Clinical and laboratory evaluation of a real-time PCR for Clostridium difficile toxin A and B genes.

Abstract

Many laboratories use enzyme immunoassays (EIAs) for the diagnosis of Clostridium difficile infection (CDI). More recently, polymerase chain reaction (PCR)-based diagnosis has been described as a sensitive test. Real-time PCR for the detection of C. difficile toxin A and B genes was evaluated. A prospective evaluation was performed on stool samples from 150 hospitalized adult patients and 141 healthy volunteers. PCR was compared to toxigenic culture (TC), direct cytotoxicity test (CTT), ImmunoCard® Toxin A and B (Meridian Bioscience), and enzyme-linked immunosorbent assay (ELISA) (Vidas). The results were correlated with clinical data using a standardized questionnaire. The diagnostic yield of the PCR was further evaluated after implementation. Using toxigenic culture as the gold standard, the sensitivity and specificity of PCR were 100 and 99.2%, respectively. Patients were categorized as follows: TC/PCR-positive (n = 17) and negative TC (n = 133). The differences in these groups were more frequent use of antibiotics and leukocytosis (p < 0.05). The diagnostic yield of PCR was evaluated during a period of 6 months and showed an increase of positive patients by 50%. PCR for the detection of toxigenic C. difficile has a high sensitivity and can rule out CDI, but cannot differentiate CDI from asymptomatic carriage. Clinicians should be aware of this in order to prevent inappropriate treatment and delay of other diagnostics.

• Authors: E de Jong, A S de Jong, C J M Bartels, C van der Rijt-van den Biggelaar, W J G Melchers, P D J Sturm
• Journal: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology (Eur J Clin Microbiol Infect Dis) Vol. 31 Issue 9 Pg. 2219-25 (Sep 2012) ISSN: 1435-4373 [Electronic] Germany
• PMID: 22327373 (Publication Type: Comparative Study, Evaluation Study, Journal Article)

Chemical References

• Bacterial Proteins
• Bacterial Toxins
• Enterotoxins
• tcdA protein, Clostridium difficile
• toxB protein, Clostridium difficile

Topics

• Adult
• Aged
• Aged, 80 and over
• Bacterial Proteins (genetics)
• Bacterial Toxins (genetics)
• Clostridioides difficile (genetics)
• Clostridium Infections (diagnosis)
• Enterotoxins (genetics)
• Female
• Humans
• Male
• Middle Aged
• Molecular Diagnostic Techniques (methods)
• Prospective Studies
• Real-Time Polymerase Chain Reaction (methods)
• Sensitivity and Specificity
• Young Adult