Detection of Clostridium Difficile from Faecal Specimens of Hospitalized Patients at Theodor Bilharz Research Institute

Abstract

Background: C. difficile is the leading cause of healthcare-associated diarrhea in Western countries. Objectives: To investigate the prevalence of C. difficile colonization among hospital inpatients at TBRI, its role in antibiotic-associated diarrhea; and developing an algorithm that can provide a specific, cost-effective approach to detect toxigenic C. difficile. Methodology: 87 faecal specimens obtained from 54 patients with abdominal pain and diarrhea (group A) and 33 patients with no gastrointestinal symptoms (group B) were included. All specimens subjected to screening by anaerobic culture on CCFA, GDH detection by EIA and real time PCR for genes of C. difficile; toxin production was also tested for by EIA for C. difficile toxins and real time PCR for detection of C. difficile toxins genes. Results: Using PCR, the prevalence of C. difficile was 21.8% (19 out of 87 specimens). Out of the 19 C. difficile positive specimens, 17(90%) harboured non-toxigenic organism and only 2 specimens (10%) harbour toxigenic C. difficile. By culture, sensitivity was 26.3% and specificity was 83.8%. Combining results of both culture and EIA for GDH has improved the specificity to 94.1%. Sensitivity of 100% and specificity of 87.1% were recorded when EIA for toxins was compared to PCR. Conclusions: C. difficile colonization is common among our inpatients. The high prevalence of non-toxigenic C. difficile colonization may have a protective role against infection with toxigenic strains. The use of EIA for GDH for screening for presence of C. difficile in faecal specimens followed by real-time PCR for presence of toxins genes in the samples provides a convenient, rapid and specific strategy for diagnosis of CDI.