Bacteriological and molecular studies on Clostridium difficile in small ruminants and poultry under desert conditions

Abstract

Clostridium difficile is a Gram-positive bacilli that mostly causes pseudomembranous colitis and antibiotic associated diarrhea in humans, known as Clostridium difficile infection (CDI). CDI is known as a nosocomial infection due to its high prevalence in hospitalized patients who are exposed to high, continuous doses of antibiotics. Afterwards, this infection rapidly finds its way toward the community outside hospitals and subsequently, community acquired infections has been emerged. Several studies confirmed the presence of C. difficile among diseased and apparently healthy food animals such as cattle, sheep, pigs and poultry to underscore the potential role of such animals in the epidemiology of such bacterium. Unfortunately, most available laboratory diagnostic assays have been adjusted for human stool samples. Accordingly, the present study focuses on the performance of three laboratory diagnostic techniques in the detection of C. difficile in animal fecal samples. Ninety fecal samples collected from diarrheic sheep, goats and poultry. Each sample was tested by three laboratory methods (direct PCR on DNA extracted from fecal samples, conventional culture technique followed by molecular confirmation, and glutamate dehydrogenase ELISA on feces). The results showed that C. difficile detection rates were 45.6%, 16.7% and 8.9% for direct PCR, conventional culture followed by molecular confirmation and GDH-ELISA, respectively. Markedly, direct PCR revealed the highest detection rate; nonetheless, false negative results were recorded in 3 samples being positive by culture technique. Conversely, GDH ELISA yielded the lowest detection rate, but without any false negative result as all ELISA-positive samples were also positive by both direct fecal PCR and culture method highlighting that GDH-ELISA is highly specific.