Drug resistance profile and detection of genes responsible for methicillin resistance in Staphylococcus aureus isolated from municipal waste

Currently, we are facing the ever-increasing phenomenon of bacteria being resistant to antibiotics. It is the consequence of excessive and incorrect use of drugs. The phenomenon is a global problem affecting bacteria both in their hospital population and in the natural environment. Municipal waste is an environment conducive to the development of microorganisms, therefore it contains various groups of bacteria, including drug-resistant staphylococci. The aim of the study was to identify species of bacteria, determine their antibiotic resistance, and assess the occurrence of genes responsible for methicillin resistance in Staphylococcus aureus isolated from mixed municipal waste. Strains were isolated by Koch’s serial dilution method with the use of microbiological media. Species were identified using the MALDI TOF-MS technique, whereas the drug resistance profile was determined by disk diffusion and molecular PCR methods. 250 isolates of S. aureus were collected. The highest resistance found was to cefoxitin, erythromycin and tetracycline. Among the bacteria collected, resistance to 1, 2, 3 or 4 antibiotics at the same time was the most common, with a maximum of 10. Additionally, 45 (18%) MDR (multidrug-resistant) isolates were detected. Methicillin resistance was found by the disk diffusion test in 60 (24%) strains, while the mecA gene was detected in as many as 180 (72%) isolates.