Content uploaded by Angela H A M van Hoek
Author content
All content in this area was uploaded by Angela H A M van Hoek on Feb 17, 2015
Content may be subject to copyright.
A preview of the PDF is not available
Detection of ESBL-producing Escherichia coli on flies at poultry farms.
Applied and Environmental Microbiology
Abstract and Figures
In the Netherlands, ESBL- producing E. coli are highly prevalent in poultry, and chicken meat has been implicated as a source of ESBL-producing E. coli present in the human population. The current study describes the isolation of ESBL-producing E. coli from house flies and blow flies caught at two poultry farms, offering a potential alternative route of transmission of ESBL-producing E. coli from poultry to humans. Overall, 87 flies were analysed in 19 pools. ESBL-producing E. coli were detected in two fly pools (10.5%): a pool of three blow flies from a broiler farm, and a pool of eight house flies from a laying hen farm. From each positive fly pool six isolates were characterized and compared with isolates obtained from manure (n=53) sampled at both farms, and rinse water (n=10) from the broiler farm. Among six fly-isolates from the broiler farm, four different types were detected with respect to phylogenetic group, sequence type and ESBL-genotype: A0/ST3519/SHV-12, A1/ST10/SHV-12, A1/ST58/SHV-12 and B1/ST448/CTX-M-1. These types, as well as six additional types, were also present in manure and/or rinse water at the same farm. At the laying hen farm all fly and manure isolates were identical, carrying blaTEM-52 in an A1/ST48 genetic background. The data imply that flies acquire ESBL-producing E. coli at poultry farms, warranting further evaluation of the contribution of flies to dissemination of ESBL-producing E. coli in the community.
Figures - uploaded by Angela H A M van Hoek
Author content
All figure content in this area was uploaded by Angela H A M van Hoek
Content may be subject to copyright.
... Out of 1346 single flies obtained from an urban and rural area in Germany, 123 flies had ESBL producers (9.1% prevalence) (Schaumburg et al. 2016). Flies at poultry farms had a 10.5% prevalence of ESBL-producing E. coli (2/19) and houseflies and barn flies obtained from a cattle barn showed 10% prevalence (Usui et al. 2013;Blaak et al. 2014). ...
... ESBL-producing E. coli ST38, ST131, and ST2852 were isolated across these three interfaces, showing dissemination of clonal isolates regardless of the original sources (Seni et al. 2018 M€ uller et al. 2016). In poultry farms, the ESBL-producing E. coli isolates from all parasitic bird flies, and excreted manure carried identical ST with the bla TEM-52 gene, suggesting a clonal transfer between flies and birds happening at the poultry farms (Blaak et al. 2014). Bui et al. (Bui et al. 2018) found identical strains, based on genotyping using pulsed-field gel electrophoresis (PFGE), among chickens in the same farms. ...
The effectiveness of antibiotics has been challenged by the increasing frequency of antimicrobial resistance (AR), which has emerged as a major threat to global health. Despite the negative impact of AR on health, there are few effective strategies for reducing AR in food-producing animals. Of the antimicrobial resistant microorganisms (ARMs), extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriaceae are an emerging global threat due to their increasing prevalence in livestock, even in animals raised without antibiotics. Many reviews are available for the positive selection of AR associated with antibiotic use in livestock, but less attention has been given to how other factors including soil, water, manure, wildlife, and farm workers, are associated with the emergence of ESBL-producing bacteria. Understanding of antibiotic resistance genes and bacteria transfer at the interfaces of livestock and other potential reservoirs will provide insights for the development of mitigation strategies for AR.
... However, the proximity of animals and fresh produce predisposes the crops to contamination by enteric pathogens that are often shed in the feces of food animals (Loncarevic et al., 2005). Filth fly behavior and feeding habits makes them ideal agents for the dispersal of pathogens, and are recognized contributors to the spread of enteric bacteria, including Salmonella and E. coli (Echeverria et al., 1983; Holt et al., 2007; Blaak et al., 2014). The potential role of filth flies to harbor and transmit E. coli O157:H7 to leafy green vegetables has been reported (Talley et al., 2009). ...
... Poultry act as a natural pest control by eating insects; however, insects can be vectors of various pathogens. Many insects and pests are carriers of many microbial pathogens such as E. coli, Campylobacter, Salmonella, and Klebsiella (Blaak et al., 2014; Shane et al., 1985; Echeverria et al., 1983; Fotedar et al., 1992; Holt et al., 2007). Flies alone are widely recognized as reservoirs and vectors of more than 200 human diseases, including Salmonella. ...
Use of mixed crop-livestock farms (MCLFs) is one of the oldest and most traditional farming methods practiced all over the world, and MCLFs are still one of the major systems of food production, particularly for organic foods. On these typically small farms, livestock are reared primarily on grass and naturally grown crops, while composted animal wastes are used to fertilize the soil for growing crops. Specific to organic MCLFs, biosecurity challenges arise from the fact that animals are reared outdoors, which increases potential for contact with disease vectors including wild birds, rodents, and insects. Organic regulations do not allow the use of chemicals and antibiotics; therefore, alternative methods for control of disease and zoonotic pathogens must be used. Due to the biosecurity challenges and the complexity of the MCLF environment, methods for control of zoonotic pathogens need to be carefully considered in order to be effective and to abide by organic regulations if required. The objectives of this study are to define the complex routes of transmission, as well as the prevalence of potential zoonotic and possible interruption strategies of these pathogens among the food animals and crops produced on MCLFs.
© 2015 Poultry Science Association Inc.
... and Citrobacter spp., respectively (Jacoby, 2009;Verdet et al., 2009). Due to the increased use of β-lactams and subsequent relocation of ESBL and AmpC β-lactamase genes to plasmids, ESBL/AmpC producing E. coli are widely disseminated into the environment and into the food-producing animals ( Blaak et al., 2014;Ma et al., 2018. This allows for zoonotic transmission to humans through contaminated food products, creating a feedback loop for evolution and positive selection of new resistance genes ( Ewers et al., 2012;Ibrahim et al., 2016). ...
The emergence of extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase producing Escherichia coli represent a contemporary public health threat. ESBL and AmpC β-lactamase genes translocate between chromosomes and plasmids, facilitating rapid spread throughout the environment. In this study, ESBL/AmpC producing bacteria were isolated from beef cattle farms with seldom antibiotic use. Eleven farms out of 17 tested, had ESBL/AmpC producing E. coli in animals, soil, and forage samples. Fifty-nine CTX-M or CMY-2 positive E. coli isolates were further characterized with whole-genome sequencing. The isolates commonly carried CMY-2, TEM, or CTX-M genes, and over half encoded both CTX-M and TEM genes. Using comparative genomics, antimicrobial resistance genes from 12 classes of antimicrobial were identified and confirmed by antibiotic susceptibility test, revealing multidrug resistance against multiple classes of antibiotics. Virulence factors related to adherence, invasion, iron uptake, and bacterial secretion systems were shared by all isolates; some of which were identified as enteropathogenic E. coli. Phylogenetic analyses revealed a pattern of close genetic relatedness, suggesting that ESBL/AmpC producing E. coli were transmitted among farms as well as independent evolution within farms. Our results indicate that ESBL and AmpC β-lactamases prevail in food animal production system regardless antibiotic use and have the characteristics for zoonotic transmission.
... The most prominent CCs identified in the current study have been described internationally among ESBL producers from various sources. For example, ESBL-producing E. coli ST58 and ST155 (CC155) are described globally from a wide range of sources, including healthy humans, livestock and wildlife [52][53][54][55]. ...
Feeding pets raw meat-based diets (RMBDs) has become increasingly popular but may constitute a risk due to the contamination with pathogenic and antimicrobial-resistant (AMR) bacteria. The aim of this study was to evaluate commercially available RMBDs with regard to microbiological quality and occurrence of AMR Enterobacteriaceae. Of 51 RMBD samples, 72.5% did not meet the microbiological standards for Enterobacteriaceae set out by EU regulations for animal by-products intended for pet food. Furthermore, Salmonella was detected in 3.9% of the samples. AMR bacteria were found in 62.7% of the samples, the majority thereof were resistant to third-generation cephalosporins due to the production of extended-spectrum β-lactamases (ESBLs) including CTX-M-1, which is widespread in livestock, and CTX-M-15, which is the most common ESBL variant worldwide. Colistin- and aminoglycoside-resistant isolates, producing MCR-1 and RMTB, were identified in 3.9 and 2% of the samples, respectively. The majority of the AMR Escherichia coli belonged to commensal groups A or B1 and were associated with clonal complexes CC155 and CC10. Two belonged to the emerging extraintestinal pathogenic CC648, and one to the globally disseminated uropathogenic E. coli sequence type ST69, suggesting zoonotic potential. The microbiological quality and the high prevalence of AMR producing Enterobacteriaceae in RMBDs raise concerns for animal and public health.
Introduction: Infections due to extended spectrum β-lactamase (ESBL) strains pose a major challenge in the management of infections worldwide.
Aim: This study was conducted to detect ESBL producing Escherichia coli associated with retail chicken meat and humans in Bulawayo, Zimbabwe.
Materials & methods: A total of 120 E.coli isolates obtained from poultry samples and 64 isolates associated with urinary tract infections in humans were collected and analyzed for ESBL production. ESBL producers were determined using antimicrobial susceptibility tests and the polymerase chain reaction was used to detect ESBL genes (BlaTEM, BlaSHV, BlaCTX-M and BlaOXA). A Klebsiella pneumonia isolate which was positive for the BlaTEM (Genbank accession number KT818790), BlaSHV (KT818791) & BlaCTX-M (KT818792) was used as the positive control.
Results: Fifty nine (49%) of the isolates (chicken meat) and 40 (63%) (UTI) were found to be ESBL producers. The TEM, CTX-M and SHV genes were successfully detected in both meat and UTI samples. No OXA genes were detected. The prevalences of the ESBL genes were; TEM 23.3% (chicken isolates) and 29.7% (UTI isolates), CTX-M, 5 and 20,3%, SHV 4.2 and 10.9%. Typing of the E.coli isolates using Amplified Ribosomal DNA Restriction Analysis (ARDRA) showed a high degree of similarity between human and meat isolates. Conclusion: Presence of ESBL genes in poultry destined for human consumption points to a potential reservoir for transmission of these genes to humans.
Key words: Extended spectrum β-lactamase, Escherichia coli, poultry, Zimbabwe
The public health significance of transmission of ESBL-producing Escherichia coli and Campylobacter from poultry farms to humans through flies was investigated using a worst-case risk model. Human exposure was modeled by the fraction of contaminated flies, the number of specific bacteria per fly, the number of flies leaving the poultry farm, and the number of positive poultry houses in the Netherlands. Simplified risk calculations for transmission through consumption of chicken fillet were used for comparison, in terms of the number of human exposures, the total human exposure, and, for Campylobacter only, the number of human cases of illness. Comparing estimates of the worst-case risk of transmission through flies with estimates of the real risk of chicken fillet consumption, the number of human exposures to ESBL-producing E. coli was higher for chicken fillet as compared with flies, but the total level of exposure was higher for flies. For Campylobacter, risk values were nearly consistently higher for transmission through flies than for chicken fillet consumption. This indicates that the public health risk of transmission of both ESBL-producing E. coli and Campylobacter to humans through flies might be of importance. It justifies further modeling of transmission through flies for which additional data (fly emigration, human exposure) are required. Similar analyses of other environmental transmission routes from poultry farms are suggested to precede further investigations into flies.
© 2015 Society for Risk Analysis.
Flies may act as potential vectors for the spread of resistant bacteria into different environments. This study intends to evaluate the presence of E. coli resistant to cephalosporins in flies captured in the surroundings of five broiler farms. Phenotypic and molecular characterization of the resistant population was performed by different methods: minimum inhibitory concentration, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and phylotyping. The presence of extended spectrum beta-lactamase (ESBL) genes, its plasmid location and the characterization of the mobile genetic elements involved in its mobilization were studied. Additionally, presence of 35 genes associated to virulence was evaluated. Out of 682 flies captured, 42 yielded ESBL-producing E. coli. Of those, 23 contained blaCTX-M-1, 18 blaCTX-M-14 and one blaCTX-M-9. ESBL genes were mainly associated to the presence of IncI1 and IncFIB replicons. Additionally, all the strains were multi-resistant and five of them also harboured qnrS. Identical PFGE profiles were found in E. coli obtained from flies at different sampling times indicating persistence of the same clones in the farm environment over the months. According to virulence genes, 81% of the isolates were considered avian pathogenic E. coli (APEC) and 29% extraintestinal pathogenic E. coli (ExPEC). The entrance of flies to broiler houses constitutes a considerable risk for colonization of broilers with multi-drug resistant E. coli. ESBLs in the flies reflect the contamination status of the farm environment. Additionally, this study demonstrates the potential contribution of flies to the dissemination of virulence and resistance genes into different ecological niches.
Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Antimicrobial resistance, including multidrug resistance (MDR), is an increasing problem globally. MDR bacteria are frequently detected in humans and animals from both more- and less-developed countries and pose a serious concern for human health. Infections caused by MDR microbes may increase morbidity and mortality and require use of expensive drugs and prolonged hospitalization. Humans may be exposed to MDR pathogens through exposure to environments at health-care facilities and farms, livestock and companion animals, human food, and exposure to other individuals carrying MDR microbes. The Centers for Disease Control and Prevention classifies drug-resistant foodborne bacteria, including Campylobacter, Salmonella Typhi, nontyphoidal salmonellae, and Shigella, as serious threats. MDR bacteria have been detected in both meat and fresh produce. Salmonellae carrying genes coding for resistance to multiple antibiotics have caused numerous foodborne MDR outbreaks. While there is some level of resistance to antimicrobials in environmental bacteria, the widespread use of antibiotics in medicine and agriculture has driven the selection of a great variety of microbes with resistance to multiple antimicrobials. MDR bacteria on meat may have originated in veterinary health-care settings or on farms where animals are given antibiotics in feed or to treat infections. Fresh produce may be contaminated by irrigation or wash water containing MDR bacteria. Livestock, fruits, and vegetables may also be contaminated by food handlers, farmers, and animal caretakers who carry MDR bacteria. All potential sources of MDR bacteria should be considered and strategies devised to reduce their presence in foods. Surveillance studies have documented increasing trends in MDR in many pathogens, although there are a few reports of the decline of certain multidrug pathogens. Better coordination of surveillance programs and strategies for controlling use of antimicrobials need to be implemented in both human and animal medicine and agriculture and in countries around the world.
Members of the Enterobacteriaceae with extended-spectrum beta-lactamases (ESBLs) of the CTX-M type have disseminated rapidly in recent years and have become
a threat to public health. In parallel with the CTX-M type expansion, the consumption and widespread use of silver-containing
products has increased. To determine the carriage rates of silver resistance genes in different Escherichia coli populations, the presence of three silver resistance genes (silE, silP, and silS) and genes encoding CTX-M-, TEM-, and SHV-type enzymes were explored in E. coli isolates of human (n = 105) and avian (n = 111) origin. The antibiotic profiles were also determined. Isolates harboring CTX-M genes were further characterized, and
phenotypic silver resistance was examined. The silE gene was present in 13 of the isolates. All of them were of human origin. Eleven of these isolates harbored ESBLs of the
CTX-M type (P = 0.007), and eight of them were typed as CTX-M-15 and three as CTX-M-14. None of the silE-positive isolates was related to the O25b-ST131 clone, but 10 out of 13 belonged to the ST10 or ST58 complexes. Phenotypic
silver resistance (silver nitrate MIC > 512 mg/liter) was observed after silver exposure in 12 of them, and a concomitant
reduced susceptibility to piperacillin-tazobactam developed in three. In conclusion, 12% of the human E. coli isolates but none of the avian isolates harbored silver resistance genes. This indicates another route for or level of silver
exposure for humans than that caused by common environmental contamination. Since silE-positive isolates were significantly more often found in CTX-M-positive isolates, it is possible that silver may exert a
selective pressure on CTX-M-producing E. coli isolates.
Antibiotic resistant bacterial infections result in higher patient mortality rates, prolonged hospitalization, and increased healthcare costs. Extensive use of antibiotics as growth promoters in the animal industry represents great pressure for evolution and selection of antibiotic resistant bacteria on farms. Despite growing evidence showing that antibiotic use and bacterial resistance in food animals correlate with resistance in human pathogens, the proof for direct transmission of antibiotic resistance is difficult to provide. In this review, we make a case that insects commonly associated with food animals likely represent a direct and important link between animal farms and urban communities for antibiotic resistance traits. Houseflies and cockroaches have been shown to carry multi-drug resistant clonal lineages of bacteria identical to those found in animal manure. Furthermore, several studies demonstrated proliferation of bacteria and horizontal transfer of resistance genes in the insect digestive tract as well as transmission of resistant bacteria by insects to new substrates. We propose that insect management should be an integral part of pre- and post-harvest food safety strategies to minimize spread of zoonotic pathogens and antibiotic resistance traits from animal farms. Furthermore, the insect link between the agricultural and urban environment presents an additional argument for adopting prudent use of antibiotics in the food animal industry.
Objectives:
The aims of this study were (i) to detect extended-spectrum β-lactamase (ESBL) genes among 1378 Escherichia coli isolates from defined disease conditions of companion and farm animals and (ii) to determine the localization and organization of ESBL genes.
Methods:
E. coli isolates from the German resistance monitoring programme GERM-Vet were included in the study. Plasmids were transferred by conjugation or transformation and typed by PCR-based replicon typing. ESBL genes were detected by PCR; the complete ESBL genes and their flanking regions were sequenced by primer walking. Phylogenetic grouping and multilocus sequence typing (MLST) were performed for all ESBL-producing E. coli isolates.
Results:
Of the 27 ESBL-producing E. coli isolates detected, 22 carried blaCTX-M-1 genes on IncN (n = 16), IncF (n = 3), IncI1 (n = 2) or multireplicon (n = 1) plasmids. A blaCTX-M-3 gene was located on an IncN plasmid and a blaCTX-M-15 gene was located on an IncF plasmid. A multireplicon plasmid and an IncHI1 plasmid harboured blaCTX-M-2. A blaTEM-52c gene was identified within Tn2 on an IncI1 plasmid. The blaCTX-M genes located within the same or related genetic contexts showed differences due to the integration of insertion sequences. Various MLST types were detected, with ST10 (n = 7), ST167 (n = 4) and ST100 (n = 3) being the most common.
Conclusions:
This study showed that the blaCTX-M-1 gene is the predominant ESBL gene among E. coli isolates from diseased animals in Germany and a considerable structural heterogeneity was found in the regions flanking the blaCTX-M-1 gene. Insertion sequences, transposons and recombination events are likely to be involved in alterations of the ESBL gene regions.
Objectives:
The aim of this study was to establish the prevalence of extended-spectrum β-lactamase (ESBL)- and AmpC β-lactamase-producing Escherichia coli at Dutch broiler farms and in farmers and to compare ESBL/AmpC-producing isolates from farmers and their animals.
Methods:
Twenty-five to 41 cloacal swabs collected from broilers at each of 26 farms and 18 faecal samples from 18 broiler farmers were analysed for determination of the presence of ESBL/AmpC-producing E. coli. ESBL/AmpC genes were characterized by microarray, PCR and sequencing. Plasmids were characterized by transformation and PCR-based replicon typing. Subtyping of plasmids was done by plasmid multilocus sequence typing or restriction fragment length polymorphism. E. coli genotypes were determined by multilocus sequence typing.
Results:
Birds from all farms were positive for ESBL/AmpC-producing E. coli, and on 22/26 farms the within-farm prevalence was ≥ 80%. Six of 18 farmers carried isolates containing ESBL/AmpC genes bla(CTX-M-1), bla(CMY-2) and/or bla(SHV-12), which were also present in the samples from their animals. In five of these isolates, the genes were located on identical plasmid families [IncI1 (n = 3), IncK (n = 1) or IncN (n = 1)], and in isolates from two farmers the genes were carried on identical plasmid subtypes (IncI1 ST12 and IncN ST1, where ST stands for sequence type) as in the isolates from their animals.
Conclusions:
This study shows a high prevalence of birds carrying ESBL/AmpC-producing E. coli at Dutch broiler farms and a high prevalence of ESBL/AmpC-producing E. coli in farmers. This is undesirable due to the risk this poses to human health. Future research should focus on identification of the source of these isolates in the broiler production chain to make interventions resulting in reduction of these isolates possible.
Although flies are important vectors of food-borne pathogens, there is little information to accurately assess the food-related
health risk of the presence of individual flies, especially in urban areas. This study quantifies the prevalence and the relative
risk of food-borne pathogens associated with the body surfaces and guts of individual wild flies. One hundred flies were collected
from the dumpsters of 10 randomly selected urban restaurants. Flies were identified using taxonomic keys before being individually
dissected. Cronobacter spp., Salmonella spp., and Listeria monocytogenes were detected using the PCR-based BAX system Q7. Positive samples were confirmed by culture on specific media and through
PCR amplification and sequencing or ribotyping. Among collected flies were the housefly, Musca domestica (47%), the blowflies, Lucilia cuprina (33%) and Lucilia sericata (14%), and others (6%). Cronobacter species were detected in 14% of flies, including C. sakazakii, C. turicensis, and C. universalis, leading to the proposal of flies as a natural reservoir of this food-borne pathogen. Six percent of flies carried Salmonella enterica, including the serovars Poona, Hadar, Schwarzengrund, Senftenberg, and Brackenridge. L. monocytogenes was detected in 3% of flies. Overall, the prevalence of food-borne pathogens was three times greater in the guts than on
the body surfaces of the flies. The relative risk of flies carrying any of the three pathogens was associated with the type
of pathogen, the body part of the fly, and the ambient temperature. These data enhance the ability to predict the microbiological
risk associated with the presence of individual flies in food and food facilities.
The spreading of antimicrobial-resistant bacteria and genes from food-producing animals to humans has been a subject of increasing concern. To clarify the role of flies in spreading the extended-spectrum β-lactamase (ESBL) gene from food-producing animals to humans, we isolated and characterized a third-generation cephalosporin-resistant Escherichia coli strain from flies and cattle feces from a cattle barn. Cephalosporin-resistant strains were isolated from 14.3% (13/91) of houseflies, 10.3% (7/68) of false stable flies, and 7.5% (7/93) of cattle feces. Twenty-seven cephalosporin-resistant strains were tested for the presence of antimicrobial resistance genes. Of the 27 samples, 22 isolates from 11 houseflies, 5 false stable flies, and 6 cattle feces samples harbored the blaCTX-M-15 gene. All blaCTX-M-15-harboring isolates belonged to phylogenetic group D and the ST38 clonal group. Analysis of pulsed-field gel electrophoresis showed that these isolates were divided into two clusters, indicating that flies carried several of the same clones that were detected in cattle feces. All blaCTX-M-15 gene-harboring plasmids were transferable and were members of incompatibility group FIB. These results suggest that transferable plasmids encoding ESBL were prevalent among flies and cattle. As vectors, flies may play an important role in spreading ESBL-producing bacteria from food-producing animals to humans.
Prevalence of, and risk factors for, carriage of extended-spectrum β-lactamase (ESBL) -producing Enterobacteriaceae were determined for 1025 Dutch adults in municipalities with either high or low broiler densities. Overall prevalence of ESBL carriage was 5.1%. The hypothesis that individuals in areas with high broiler densities are at greater risk for ESBL carriage was rejected, as the risk was lower (OR = 0.45; p 0.009) for these individuals. Owning a horse increased the risk (OR = 4.69; p ≤0.0001), but horse owners often owned multiple species of companion animals. Routes of transmission from animals to humans in the community, and the role of poultry in this process, remain to be elucidated.
Although β-lactams remain a cornerstone of veterinary therapeutics, only a restricted number are actually approved for use in food-producing livestock in comparison to companion animals and wildlife. Nevertheless, both registered and off-label use of third and fourth-generation cephalosporins in livestock may have influenced the emergence of plasmid-encoded AmpC β-lactamases (pAmpC) (mainly CMY-2) and CTX-M extended-spectrum β-lactamases (ESBLs) in both Gram-negative pathogens and commensals isolated from animals. This presents a public health concern due to the potential risk of transfer of β-lactam-resistant pathogens from livestock to humans through food. The recent detection of pAmpC and ESBLs in multidrug-resistant Enterobacteriaceae isolated from dogs has also confirmed the public health importance of β-lactam resistance in companion animals, though in this case, human-to-animal transmission may be equally as relevant as animal-to-human transmission. Identification of pAmpC and ESBLs in Enterobacteriaceae isolated from wildlife and aquaculture species may be evidence of environmental selection pressure arising from both human and veterinary use of β-lactams. Such selection pressure in animals could be reduced by the availability of reliable alternative control measures such as vaccines, bacteriophage treatments and/or competitive exclusion models for endemic production animal diseases such as colibacillosis. The global emergence and pandemic spread of extraintestinal pathogenic E. coli O25-ST131 strains expressing CTX-M-15 ESBL in humans and its recent detection in livestock, companion animals and wildlife is a major cause for concern and goes against the paradigm that Gram-negative pathogens do not necessarily have to lose virulence in compensation for acquiring resistance.
Clin Microbiol Infect
The aim of this study was to determine the rate of carriage of ESBL-producing Enterobacteriaceae (ESBL-E) in the community in the Netherlands and to gain understanding of the epidemiology of these resistant strains. Faecal samples from 720 consecutive patients presenting to their general practitioner, obtained in May 2010, and between December 2010 and January 2011, were analysed for presence of ESBL-E. Species identification and antibiotic susceptibility testing were performed according to the Dutch national guidelines. PCR, sequencing and microarray were used to characterize the genes encoding for ESBL. Strain typing was performed with amplified fragment length polymorphism (AFLP) and multilocus sequence typing (MLST). Seventy-three of 720 (10.1%) samples yielded ESBL-producing organisms, predominantly E. coli. No carbapenemases were detected. The most frequent ESBL was CTX-M-15 (34/73, 47%). Co-resistance to gentamicin, ciprofloxacin and cotrimoxazole was found in (9/73) 12% of the ESBL-E strains. AFLP did not show any clusters, and MLST revealed that CTX-M-15-producing E. coli belonged to various clonal complexes. Clonal complex ST10 was predominant. This study showed a high prevalence of ESBL-producing Enterobacteriaceae in Dutch primary care patients with presumed gastrointestinal discomfort. Hence, also in the Netherlands, a country with a low rate of consumption of antibiotics in humans, resistance due to the expansion of CTX-M ESBLs, in particular CTX-M-15, is emerging. The majority of ESBL-producing strains do not appear to be related to the international clonal complex ST131.
Clin Microbiol Infect 2012; 18: 413–431
Plasmid-acquired carbapenemases in Enterobacteriaceae, which were first discovered in Europe in the 1990s, are now increasingly being identified at an alarming rate. Although their hydrolysis spectrum may vary, they hydrolyse most β-lactams, including carbapenems. They are mostly of the KPC, VIM, NDM and OXA-48 types. Their prevalence in Europe as reported in 2011 varies significantly from high (Greece and Italy) to low (Nordic countries). The types of carbapenemase vary among countries, partially depending on the cultural/population exchange relationship between the European countries and the possible reservoirs of each carbapenemase. Carbapenemase producers are mainly identified among Klebsiella pneumoniae and Escherichia coli, and still mostly in hospital settings and rarely in the community. Although important nosocomial outbreaks with carbapenemase-producing Enterobacteriaceae have been extensively reported, many new cases are still related to importation from a foreign country. Rapid identification of colonized or infected patients and screening of carriers is possible, and will probably be effective for prevention of a scenario of endemicity, as now reported for extended-spectrum β-lactamase (mainly CTX-M) producers in all European countries.
To investigate the occurrence and characteristics of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Enterobacteriaceae isolates in clinical samples of companion animals and horses and compare the results with ESBL/AmpC-producing isolates described in humans.
Between October 2007 and August 2009, 2700 Enterobacteriaceae derived from clinical infections in companion animals and horses were collected. Isolates displaying inhibition zones of ≤ 25 mm for ceftiofur and/or cefquinome by disc diffusion were included. ESBL/AmpC production was confirmed by combination disc tests. The presence of resistance genes was identified by microarray, PCR and sequencing, Escherichia coli genotypes by multilocus sequence typing and antimicrobial susceptibility by broth microdilution.
Sixty-five isolates from dogs (n = 38), cats (n = 14), horses (n = 12) and a turtle were included. Six Enterobacteriaceae species were observed, mostly derived from urinary tract infections (n = 32). All except 10 isolates tested resistant to cefotaxime and ceftazidime by broth microdilution using clinical breakpoints. ESBL/AmpC genes observed were bla(CTX-M-1, -2, -9, -14, -15,) bla(TEM-52), bla(CMY-2) and bla(CMY-)(39). bla(CTX-M-1) was predominant (n = 17). bla(CTX-M-9) occurred in combination with qnrA1 in 3 of the 11 Enterobacter cloacae isolates. Twenty-eight different E. coli sequence types (STs) were found. E. coli carrying bla(CTX-M-1) belonged to 13 STs of which 3 were previously described in Dutch poultry and patients.
This is the first study among a large collection of Dutch companion animals and horses characterizing ESBL/AmpC-producing isolates. A similarity in resistance genes and E. coli STs among these isolates and isolates from Dutch poultry and humans may suggest exchange of resistance between different reservoirs.