Molecular Characteristics and spa-Types of Staphylococcus aureus from Food-animals in the Federal Capital Territory, Abuja-Nigeria

Aim: This study was undertaken to investigate the molecular characteristics of S. aureus isolates from chickens, sheep and goats in the Federal Capital Territory (FCT), Nigeria.

Study Design: The study was designed to be a cross-sectional study. A simple random sampling method was used to collect a total of 684 nasal and tracheal swabs from chickens (n=228), sheep (228) and goats (228) in livestock markets in FCT from February to June, 2023.

Methodology: Samples were analyzed using standard bacteriological techniques. Antimicrobial susceptibility testing was determined using disk diffusion, and E-test methods. S. aureus isolates were genotypically characterized using DNA microarray analysis and spa-typing.

Results: Twenty-two (3.2%), were confirmed as S. aureus. Eleven (4.8 %), six (2.6%), and five (2.2%) isolates were obtained from sheep, chickens, and goats respectively. All isolates exhibited susceptibility to vancomycin, teicoplanin, mupirocin, and tigecycline. The isolates from chickens were resistant to Penicillin G (33.0 %), Erythromycin (16.6 %), Chloramphenicol (16.6%) and Tetracycline (50.0 %) mediated by blaZ/IR, ermB, fexA tetK/M respectively, one isolate from sheep was resistant to linezolid (MIC 8 mg/L). The S. aureus clustered in three clonal complexes and five spa types. Whereas the isolates from sheep and goats belonged to the same clone, t4735-CC133, isolates from chickens belonged to different clones, t311-CC5, t448-CC88 and t786-CC88. None of the isolates was positive for genes for Panton Valentine leukocidin. The CC5 isolates from chickens harbored the egc (seg, sei, selm, seln, selo, selu), and the immune invasion genes (sak, scn and chp).

Conclusion: This study has established baseline data on the prevalence and molecular characteristics of S. aureus in food animals in the FCT.