Survival of Acid-Adapted or Non-Adapted E. coli O157:H7 and Listeria monocytogenes during Ripening of Şavak Tulum Cheese

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The aim of this study was to investigate the survival of acid adapted or non-adapted E. coli O157:H7 and Listeria monocytogenes in Şavak tulum cheese during ripening. Şavak tulum cheeses were contaminated with acid- and non-acidified E. coli O157:H7 and Listeria monocytogenes at the beginning of the ripening, and counted for 120 days. For both pathogenic bacteria, it was found that the differences between acid and non-acid-adapted groups were found to be insignificant throughout the ripening period (P 0.05). Acid adapted and non adapted E. coli O157:H7 counts on day 0 were 5.39 and 5.70 log10 cfu/g, while these numbers were 3.64 and 4.17 log10 cfu/g on day 120, espectively. Acid adapted and non- adapted L. monocytogenes numbers on day 0 of the ripening period were 5.95 and 6.84 log10 cfu/g, while these numbers were 3.53 and 3.01 log10 cfu/g on the last day, respectively. As a result, the effect of acid adaptation on the survival of L. monocytogenes and E. coli O157:H7 during 120 days of ripening in experimentally contaminated Şavak tulum cheese samples was not found to be significant. Although the number of these pathogenic bacteria counts were decreased 2.0 log at the end of the ripening period, their numbers were still remained well above the infective doses. Contamination of the cheeses that was made from raw milk and ripened for a long period at low temperatures, such as Şavak tulum cheese, with L. monocytogenes or E. coli O157:H7 may result in serious threats for public health.

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Acid adaptation , ripening , E. coli , Listeria , Şavak tulum cheese

Fırat University Veterinary Journal Of Health Sciences

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Fırat University Veterinary Journal Of Health Sciences