Bacteria recovered from ear swab samples of cats with otitis externa and their antimicrobial resistance profiles in Kayseri, Türkiye

Abstract

This study aimed to isolate and identify bacteria from ear swab samples taken from cats with otitis externa and to determine the antimicrobial resistance profiles of the recovered isolates. For this purpose, ear swab samples from 100 domestic cats diagnosed with otitis externa were used. The samples collected from the animals were inoculated onto 7% defibrinated sheep blood agar and MacConkey agar, and the media were incubated at 37 degrees C for 24-72 h under aerobic/microaerobic conditions. The identification of the isolates was conducted by phenotypic tests, MALDI-TOF MS analysis, and 16S rRNA gene sequencing. Antimicrobial susceptibilities of the obtained isolates were determined via the disk diffusion method. Seventy-one samples were found to be positive for bacterial growth, and 75 isolates (2 isolates from 4 samples) were obtained. The most commonly identified genera were Staphylococcus (33.3%), Enterococcus (20%), and Bacillus (13.3%), while the most commonly identified species were Enterococcus faecalis (10.7%), Staphylococcus felis (8%), and Staphylococcus epidermidis (8%). The highest antimicrobial resistance among staphylococci isolates was observed against penicillin (48%) and trimethoprim/sulfamethoxazole (48%). All enterococci isolates were resistant to gentamicin, ciprofloxacin, clindamycin, penicillin, and trimethoprim/sulfamethoxazole. In addition, the multidrug resistance rates in the staphylococci and streptococci isolates were detected as 44% and 100%, respectively. In conclusion of the current study, in samples from cats with otitis externa, staphylococci and enterococci are obtained to be the dominant etiological agents, and these organisms exhibited high resistance rates to commonly used antimicrobials. Given the public health implications of these findings, the results obtained may be useful in the selection of drugs to be used in treatment.