Abstract:

In this study, the presence and incidence of enterohemorrhagic Escherichia coli O157:H7 strain, fecal E. coli and coliform bacteria in 100 raw cheese collected in public open markets in Kayseri province were investigated. For this purpose, prefortified cheese samples were inoculated on the Lauryl Sulphate Tryptose Broth (LSTB) containing 4methylumbelliferyl-b-D-glucuronide (MUG) and growth was established in 86 cheese samples. In 17 of 86 cheese samples, in which the colony formation was seen, colorless and middle sized colonies were observed on Sorbitol MacConkey Agar (SMAC). Motile agents were determined in 13 cheese samples by microscopic examination and four cheese samples were indol positive. For the confirmation of the presence of E. coli O157:H7 strain in these 4 cheese samples, Latex agglutination test was performed and no agglutination was observed in all samples. The agents forming colourless colonies on SMAC agar contained 5 Hafnia alvei, 4 Proteus mirabilis, 2 Proteus vulgaris and 2 Morgenalla morganii. Approximately 2.2x101 MPN/100 g coliform bacteria were determined in cheese samples. In addition, fecal E. coli were determined in 58 cheese samples. In conclusion, E. coli O157:H7 strain, which is a fecal agent, was isolated in none of the cheese samples. However, the levels of microorganisms such as coliform and fecal E. coli, which are indicators of hygiene were higher than the levels indicated by Directions of Microbiological Criteria of the Turkish Food Codex

Keywords: