Investigation of the presence of methicillin-resistant Staphylococcus aureus in tulum cheeses

In this Thesis study, it was aimed to investigate the presence of methicillin-resistant Staphylococcus aureus (MRSA) in tulum cheeses sold unpackaged in public bazaars in Uşak center, nearby districts and villages, using molecular methods. For this purpose, a total of 100 tulum cheese samples were collected from the bazaars under aseptic conditions. Firstly, 11 S. aureus suspected isolates were obtained from 100 tulum cheese using conventional methods. Following phenotypic isolation, the 16S rDNA and nuc genes in 11 suspected isolates was investigated by Polymerase Chain Reaction. While all of isolates were determined to be Staphylococcus spp., 10 isolates (10%) were typed to be S. aureus. In the isolates identified to be S. aureus, methicillin resistance was investigated phenotypically by the Kirby-Bauer disk diffusion test using cefoxitin disk, and genotypically by the presence of mecA and mecC genes. Phenotypic resistance to methicillin was determined in five of the isolates. It was determined that one of the five isolates with phenotypic resistance harboured the mecA gene and one harboured the mecC gene. Thus, two of 10 S. aureus isolates isolated from 100 tulum cheeses were identified to be MRSA (20%). Consequently, it was thought that the detection of the presence of MRSA in the sampled tulum cheeses could pose a potential risk to public health. To our knowledge, the presented study is the first to report the presence of the mecC gene in S. aureus isolates isolated from tulum cheese in Turkey.