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Comprative study of diagnostic procedures in Salmonella Infection, causative agent of typhoid fever- A Overview study
Abstract
Comprative study of diagnostic procedures in Salmonella Infection, causative agent of typhoid fever- A Overview study
Supplementary resource (1)
... The bacteria definitive diagnosis always depends on the Salmonella bacteria isolation from blood, stool, urine, or other body fluids. [5] Distribution of Typhoid Patients CRP Figure 1 shows the distribution of typhoid patients by CRP. The results of the measurement of the concentration of the CRP showed an increase in the concentration of the age group, as shown in Figure 1 and the result was positive for all ages and did not show the control because it is negative in healthy people. ...
Abstract: Background: Salmonella spp. are creatures which might discover likewise normal commensals in the gastrointestinal tracts of man also animals or alternately result in malady that reaches from self-set looseness of the bowels. Salmonella enterica serotype Typhi (Salmonella Typhi) is responsible for a potentially fatal multisystemic illness, these known as typhoid fever or enteric fever. Materials and Methods: Subjects for this study included 40 patients with typhoid fever. Forty blood samples were collected from patients with typhoid fever and clinically diagnosed by doctors based on clinical symptoms of high fever for at least 2 days and severe headache with nausea, abdominal pain, and joints, include 30 females and 10 males with age 10-40 years, the control group study included 15 people apparently healthy that included nine males and six females with age average 20-30 years. Results: Patients of typhoid were divided by age into group, the age group (11-20) was the first age group, the disease rate was 25%, while the second age group (21-30), the disease rate was 55%, was the highest, and the third age group (31-40), the disease rate was 20%. Results of the distribution of study group by gender showed infection that appears in both sexes, with a significant association between the study groups and sex patients of typhoid disease which was more in female. Bacterial growth on growth media after incubation of the plates for 24-48 h showed that the bacterial colonies growing on the growth media were as follows: Transparent with a black center, colorless or pale pink. While microscopic examination, Salmonella, Gram stained bacteria, are characterized by Gram-negative rod cells. The results of the measurement of the concentration of the C-reactive protein showed an increase in the concentration of the age group. The distribution of typhoid patients immunoglobulin (IgM and IgG) measured by rapid cassette, IgM was highest among patients with typhoid (95%), while IgG was 45% and IgM and IgG were among patients (40%). Conclusion: Typhoid fever disease is more common among females than males. Patients with typhoid fever have elevated levels CRP.
... The bacteria definitive diagnosis always depends on the Salmonella bacteria isolation from blood, stool, urine, or other body fluids. [5] Distribution of Typhoid Patients CRP Figure 1 shows the distribution of typhoid patients by CRP. The results of the measurement of the concentration of the CRP showed an increase in the concentration of the age group, as shown in Figure 1 and the result was positive for all ages and did not show the control because it is negative in healthy people. ...
... Typhoid fever is a systemic disease caused by Salmonella enterica serotype typhi and is a major cause of morbidity and mortality worldwide [1]. It emerged as an important infectious disease in the early 19th century. ...
The "gold standard" for diagnosis of typhoid fever is the isolation of Salmonella typhi from appropriate samples including blood, stool and urine. The study was aimed to compare Widal test against stool culture for diagnosis of typhoid fever cases in Kano, Northern Nigeria. A completely randomized design is used. A total of 125 subjects (male, n= 57 and female, n=68) presenting febrile conditions in 4 different health care centers within Kumbotso Local Government Kano State were used for the study. About 5ml of blood was obtained from each study participant for Widal test and freshly passed faeces were collected for stool culture. The result showed that 22 (17.6%) tested positive for Salmonella typhi by Widal test, whereas 17 (13.6%) tested positive by stool culture. From the result, patients within the age category 21-40 years has the highest incidence 9 (7.2%) and 7 (5.6%) for Widal test and stool culture respectively while male has the highest prevalence with 12 and 10 individuals (9.6% and 8%) while 10 and 7 individual positive samples were female accounted for 8% and 5.6% for widal test and stool microcopy respectively. In relation to stool culture, Widal test has high sensitivity (78.3%), specificity (93.6%), positive predictive value (68.2%) and negative predictive value (98.1%). There is no significant difference on the prevalence of the infection on the basis of gender, age category and diagnostic methods at p<0.05. It is concluded that Widal test can be used as a diagnostic method for detection of Salmonella typhi.
... The other factor that may affect the stool culture is its proneness to contamination that may result in misdiagnosis. Additionally, increasing the quantity of stool used for culture has been shown to increase the sensitivity with culturing two grams of stool rather than the standard one gram increasing isolation by 10% [40]. ...
... In many areas where sewage transfer is missing or insufficient, open water supplies and food are contaminated by food handlers who are carriers, frames the second commonest course of infection, because fecal-oral transmission in this type of disease is common. For this reason, prevent this cycle by diagnosis of carrier's patients and use effective treatment leads to effective control of the disease [4]. ...
... In many areas where sewage transfer is missing or insufficient, open water supplies and food are contaminated by food handlers who are carriers, frames the second commonest course of infection, because fecal-oral transmission in this type of disease is common. For this reason, prevent this cycle by diagnosis of carrier's patients and use effective treatment leads to effective control of the disease [4]. ...
Typhoid fever is an extreme multi-systemic infection, constitutional symptoms is a major findings with classic prolonged fever. The simplicity, sensitivity, specificity and cost effective of diagnostic test which will be used in diagnosis of typhoid fever in human carriers, would give a compelling apparatus in controlling and preventing typhoid. The aims of this investigation were to determine the proportion of typhoid carriers by using homemade ELISA test based on OMP extraction. This study included fifty febrile patients and thirty age and sex matched apparently healthy individual as control with no history of immunization in the recent past, they were 24 (48%) males and 26 (52%) females, the age was ranged between 18-40 year with mean (33.6) .Blood and stool samples were collected from each participant and these samples underwent culturing on special media, after OMPs extraction from Salmonella typhi. Sandwich homemade ELISA were developed for detection of anti typhoid IgG and IgM using crud OMPS as antigen .The results showed that 18 (36.0%) out of 50 patients were stool culture positive, while blood culture results confirmed typhoid fever in 7 (14.0%) patients. Out of 50 serum samples were tested by homemade ELISA kit, which prepared in this study for IgG /IgM detection, there were 35(70.0%) IgG positive and only 8 (16.0%) was IgM positive. For IgG and/or IgM, as tested by ELISA positive results in accordance with stool and blood culture assays .For stool positive culture, IgG ELISA (26%) 13/50, showed positive results, while IgM (6.0 %) 3/50.
... The Salmonella yield is much higher than the reports from other studies. [18,20] Most of the growths seen in stool specimen were from the sample enriched for 6-8 h in Selenite F broth compared to direct inoculation on agar plates. ...
Introduction: Enteric fever, caused by Salmonella enterica subsp. enterica
serotype Typhi and Paratyphi, is endemic in India with an incidence of
102–2219/100,000 populations. The definitive diagnosis of enteric fever in
patients with compatible clinical picture is isolation of Salmonellae from blood,
bone marrow, stool or urine, and demonstration of four‑fold rise in antibody titer
to both O and H antigen of the organism between acute and convalescent‑phase
sera. Aim: The aim of the study was to study the prevalence of various
serotypes of S. enterica and their antibiogram in foot hills of Himalayas.
Materials and Methods: During February 2012–January 2013, all clinically
suspected patients were screened for enteric fever by Widal tube agglutination
test. For the isolation of etiology, venous blood, stool and urine specimen were
obtained from patients with antibody titer of ≥80 and 160 for anti‑O agglutinin
and anti‑H agglutinin of Salmonella typhi, respectively, and ≥20 for anti-H
agglutinin of S. paratyphi A and S. paratyphi B. Characterization and antibiogram
determination of the isolates was done by conventional microbiological methods
including Kirby–Bauer’s disc diffusion technique. Result: Among 1173 suspected
cases, 373 showed a high titer of antibodies against O (≥80), H (≥160), AH (≥20),
and BH (≥20) antigens. A total of 81 isolates were obtained from 76 patients (29
from blood and 49 from stool and three from urine), of which 54 were identified as
Salmonella typhi, 20 as Paratyphi A and seven as Paratyphi B. Extended‑spectrum
beta‑lactamase production was observed in four isolates of S. typhi. Ciprofloxacin
followed by co‑trimoxazole was resistant to 46.5 and 36.5% of the isolates,
respectively. Conclusion: This report indicates a significant percentage of drug
resistance in S. enterica serotypes in Garhwal region. Periodic monitoring of the
antibiogram pattern along with the implementation of strict antibiotic policies and
patient education is needed.
Background: The development of bacteria resistance to present available antibiotics has necessitated the needs to search for new effective and cheaper antibacterial agents. Resistance of Salmonella to antibiotics is a serious health problem in the world more especially in developing countries and Cameroon in particular. This study aimed at comparing the antibacterial activity of medicinal plant extracts (Cymbopogon citatus leaves, Carica papaya leaves, Bidens pilosa, and Mangifera indica leaves) used by traditional herbalist against Salmonella typhi, compared to Ciprofloxacin.
Methods: This study was carried out at the Standard Medical Diagnostic and Research Center – Bamenda. Plant samples were collected, dried away from sunlight and ground into powder form. 25g of each plant powder was weighed to form a pool mixture of medicinal plant powder and dispensed in 95% methanol and distilled water and kept still for 7days. Isolation of Salmonella typhi from human feces was done using Salmonella Shigella agar (SSA) and sub-cultured on Muella Hinton Agar. Two fold serial dilutions were made on the methanol and water while two methods of sensitivity testing (well diffusion and disc diffusion) were carried out on different Mueller Hinton agar plates and incubated at 37°C for 18-24hrs. The zones of inhibition were measured in mm, compared and analyzed in SPSS version 21.
Results: The sensitivity studies conducted on the medicinal plant extracts and ciprofloxacin indicated that the buffered alcohol extract inhibited S. typhi to a zone of 13.34mm and 7.45mm for distilled water extract (p˂0.05). Alcohol extract also recorded an inhibitory zone of 23.05mm by well diffusion and 19.55mm by disc diffusion (p˂0.05). Again, sensitivity studies using ciprofloxacin 5µg gave a zone of inhibition of 5.0. Significant differences were observed among the extracts, on well diffusion versus disc diffusion and ciprofloxacin
(p<0.05).
Conclusion: Despite the fact that methanol and aqueous extracts of the plants proved inhibitory actions to S. typhi more than the drug of choice in hospitals (Ciprofloxacin), Methanol extract of medicinal plants proved to inhibit the growth of S typhi strains more.
Key words: Susceptibility, Salmonella typhi, medicinal plant extracts, ciprofloxacin.
La typhoïde, maladie infectieuse due à Salmonella typhi, atteint chaque année environ 200 millions de personnes dans le monde et est responsable de 200 000 décès, essentiellement en zones tropicales. En France, environ 200 cas sont répertoriés chaque année. Il s'agit surtout de cas importés de pays tropicaux ou des départements d'outre-mer, en particulier de Mayotte (54 cas depuis janvier 2022) où, par exemple, deux observations sont rapportées chez des femmes enceintes. Après une incubation d'une semaine, le patient atteint de typhoïde se plaint d'asthénie et de diarrhée fébrile, mais avec un pouls normal. Les complications digestives (perforation intestinale) sont parfois mortelles. Le diagnostic est établi par l'hémoculture et parfois par la sérologie. Le traitement par antibiotiques (fluoroquinolones et céphalosporines) est efficace. La prévention est basée sur les mesures d'hygiène et la vaccination. Typhoid fever, an infectious disease due to Salmonella typhi, is estimated to cause, each year, about 20 million cases worldwide and 200 000 deaths, mainly in tropical areas. In France, about 200 cases are recorded annually, mostly concerning cases imported from tropical countries or overseas departments, in particular Mayotte (54 cases since January 2022), where, for example, two cases are reported in pregnant women. After incubation of a week, the patient with typhoid fever complains of asthenia and febrile diarrhea, but with a normal pulse. Digestive complications (intestinal perforation) are sometimes fatal. The diagnosis is established by blood culture and sometimes by serology. Treatment with antibiotics (fluoroquinone and cephalosporin) is effective. Prevention is based on hygiene measures and vaccination. Typhoïde-Salmonella typhi-Diarrhée fébrile-Vaccin-Mayotte Typhoid fever-Salmonella typhi-Febrile diarrhea-Vaccination-Mayotte
Background:
Differentiating both typhoid (Salmonella Typhi) and paratyphoid (Salmonella Paratyphi A) infection from other causes of fever in endemic areas is a diagnostic challenge. Although commercial point-of-care rapid diagnostic tests (RDTs) for enteric fever are available as alternatives to the current reference standard test of blood or bone marrow culture, or to the widely used Widal Test, their diagnostic accuracy is unclear. If accurate, they could potentially replace blood culture as the World Health Organization (WHO)-recommended main diagnostic test for enteric fever.
Objectives:
To assess the diagnostic accuracy of commercially available rapid diagnostic tests (RDTs) and prototypes for detecting Salmonella Typhi or Paratyphi A infection in symptomatic persons living in endemic areas.
Search methods:
We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, IndMED, African Index Medicus, LILACS, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) up to 4 March 2016. We manually searched WHO reports, and papers from international conferences on Salmonella infections. We also contacted test manufacturers to identify studies.
Selection criteria:
We included diagnostic accuracy studies of enteric fever RDTs in patients with fever or with symptoms suggestive of enteric fever living in endemic areas. We classified the reference standard used as either Grade 1 (result from a blood culture and a bone marrow culture) or Grade 2 (result from blood culture and blood polymerase chain reaction, or from blood culture alone).
Data collection and analysis:
Two review authors independently extracted the test result data. We used a modified QUADAS-2 extraction form to assess methodological quality. We performed a meta-analysis when there were sufficient studies for the test and heterogeneity was reasonable.
Main results:
Thirty-seven studies met the inclusion criteria and included a total of 5080 participants (range 50 to 1732). Enteric fever prevalence rates in the study populations ranged from 1% to 75% (median prevalence 24%, interquartile range (IQR) 11% to 46%). The included studies evaluated 16 different RDTs, and 16 studies compared two or more different RDTs. Only three studies used the Grade 1 reference standard, and only 11 studies recruited unselected febrile patients. Most included studies were from Asia, with five studies from sub-Saharan Africa. All of the RDTs were designed to detect S.Typhi infection only.Most studies evaluated three RDTs and their variants: TUBEX in 14 studies; Typhidot (Typhidot, Typhidot-M, and TyphiRapid-Tr02) in 22 studies; and the Test-It Typhoid immunochromatographic lateral flow assay, and its earlier prototypes (dipstick, latex agglutination) developed by the Royal Tropical Institute, Amsterdam (KIT) in nine studies. Meta-analyses showed an average sensitivity of 78% (95% confidence interval (CI) 71% to 85%) and specificity of 87% (95% CI 82% to 91%) for TUBEX; and an average sensitivity of 69% (95% CI 59% to 78%) and specificity of 90% (95% CI 78% to 93%) for all Test-It Typhoid and prototype tests (KIT). Across all forms of the Typhidot test, the average sensitivity was 84% (95% CI 73% to 91%) and specificity was 79% (95% CI 70% to 87%). When we based the analysis on the 13 studies of the Typhidot test that either reported indeterminate test results or where the test format means there are no indeterminate results, the average sensitivity was 78% (95% CI 65% to 87%) and specificity was 77% (95% CI 66% to 86%). We did not identify any difference in either sensitivity or specificity between TUBEX, Typhidot, and Test-it Typhoid tests when based on comparison to the 13 Typhidot studies where indeterminate results are either reported or not applicable. If TUBEX and Test-it Typhoid are compared to all Typhidot studies, the sensitivity of Typhidot was higher than Test-it Typhoid (15% (95% CI 2% to 28%), but other comparisons did not show a difference at the 95% level of CIs.In a hypothetical cohort of 1000 patients presenting with fever where 30% (300 patients) have enteric fever, on average Typhidot tests reporting indeterminate results or where tests do not produce indeterminate results will miss the diagnosis in 66 patients with enteric fever, TUBEX will miss 66, and Test-It Typhoid and prototype (KIT) tests will miss 93. In the 700 people without enteric fever, the number of people incorrectly diagnosed with enteric fever would be 161 with Typhidot tests, 91 with TUBEX, and 70 with Test-It Typhoid and prototype (KIT) tests. The CIs around these estimates were wide, with no difference in false positive results shown between tests.The quality of the data for each study was evaluated using a standardized checklist called QUADAS-2. Overall, the certainty of the evidence in the studies that evaluated enteric fever RDTs was low.
Authors' conclusions:
In 37 studies that evaluated the diagnostic accuracy of RDTs for enteric fever, few studies were at a low risk of bias. The three main RDT tests and variants had moderate diagnostic accuracy. There was no evidence of a difference between the average sensitivity and specificity of the three main RDT tests. More robust evaluations of alternative RDTs for enteric fever are needed.
Detection of Salmonella typhi in blood by culture of the mononuclear cell-platelet layer was compared with other methods currently used for the diagnosis of typhoid fever. Colonies of S. typhi were present in all mononuclear cell-platelet layer-positive cultures within 18 h of plating and were identified within an additional 10 min by a coagglutination technique. In contrast, identification of all positive cultures by conventional blood culture required 3 days.
A DNA probe was used to detect Salmonella typhi from blood samples from 14 of 33 patients with culture-confirmed typhoid fever, using the equivalent of 2.5 ml of blood. In contrast, S. typhi was detected in 17 of the same 33 patients by culture of 8 ml of blood. The probe hybridized to blood samples of 4 of 47 patients from whom S. typhi was not isolated.
Typhoid fever is a serious public health problem in many developing countries. Although several assays for detecting typhoid antigens or antibodies have been reported, no nonculture test for typhoid fever has repeatedly been shown to be highly sensitive and specific. We have previously reported the construction of a DNA probe that recognizes DNA coding for production of Vi capsular antigen and have determined in preliminary testing that it is specific and sensitive for detecting laboratory-maintained S. typhi. The present study was undertaken to determine the sensitivity and specificity of this DNA probe, using in situ colony hybridization studies, to detect S. typhi among gram-negative bacteria freshly isolated from patients from two geographically distant areas. Initial studies conducted in Lima, Peru, were used to establish the conditions used in the subsequent study in Jakarta, Indonesia.
The recovery of Salmonella typhi from blood, rectal swab, urine, bone-marrow, and rose spots was compared in 62 patients with typhoid fever, most of whom had received some antibiotic therapy before presentation. S. typhi was isolated from culture of bone-marrow in 56 patients (90%); in contrast, S. typhi was recovered from blood in only 25 (40%), from stool in 23 (37%), and urine in 4 (7%). S. typhi was isolated from 24 (63%) of 38 patients who had rose-spot cultures. If culture sites had been limited to blood, stool, and urine, the bacteriological diagnosis would have been missed in 24 patients.
The diagnostic efficacy of bone-marrow culture, serial blood cultures and agglutination tests was compared in a prospective study of 60 patients with typhoid fever, two thirds of whom had received prior antibacterial therapy. Salmonella typhi was recovered from marrow cultures in 95% of patients but blood cultures were positive in only 43.3% (P less than 0.001). Agglutination tests were eventually diagnostic in 56.7% of patients, but in only 25% at the time of admission. If procedures had been limited to blood cultures and agglutination tests, diagnosis would have been missed in 21.7% of cases. The efficacy of marrow cultures was affected not by the duration of disease but by the extent of antibacterial therapy before presentation. Bacteriological recovery was faster from marrow cultures.
The usefulness of a single Widal test to diagnose typhoid fever in endemic areas was investigated. Reciprocal Salmonella typhi O and H titers greater than or equal to 40 and greater than or equal to 80, respectively, occurred in approximately 90% of 42 Mexican patients with bacteriologically-confirmed typhoid fever at the time of presentation to hospital and, by day 4 to 5 of clinical illness, in 70% of U.S. adult volunteers who developed typhoid fever in the course of vaccine efficacy trials but in only 0.7% (O) to 3% (H) of 275 healthy individuals from a non-endemic area. Healthy Peruvians from areas endemic for typhoid fever commonly had antibody which was age-related. Peak prevalence was found in 15- to 19-yr-olds in whom 29% had O titers greater than or equal to 40 and 76% had H titers greater than or equal to 80. A single Widal test in an unvaccinated individual showing elevated O and H titers is strongly suggestive of typhoid fever if the person comes from a non-endemic area or is a child less than 10 yr of age in an endemic area. Because of the high prevalence of antibody amongst healthy invididuals over 10 yr of age in endemic, areas, a single Widal test offers virtually no diagnostic assistance in adolescents and adults.
Salmonella typhi, the etiologic agent of typhoid fever, typically has only a phase-1 flagellar antigen, d, but some isolates, found only in Indonesia, have antigen j instead, and may have a second flagellar antigen, z66. It appears that intragenic recombination involving a directly repeated 11 bp sequence in the H1-d flagellin gene changed the flagellar antigen to j, by deleting 261 bp in its central, antigenically determinant, part. Sequencing of the hypervariable regions of genes H1-d and H1-j, and hybridization of such genes, after amplification by the polymerase chain reaction, with oligonucleotide probes specific for the deleted segment or for the sequence produced by the recombination confirmed that all the j alleles have the postulated deletion. By applying the polymerase chain reaction to study S. typhi isolates from Jakarta, not previously tested in respect to flagellar antigen, we showed that gene H1-j was nearly as common as H1-d in these isolates.
The H1 (now renamed fliC; lino et al., 1988) alleles specifying antigenically different Salmonella flagellins are identical at their ends but differ greatly towards the middle, where there are two hypervariable segments (regions IV and VI). The flagellar antigen, d, of Salmonella typhi, is found also as phase-1 antigen in many other Salmonella species. We cloned the H1-d gene of a strain of S. typhi and determined the nucleotide sequence of its two hypervariable regions. Comparison with gene H1-d of Salmonella muenchen showed substantial differences in region VI: four scattered amino acid differences and ten adjacent amino acids in the inferred S. typhi sequence, all of which differ from the corresponding nine amino acids in the S. muenchen sequence. The results of polymerase chain reaction amplification indicated the presence of the S. typhi version in all of 18 additional S. typhi strains and the presence of the S. muenchen version in all four non-S. typhi species with flagellar antigen d. The difference in amino acid sequence in segment VI may be responsible for the minor serological differences between antigens d of S. typhi and antigen d of S. muenchen.
This study was undertaken to identify a DNA sequence that could be used to facilitate the diagnostic identification of Salmonella typhi, the causative agent of typhoid fever. All virulent S. typhi strains encode a relatively unique capsular antigen termed the virulence (Vi) antigen. Two distinct genetic loci, viaA and viaB, are involved in the synthesis of this antigen. The structural genes, located at viaB, were considered as a possible specific DNA probe. The viaB locus, contained in a recombinant cosmid, was subcloned to various plasmid vectors for this purpose. Selected viaB-region DNA fragments were then analyzed for specificity in DNA colony hybridization reactions with more than 170 strains representing a variety of enteric bacteria. An 8.6-kilobase EcoRI fragment was highly specific for the viaB gene region and was considered a good hybridization probe. This DNA probe should prove useful in rapid diagnostic assays set up to detect S. typhi in mixed bacterial samples (e.g., stools) within a few hours of specimen collection.
We compared the sensitivities of bone marrow aspirate culture (BMAC), 3 ml 1:4 and 8 ml 1:10 blood-to-broth ratio blood cultures (BC), 8 ml streptokinase clot culture (STKCC) and rectal swab culture (RSC) for isolating Salmonella typhi and S. paratyphi A from 61 patients with typhoid or paratyphoid fever in Jakarta, Indonesia. BMAC (92%) was significantly more sensitive than 8 ml BC (62%), 8 ml STKCC (51%), 3 ml BC (44%), RSC (56%) and the 19 ml combination of all three BC methods (71%). The combination of the three BC methods and RSC had an isolation rate of 87%. In Jakarta the diagnosis of typhoid fever cannot be confidently excluded unless a BMAC is done.