Characterization of antimicrobial resistance in pathogenic staphylococcus aureus isolated from animals in Uganda

Abstract

Antibiotics, are widely used in animals for health management, but their indiscriminate use has led to the emergence of antimicrobial resistance (AMR) which ultimately drives drug failures and costly treatment outcomes. The aim of the study was to characterize AMR in Staphylococcus aureus isolated from animal clinical cases at the Central Diagnostic Laboratory, Uganda. A retrospective study was performed on 92 bio-banked S. aureus isolates majorly from cattle (n = 55) (mastitis: 55) and dog cases (n = 37) (dermatitis: 30, otitis: 5, vaginosis: 2). The recovered isolates were bio-typed as S. aureus by Matrix Assisted Laser desorption/ionization-time of flight Mass Spectrometry (MALDITOF-MS) and then antimicrobial sensitivity tests done by Kirby Bauer disk diffusion assay with a panel of 8 antibiotics. Only tetracycline resistance genes Tet (M, K, O, L) were detected using polymerase chain reaction (PCR). Data was analyzed using SPSS to generate AMR prevalence rates and chi-square test used to tell associations between AMR prevalence rates and variables (p < 0.05). The highest resistance was to penicillin, 91.3% (84/92) and the least to cefoxitin, 3.3% (3/92). The overall prevalence of multidrug resistance (MDR) was 75.0% (69/92). Among the isolates, the prevalence of tet M, was 25%, tet K 35.4% and no tet L and tet O detected. In conclusion, the bacteria exhibited alarming AMR prevalence rates to penicillin, vancomycin and tetracycline. Routine surveillance on AMR phenotypes and genotypes is needed so as to detect emergence and genetic mechanisms in pathogenic bacteria of animals in Uganda.