Use of culture- and ELISA-based toxin assay for detecting Clostridium Difficile, a neglected pathogen: A single-center study from a tertiary care setting (original) (raw)
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Laboratory diagnosis of Clostridium difficile-associated diarrhoea: a plea for culture
Journal of medical microbiology, 2005
A routine protocol for diagnosing Clostridium difficile-associated diarrhoea (CDAD) based on both faecal-cytotoxin detection and toxigenic culture was adopted by the microbiology laboratory of the St Luc-UCL University Hospital in Brussels in 1997. A toxigenic culture is a faecal culture followed, in the case of positivity, by a direct immunoassay on colonies to detect toxin A production. The results obtained over the past 7 years in the hospital are reviewed here. A total of 10,552 diarrhoeal stools from 7042 patients were analysed, of which 9494 were negative for all tests. A total of 1058 samples (10 %) from 794 patients were culture-positive, of which 460 (4.4 %) were positive for a faecal cytotoxin. The remaining 598 cultures were tested for toxin A on colonies; 355 of them were positive, which is 3.4 % of the total, and the remaining 243 (2.3 %) were negative. The positivity of the faecal-cytotoxin assay was statistically linked to the number of colonies observed on the cultur...
American Journal of Clinical Pathology, 2003
We studied 557 nonduplicate fresh stool specimens from adult patients clinically suspected of having Clostridium difficile-associated diarrhea. All samples were tested in parallel with an in-house cytotoxin B tissue culture assay (CTA), the C DIFFICILE TOX A/B II test (TA/B; TECHLAB, Blacksburg, VA), and the Triage Micro C DIFFICILE Panel (Biosite Diagnostics, San Diego, CA). The Triage device detects toxin A (TA) and glutamate dehydrogenase (GDH) simultaneously. Of the specimens, 350 were negative and 95 were positive for all markers. Another 112 specimens yielded discrepant results. The CTA found 143 positive specimens. Results of the components of the Triage and TA/B were compared separately with those of CTA.
Diagnostic Microbiology and Infectious Disease, 1988
An 18-mo evaluation of culture, cytotoxin, and latex testing for Clostridium difficile was performed between July 1, 1985, and December 31, 1986, on 1,536 specimens from 1,406 patients during evaluation of diarrhea. All cases with at least one test positive were investigated for clinical status. There were 144 Clostridium difficile-associated diarrhea (CAD) patients; 139 (97%) were positive by culture, 96 (67%) by cytotoxin, and 98 (68%) by latex testing. In the 1,262 non-CAD patients with diarrheal stool, 89 (7.1%) were positive by culture, 18 (1.4%) by cytotoxin, and 68 (5.4%) by the latex test. No CAD patient was positive by cytotoxin testing only, and two were positive by latex testing only. The culture and cytotoxin positivity were similar to our previous reports of 90-97% and 70-73%, respectively. Latex sensitivity (68%) was comparable to that of cytotoxin testing in this large group of patients (p > 0.5). Overall, in the 1,262 patients without clinical evidence of Clostridium difficile disease, positive tests by latex testing (5.4%) were intermediate between those of culture (7.1%, p < O. 1) and cytotoxin (1.4%, p < 0.001). Enzyme immunoassay for detection of Clostridium difficile ~oxins A and B in patients with antibiotic-associated diarrhoea and colitis. Eur J Clin Microbiol 4:102-107. Aronsson B, Mollby R, Nord CE (1984) Diagnosis and epidemiology of Clostridium difficile enterocolitis in Sweden.
Rapid detection of Clostridium difficile toxin A in stool specimens
Clinical Microbiology and Infection, 1997
Objective: To evaluate a rapid (15-min) enzyme immunoassay in the format of an individual cassette (ImmunoCard toxin A, Meridian, BMD, Marne-la-Vallee, France) for the detection of Clostridium difficile toxin A in stool specimens.
Clinical Microbiology and Infection, 2001
Objective To evaluate six commercially available assays for the detection of Clostridium difficile toxin andlor antigen in stool samples: one latex agglutination test (Culturette brand CDT, Becton Dickinson), two ELISAs (Culturette brand Toxin CD, Becton Dickinson, and Ridascreen C. difficile Toxin AlB, R-biopharm), two chromatographic assays (Clearview C. difficile A, Oxoid, and ColorPac Toxin A, Becton Dickinson) and one enzyme immunoassay for the simultaneous detection of C. difficile common antigen and toxin A (Triage C. difficile Panel, Biosite). Methods Over a period of 3 months, 366 liquid or semi-liquid stool samples were tested using cell-culture cytotoxin assay as standard, ethanol shock stool culture and latex agglutination (Culturette brand CDT). Of these, 78 samples, positive with at least one of these three methods, and 98 randomly selected negative samples were further evaluated using the other five kits. PCR was also performed on positive cultures to confirm the presence of toxin A and B genes. Results Triage C. difficile Panel had the best sensitivity (95%), followed by Clearview C. difficile and ColorPac Toxin A (both 89%), Culturette brand Toxin CD (73%), Ridascreen C. difficile Toxin AlB (57%) and Culturette brand CDT (23%). For Triage, the sensitivity of C. difficile antigen detection was 93%, and the sensitivity oftoxin detection was lower (77%). Most false-positive results were obtained with the Triage C. difficile Panel (25 specimens) and Clearview C. difficile A (20 specimens). Culturette brand CDT had the best specificity (99%); followed by Ridascreen C. difficile Toxin AlB (97%), Culturette brand Toxin CD (95%), ColorPac Toxin A (89%), Clearview C. difficile A (83%) and Triage C. difficile Panel (75%). The positive predictive values ranged from 68% to 94%, and the negative predictive values from 83% to 98%. Conclusions The sensitivity is much higher for Triage and the two new chromatographic assays than for the conventional ElAs. These tests also have a high negative predictive value. For Triage, C. difficile antigen-positive, toxin A-negative results can be obtained; the clinical value of these must be established by additional studies. Overall, the new-generation assays are still less sensitive than the cytotoxin assay; however, they provided sameday results, could be used as a screening test and may be useful in laboratories without tissue-culture facilities. Our results do not allow the recommendation of one single assay for the diagnosis of C. difficile-associated diarrhea. It remains the case that laboratory results must be correlated and interpreted with the clinical presentation of the patient.
Diagnosis of Clostridium difficile infection in patients with hospital-acquired diarrhea
2018
Clostridium difficile infection (CDI) is a rapidly emerging infection that may have devastating consequences. Prompt and accurate diagnosis is crucial for management and control. The aim of this study was to determine the incidence of C. difficile associated diarrhea among hospitalized patients, and to compare different diagnostic laboratory methods for detection of toxin producing strains in clinical specimens. The study was conducted at a university hospital in Cairo during the period from May 2013 till June 2015. Subjects were under antibiotic therapy and presented with hospital-acquired diarrhea. Four hundred and sixty-five stool specimens were processed by different microbiological methods. C. difficile was recovered in culture in 51 of stool specimens. Of these, 86.3% to 98% were positive for toxin production by 2 different methods. This study showed that antibiotic intake is the major risk factor for development of hospital-acquired diarrhea. We evaluated different microbiological methods for diagnosis of C. difficile. We recommend the use of toxigenic culture as a gold standard for microbiological diagnosis of C. difficile.
European Journal of Clinical Microbiology, 1985
Consecutive serum samples from 61 patients with Clostridium difficile diarrhoea were investigated for antibody response to C. difficile toxins A and B in an indirect enzyme immunoassay (ELISA) and in a neutralization assay against C. difficile cytotoxin. Sera from 64 blood donors, elderly healthy females and patients with other known intestinal enteropathogens served as controls. An immune response was detected by E L I S A in approximately half of the patients with C. difficile diarrhoea. The specificity of the E L I S A was 94% or 97%, depending on the control material used. Furthermore, a correlation was found between clinical recovery without relapse of C. difficile diarrhoea and high I g G titers to toxin B in the E L I S A , and/or appearance of neutralizing antibodies. It is concluded that the E L I S A for detection of serum antibodies to C. difficile toxins may be of diagnostic value in combination with the conventional tissue culture assay for cytotoxin in stool. High E L I S A IgG titres to toxin B and/ or the appearance of neutralizing antibodies may also be a positive prognostic sign in patients with C. difficile diarrhoea. Zusammenfassung: Serum-Antik6rper-Antwort auf Clostridium difficile-Toxine bei Patienten mit Clostridium difficile-Diarrhoe. Von 61 Patienten mit Clostridium difficile-Diarrhoe wurden konsekutive Serumproben mit einem indirekten Enzymimmunassay (ELISA) und einem Neutralisationstest fiir C. difficile Cytotoxin auf die Antik6rperantwort gegen die Toxine A und B von C. difficile untersucht. Als Kontrollen wurden Seren von 64 Blutspendern, filteren gesunden Frauen und Patienten, die an Krankheiten durch andere bekannte enteropathogene Erreger litten, verwendet. Bei annfihernd der Hfilfte der Patienten mit C. difficile-Diarrhoe wurde mittels E L I S A eine Immunantwort entdeckt. In Abhfingigkeit vom Kontrollmaterial ergab sich fiir den ELISA-Test eine Spezifitfit von 94% oder 97%. Bei Patienten, die sich ohne Rezidiv v o n d e r C. difficile-Diarrhoe erholten, bestand eine Korrelation zu hohen IgG-Titern gegen Toxin B im ELISA-Test und/oder Auftreten von neutralisierenden Antik6rpern. Daraus lfigt sich schlief3en, dab die Bestimmung der Antik6rper gegen C. difficile-Toxine im Serum mit E L I S A in Kombination mit dem herk6mmlichen Gewebekultur-Test auf Cytotoxin von diagnostischem Wert ist. Hohe E L I S A IgG-Titer gegen Toxin B und/ oder das Auftreten neutralisierender Antik6rper im Serum k6nnen bei Patienten mit C. difficile-Diarrhoe als positives prognostisches Zeichen gewertet werden.
Introduction: Clostridium difficile is anaerobic spore-forming bacillus, produces two major toxins (Tcd A and Tcd B). Disease caused by toxigenic C.difficile (Tcd) varies from mild diarrhea to fulminant disease and death. Aims and Objectives:-This study describes the prevalence of C.difficile toxins (CDT) in stool samples from in patients and outpatients of all age groups. Materials and Methods:-A total of 146 samples were examined from 2011 to 2012 were analyzed for the presence of CDT tests, DNA amplification test, and the stool samples were cultured anaerobically on CCFA selective medium for growth-Morphology, identification and other tests. The patient's details are collected from the medical records. Results:-Out of 146 specimens, only 20 (13.7%) were positive for C.difficile toxins. Male and female were 12 (60%) and 8(40%) respectively, with the majority of them aged between 16 to 71 years. Majority of them were from out patient units (n = 5, 25%) with rest from intensive care units (n = 3, 15%), male medical ward (n =3, 15%) and surgical wards (n = 1, 5%). All the CDT positive patients had history of prior antibiotic usage before the detection of toxin. Mean duration of antibiotic usage was a 16.75 (±12.75) days, and the mean duration of diarrhea was 4.21 (±4.85) days, 16 patients had underlying medical illness, like hypertension, diabetic mellitus etc; Stool with pus cells and occult blood test was positive among that 18 patients were positive for CDT. The hospitalized patient duration was 20.96 (±16.25) days. Conclusion:-The detection of CDT in the diagnosis of CDI requires vigilance by both clinician and microbiologist to look out for possible infected patients. Antibiotic usage is a known risk factor; thus restricted use of antibiotics may results the reduction of CDI.
Journal of Clinical Microbiology, 1996
A three-center study was undertaken to compare several test methods for the detection of Clostridium difficile, associated toxin, or related markers by using 927 stool specimens. Methods included direct assay of cytotoxin in stool by tissue culture, C. difficile bacterial culture followed by cytotoxin assay, bacterial culture alone, latex agglutination assay, and the ImmunoCard C. difficile test (Meridian Diagnostics, Inc.). The sensitivities, as determined against direct cytotoxin assay results, of the ImmunoCard C. difficile and latex agglutination assays were 84 and 67%, respectively (92 and 77%, respectively, when adjusted for bacterial culture outcomes). Evaluation for C. difficile-associated disease (CDAD) among 864 patients was based on clinical criteria for antibiotic-associated diarrhea combined with laboratory evidence of toxin or toxin-producing C. difficile in stool specimens. The sensitivity of each test method for screening of CDAD was as follows: bacterial culture, 95...