Antibiotic Resistance Profile of Staphylococcus aureus Isolated from Clinical Specimens at University of Calabar Teaching Hospital

The emergence of antibiotic-resistant Staphylococcus aureus strains in Nigerian healthcare settings represents a growing threat to patient safety and clinical management outcomes. This study determines the antibiotic resistance profile of Staphylococcus aureus isolated from clinical specimens at the University of Calabar Teaching Hospital (UCTH), Cross River State, South South Nigeria. A total of 120 clinical specimens comprising wound swabs, blood, urine, and sputum were collected from hospitalised patients over six months. Standard microbiological procedures including cultural isolation on mannitol salt agar, coagulase testing, and Gram staining were employed for organism identification. Antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method against 12 commonly used antibiotics including oxacillin, penicillin, erythromycin, ciprofloxacin, and vancomycin, following Clinical and Laboratory Standards Institute guidelines. Methicillin-resistant Staphylococcus aureus (MRSA) was identified in 34 percent of isolates using oxacillin disk testing. Highest resistance rates were recorded for penicillin (87 percent) and ampicillin (81 percent), while vancomycin and linezolid retained 100 percent susceptibility. Wound swabs yielded the highest proportion of resistant isolates. The study identifies indiscriminate antibiotic use and inadequate infection prevention protocols as key drivers of resistance within the hospital environment. Recommendations include antibiogram-guided prescribing, enhanced hand hygiene enforcement, and routine MRSA surveillance at UCTH. Keywords: Staphylococcus aureus, antibiotic resistance, MRSA, UCTH, clinical isolates