Antimicrobial susceptibilities of methicillin resistant Staphylococcus Aureus (MRSA) isolates recovered from perineum and nasal mucosa swab samples of dogs in Niger

Methicillin Resistant Staphylococcus aureus (MRSA) is an important opportunistic pathogens of dogs, other domestic animals and humans. The proximity between humans, livestock and antimicrobial use in animals facilitates the emergence and spread of MRSA. In this study, 400 swab samples taken from the perineum and nasal mucosa of dogs. Swab samples were inoculated on 5% blood agar (Sigma® Switzerland) for 24 hours of aerobic incubation at 37 °C, growth with yellowish-white colonies with smooth, slightly raised surfaces were further gram stain and biochemical test of Coagulase and catalase tests was performed. Positive isolates were then inoculated mannitol salt agar (MSA, Oxoid) and incubated for 24 hours at 37 °C and further confirmed using Oxacillin Resistance Screening Basal (ORSAB) medium (Oxoid, Basingstoke, United Kingdom). Antibiotics susceptibility testing was determined using the Kirby Bauer’s disc diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guideline and positive S. aureus were inoculated on Mueller-Hilton Agar (Oxoid) plates and Vanier callipers were used to measure the zones of inhibition in millimetres (mm). Out of the 200 samples each from the nasal mucosa and perineum, 55%(72) and 39.5% (49) were positive for MRSA respectively. Out of the 206 male and 194 female dog sampled, 57.0% (69) and 43.0%(52) were positive for MRSA respectively. Nigerian indigenous breed (Mongrel) has the highest proportion of MRSA isolates with 48.8% (59) while Golden retriever has the least proportion of MRSA isolates with 0.8% (1). Most of the MRSA isolates were resistant to oxacillin, cefoxitin, tetracycline, erythromycin and cephazolin but susceptibile to gentamycin, ciprofloxacin and chloramphenicol.