EVALUATION OF CONTAMINATION OF TRADITIONAL LACTIC CHEESES TO ESCHERICHIA COLI, STAPHYLOCOCCUS AUREUS AND LISTERIA MONOCYTOGENES

Background and Aim:Lactic cheese is a group of fresh and semi-hard cheeses that are traditionally produced from raw milk in some provinces of the country, including Golestan province. The aim of this study was to determine the prevalence of contamination of traditional lactic cheeses in Gorgan and the suburbs with Escherichia coli, Staphylococcus aureus and Listeria monocytogenesMethods:In this study, 40 traditional lactic bovine and sheep cheeses and 5 bovine pasteurized lactic cheese samples from dairy stores in Gorgan and the suburbs of Golestan province were evaluated for their contamination with these bacteria.Results:Based on the results obtained from 20 bovine cheese samples, only 2 samples (10%) and from 20 sheep cheese samples 6 samples (30%) had contamination with E. coli. Contamination with S. aureus was observed in 3 (15%) and 5 (25%) samples of bovine cheese and sheep cheese samples in respect. Contamination with L. monocytogenes was not obser ved in any cheese samples. Industrial pasteurized cheeses did not have contamination with any of the bacteria studied in this research. According to the results, sheep s cheeses were more contaminated with E. coli and S. aureus than bovine cheeses.Conclusion:The results of this study showed that contamination with food borne pathogenic bacteria is high in traditional cheeses supplied in Gorgan and the suburbs. Therefore, considering the great popularity of these types of cheeses among consumers, it seems necessary to observe sanitary notes and use of pasteurized milk to prepare these cheeses.

Keywords:

Escherichia coli , Lactic cheese , Listeria monocytogenes , Staphylococcus aureus