Screening Of Multidrug-Resistant Bacteria In Bovine Infectious Mastitis Isolates

Background: Antibiotic resistance has negative implications for treating infections in humans and animals. Rapid identification of the pathogen causing the disease is one of the determining factors for effective treatment. This study aimed to use MALDI-TOF MS to investigate multidrug-resistant bacterial strains in bacterial isolates from infectious bovine mastitis. Materials and Methods: Fifty-four milk samples from cows with subclinical mastitis were sown on sheep blood agar, and the bacterial isolates were identified by MALDI-TOF MS. The disk diffusion test verified susceptibility to antimicrobials. Results: The largest number of isolates were resistant to OXA (69%), followed by CFO (52%), AMP (48%), PEN (44%) and AMO (41%). The lowest number of resistant strains was observed against the antibiotic VAN. Although less significant, some bacterial strains were resistant to carbapenems. All the multidrug-resistant strains were identified on the MALDI-TOF MS system, including Staphylococcus aureus and non-aureus, Enterobacter asburiae, Enterobacter cloacae and Enterococcus faecalis. The species Staphylococcus aureus was detected most frequently. Conclusion: The detection of bacteria resistant to two or more antibiotics usually used to treat bovine mastitis indicates the need to look for alternative treatments to control this disease.