ISOLATION AND ANTIBIOGRAM OF PATHOGENIC BACTERIA (Escherichia coli and Staphylococcus sp.) FROM DIFFERENT KINDS OF CHEESE AVAILABLE IN MARKET OF CHATTOGRAM IN BANGLADESH

Cheese is a solid, fresh or ripened product obtained by adding the enzyme rennet in the presence of lactic acid produced by the adventitious microorganisms that causes coagulation and whey separation of milk, cream or partly skimmed milk, buttermilk. Cheeses of different types especially soft and semi-soft are suspected to the presence of pathogenic E. coli and Staphylococcus sp. which are harmful for public health. The purpose of the current research was to investigate the qualities of cheese collected from super-shops of Chattogram. A total of 15 cheese samples were collected from three super-shops of Chattogram. Among 15 cheese samples, the S3 sample collected from shop-B had the highest bacterial load (1.80×107 cfu/ml) than those in shop-A and shop-C. Isolation of pathogenic E. coli, Staphylococcus sp. was done by using selective media. Four out of the total 15 cheese samples were found to be contaminated with E. coli (26.67%) while ten were detected as contaminated with Staphylococcus sp. (67%). The antibiotic susceptibility test was done to detect susceptibility to selective antibiotics. E. coli and Staphylococcus sp. showed almost 100% resistant behavior to ampicillin, amoxycilin, tetracycline and 50% sensitivity of E. coli to gentamicin and ciprofloxacin while for Staphylococcus sp. sensitivity to gentamicin, ceftriaxone, ciprofloxacin was 27.27%, 90.91%, 18.18% respectively. The screening for shiga-toxin strains in E. coli isolates was based on the detection of the two genes stx1 & stx2 and tetracycline resistant strains of E. coli were detected for Tet A, Tet B & Tet C genes by polymerase chain reaction (PCR). The screening for methicillin resistant in Staphylococcus sp. isolates was based on the detection of the mecA gene by polymerase chain reaction (PCR). In conclusion, the risk of pathogenic bacteria is higher in cheese if safety measures not maintained & could pose a massive health risk.