An investigation on biocontrol of Escherichia coli O157:H7 by a bacteriophage cocktail in pastirma

In this study, it was aimed to investigate the biocontrol of Escherichia coli O157:H7 in pastirma (a traditional Turkish meat product produced and consumed without heat treatment) by bacteriophages. A cocktail was prepared from two pre-characterized phages which were isolated from cattle slaughterhouse wastewaters and were found to have lytic activity against E. coli O157: H7. The phage cocktail at a concentration of 10(9) pfu/ml was applied to pastirma slices which experimentally contaminated at 6,9 x 10(3) cfu/ml and incubated for one week at room temperature (22-24 degrees C). During the incubation period, reduction effects of bacteriophages on E. coli O157: H7 were investigated on certain times and days. As a result, the phage cocktail was able to reduce the bacterial count approximately 2 log cfu/g in the bacteriophage applied group, therefore the number of E. coli O157: H7 decreased and remained below the detection limit (< 10 cfu/g) during the experiment. The bacteriophage cocktail consisting of phage M8AEC16 and phage M12BEC16 has been found to be effectively usable for biocontrol of E. coli O157:H7 in pastirma.