to humans as doubtful [7]. According to Fulde and Valentin [39], bacteria may also enter the organism of workers through the conjunctiva. ...
i>Streptococcus suis (ex Elliot 1966, Kilpper-Bälz & Schleifer 1987) is a facultatively anaerobic Gram-positive ovoid or coccal bacterium surrounded by a polysaccharide capsule. Based on the antigenic diversity of the capsule, S. suis strains are classified serologically into 35 serotypes. Streptococcus suis is a commensal of pigs, commonly colonizing their tonsils and nasal cavities, mostly in weaning piglets between 4-10 weeks of age. This species occurs also in cattle and other mammals, in birds and in humans. Some strains, mostly those belonging to serotype 2, are also pathogenic for pigs, as well as for other animals and humans. Meningitis is the primary disease syndrome caused by S. suis , both in pigs and in humans. It is estimated that meningitis accounted for 68.0% of all cases of human disease reported until the end of 2012, followed by septicaemia (including life-threatening condition described as 'streptococcal toxic shock-like syndrome' - STSLS), arthritis, endocarditis, and endophthalmitis. Hearing loss and/or ves tibular dysfunction are the most common sequelae after recovery from meningitis caused by S. suis , occurring in more than 50% of patients. In the last two decades, the number of reported human cases due to S. suis has dramatically increased, mostly due to epidemics recorded in China in 1998 and 2005, and the fulminant increase in morbidity in the countries of south-eastern Asia, mostly Vietnam and Thailand. Out of 1,642 cases of S. suis infections identified between 2002-2013 worldwide in humans, 90.2% occurred in Asia, 8.5% in Europe and 1.3% in other parts of the globe. The human disease has mostly a zoonotic and occupational origin and occurs in pig breeders, abattoir workers, butchers and workers of meat processing facilities, veterinarians and meat inspectors. Bacteria are transmitted to workers by close contact with pigs or pig products, usually through contamination of minor cuts or abrasions on skin of hands and/or arms, or by pig bite. A different epidemiologic situation occurs in the Southeast Asian countries where most people become infected by habitual consumption of raw or undercooked pork, blood and offal products in the form of traditional dishes. Prevention of S. suis infections in pigs includes vaccination, improvement in pig-raising conditions, disinfection and/or fumigation of animal houses, and isolation of sick animals at the outbreak of disease. Prevention of human infections comprises: protection of skin from pig bite or injury with sharp tools by people occupationally exposed to pigs and pig products, prompt disinfection and dressing of wounds and abrasions at work, protection of the respiratory tract by wearing appropriate masks or repirators, consulting a doctor in the case of febrile illness after exposure to pigs or pork meat, avoidance of occupations associated with exposure to pigs and pork by immunocompomised people, avoidance of consumption of raw pork or pig blood, adequate cooking of pork, and health education.
... In humans, resistance of clinical S. suis isolates to clindamycin and macrolides has also been acknowledged, with higher prevalence in recent studies in Asia (approximately 20%) (Ma et al., 2008;Hoa et al., 2011) than in an older study in Canada (8%) (Cantin et al., 1992). In contrast, S. suis strains isolated from healthy German workers occupied in the pig slaughtering, pork dissecting, and processing industries were highly susceptible to most antibiotics tested, including erythromycin (Strangmann et al., 2002). ...
... In Asia, tetracycline resistance in S. suis isolates from both diseased and healthy pigs is also common (up to 92%) (Kataoka et al., 2000;Zhang et al., 2008). High levels of tetracycline resistance (up to 90%) have also been reported among S. suis isolates from diseased and clinically healthy persons (Strangmann et al., 2002;Ma et al., 2008;Hoa et al., 2011). In contrast, a 1992 report showed that only 8% of 12 S. suis isolates from human cases in the Netherlands were resistant to tetracyclines (Cantin et al., 1992). ...
... In a US study, 25% of 65 isolates of S. suis were resistant to penicillin (Reams et al., 1993). Human studies report that S. suis isolates from both diseased and clinically healthy persons are highly susceptible to penicillin, with 0% resistance (Cantin et al., 1992;Strangmann et al., 2002;Ma et al., 2008;Hoa et al., 2011). ...
This paper reviews information on antimicrobial resistance patterns and prudent use of antimicrobials to reduce the impact and spread of resistant Streptococcus suis strains. S. suis is an important pathogen in swine, which can cause significant economic loss. Prudent use of antimicrobials for S. suis is essential to preserve the therapeutic efficacy of broad-spectrum antimicrobials and to minimize selection of resistant S. suis strains. Resistance of S. suis to antimicrobials commonly used in swine, including lincosamides, macrolides, sulphonamides, and tetracycline, has been documented worldwide, with resistance in up to 85% of strains. Among antimicrobials examined, resistance of S. suis has been demonstrated to be relatively low for penicillin (0-27%), ampicillin (0.6-23%), and ceftiofur (0-23%). For penicillin, this result may be due in part to the unique mechanism by which resistance is acquired through modifications in the structure of penicillin-binding proteins. Recommendations to control S. suis infection include focused and careful choice and appropriate use of antimicrobials, together with preventive measures intended to improve swine management.
... S. suis has also been isolated from clinically ill fallow deer and birds, as well as wild European rabbits and boars (Devriese et al., 1993;Sánchez del Rey et al., 2013;Sánchez del Rey et al., 2016). Although humans are not considered reservoirs, colonisation by S. suis has been confirmed in those with close contact with both swine and associated pork products, at an estimated rate of 5%, although this figure is likely to be an underestimation (Strangmann, Fröleke and Kohse, 2002;. ...
... Meta analyses have identified that more than eighty percent of infections occur in healthy middle-aged adult males and infections appear to be most greatly associated with close occupational contact with infected pigs or pork products, particularly where appropriate personal protective equipment practices are not adopted (Zhu et al., 2008;Wertheim et al., 2009;van Samkar et al., 2015;Rayanakorn et al., 2018) An increased risk of infection has been reported for immunocompromised patients including those with alcoholism, diabetes mellitus, cancer and structural heart disease (Voutsadakis, 2006;Gomez et al., 2014;van Samkar et al., 2015;Mancini et al., 2016). Highest occupational risks are found in swine farmers and transporters, abattoir workers, butchers and veterinarians (Strangmann, Fröleke and Kohse, 2002;Ibaraki et al., 2003;Voutsadakis, 2006;Zalas-Wiecek et al., 2013;Dutkiewicz et al., 2017b), with occasional reports in those handling carcasses including chefs and hunters (Halaby et al., 2000;Piech et al., 2009;Malezieux et al., 2014). Oral infection is rarely observed in Western countries, however S. suis is considered an emerging food-borne pathogen in Southeast Asia where consumption of traditional "high-risk" dishes containing raw blood and tissues increases the risk of infection alongside backyard slaughtering and the consumption of sick animals (Hanterdsith et al., 2013;Dutkiewicz et al., 2017b). ...
Streptococcus (S.) suis is a commensal porcine pathogen that is the leading causative agent of bacterial meningitis and sepsis in young pigs globally. Systemic infection in swine is associated with considerable mortality and has significant animal welfare and economic consequences. This zoonotic pathogen causes similar clinical pathology in humans as seen in pigs, which can result in life-changing post-streptococcal sequelae. S. suis is recognised as an emerging zoonotic disease and is the primary cause of meningitis in human adults in South East Asia, with two recent outbreaks in China manifesting as Streptococcal toxic shock-like syndrome in patients. The virulence mechanisms by which S. suis transitions from a commensal species within the nasopharynx and tonsillar microflora to a pathogenic species proliferating within host blood and disseminating into peripheral organs and the brain are still largely unknown. Proposed virulence mechanisms are often extrapolated from current knowledge about the pathogenesis of similar infections caused by Group A and Group B Streptococci. Whilst S. suis infections are readily treatable with β-lactam antibiotics, reports of antimicrobial resistance are increasing and driving the need for alternative therapeutics with novel targets and mechanisms of action. Maintaining effective treatment options are critical as the genetic diversity of serotypes within the S. suis strain population has meant that an effective commercial vaccine has yet to be developed. Establishing a more comprehensive understanding of the mechanisms of S. suis pathogenesis must be achieved to identify molecular targets for novel therapies and diagnostic tools. Transposon mutagenesis is frequently used in bacteriology to identify genes which are associated with increased fitness or essential for life. The Pragmatic Insertional Mutation Mapping System is a mapping-based tool which utilises the mutagen pG+host::ISS1 to identify essential genes in Gram-positive species in varying growth conditions. The PIMMS protocol was successfully used to elucidate genes which were essential for the growth of S. suis P1/7 in Brain-Heart Infusion (BHI) media with the addition of hydrogen peroxide (H2O2) to model a phagocytic respiratory burst in vitro. In total, 160 genes were identified as being essential for general survival and growth in media. Of these, functional annotation revealed that the majority of genes were associated with basic cellular functions including metabolism and information processing. Further analysis revealed that several genes were associated with the cell division cycle and the signal recognition particle pathway. A total of 35 genes were identified as important for survival and growth in the presence of H2O2. Statistical analysis revealed that a switch from carbohydrate metabolism to general metabolism occurred in the transition from the BHI to the H2O2 environment, evidenced by an overrepresentation of genes associated with general metabolism in the H2O2 phenotype. Genes associated with alternative metabolic pathways in the presence of H2O2 and the direct and indirect expression and secretion of 3 virulence factors were identified following further investigation. The FtsEX, complex, FtsY, Fhs, FolD, CcpA, SecE, putative signal peptidase I (SSU0212), OppD and putative haemolysin-III (Hly-III) (SSU0854) were identified as having promising novel therapeutic or diagnostic potential which require greater investigation and may be utilised in the control of future S. suis infections.
... Originally, 35 serotypes were identified. However, phylogenetic and/or sequence analyses showed that the reference strains of serotypes 20,22,26,32,33, and 34 should be taxonomically removed from the S. suis species. Serotypes 32 and 34 were reclassified as Streptococcus orisratti. ...
... In fact, piglets are first colonised by S. suis from birth as soon as they pass through the birth canal, since S. suis is found in the sow vagina. In humans, S. suis nasopharyngeal colonisation has been reported in people working in close contact with infected animals, such as butchers and abattoir workers [1,19,33]. The bacteria may also colonise the gastrointestinal tract in people consuming fresh/raw contaminated pork meat [19]. ...
Streptococcus suis is a swine pathogen and a zoonotic agent afflicting people in close contact with infected pigs or pork meat. Sporadic cases of human infections have been reported worldwide. In addition, S. suis outbreaks emerged in Asia, making this bacterium a primary health concern in this part of the globe. In pigs, S. suis disease results in decreased performance and increased mortality, which have a significant economic impact on swine production worldwide. Facing the new regulations in preventive use of antimicrobials in livestock and lack of effective vaccines, control of S. suis infections is worrisome. Increasing and sharing of knowledge on this pathogen is of utmost importance. As such, the pathogenesis and epidemiology of the infection, antimicrobial resistance, progress on diagnosis, prevention, and control were among the topics discussed during the 4th International Workshop on Streptococcus suis (held in Montreal, Canada, June 2019). This review gathers together recent findings on this important pathogen from lectures performed by lead researchers from several countries including Australia, Canada, France, Germany, Japan, Spain, Thailand, The Netherlands, UK, and USA. Finally, policies and recommendations for the manufacture, quality control, and use of inactivated autogenous vaccines are addressed to advance this important field in veterinary medicine.
... However, the development of resistance of S. suis has been increasingly reported [2][3][4][5]. The resistance of S. suis to antimicrobials commonly used in swine, including lincosamides (lincomycin and clindamycin), macrolides (erythromycin, spiramycin, and tylosin), sulfonamides, oxytetracycline, and tetracycline, has been acknowledged in many countries [4,[6][7][8]. In human strains, resistance to tetracycline and macrolides has been reported since 2000 [9], and increased resistance rate has recently been reported in Asia [6,8,[10][11][12][13][14]. Penicillin and cephalosporins have been considered the primary drugs of choice for S. suis infection. ...
... The resistance of S. suis to antimicrobials commonly used in swine, including lincosamides (lincomycin and clindamycin), macrolides (erythromycin, spiramycin, and tylosin), sulfonamides, oxytetracycline, and tetracycline, has been acknowledged in many countries [4,[6][7][8]. In human strains, resistance to tetracycline and macrolides has been reported since 2000 [9], and increased resistance rate has recently been reported in Asia [6,8,[10][11][12][13][14]. Penicillin and cephalosporins have been considered the primary drugs of choice for S. suis infection. ...
Streptococcus suis is a zoonotic pathogen that is currently considered an emerging multidrug-resistant (MDR). Increasing antibiotic resistance can lead to the unsuccessful treatment of S. suis infection. Recently, many investigations of medicinal plants were conducted for the treatment of infection as a result of the increase of antibiotic-resistant bacteria. The aims of this study were to determine the chemical composition of essential oil from Syzygium aromaticum (L.) Merr. & L.M. Perry and the antibacterial activities of clove oil on MDR S. suis. Using gas chromatography coupled to a mass spectrometer, eugenol (97.76%) was found to be the major active ingredient of clove oil. In vitro antibacterial activities of clove oil against MDR S. suis were evaluated. Using the agar disc diffusion test, the clove oil showed a maximum zone of inhibition at 15% (v/v) oil concentration. In a broth microdilution method, the minimum bactericidal concentration of clove oil against all MDR S. suis isolates was 0.1% (v/v). A time-kill analysis was performed, and the killing kinetics of clove oil showed that MDR S. suis was completely reduced after 15 min of exposure to clove oil. In addition, clove oil exhibited a strong antibacterial activity at all pH values applied following incubation of MDR S. suis in pH-adjusted media with clove oil. Moreover, scanning electron microscopy revealed the nonviable S. suis isolates clearly showed atypical form and cell membrane lysis after incubation with clove oil. This study confirms the efficacy of clove oil as a natural antimicrobial against MDR S. suis and suggests the possibility of employing it as a promising alternative product for control of infectious diseases caused by S. suis in animal and human patients.
... A high prevalence of tetracycline resistance was reported for S. suis isolates in many countries including those of North America, Asia and some from Europe [16,19,20]. A significant increase in tetracycline resistance was found in meningitis patients from Asia [41][42][43] and high prevalence of tetracycline-resistant S. suis isolated from pigs was clearly found in different regions of China [44]. Resistance to cephalosporin was reported in both China and Europe [45][46][47]. ...
... The third-generation cephalosporin, ceftiofur has been the most effective antibiotic drug for both humans and pigs until now. Nonetheless, recent evidences from China and Europe showed the emergence of resistance to the third-generation cephalosporins [39,41,42]. Our study also revealed the presence of ceftiofur-resistant S. suis in Thailand. ...
Background
Prophylaxis and treatment of emerging zoonotic Streptococcus suis infection in agricultural and healthcare settings mainly rely on antibiotics. However, continued use of antibiotics contributing to emergence and widespread of antibiotic resistant S. suis becomes a significant challenge in many endemic countries, including Thailand. Meanwhile, the knowledge of antibiotic susceptibility patterns of bacterial pathogens is required for overcoming the antimicrobial resistance problem, the information of antibiotic susceptibility of S. suis strains isolated in Thailand remains limited. This study aims to assess the susceptibility of Thai-isolated S. suis strains to different antibiotic classes in order to gain an insight into the distribution of antibiotic-resistant patterns of S. suis strains in different regions of Thailand.
Results
This study revealed the antimicrobial resistance and multidrug resistance of 262 S. suis strains isolated in different regions of Thailand. Susceptibility testing indicated widespread resistance to macrolides and tetracyclines of S. suis strains in the country. Beta-lactam antibiotic drugs (including cefotaxime and ceftiofur), vancomycin, chloramphenicol, as well as florfenicol were potentially the most effective therapeutic drugs for the treatment of S. suis infection in both pigs and humans. High prevalence of intermediate susceptibility of S. suis isolated from asymptomatic pigs for penicillin G, gentamicin, enrofloxacin, and norfloxacin could be the premise of the emergence of S. suis antibiotic resistance. Resistance was also found in S. suis strains isolated from asymptomatic pigs indicating that they could act as reservoirs of antibiotic resistance genes.
Conclusions
To the best of our knowledge, this is the first report on antimicrobial resistance of a large collection of S. suis strains isolated from pigs and humans in Thailand. It revealed the multidrug resistance of S. suis strains in pigs and humans. The information gained from this study raises an awareness and encourage best practices of appropriate antibiotic drug prescribing and use among human health and agriculture sectors.
Electronic supplementary material
The online version of this article (10.1186/s12917-018-1732-5) contains supplementary material, which is available to authorized users.
... According to Strangmann et al. [14], involvement of the 8 th cranial nerve, a characteristic of S. suis meningitis that occurs in the days following the onset of the meningeal syndrome, can lead to permanent deafness. Another mechanism is proposed by Gottschalk et al. [11] who expressed an opinion that the accumulation of inflammatory cells observed around the vestibular-cochlear (8 th cranial) nerve in S. suis meningitis is insufficient to impede normal neural conduction. ...
... Ye et al. [19] proposed the following 2-stage model of the pathogenesis of severe human disease caused by the epidemic S. suis strain ST7: In stage 1, on entry of the pathogen into the bloodstream, bacterial cell-wall components interact with the host immune system via pattern-recognition receptors, such as TLR-2 (Toll-like receptor 2) and CD14 (cluster of differentiation 14), and probably by the 2-component signal-transduction system. In stage 2, these host-pathogen interactions trigger a burst of pro-inflammatory cytokines, which may contribute to the development of toxic shock. ...
Streptococcus suis is a re-emerging zoonotic pathogen that may cause severe disease, mostly meningitis, in pigs and in humans having occupational contact with pigs and pork, such as farmers, slaughterhose workers and butchers. The first stage of the pathogenic process, similar in pigs and humans, is adherence to and colonisation of mucosal and/or epithelial surface(s) of the host. The second stage is invasion into deeper tissue and extracellular translocation of bacterium in the bloodstream, either free in circulation or attached to the surface of monocytes. If S. suis present in blood fails to cause fatal septicaemia, it is able to progress into the third stage comprising penetration into host’s organs, mostly by crossing the blood-brain barrier and/or blood–cerebrospinal fluid barrier to gain access to the central nervous system (CNS) and cause meningitis. The fourth stage is inflammation that plays a key role in the pathogen esis of both systemic and CNS infections caused by S. suis . The pathogen may induce the overproduction of pro-inflammatory cytokines that cause septic shock and/or the recruitment and activation of different leukocyte populations, causing acute inflammation of the CNS. Streptococcus suis can also evoke – through activation of microglial cells, astrocytes and possibly other cell types – a fulminant inflammatory reaction of the brain which leads to intracranial complications, including brain oedema, increased intracranial pressure, cerebrovascular insults, and deafness, as a result of cochlear sepsis. In all stages of the pathogenic process, S. suis interacts with many types of immunocompetent host’s cells, such as polymorphonuclear leukocytes, mononuclear macrophages, lymphocytes, dendritic cells and microglia, using a range of versatile virulence factors for evasion of the innate and adaptive immune defence of the host, and for overcoming environmental stress. It is estimated that S. suis produces more than 100 different virulence factors that could be classified into 4 groups: surface components or secreted elements, enzymes, transcription factors or regulatory systems and transporter factors or secretion systems. A major virulence factor is capsular polysaccharide (CPS) that protects bacteria from phagocytosis. However, it hampers adhesion to and invasion of host’s cells, release of inflammatory cytokines and formation of the resistant biofilm which, in many cases, is vital for the persistence of bacteria. It has been demonstrated that the arising by mutation unencapsulated S. suis clones, which are more successful in penetration to and propagation within the host’s cells, may coexist in the organism of a single host together with those that are encapsulated. Both ‘complementary’ clones assist each other in the successful colonization of host’s tissues and persistence therein. S. suis has an open pan-genome characterized by a frequent gene transfer and a large diversity. Of the genetic determinants of S. suis pathogenicity, the most important are pathogenicity islands (PAI), in particular, a novel DNA segment of 89 kb length with evident pathogenic traits that has been designated as 89K PAI. It has been estimated that more than one-third of the S. suis virulence factors is associated with this PAI. It has been proved that the virulent S. suis strains possess smaller genomes, compared to avirulent ones, but more genes associated with virulence. Overall, the evolution of the species most probably aims towards increased pathogenicity, and hence the most significant task of the current research is an elaboration of a vaccine, efficient both for humans and pigs.
... The association between human S. suis infection and occupational exposures to pigs or pork has been reported in Europe and Asia since 1968 [6,15,16]. In Vietnam, the proportion of patients reported to have occupational exposures was lower than reported in European patients but it remained an important independent risk factor. ...
... We were unable to demonstrate S. suis serotype 2 carriage in 1522 healthy persons or patients without S. suis infection, including those with pig exposures. In contrast, 6/101 (6%) of patients had PCR positive swab samples, a rate similar to what was found in slaughterhouse workers in Germany [16]. Eating pig intestines in the few days prior to admission was reported in 3/6 of the patients with a PCR positive throat or rectal swab, two of which were also culture positive. ...
Background: Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors underlying the disease.
... Many of those infected had sequelae and 50% developed severe hearing impairment. Streptococcus suis as a cause of endocarditis and septic shock has also been reported in case reports [4,5]. ...
... Compared with the large number of workers exposed to S. suis, the number of reported cases of serious infection is small. The true incidence might be higher due to misclassification [4]. ...
Workers exposed to pigs can develop meningitis, sepsis or endocarditis due to infection with Streptococcus suis transmitted from pigs to man.
To estimate the risk of these diseases.
We used the Occupational Hospitalization Register (OHR) which holds information about occupation and hospital treatments for all adults in Denmark. A dynamic population of male workers exposed to pigs was identified every year from 1995 to 2006 by occupational and industrial groups. First hospital treatment or death in the following year due to meningitis, sepsis or endocarditis was identified by ICD-10 codes from the OHR. By comparison with all other economically active men in Denmark, the standardized incidence ratio (SIR) was calculated for these diseases.
Among those exposed, we observed 32 cases of meningitis, sepsis and endocarditis during 140,118 person-years. In the reference group, we observed 2680 cases during 15,209,394 person-years. The SIR of the exposed group was 1.35 (95% CI: 0.95-1.92). Among the 32 cases, 7 cases of meningitis and sepsis were specified as caused by infection with streptococci. The SIR for these seven cases was 2.4 (95% CI: 1.1-5.0).
Our study did not find that workers exposed to pigs had an overall increased risk of developing meningitis, sepsis or endocarditis.
... In contrast, pediatric infections with S. suis are extremely rare, presumably related to a lack of exposure associated with increased risk of S. suis infection, in children. The association between human S. suis infection and occupational exposures to pigs or pork has been reported in Europe and Asia since 1968 [6,15,16]. In Vietnam, the proportion of patients reported to have occupational exposures was lower than reported in European patients but it remained an important independent risk factor. ...
... We were unable to demonstrate S. suis serotype 2 carriage in 1522 healthy persons or patients without S. suis infection, including those with pig exposures. In contrast, 6/101 (6%) of patients had PCR positive swab samples, a rate similar to what was found in slaughterhouse workers in Germany [16]. Eating pig intestines in the few days prior to admission was reported in 3/6 of the patients with a PCR positive throat or rectal swab, two of which were also culture positive. ...
[This corrects the article on p. e17604 in vol. 6.].
... Similar to S. suis in pigs, oral streptococci colonize the oral cavity with high-affinity adhesins and form a complex community with another commensal [26]. Studies investigating S. suis carrier status among abattoir employees, swine producers, and meat processing workers have revealed very low detection rates from the tonsillar, nasal, and pharyngeal samples [11,27,28]. However, there is still a gap in the carrier status of S. suis in healthy humans. ...
Background and Aim
Streptococcus suis is a zoonotic pathogen that is highly associated with contact between live pigs and raw pig material. In view of the recent reports of human infections in Malaysia, epidemiological data on the status of S. suis in the human population, especially among people working closely with pigs and/or raw pork, should be provided. The aim of this study was to detect S. suis among individuals working in the swine industry in several major pig production areas in Peninsular Malaysia.
Materials and Methods
Demographic information, exposure determinants, and oral swabs were collected from swine personnel, including farmers, butchers, and veterinarians. Oral swabs were subjected to bacterial isolation and conventional polymerase chain reaction (PCR) assays for S. suis detection.
Results
The study included 40 participants working in the swine industry, with a predominant representation of males (62.5%) and Malaysian Chinese individuals (60.0%) who consumed pork (92.5%). Notably, none of the participants reported consuming raw or partially cooked pork. In spite of their occupational exposure risk, none of the oral swabs showed positive results for S. suis infection.
Conclusion
To the best of our knowledge, this is the first report and detection study of S. suis using oral swabs obtained from swine personnel in Peninsular Malaysia.
... zooepidemicus after contact with domestic animals [53]. S. suis, a commensal and opportunistic pathogen of pigs, is also known to cause infections in humans [54,55]. S. canis and S. iniae are also zoonotic pathogens [56][57][58]. ...
Marine mammals are sentinels for the marine ecosystem and threatened by numerous factors including infectious diseases. One of the most frequently isolated bacteria are beta-hemolytic streptococci. However, knowledge on ecology and epidemiology of streptococcal species in marine mammals is very limited. This review summarizes published reports on streptococcal species, which have been detected in marine mammals. Furthermore, we discuss streptococcal transmission between and adaptation to their marine mammalian hosts. We conclude that streptococci colonize and/or infect marine mammals very frequently, but in many cases, streptococci isolated from marine mammals have not been further identified. How these bacteria disseminate and adapt to their specific niches can only be speculated due to the lack of respective research. Considering the relevance of pathogenic streptococci for marine mammals as part of the marine ecosystem, it seems that they have been neglected and should receive scientific interest in the future.
... Tiếp xúc nghề nghiệp với heo và thịt heo cũng như tiêu thụ sản phẩm từ heo chưa nấu kỹ hay còn sống được xác định là yếu tố nguy cơ của nhiễm S. suis trên người (Nghia et al., 2011). Nhiễm S. suis không triệu chứng lâm sàng trên nhóm người có nghề nghiệp tiếp xúc với heo tại các nước phát triển thay đổi từ 1%-21% (Elbers et al., 1999, Robertson, Blackmore, 1989, Strangmann et al., 2002. S. suis được chứng minh là tác nhân bội nhiễm phổ biến (15%) trên heo bị bệnh tai xanh tại Việt Nam (Hoa et al., 2013). ...
Streptococcus suis (S. suis) is one of the most important pathogens to cause acute bacterial meningitis in Viet Nam and other Asia countries including Thailand and Hongkong. We investigated the potential of using ELISA with the SAO protein as antigen to detect for S. suis specific sero positive. An SAO specific antibody collected from hyperimmunised rabbits was employed to develop the prototype ELISA. S. suis and other bacterial pathogens were used to validate the sensitivity and specificity of this method. This prototype ELISA was validated using serum samples collected from meningitis patients to evaluate its application in sero surveillance. The prototype ELISA protocol included a 0.1mg/well concentration of the cloned and purified SAO-M antigen; the primary antibody, anti SAO-M protein, and secondary antibody were used at the dilution of 1:500 and 1:10000, respectively. Rabbit antisera contained specific SAO-M antibody with 100% specificity and titer of >1:16000. Validating the prototype ELISA using serum samples collected from patients infected with S. suis and other common pathogens for bacterial meningitis in Vietnam showed the specificity of 95% and sensitivity of 90%. Our current results confirmed the initial success in developing the prototype ELISA in diagnosis for S. suis infections and the potential for its future application.
... In contrast to swine, humans seem to be rarely colonized by S. suis. However, this remains to be studied in more detail and, therefore, human carrier rates (reported to be approximately 5% on average worldwide with respect to people in contact with pigs or pig products) may be underestimated (Strangmann et al., 2002;Goyette-Desjardins et al., 2014). ...
Streptococcus (S.) suis
is a frequent early colonizer of the upper respiratory tract of pigs. In fact, it is difficult to findS. suis-free animals under natural conditions, showing the successful adaptation of this pathogen to its porcine reservoir host. On the other hand,S. suiscan cause life-threatening diseases and represents the most important bacterial cause of meningitis in pigs worldwide. Notably,S. suiscan also cause zoonotic infections, such as meningitis, septicemia, endocarditis, and other diseases in humans. In Asia, it is classified as an emerging zoonotic pathogen and currently considered as one of the most important causes of bacterial meningitis in adults. The "two faces" ofS. suis, one of a colonizing microbe and the other of a highly invasive pathogen, have raised many questions concerning the interpretation of diagnostic detection and the definition of virulence. Thus, one major research challenge is the identification of virulence-markers which allow differentiation of commensal and virulent strains. This is complicated by the high phenotypic and genotypic diversity ofS. suis, as reflected by the occurrence of (at least) 33 capsular serotypes. In this review, we present current knowledge in the context ofS. suisas a highly diverse pathobiont in the porcine respiratory tract that can exploit disrupted host homeostasis to flourish and promote inflammatory processes and invasive diseases in pigs and humans.
... Also, there are reports that confirm carrier state in humans, especially abattoir workers (Sala et al. 1989, Rohas et al. 2001). Strangmann et al. (2002) determined nasopharyngealcarriage rate of S. suis serotype 2 in the highrisk group (butchers, abattoir workers, and meat processing employees) was 5.3%, while those without contact with pigs or pork consistently tested negative. This kind of nasopharyngealcarriage ratehas also been shown in pigs (Higginsand . ...
Streptococcus suis infection is one of the major health problem in the swine industry worldwide.During the last decade, the numberof reported human cases due to S. suis has dramatically increased, andwhile most sporadic human cases of infection appear to be due to closeoccupational contact with pigs/pork products, particularly in Westerncountries (farmers, veterinarians, butchers, food processing workers, etc.), two epidemics were recorded in China in 1998 and 2005.
... More than 87% of S. suis isolates are resistant to oxytetracycline, erythromycin, tylosin tartrate, and clindamycin in Spain (Vela et al. 2005). In addition, high levels of tetracycline resistance (upto 90%) have also been reported from diseased and clinically healthy persons (Hoa et al. 2011;Strangmann et al. 2002). Integrative conjugative elements (ICE) seem to play a key role in the transmission of resistance determinants, as demonstrated by genomic studies. ...
NZ2114 is a promising candidate for therapeutic application owing to potent activity to gram-positive bacterium such as Streptococcus pneumoniae and Staphylococcus aureus. This work is the first report to describe the in vitro and in vivo antibacterial characteristics of NZ2114 against Streptococcus suis. It exhibited strong antimicrobial activity against S. suis type 2 strains CVCC 606, CVCC 3309, and CVCC 3928 at a low minimal inhibitory concentration (MIC) of 0.03–0.06 μM. The NZ2114 killed over 99.9% of tested S. suis CVCC 606 in Mueller–Hinton medium within 4 h when treated with 4 × MIC. It caused only less than 0.25% hemolytic activity in the concentration of 256 μg/ml. Additionally, NZ2114 exhibited potent in vivo activity to S. suis. All mice were survival when the dosage was low to 0.2 mg/kg. Over 99% of S. suis cells were killed within 4 h in blood, lung, liver and spleen with dosage of 10, 20, and 40 mg/kg in mice peritonitis models and no pathogen were detected after 24 h of treatment. Further, no pathological phenomenon in lung and low level of inflammatory cytokines in blood were detected. These results indicate that NZ2114 has the potential to be a new antimicrobial agent candidate for the clinical treatment of infection caused by S. suis type 2.
... For this study, human carriage S. suis isolates were not available for comparison, but it should be noted that evidence for persistent carriage of S. suis in humans is lacking. Previous studies have suggested that the human pharynx of slaughterhouse workers can be colonised with S. suis 49,50 . However, this finding is insufficient to support persistent healthy carriage. ...
Streptococcus suis is a zoonotic swine pathogen and a major public health concern in Asia, where it emerged as an important cause of bacterial meningitis in adults. While associated with food-borne transmission in Asia, zoonotic S. suis infections are mainly occupational hazards elsewhere. To identify genomic differences that can explain zoonotic potential, we compared whole genomes of 98 S. suis isolates from human patients and pigs with invasive disease in the Netherlands, and validated our observations with 18 complete and publicly available sequences. Zoonotic isolates have smaller genomes than non-zoonotic isolates, but contain more virulence factors. We identified a zoonotic S. suis clone that diverged from a non-zoonotic clone by means of gene loss, a capsule switch, and acquisition of a two-component signalling system in the late 19th century, when foreign pig breeds were introduced. Our results indicate that zoonotic potential of S. suis results from gene loss, recombination and horizontal gene transfer events.
... Of the 132 persons in the case group, 5.3% were colonized by S. suis and in good health, but potentially at risk. In contrast, S. suis could not be isolated in a single case within the control group [18]. Cases of human-to-human transmission have not yet been reported. ...
... Exposure to S. suis may lead to subclinical infections, induction of antibodies, serious disease, as was the case in the human cases discussed previously, or just an insignificant and transitory atypical colonization of the mucosal membranes within the respiratory route. 110,181 The annual risk of developing meningitis due to S. suis in the Netherlands was estimated to be 3.5/100 000 for slaughterhouse workers, 2.7/100 000 for pig breeders and 1.2/100 000 for butchers. 14 Compared to the non-exposed general population (0.002/100 000), the risk for slaughterhouse workers is 1500 times higher. ...
Streptococcus suis is an important pathogen causing economic problems in the pig industry. Moreover, it is a zoonotic agent causing severe infections to people in close contact with infected pigs or pork-derived products. Although considered sporadic in the past, human S. suis infections have been reported during the last 45 years, with two large outbreaks recorded in China. In fact, the number of reported human cases has significantly increased in recent years. In this review, we present the worldwide distribution of serotypes and sequence types (STs), as determined by multilocus sequence typing, for pigs (between 2002 and 2013) and humans (between 1968 and 2013). The methods employed for S. suis identification and typing, the current epidemiological knowledge regarding serotypes and STs and the zoonotic potential of S. suis are discussed. Increased awareness of S. suis in both human and veterinary diagnostic laboratories and further establishment of typing methods will contribute to our knowledge of this pathogen, especially in regions where complete and/or recent data is lacking. More research is required to understand differences in virulence that occur among S. suis strains and if these differences can be associated with specific serotypes or STs.
... Al respecto, un estudio de seroprevalencia realizado en Holanda, reveló presencia de anticuerpos contra S. suis serotipo 2 en 6% de un grupo de 102 veterinarios, y en 1% de 191 criadores de cerdos 6,23 . Un reporte realizado en Alemania sobre portación nasofaríngea, realizado en un grupo de 132 individuos con exposición laboral recurrente (carniceros, empleados procesadores de carne), demostró que 5,3% eran portadores; en cambio, no se encontraron portadores en el grupo control (130 individuos) 6,24 . ...
La infección humana por Streptococcus suis es una zoonosis con riesgo ocupacional conocido, siendo la meningitis aguda su manifestación clínica más frecuente. Se presentan los dos primeros casos en Chile. Primer caso: Mujer de 54 años con un cuadro de cefalea y vómitos, confusión y signos meníngeos. Evolucionó con un shock séptico. Segundo caso: Varón de 48 años, refirió cefalea y vómitos. Presentó signos meníngeos al examen físico. En ambos casos en la tinción de Gram de líquido cefalorraquídeo (LCR) se observaron cocáceas grampositivas. Fueron tratados con ceftriaxona y dexametasona. El cultivo de LCR fue positivo en ambos casos para S. suis serotipo 2. En los dos pacientes la evolución clínica fue favorable, sin alteraciones neurológicas al alta. En ambos casos se obtuvo en forma retrospectiva el antecedente de realizar labores de crianza de ganado porcino. Se destaca la importancia de investigar los antecedentes epidemiológicos para sospechar este agente etiológico en meningitis aguda. Se debe considerar el riesgo ocupacional en una posible infección por este patógeno humano emergente y educar a la población en riesgo sobre medidas preventivas simples.
... It is believed that humans can become infected through skin lesions, surface mucosa and/or the oral route following the ingestion of contaminated pork products [4]. Tonsil carriage of S. suis by humans without clinical signs (usually slaughterhouse workers) has also been described [5,6]. ...
Swine influenza is a highly contagious viral infection in pigs affecting the respiratory tract that can have significant economic impacts. Streptococcus suis serotype 2 is one of the most important post-weaning bacterial pathogens in swine causing different infections, including pneumonia. Both pathogens are important contributors to the porcine respiratory disease complex. Outbreaks of swine influenza virus with a significant level of co-infections due to S. suis have lately been reported. In order to analyze, for the first time, the transcriptional host response of swine tracheal epithelial (NPTr) cells to H1N1 swine influenza virus (swH1N1) infection, S. suis serotype 2 infection and a dual infection, we carried out a comprehensive gene expression profiling using a microarray approach.
Gene clustering showed that the swH1N1 and swH1N1/S. suis infections modified the expression of genes in a similar manner. Additionally, infection of NPTr cells by S. suis alone resulted in fewer differentially expressed genes compared to mock-infected cells. However, some important genes coding for inflammatory mediators such as chemokines, interleukins, cell adhesion molecules, and eicosanoids were significantly upregulated in the presence of both pathogens compared to infection with each pathogen individually. This synergy may be the consequence, at least in part, of an increased bacterial adhesion/invasion of epithelial cells previously infected by swH1N1, as recently reported.
Influenza virus would replicate in the respiratory epithelium and induce an inflammatory infiltrate comprised of mononuclear cells and neutrophils. In a co-infection situation, although these cells would be unable to phagocyte and kill S. suis, they are highly activated by this pathogen. S. suis is not considered a primary pulmonary pathogen, but an exacerbated production of proinflammatory mediators during a co-infection with influenza virus may be important in the pathogenesis and clinical outcome of S. suis-induced respiratory diseases.
... Petersen et al. showed that the risk of meningitis caused by streptococci increased significantly when workers were in close proximity to pigs (19). The number of reported infections remains low, considering the large number of worker exposed to S. suis; the true incidence might be higher, due to misidentification of the bacterium in clinical cases (19,33). Another potential explanation for underreporting S. suis infections is that the bacteria are sensitive to antibiotics commonly used to treat infections in humans. ...
Streptococcus suis is an important swine pathogen that can cause septicemia, meningitis, and pneumonia. Also recognized as an emerging zoonotic
agent, it is responsible for outbreaks of human infections in Asian countries. Serotype 2 is the predominant isolate from
diseased animals and humans. The aerosolization of S. suis in the air of swine confinement buildings (SCB) was studied. The presence of S. suis in bioaerosols was monitored in SCB where cases of infection had been reported and in healthy SCB without reported infections.
Using a quantitative-PCR (qPCR) method, we determined the total number of bacteria (1 × 108 to 2 × 108 airborne/m3), total number of S. suis bacteria (4 × 105 to 10 × 105 airborne/m3), and number of S. suis serotype 2 and 1/2 bacteria (1 × 103 to 30 × 103 airborne/m3) present in the air. S. suis serotypes 2 and 1/2 were detected in the air of all growing/finishing SCB that had documented cases of S. suis infection and in 50% of healthy SCB. The total number of bacteria and total numbers of S. suis and S. suis serotype 2 and 1/2 bacteria were monitored in one positive SCB during a 5-week period, and it was shown that the aerosolized
S. suis serotypes 2 and 1/2 remain airborne for a prolonged period. When the effect of aerosolization on S. suis was observed, the percentage of intact S. suis bacteria (showing cell membrane integrity) in the air might have been up to 13%. Finally S. suis was found in nasal swabs from 14 out of 21 healthy finishing-SCB workers, suggesting significant exposure to the pathogen.
This report provides a better understanding of the aerosolization, prevalence, and persistence of S. suis in SCB.
... Al respecto, un estudio de seroprevalencia realizado en Holanda, reveló presencia de anticuerpos contra S. suis serotipo 2 en 6% de un grupo de 102 veterinarios, y en 1% de 191 criadores de cerdos 6,23 . Un reporte realizado en Alemania sobre portación nasofaríngea, realizado en un grupo de 132 individuos con exposición laboral recurrente (carniceros, empleados procesadores de carne), demostró que 5,3% eran portadores; en cambio, no se encontraron portadores en el grupo control (130 individuos) 6,24 . ...
Human infection by Streptococcus suis is a zoonosis with a known occupational risk. Meningitis is its most frequent clinical manifestation. We present the first two cases in Chile.
FIRST CASE:
54-year-old female patient, pig-farmer. She presented headache, vomiting, confusion and meningismus. She presented septic shock. Second case: 48-year-old male patient, also pig farmer, presented headache, vomiting and meningismus. A Gram's staining of cerebrospinal fluid (CSF) showed gram-positive cocci in both cases. Ceftriaxone and dexamethasone treatment was administered. The CSF cultures were positive for Streptococcus suis serotype 2. The patients experienced a good outcome, without neurological sequelae at the time of discharge. It is considerable to evaluate epidemiologic factors in order to suspect this etiological agent in cases of meningitis. These cases enhance the need of heighten awareness of potential for occupational exposure and infection by this emerging human pathogen. Educating population at risk about simple preventive measures must be considered.
... This organism is one of the few streptococcal species that appear to be pathogens, primarily in animals (pigs), in which it can also be asymptomatically carried, particularly in the tonsils. It has rarely been documented as an agent of human infection, such as meningitis, septicemia, and endocarditis (3,8,10,16,23,24). Thus, S. suis infection appears to be a real zoonosis (25). ...
... Streptococcus suis is an important swine pathogen worldwide, which can be transmitted to human beings by direct contact; therefore, S. suis infections occur mainly in people who handle pigs or pork, such as pig farmers, abattoir workers, meat processing workers, people who transport pork, meat inspectors, and veterinary practitioners (Mai et al., 2008;van de Beek et al., 2008;Strangmann et al., 2002). S. suis causes arthritis, meningitis, pneumonia, septicaemia, endocarditis and septic shock in both pigs and humans (Staats et al., 1997). ...
Streptococcus suis is an important swine pathogen worldwide that can be transmitted to human beings by a direct contact. Therefore, S. suis infections occur mainly in people who handle pigs or pork. We present a case of a patient with S. suis meningitis who worked as a butcher in a meat processing plant for 5 years. The 35-year-old man was admitted to the Department of Infectious Diseases in T. Browicz Memorial Central Infectious Disease and Observation Hospital in Bydgoszcz with suspected bacterial meningitis. According to his medical history, the patient had been injured during the processing of pork. A microbiological examination of the cerebrospinal fluid and blood revealed S. suis as a single etiological factor of this infection. The patient was empirically administered cefotaxime (2.0 g at 8 hourly intervals) and penicillin (9 million U at 8 hourly intervals). The patient made a complete recovery and his inflammatory markers normalized. Only the hearing deficit of his right ear did not disappear. An otolaryngologist recommended a 4-week steroid therapy. The patient was not examined because he did not report to the clinic. To our knowledge this is the first described case of human meningitis caused by S. suis in Poland.
... In contrast, pediatric infections with S. suis are extremely rare, presumably related to a lack of exposure associated with increased risk of S. suis infection, in children. The association between human S. suis infection and occupational exposures to pigs or pork has been reported in Europe and Asia since 1968 [6,15,16]. In Vietnam, the proportion of patients reported to have occupational exposures was lower than reported in European patients but it remained an important independent risk factor. ...
Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors underlying the disease.
A case-control study with appropriate hospital and matched community controls for each patient was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating "high risk" dishes, including such dishes as undercooked pig blood and pig intestine (OR(1) = 2.22; 95%CI = [1.15-4.28] and OR(2) = 4.44; 95%CI = [2.15-9.15]), occupations related to pigs (OR(1) = 3.84; 95%CI = [1.32-11.11] and OR(2) = 5.52; 95%CI = [1.49-20.39]), and exposures to pigs or pork in the presence of skin injuries (OR(1) = 7.48; 95%CI = [1.97-28.44] and OR(2) = 15.96; 95%CI = [2.97-85.72]). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2 rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection.
This case control study, the largest prospective epidemiological assessment of this disease, has identified the most important risk factors associated with S. suis bacterial meningitis to be eating 'high risk' dishes popular in parts of Asia, occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors can be addressed in public health campaigns aimed at preventing S. suis infection.
... Intestinal translocation of EF-positive S. suis serotype 2 in piglets has been demonstrated under experimental conditions [31], and ingestion of S. suis may be an important route of entry in humans. Asymptomatic pharyngeal carriage of S. suis has been observed in slaughterhouse workers in Germany [32], and asymptomatic nasopharyngeal or intestinal carriage of S. suis may contribute to transmission of S. suis among humans. However, it is unknown how common asymptomatic carriage of S. suis is in humans in endemic areas and whether it increases the probability of infection. ...
Streptococcus suis, a zoonotic bacterial pathogen circulated through swine, can cause severe infections in humans. Because human S. suis infections are not notifiable in most countries, incidence is underestimated. We aimed to increase insight into the molecular epidemiology of human S. suis infections in Europe. To procure data, we surveyed 7 reference laboratories and performed a systematic review of the scientific literature. We identified 236 cases of human S. suis infection from those sources and an additional 87 by scanning gray literature. We performed whole-genome sequencing to type 46 zoonotic S. suis isolates and combined them with 28 publicly available genomes in a core-genome phylogeny. Clonal complex (CC) 1 isolates accounted for 87% of typed human infections; CC20, CC25, CC87, and CC94 also caused infections. Emergence of diverse zoonotic clades and notable severity of illness in humans support classifying S. suis infection as a notifiable condition.
Domuz ve domuz ürünleri, dünya çapında gıda sistemlerinin merkezi bir parçası
haline gelmiş bulunmaktadır. Küresel domuz eti üretimi, son 30 yılda hızla artarak
domuz endüstrisinin yoğunlaşmasına yol açmıştır. Günümüzde domuz yetiştiriciliğine
yapılan daha az çiftlik olmasına rağmen, bu çiftliklerde daha fazla sayıda hayvan
yetiştirilmektedir. Bu durum, patojen etkenlerin hem hayvan sürüleri arasında hem de
hayvanlardan sorumlu personele bulaşını artırmaktadır. Ayrıca artan stres faktörleri ve
tarımsal ortamda patojenlerin çoğalma potansiyeli, et ürünlerinden hastalıkların yayılmasına
yol açan mikroorganizma yükünün artmasına neden olabilmektedir. Sonuç
olarak dünya çapında domuz eti tüketen bireylerin sağlığının etkilenmesi riski bulunmaktadır.
Bu nedenle, domuz ve domuz eti ürünleri ile, çeşitli bulaşma yolları ile yeni
zoonotik hastalıkların popülasyonlarda yayılması potansiyeli bulunmaktadır. Bu bölümde
bakteriyel, viral ve paraziter etkenlerden ileri gelen bazı önemli domuz kökenli
zoonotik hastalıklar incelenecektir.
The quantitative polymerase chain reaction (qPCR) method presented in this study allows the identification of pneumococcal capsular serotypes in cerebrospinal fluid without first performing DNA extraction. This testing approach, which saves time and resources, demonstrated similar sensitivity and a high level of agreement between cycle threshold values when it was compared side-by-side with the standard qPCR method with extracted DNA.
Streptococcus suis is a major cause of respiratory tract and invasive infections in pigs and is responsible for a substantial disease burden in the pig industry. S. suis is also a significant cause of bacterial meningitis in humans, particularly in South East Asia. S. suis expresses a wide array of virulence factors, and although many are described as being required for disease, no single factor has been demonstrated to be absolutely required. The lack of uniform distribution of known virulence factors among individual strains and lack of evidence that any particular virulence factor is essential for disease makes the development of vaccines and treatments challenging. Here we review the current understanding of S. suis virulence factors and their role in the pathogenesis of this important zoonotic pathogen.
Meningitis confirmation in Burkina Faso uses PCR for detecting Streptococcus pneumoniae, Neisseria meningitidis, or Hemophilus influenzae. We identified 38 cases of meningitis among 590 that were PCR-positive for 3 nonpneumococcal streptococcal pathogens, including 21 cases of Streptococcus suis. Among the country's 13 regions, 10 had S. suis-positive cases.
Use of antimicrobial agents in veterinary medicine is essential to control infectious diseases, thereby keeping animals healthy and animal products safe for the consumer. On the other hand, development and spread of antimicrobial resistance is of major concern for public health. Streptococcus (S.) suis reflects a typical bacterial pathogen in modern swine production due to its facultative pathogenic nature and wide spread in the pig population. Thus, in the present review we focus on certain current aspects and problems related to antimicrobial use and resistance in S. suis as a paradigm for a bacterial pathogen affecting swine husbandry worldwide. The review includes (i) general aspects of antimicrobial use and resistance in veterinary medicine with emphasis on swine, (ii) genetic resistance mechanisms of S. suis known to contribute to bacterial survival under antibiotic selection pressure, and (iii) possible other factors which may contribute to problems in antimicrobial therapy of S. suis infections, such as bacterial persister cell formation, biofilm production, and co-infections. The latter shows that we hardly understand the complexity of factors affecting the success of antimicrobial treatment of (porcine) infectious diseases and underlines the need for further research in this field.
Streptococcus suis is an important pathogen in the swine industry. This article is the first to report the occurrence, risk factors, serotype distribution, and antimicrobial susceptibility of S. suis recovered from employees and environmental samples of swine slaughterhouses in Brazil. Tonsillar swabs from all 139 pig-slaughtering employees and 261 environmental swabs were collected for detection of S. suis and serotyping by monoplex and multiplex polymerase chain reaction, respectively. Antimicrobial susceptibility was determined by the disk-diffusion method. Although S. suis was not detected in any of the tested employees, it was isolated from 25% of the environmental samples. Significant differences (P < 0.05) in the occurrence of S. suis were observed between slaughterhouses and between areas of low, medium, and high risk. The most frequent serotypes were 4 and 29, each accounting for 12% of the isolates, followed by 5, 12, 21, and 31, each accounting for 6%. High rates of susceptibility to the antimicrobials doxycycline (100%), ceftiofur (94%), ampicillin (81%), and cephalexin (75%) were observed. However, multidrug resistance was observed in all the isolates. Because S. suis is present in the environment of swine slaughterhouses, on carcasses and knives, as well as on the hands of employees in all areas, all employees are at risk of infection. © 2015, Canadian Veterinary Medical Association. All rights reserved.
Swine and their products have become a central part of food systems around the world. Global pork production has rapidly increased over the past 30 years, leading to the intensification of the swine industry: though there are fewer farms now, those farms that do persist raise ever-larger numbers of animals. This increases the transmission of pathogens both amongst animal herds, and between animals and their human caretakers. Furthermore, increased stress to animals and the potential for amplification of pathogens in the farming environment can lead to a higher burden of disease-causing organisms in and on meat products, which then make their way to consumers world-wide. As such, swine and their meat products have the potential to introduce new zoonotic diseases into populations via multiple routes of transmission. Here we discuss several examples of zoonotic diseases of swine origin, reviewing diseases with bacterial, viral, or parasitic causes.
The cold storage unit and meat production industry has made Brazil one of the leading suppliers and exporters of products of animal origin. The rapid expansion of the market has led to a rise in competitiveness from a capitalist standpoint, and in this respect corporate profit often leads to the need to adapt human actions to new functions in order to reduce costs and maximize production. These routine activities involve repetitive work, multi-tasking, long hours and operating machines with the use of sharp cutting tools, which is why the work is conducted wearing protective gear. Among the main hazards present, biological risks are the most important due to direct exposure to internal organs, blood, fecal matter, urine and placental or fetal fluids from slaughtered animals that may be infected with pathogens of zoonotic origin. This paper discusses the risks to which slaughterhouse-cold storage unit professionals are exposed, conducting a thorough bibliographical review of the literature that takes into consideration the conceptual framework of Biosafety, which contributes to improve the safety and health conditions of these workers.
Infections caused by Streptococcus suis are an important economic problem in the swine industry. Moreover, S. suis (especially serotype 2) is an agent of zoonosis that has the potential to afflict those who are in close contact with infected pigs or pork-derived products. Although sporadic cases of S. suis infections in humans have been reported during the last 40 years, a large outbreak in China emerged in 2005. The severity of the infection in humans during the outbreak, such as clinical signs of streptococcal toxic shock syndrome, attracted much attention from the scientific community and the public press. This two-part review will focus on this organism and the infections it causes, highlighting the differences between Asian and Western countries, particularly with respect to its epidemiology. In part I, the general characteristics of the organism are reviewed, as well as the clinical characteristics associated with S. suis infection in humans, the pathogenesis of infection and associated virulence factors, and, finally, the interactions between S. suis and the host's immune system.
This article aims to analyze factors associated with unawareness of prenatal HIV serostatus at admittance for delivery. A cross-sectional study was performed in 2006 in "Friends of Children" Hospitals from the High-risk Pregnancy System, belonging to the Unified Health System, in Rio de Janeiro City. Data were collected through interviews applied to 873 rooming-in mothers submitted to a rapid HIV test at the hospital. Prevalence ratios (PR) of the lack of HIV serologic status were estimated by Poisson regression with robust variance, controlled by maternal and familiar socio-demographic characteristics, pregnancy and prenatal care. Prevalence of unawareness of HIV status was 32.2%. Mothers with low educational level, low-income, more than one relationship in the last year, enrolling late in prenatal care, and low number of prenatal visits were more likely to have unknown HIV status. The main predictor for unawareness of HIV serostatus at hospital admittance was the low number of prenatal visits. It is recommended that coverage of HIV testing during prenatal care be broadened with timely delivery of results, improving early access of pregnant women and increasing the number of prenatal visits, focusing on clients with low socio-economic level.
The outbreak of Streptococcus suis recently in some districts of Sichuan Province in China has caused over 30 deaths and over 200 infections in human beings.
In order to study the pathogenicity mechanism and to prevent the bacteria from spreading and infecting human beings and swine,
we have annotated and analyzed the genomes of two strains, Streptococcus suis P1/7 and 89-1591 respectively. The whole length of P1/7 is 2.007 Mb, and has 1969 ORFs. In contrast, the partial genome sequence
of 89-1591 is 1.98 Mb in length and exists in 177 contigs with 1918 ORFs. Analysis shows that the average lengths of CDSs
in two genomes are very close, and the numbers of the homolog ORFs are 1306 between those two strains. Most of the toxicity
factors of the two strains are homologeous, but there are still some significant differences between those two strains. For
example, among the 11 genes (cps2A-cps2K) encoding for the capsules in P1/7, 4 (cps2A, 2B, 2I, 2J) are not detected in strain 89-1591. At the same time, the genes encoding EF and Haemolysin in P1/7 are also not found in
strain 89-1591. Besides, the genes related to DNA replication, repair and recombination differ from each other significantly
and there also exist certain differences among the surface proteins. Those characteristics indicate that those two strains
have evolved their own specific functions to adapt to the different environments and that the pathogenesis of the two strains
is different. We have accumulated comprehensive genomics information for future systematic studies of S. sui. Our results are helpful for disease prevention, vaccine development, as well as drug design for S. suis.
Streptococcus suis is a major porcine pathogen, causing economical health worldwide problems in the global swine industry. It is also emerging as a zoonotic agent capable of causing severe invasive disease in humans exposed to pigs or pork products. The most important clinical sign in swine and human is meningitis, but other pathological conditions have also been described. Serotype 2 is the most commonly associated with diseases in pigs and humans, and also the most frequently reported serotype isolated from diseased animals worldwide. The majority of human infection occurs in pork handlers, particularly in slaughterhouse workers and by minor wounds or skin abrasions contaminated by raw pork or viscera of pigs. Veterinarians should also be aware that a low but real risk may be present when manipulating S. suis-diseased animals that are probably shedding high numbers of this pathogen. Up today, in Greece there is no published epidemiological data for S. suis serotypes in swine herds and the zoonotic risk of S. suis infection in human with daily contact with pigs and pork meat. However, in our experience clinical forms of S. suis infection are common in most greek swine farms. The aim of this review study is to perform recent information about S. suis infection in swine and human, focus on zoonotic risk of this emerging pathogen and prevention strategies.
Meat inspection in the EU is based on Regulation (EC) 854/2004. Accordingly a risk based meat inspection should be implemented. In this paper, the incision of the heart in pig meat inspection is discussed with respect to efficacy. The incision especially can reveal the presence of endocarditis. Here, Erysipelothrixrhusiopathiae (E. rhusiopathiae) and/or Streptococcussuis (S. suis) are of particular concern. Both agents are regarded to be zoonotic agents. There is some evidence for infection of humans via an alimentary pathway. Hence, the occurrence of E. rhusiopathiae and S. suis is a concern of public health (PH) as well as veterinary public health (VPH). However, other measures, including on-farm disease prevention and diagnosis, seem to be more important for food safety. It is concluded that the incision and inspection of the heart is not justifiable with respect to PH aspects.
Infections caused by Streptococcus suis are considered a global and an economical problem in the swine industry. Moreover, S. suis is an agent of zoonosis that afflicts people in close contact with infected pigs or pork-derived products. Although sporadic cases of S. suis infections in humans (mainly meningitis) have been reported during the last 40 years, a large outbreak due to this pathogen emerged in the summer of 2005 in China. The severity of the infection in humans during the outbreak, such as a shorter incubation time, more rapid disease progression and higher rate of mortality, attracted a lot of attention from the scientific community and the general press. In fact, the number of publications on S. suis (including the number of reported human cases) has significantly increased during recent years. In this article we critically review the present knowledge on S. suis infection in humans, we discuss the hypotheses that may explain the 2005 outbreak and the repercussion of such an episode on the scientific community.
Streptococcus suis, type II, is now recognised to be an important cause of meningitis, septicaemia, and purulent arthritis in young pigs. Human infections are rare, but have been reported in Holland and Denmark and the first British case has been recently described. In the case reported here the patient presented with severe bilateral endophthalmitis as well as other reported manifestations of Str suis infection. The meningitis and septicaemia were treated with benzylpenicillin, 20000 units intrathecally immediately and 4 million units intravenously every four hours for two days, followed by amoxycillin, 0.5 g 6-hourly. The endophthalmitis and glaucoma responded to acetazolamide, 250 mg, and prednisolone, 10 mg every six hours- together with local eyedrops of atropine, bacitracin, and Maxidex. Benzylpenicillin, 0.5 megaunits, was given subconjunctivally followed by ampicillin, 100 mg, and betamethasone, 4 mg, on alternate days. Systemic antibiotic therapy was continued for a total of six weeks. The patient recovered but was left with high tone deafness, unsteadiness of gait, and impairment of vision in the left eye.
The protein profiles of various cell fractions of 180 strains of Streptococcus suis type 2, which were isolated from diseased pigs, from healthy pigs when they were slaughtered, and from human patients, were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. The isolates from diseased pigs contained two proteins that were absent in most of the isolates from healthy pigs. One of these proteins was a 136-kDa protein that was previously identified as the muramidase-released protein (MRP). This protein was predominantly detected in protoplast supernatants and culture supernatants. The second protein was a 110-kDa protein that was detected only in culture supernatants and therefore was provisionally called extracellular factor (EF). Three phenotypes of S. suis type 2 strains were recognized. Isolates from organs of diseased pigs mainly belonged to the MRP+ EF+ phenotype (77%), while isolates from tonsils of healthy pigs mainly had the MRP- EF- phenotype (86%). Most of the isolates from human patients contained MRP (89%); 74% had the MRP+ EF- phenotype. These findings confirm the results of previous investigations which demonstrated that S. suis type 2 strains differ in virulence. Monoclonal antibodies raised against the 110-kDa EF recognized proteins with higher molecular weights in culture supernatants of all of the strains with the MRP+ EF- phenotype. However, none of the strains with the MRP+ EF+ phenotype produced these high-molecular-weight proteins. Our results demonstrate that MRP and EF are associated with virulence. This suggests that one or both of these proteins are virulence factors that play a role in the pathogenesis of S. suis type 2 infections in pigs and human patients.
Antibody titres to Streptococcus suis type 2 were measured with an enzyme linked immunosorbent assay (ELISA) in four occupational groups in New Zealand. No veterinary students, 9% of dairy farmers, 10% of meat inspectors and 21% of pig farmers were seropositive to S. suis type 2. The development of antibody to S. suis type 2 was associated with occupational contact with pigs or their meat products. Subclinical infection with S. suis type 2 appears to occur in humans and the antibody produced is of only short duration. The annual incidence of subclinical infection and seroconversion in pig farmers may approach 28%. Thus S. suis type 2 may be one of the most infectious potentially zoonotic agents present in New Zealand, although very rarely resulting in clinical disease.
Die äußere Haut, die Schleimhäute des Oropharynx, des oberen Respirationstraktes, des Dickdarms und des unteren Urogenitaltrakts sind von einer Bakterienflora besiedelt, die sich in ihrer Zusammensetzung von Individuum zu Individuum ähnelt und als physiologische oder Normalflora bezeichnet wird.
From 1968 to 1974 seven cases of septicæmia and purulent meningitis caused by porcine streptococci of the Lancefield group R and three cases caused by similar streptococci lacking R antigen occurred in the Netherlands. Bacteria isolated from all ten patients shared the characteristics of a biochemically well defined bacterial species (provisionally called Streptococcus subacidus) which until 1968 was only found in pigs. Nine of the ten patients had had intensive contact with live or slaughtered pigs.
Bei einem 49jährigen Fleischer konnten als Erreger einer septischen Allgemeininfektion mit meningealer Beteiligung aus einer Blutkultur und aus dem Liquor cerebrospinalis Streptokokken der serologischen »Gruppe R« (Streptococcus suis Typ 2) isoliert werden. Nach hochdosierter Therapie mit Penicillin G kam es zu rascher Entfieberung und vollständiger Rückbildung der neurologischen Symptomatik. Streptococcus suis Typ 2 ist Erreger einer Zoonose, die meist als Berufskrankheit bei Personen auftritt, die häufig mit Schweinen oder Schweinefleisch (Landwirte, Schlachter usw.) in Berührung kommen. Nicht seltene Folgeerscheinungen der S.-suis-Infektion beim Menschen sind Schädigungen des VIII. Hirnnerven, besonders Hörverlust.
A total of 522 Streptococcus suis isolates were recovered from the tonsils of slaughtered pigs by culturing on media containing different specific antisera. The serogroup reactions were determined by coagglutination. The most frequently isolated serotype was serotype 4 (representing 28.7 % of the isolates), followed by serotype 3 (24.9 %) and serotype 2 (22.6 %). Typable isolates were examined by growth in 6.5 % NaCl, amylase activity, acetoin production, susceptibility to optochin and production of acid from mannitol, melibiose, raffinose, salicin, sorbitol and trehalose. Finally, all isolates were tested for antimicrobial susceptibility against ampicillin, cephalotin, lincomycin, neomycin, penicillin, spiramycin and trimethoprim-sulphamethoxazole using the disk-diffusion technique.
All isolates were amylase-positive and acetoin-negative, and failed to grow in 6.5 % NaCl broth. Nine isolates were optochin-susceptible. Moreover, 10 isolates produced acid from mannitol, 21 produced acid from sorbitol, and 36 and 37 did not produce acid from salicin and trehalose, respectively. Six salicin- and trehalose-negative isolates and two mannitol- and sorbitol-fermenting isolates were found. Biochemical differences between serotypes were not observed.
The most active drugs against S. suis were the beta-lactam antibiotics, although only 83.3 %, 70 % and 78.5 % of isolates were susceptible to ampicillin, cephalotin and penicillin, respectively. Half of the isolates were resistant to trimethoprim-sulphamethoxazole, and resistance to lincomycin, neomycin and spiramycin appeared to be very high.
In den letzten anderthalb Jahren hat die Diskussion um den Einsatz antimikrobiell wirksamer Substanzen in der Veterinärmedizin wesentlich an Intensität zugenommen. Die Gründe dafür liegen im Anstieg der Resistenzraten bei bakteriellen Krankheitserregern, sowohl im human- als auch im veterinärmedizinischen Bereich. Speziell in der Agrarwirtschaft und beim landwirtschaftlichen Nutztier jedoch gibt es Bereiche, die außerhalb der klassischen Therapieformen liegen. Dazu gehören vor allem rein prophylaktische Maßnahmen mit teilweise fragwürdigen Wirkstoffkombinationen und Dosierungen sowie der nutritive Einsatz antimikrobiell wirksamer Substanzen zu wachstumsfördernden Zwecken.
Im vorliegenden Artikel wird versucht, umfangreiche Expertentagungen und Berichte zum Thema der Resistenzentwicklung gegenüber antimikrobiell wirksamen Substanzen zusammenzufassen und den momentanen Stand der Diskussion im Bereich der Veterinärmedizin wiederzugeben.
Dem BgVV erscheinen die momentan vorhandenen Gesetzesgrundlagen zur Regelung und Zulassung des Gebrauchs von antimikrobiell wirksamen Substanzen ausreichend. Dabei ist es gleich, ob sie als Arzneimittel oder zu wachstumsfördernden Zwecken eingesetzt werden. Wichtig hierbei ist, daß diese Regelungen befolgt und durch entsprechende Überwachungsmaßnahmen umgesetzt und kontrolliert werden.
Die Agrarwirtschaft sollte sich darum bemühen, den Antibiotikaeinsatz in Zukunft auf die Therapie der Tiere zu beschränken und andere Anwendungen durch bereits existierende oder neu zu schaffende alternative Maßnahmen (Hygiene, Management, Impfprogramme, Probiotika, Züchtung resistenter Rassen etc.) zu ersetzen.
Meningitis caused by Streptococcus suis type 2, a rare disease first recognized in 1968 (108 cases worldwide in 1989), is contracted by occupational exposure to pigs and often results in very severe disabilities (definitive deafness and ataxia in 50% of cases). We report the case of an employee in a rendering plant whose initial symptom was deafness. A detailed analysis of medical and veterinary literature is provided concerning the epidemiology of the disease, the clinical forms in man, bacteriological diagnosis and the role of the pig as healthy carrier. It is recommended that this occupational disease be officially recognized for compensation in France.
A case of Streptococcus suis meningitis is observed in a 39-year-old and previously healthy meat factory worker. Neurological recovery was incomplete despite adequate and sustained antimicrobial therapy. Early deafness was demonstrated by brainstem auditory evoked potentials. Death due to aspiration pneumonia, cardiac arrest and subsequent cerebral anoxia occurred late in the course of the illness.
New selective and differential media were devised for the isolation and identification of Streptococcus suis type 2. The selective medium (NNCC) agar) was Todd-Hewitt broth containing 1.5% Bactoagar and 5% defibrinated sheep blood with addition of sodium azide (50 micrograms/ml), nalidixic acid (25 micrograms/ml), colistin (12.5 micrograms/ml) and crystal violet (2 micrograms/ml). The differential medium consisted of heart infusion agar and antiserum specific only for S. suis type 2. In a total of 291 pigs tested by a combination of these media, S. suis type 2 was isolated and confirmed from 40 of them (13.7%).
Between 1968 and 1984, 30 strains of Streptococcus suis causing meningitis were isolated in the Netherlands. Twenty-eight strains were type 2, one was type 4, and one was untypable.
The average age of the patients infected with these strains was 49 years (range, 21–76 years); the male-to-female ratio was
6.5. Twenty-five patients (83%) were employed in the pork industry. Two patients (7%) died. In seven cases (23%), predisposing
factors were identified. The most frequent sequela was hearing loss (54% of surviving patients). The data for these 30 patients
were compared with those for 30 patients from outside the Netherlands whose cases of meningitis due to S. suis type 2 were described between 1968 and 1985. No differences were found. The estimated annual risk of developing S. suis meningitis among Dutch abattoir workers and pig breeders was ∼3.0/100,000-a rate 1,500 times higher than that among persons
not working in the pork industry.
Streptococcus suis is a zoonotic pathogen which causes meningitis, arthritis and septicaemia in pigs, and rarely meningitis or septicaemia in humans. This organism has recently been isolated from pigs in New Zealand, where it appears to be widely distributed in pig herds. This case is the first report of human infection in New Zealand.
A case of purulent meningitis caused by Streptococcus suis type 2 (group R streptococcus) is described. It occurred in a 69-year-old farmer's wife who raised pigs on her farm. Here, as well as in nearly all other cases of S. suis meningitis reported to date, close occupational contact with pigs or pork preceded the infection; this epidemiological link can be explained by the frequent occurrence of S. suis as a commensal and opportunistic pathogen in pigs. Up until now, S. suis infection in man has been rare and has had a good prognosis. However, disturbances of the eighth cranial nerve have been found in many patients, even causing permanent deafness in some. These and other clinical, epidemiological and microbiological features of S. suis disease in man are discussed here.
The survival of Streptococcus suis type 2 was assessed in experimentally inoculated faeces and dust stored at 0, 9 and 22 to 25 degrees C. The organism survived in faeces for 104 days at 0 degrees C, up to 10 days at 9 degrees C and up to eight days at 22 to 25 degrees C. It survived in dust for up to 54 days at 0 degrees C and up to 25 days at 9 degrees C but could not be isolated from dust stored at room temperature for 24 hours. The organism survived at 4 degrees C in nutrient medium for up to nine months but in distilled water for only one to two weeks. At 50 degrees C it survived in water or broth for up to two hours but at 60 degrees C it only survived for 10 minutes. The organism was rapidly inactivated by disinfectants and cleansers, commonly used on farms and in laboratories, at concentrations less than those recommended for use by the manufacturers.
Heads were removed soon after slaughter from the dressed carcases of 155 pigs belonging to 12 herds with a history of streptococcal meningitis and from 180 pigs from four herds believed to be free from this disease. Deep scrapings from both tonsils were sown on two selective media. Streptococcus suis type 2 was detected in a proportion of pigs from the 12 herds with a history of the disease, including three herds in which no cases were noted during the year this study was made. Pigs in six of these herds had received therapeutic levels of certain antibiotics in their feed as growers. The confirmed detectable tonsillar carrier rates varied between these 12 herds from 20 to 90 per cent and between batches of heads from one herd from 0 to 100 per cent. Carrier rates could not be correlated with disease levels, herd size or husbandry system. S suis type 2 was also detected in pigs from two herds thought to be free of the disease, at rates of 20 and 1.5 per cent.
Tonsil swabs were taken from 626 pigs of all ages in four infected herds. Streptococcus suis type 2 was isolated from 106 pigs aged between three weeks and 18 months. Detectable carrier rates in different groups of pigs varied between 0 and 80 per cent and were highest in weaned pigs aged between four and 10 weeks. Deep scrape cultures carried out post mortem suggested that the actual carrier rate was higher than that detected by tonsil swabs before death. Detection was improved by using two selective media. S suis type 2 persisted in the tonsils in the presence of circulating opsonic and binding antibodies and in pigs receiving penicillin-medicated feed. It was detected in the tonsils of individuals for up to 521 days. It was rarely detected in the nose. Some carriers appeared to eliminate the infection. Weaned detectable tonsil carriers transmitted the infection to previously uninfected pigs with which they were mixed. Titres of serum binding antibodies assessed by a micro enzyme-linked immunosorbent assay were relatively low and results from infected and non-infected pigs were not always distinguishable.
Streptococcus suis has been identified as the most common cause of meningitis in adults in Hong Kong. The disease is characterized by occupational exposure to pigs or pork. It occurs in summer, and is associated with early, severe, sensory deafness, arthritis, uveitis, and loss of balance. Examination of the cerebrospinal fluid may show an elevated white cell count with a predominance of either polymorphs or lymphocytes. Misinterpretation of the microbiological findings by inexperienced staff members may lead to a failure to correctly diagnose this disease. This is the first report of a series of cases of Strept. suis meningitis outside western Europe. Health authorities are urged to be aware of this disease in pork-consuming countries.
Encapsulation is thought to be a critical virulence factor for Streptococcus suis. In this study, encapsulation of a selected S. suis culture could be stimulated by cultivation conditions. After cultivation of the S. suis culture in fluid media supplemented with serum, the culture grew with short chains and a uniform turbidity of the growth medium. Autoclave extracts of this culture reacted with capsular type-1-specific antiserum. After cultivation of the S. suis culture in fluid media without serum, the bacteria generally formed longer chains, grew in fluid medium as granular sediment with clear supernatant, and were non-typeable. In addition, the unencapsulated variant appeared to have a more hydrophobic surface and adhered significantly more to HeLa cells. In contrast to the unencapsulated variant, the encapsulated S. suis was phagocytosed to a lesser extent by polymorphonuclear leucocytes. These findings might help to elucidate the role of encapsulation in infections with this bacterial organism.
Twenty-five patients were admitted to two hospitals in Hong Kong for Streptococcus suis infection between 1984 and 1993. Among them, 15 (60%) had an occupational exposure to pigs or pork, and four had a clear history of skin injury up to 16 days before admission. Examination of the cerebrospinal fluid of 21 patients confirmed the presence of meningitis in every case; the remaining four patients who did not have lumbar punctures had each presented with arthritis, bronchopneumonia, endocarditis and pyrexia without neck stiffness. The only fatality was a patient admitted in septicaemic shock with evidence of meningitis and disseminated intravascular coagulation. Of the 24 survivors, 16 (67%) acquired varying degrees of hearing loss as a result of meningitic involvement. All the isolates of S. suis were sensitive to penicillin or ampicillin, which was used alone or in combination with other antibiotics for every patient. Two patients had a relapse of symptoms when penicillin was stopped, but were successfully treated after the antibiotic was resumed for a total of 6 weeks. Over 100 cases of S. suis infection have been described previously, with a geographic distribution heavily biased towards Northern Europe and Southeast Asia. Lack of awareness of this unique zoonosis may be a reason why it is not diagnosed more readily elsewhere.
A 61-year-old pig farmer was found to be suffering from meningitis caused by Streptococcus suis type II. He was successfully treated with intravenous penicillin G but was left with permanent deafness. B-cell lymphoma was also diagnosed one year later. S. suis is a zoonotic pathogen which causes meningitis, septicemia and endocarditis in pigs. Human infection is rare and often presents as meningitis with the sequela of permanent deafness. It has previously been reported in pig rearing countries such as Holland or Hong Kong. This is the second documented case of human meningitis caused by S. suis in Taiwan, which is also a major pig rearing country in Asia. Infections caused by viridans streptococci or other beta-hemolytic streptococci in Taiwan may therefore actually be due to S. suis. Further investigation of the possibility of the underlying deficiency of humoral immunity is warranted.
The minimal inhibitory concentrations (MICs) for thirty-three epidemiologicaly unrelated clinical isolates of Streptococcus suis capsular type 2 were determined in relation to ampicillin, ampicillin-sulbactam, amoxicillin, clavulanate-amoxicillin, penicillin G, cephalexin, gentamicin, streptomycin, erythromycin, tylosin and doxycycline, using the microtitre broth dilution procedure described by the U.S. National Committee for Clinical Laboratory Standards (NCCLS). Gentamicin was the most active compound tested, with an MIC for 90% of the strains tested (MIC(90)) of 0.4 mg/L. Overall, 70% of strains were resistant to doxycycline (MIC(90) > or = 100.0 mg/L), followed by penicillin G (51% of strains) (MIC(90) + or = 100.0 mg/L). Resistance to amoxicillin and ampicillin was 36.4% (MIC(90) 12.5 mg/L) and 33.3% (MIC(90) 50.0 mg/L), respectively. 15.2% of S. suis strains were resistant to streptomycin, tylosin and cephalexin with MIC90 values of 25.0 mg/L, 12.5 mg/L and 25.0 mg/L, respectively. A combination of ampicillin and sulbactam (MIC(90) 6.3 mg/L) and a combination of amoxicillin and clavulanate (MIC(90) 3.1 mg/L) as well as erythromycin (1.6 mg/L) were of the same efficacy, with a total of 9.1% resistant S. suis strains. This high percentage of resistance to doxycycline and penicillin G precludes the use of these antibiotics as empiric therapy of swine diseases.
Antibiotika-Resistenzen wichtiger Infektionserreger 1996 in Weser-Ems
- Klarmann
Klarmann, D.: Antibiotika-Resistenzen wichtiger Infek-tionserreger 1996 in Weser-Ems. Dtsch. Tier‰rztl. Wschr. 104, 325 ± 335 (1997).
Biochemical traits and antimicrobial suscept Streptococci in animal diseases
- C Prieto
- F J Garcia
- P Suarez
- M Imaz
- J M Castro
- C D Wilson
- G F H Salt
Prieto, C., Garcia, F. J., Suarez, P., Imaz, M., Castro, J. M.: Biochemical traits and antimicrobial suscept-Wilson, C. D., Salt, G. F. H.: Streptococci in animal diseases. In: Streptococci Soc. Appl. Bacteriol. Sym. Ser. No 7 (F. A. Skinner, L. B. Quesnel, eds.), pp. 143 ± 156. Academic Press, London etc. 1978.
Streptococcus suis meningitis
- Dupas
Streptokokken der Gruppe R (Streptococcus suis Typ 2) als humane Krankheitserreger
- Queisser
Bakteriologische Untersuchungen zum Vorkommen von Streptokokken der serologischen Gruppe R bei klinisch gesunden Schweinen
- Rickert
Streptokokken: Hochresistent und oft zu spät erkannt
- Stein
A case of human endocarditis due to Streptococcus suis in North America
- Trottier
Streptococcus suis Typ 2 (R-Streptokokken) als Erreger von Berufskrankheiten. Bericht über eine Erkrankung und Literaturübersicht
- Köhler