Antibiotic resistance profile of Staphylococcus aureus in pediatric cases from rural Gambia

Antimicrobial resistance (AMR) is a significant public health concern worldwide. Despite its impact, surveillance systems for detecting AMR in Low- and Middle-Income Countries (LMICs) are often suboptimal. Using data from a population-based surveillance study of children aged < 5 years in the Upper River and Central River Regions of The Gambia, we analysed the antibiotic resistance patterns of Staphylococcus aureus to commonly used antibiotics. We conducted a retrospective population-based cohort study in two regions of The Gambia and included data collected between 2019 and 2023. All children under 5 years old who resided in the Basse and Fulladu West Health and Demographic Surveillance Sites (HDSSs) were under surveillance and cases of invasive bacterial disease were determined at all the 11 health facilities that served the study catchment area. When indicated, blood samples, cerebrospinal fluid (CSF), lung aspirates, and/or pleural aspirates were collected for further testing based on standardised criteria for suspected sepsis, pneumonia, and meningitis. Culture-positive samples were processed using standard microbiology identification techniques. Antibiotic susceptibility testing was performed with the Kirby-Bauer disk diffusion method, and results were interpreted according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Between September 2019 and December 2023, a total of 162 Staphylococcus aureus isolates were identified. Antibiotic susceptibility testing was performed on all isolates. Penicillin showed the highest resistance at 86.4%, followed by co-trimoxazole at 26.5%, tetracycline at 25.3%, erythromycin at 17.3%, cefoxitin at 13.6%, chloramphenicol at 7.4%, and both ciprofloxacin and gentamicin at 3.1% each. Among the Staphylococcus aureus isolates tested, 22.8% were classified as multidrug-resistant (MDR), and 13.6% were identified as methicillin-resistant Staphylococcus aureus (MRSA). Resistance patterns differed by site, and most MDR isolates were from neonates (38.5%). In rural Gambia, penicillin resistance among Staphylococcus aureus isolates in children under 5 is high, whereas resistance to other commonly used antibiotics remains comparatively low. Measurable MRSA prevalence and multidrug-resistance in a subset of isolates indicate an ongoing, clinically significant threat from AMR. These findings reinforce the importance of ongoing AMR surveillance, prudent antibiotic use, and targeted interventions to mitigate AMR. Not applicable.