Sorbitol MacConkey agar and wastewaters` coliphages

A total of ۱۱۴ samples collected from hospital wastewaters and rivers in Addis Ababa, Ethiopia were tested for non-sorbitol fermenting bacteria and coliphages. Sorbitol MacConkey agar is mainly used in the detection of E. coli O۱۵۷:H۷. However, other emerging diarrhoeagenic enteropathogens such as Plesiomonas shigelloides, Edwardsiella tarda, Providencia alcalifaciens, Escherichia albertii, Escherichia vulneris and Escherichia fergusonii were detected in the samples using this medium. Information for most of the emerging enteropathogens is scarce in most countries including Ethiopia. A total of ۲۰ different genera, ۳۸ species of non-sorbitol fermenting bacteria were isolated. Escherichia coli O۱۵۷ could not be detected from any of the samples. All these backgrounds may mask the detection of Escherichia coli O۱۵۷. Even if sorbitol MacConkey agar has several background limitations, different emerging diarrhoeagenic non-sorbitol fermenting bacteria were detected in the majority of the rivers and hospitals` wastewaters samples. The correlation between coliphages and non-sorbitol fermenting bacteria were not significant. As several bacteria have been isolated on sorbitol MacConkey agar medium, it is essential that the most selective laboratory techniques will be desired for outbreak investigation of E. coli O۱۵۷, but other non-sorbitol fermenting enteropathogens should also be detected using sorbitol MacConkey agar in low resources countries.

کلیدواژه ها:

Coliphage ، Emerging diarrhoeagenic bacteria ، Hospitals wastewater ، Sorbitol MacConkey agar ، Non-sorbitol fermenting bacteria ، Rivers