Clostridium difficile isolation trials and prevalence rate in post antibiotic and non-antibiotic related diarrhoea

ABSTRACT

100 fecal specimens collected from 50 normal adults as control and 25 of each post antibiotic and antibiotic unrelated diarrhea were processed for isolation of C. difficile and deduction of its prevalence rate. Different isolation trials were resorted to as direct plating, ethanolic shock treatment and Robertson's cooked meat enrichment. Egg yolk supplemented cycloserine cefoxitin fructose agar and columbia blood agar were used for direct and indirect inoculation. They were incubated anaerobically and for different periods. C. difficile prevalence rate was 2% in the control group, 16% in post antibiotic diarrhea and 8% in miscellaneous diarrhea patients. All isolated strains of C. difficile grew from ethanolic shock treated stools and exclusively into egg yolk CCFA medium. Out of positive ethanolic shock treated stools 57.1% needed 5 days of anaerobic incubation onto egg yolk CCFA medium to grow the organism compared to 42.8% only which needed 48 hours. Moreover, 71.4% of C. difficile grew after enrichment into cooked meat medium for 48 hours prior to plating onto selective medium whereas 28.5% only could be isolated by direct plating of ethanolic shock treated stools onto the same medium