Controlling karish cheese contamination with Escherichia coli using lytic coliphages.

Escherichia coli (E. coli) is considered a major foodborne pathogen. In this study, lytic coliphages were used to control contamination of Karish cheese with E. coli. Five bacteriophages specific to E. coli were isolated and characterized. The isolated phages showed a strong killing potential against E. coli and were selected for their thermal, pH, and UV stability. On the basis of their characteristics, the five isolated coliphages were found to belong to three phage types. These three coliphages were designated ÆEc1, ÆEc2, and ÆEc3. The in vitro experiments showed that coliphages were able to markedly reduce the numbers of E. coli in Karish cheese after 24 hrs. at room temperature and at 4°C. On the other hand, with a reduction in the number of E. coli, a higher number of coliphage was observed. These results support the possibility of using phages to control pathogenic bacteria in foods.