Identification and Antimicrobial Susceptibility of Staphylococcus aureus and Coagulase Negative Staphylococci Isolated from Raw Milk and Cheese Samples

Abstract

Objective: In this study, it was aimed to evaluate raw milk and cheese samples obtained from various markets and dairies in Ankara, Turkey for the presence of coagulase positive staphylococci (CPS) and coagulase negative staphylococci (CNS) and to determine of antimicrobial resistance in these strains. Method: CPS and CNS, isolated from 190 raw milk and 90 cheese samples, were analyzed by conventional biochemical tests to identify for genus and species of these strains. Antimicrobial susceptibility features of these isolates were evaluated by disc diffusion method according to the guidelines of Clinical and Laboratory Standards Institute (CLSI). Results: Total of 330 isolates of Staphylococcus spp. which consist of 236 CPS and 94 CNS were found from raw milk and cheese samples. The predominant species of the CPS in raw milk and cheese samples were Staphylococcus intermedius (40.0 - 44.3 %) and Staphylococcus aureus (35.0 - 20.2 %); while the CNS were identified as Staphylococcus saprophyticus (26.4 - 43.0 %) and Staphylococcus caseolyticus (9.2 - 14.3 %). CPS strains isolated from raw milk more resistant to ampicillin (62.4 %) and penicillin (47.0 %); while CNS strains were more resistant to methicillin (39.0 %) and penicillin (39.0 %). Besides this, CNS strains isolated from cheese samples were resistant to ampicillin (42.8 %), methicillin (28.5 %) penicillin (28.5 %) and erythromycine (28.5 %). OZET