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Medline ® Abstracts for References 64-68

of 'Clostridium difficile infection in adults: Clinical manifestations and diagnosis'

64
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Is repeat PCR needed for diagnosis of Clostridium difficile infection?
AU
Luo RF, Banaei N
SO
J Clin Microbiol. 2010;48(10):3738. Epub 2010 Aug 4.
 
Patients with diarrhea, defined as loose or watery stool, and two or more Clostridium difficile tcdB PCR tests within 14 days of each other were investigated. Repeat PCR for 293 patients with a prior negative result yielded negative results in 396 (97.5%) of 406 tests. Ten new positives were detected, including one false positive. Repeat PCR within 7 days appears rarely useful, except for patients with evidence of a new infection.
AD
Stanford University School of Medicine, Department of Pathology, Palo Alto, CA 94304, USA. rluo2@stanford.edu
PMID
65
TI
Rapid detection of Clostridium difficile in feces by real-time PCR.
AU
Bélanger SD, Boissinot M, Clairoux N, Picard FJ, Bergeron MG
SO
J Clin Microbiol. 2003;41(2):730.
 
Clostridium difficile is the major causative agent of nosocomial antibiotic-associated diarrhea, colitis, and pseudomembranous colitis. The pathogenicity of C. difficile is closely related to the production of toxins A and B. Toxigenic C. difficile detection by a tissue culture cytotoxin assay is often considered the "gold standard." However, this assay is time consuming, as it implies an incubation period of at least 24 h. We have developed a rapid real-time fluorescence-based multiplex PCR assay targeting the C. difficile toxin genes tcdA and tcdB, with the Smart Cycler. Two molecular beacons bearing different fluorophores were used as internal probes specific for each amplicon type. The analytical sensitivity of the assay was around 10 genome copies for all nine C. difficile strains tested, representing the 6 most common toxinotypes. The specificity was demonstrated by the absence of amplification with DNA purified from bacterial species other than C. difficile (n = 14), including Clostridium sordellii for which the lethal toxin gene sequence is closely related to the toxin genes of C. difficile. Following a rapid (15 min) and simple fecal sample preparation protocol, both tcdA and tcdB were efficiently amplified from 28 of 29 cytotoxin-positive feces samples. There was no amplification observed with all 27 cytotoxin-negative feces samples tested. This is the first real-time PCR assay for the detection of C. difficile. It is rapid, sensitive, and specific and allows detection of C. difficile directly from feces samples.
AD
Centre de Recherche en Infectiologie de l'UniversitéLaval, Centre Hospitalier Universitaire de Québec (Pavillon CHUL), Québec, Canada.
PMID
66
TI
Prospective multicenter evaluation of a new immunoassay and real-time PCR for rapid diagnosis of Clostridium difficile-associated diarrhea in hospitalized patients.
AU
van den Berg RJ, Bruijnesteijn van Coppenraet LS, Gerritsen HJ, Endtz HP, van der Vorm ER, Kuijper EJ
SO
J Clin Microbiol. 2005;43(10):5338.
 
In a prospective multicenter study, 367 fecal samples from 300 patients with diarrhea were tested for Clostridium difficile-associated diarrhea (CDAD) with a new immunochromatography assay for toxins A and B (ICTAB), a real-time PCR on the toxin B gene, and the cell cytotoxicity assay. Twenty-three (6.2%) of the 367 fecal samples were positive by the cell cytotoxicity assay. With the cell cytotoxicity assay as the "gold standard," the sensitivity, specificity, positive predictive value, and negative predictive value for the ICTAB assay and real-time PCR were 91, 97, 70, and 99%, and 87, 96, 57 and 99%, respectively. In conclusion, both the ICTAB and the real-time PCR can be implemented as rapid screening methods for patients suspected of having CDAD.
AD
Department of Medical Microbiology, Center of Infectious Diseases, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
PMID
67
TI
Impact of the type of diagnostic assay on Clostridium difficile infection and complication rates in a mandatory reporting program.
AU
Longtin Y, Trottier S, Brochu G, Paquet-Bolduc B, Garenc C, Loungnarath V, Beaulieu C, Goulet D, Longtin J
SO
Clin Infect Dis. 2013;56(1):67.
 
BACKGROUND: Most Clostridium difficile infection (CDI) surveillance programs neither specify the diagnostic method to be used nor stratify rates accordingly. We assessed the difference in healthcare-associated CDI (HA-CDI) incidence and complication rates obtained by 2 validated diagnostic methods.
METHODS: This was a prospective cohort study of patients for whom a C. difficile test was ordered between 1 August 2010 and 31 July 2011. All specimens were tested in parallel by a commercial polymerase chain reaction (PCR) assay targeting toxin B gene tcdB, and a 3-step algorithm detecting glutamate dehydrogenase and toxins A and B by enzyme immunoassay and cell culture cytotoxicity assay (EIA/CCA). CDI incidence rate ratios were calculated using univariate Poisson regression.
RESULTS: A total of 1321 stool samples were tested during a period totaling 95 750 patient-days. Eighty-five HA-CDI cases were detected by PCR and 56 cases by EIA/CCA (P = .01). The overall incidence rate was 8.9 per 10 000 patient-days (95% confidence interval [CI], 7.1-10.9) by PCR and 5.8 per 10 000 patient-days (95% CI, 4.4-7.4) by EIA/CCA (P = .01). The incidence rate ratio comparing PCR and EIA/CCA was 1.52 (95% CI, 1.08-2.13; P = .015). Overall complication rate was 27% (23/85) when CDI was diagnosed by PCR and 39% (22/56) by EIA/CCA (P = .16). Cases detected by PCR only were less likely to develop a complication of CDI compared with cases detected by both PCR and EIA/CCA (3% vs 39%, respectively; P<.001).
CONCLUSIONS: Performing PCR instead of EIA/CCA is associated with a>50% increase in the CDI incidence rate. Standardization of diagnostic methods may be indicated to improve interhospital comparison.
AD
Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada. yves.longtin@crchuq.ulaval.ca
PMID
68
TI
Guidelines for diagnosis, treatment, and prevention of Clostridium difficile infections.
AU
Surawicz CM, Brandt LJ, Binion DG, Ananthakrishnan AN, Curry SR, Gilligan PH, McFarland LV, Mellow M, Zuckerbraun BS
SO
Am J Gastroenterol. 2013 Apr;108(4):478-98; quiz 499. Epub 2013 Feb 26.
 
Clostridium difficile infection (CDI) is a leading cause of hospital-associated gastrointestinal illness and places a high burden on our health-care system. Patients with CDI typically have extended lengths-of-stay in hospitals, and CDI is a frequent cause of large hospital outbreaks of disease. This guideline provides recommendations for the diagnosis and management of patients with CDI as well as for the prevention and control of outbreaks while supplementing previously published guidelines. New molecular diagnostic stool tests will likely replace current enzyme immunoassay tests. We suggest treatment of patients be stratified depending on whether they have mild-to-moderate, severe, or complicated disease. Therapy with metronidazole remains the choice for mild-to-moderate disease but may not be adequate for patients with severe or complicated disease. We propose a classification of disease severity to guide therapy that is useful for clinicians. We review current treatment options for patients with recurrent CDI and recommendations for the control and prevention of outbreaks of CDI.
AD
Division of Gastroenterology, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA. surawicz@u.washington.edu
PMID