PHENOTYPIC DETERMINATION OF ESBL- and AmpC- PRODUCING ENTEROBACTERIACEAE IN CHEESE SAMPLES

The off-label over use of antibiotics results in development of antibiotic resistance in the bacteria. Beta-lactamase producing Enterobacteriaceae adversely affects the human health by leading to therapeutic failures against infections. Although microbiological criteria have been considered appropriate to the Food Codex, an inspection for antibiotic-resistant enterobacteria has not come into force yet. Therefore, the detection of foodborne beta-lactamases has gained significant importance for the human health. The objective of this study was to determine ESBLand AmpC- producing Enterobacteriaceae in cheese phenotypically. In this study, a total of 83 cheese samples was examined by performing pre-enrichment, enrichment on selective media, and oxidase test according to the Criteria by ISO/DIS21528-2 microbiologically. Based on the microbiological results, a total of 18 isolates, including Klebsiella pneumoniae (27.8%), Hafnia alvei (27.8%), Escherichia coli (22.2%), Klebsiella oxytoca (11.2%), Enterobacter cloacae (5.5%), and Citrobacter spp. (5.5%) was identified by mass spectrometer. The phenotypic characterization of beta-lactamase type was conducted by disc diffusion, disc diffusion confirmation, and MIC determination according to the Guidelines of Clinical and Laboratory Standards Institute. The phenotypic results revealed that the most common beta-lactamase type was determined as ESBL in 9 isolates, followed by ESBL & AmpC in 4 isolates, and AmpC in 5 isolates, respectively. In conclusion, our study showed that ESBL- and Amp- type betalactamases were the most common phenotypes in Enterobacteriaceae from cheese. The cheese samples containing ESBL- and Amp- positive bacteria significantly presented a health risk for the consumers