Molecular Detection of Macrolide-Induced Clindamycin Resistance Among Clinical Isolates of Staphylococcus aureus from Selected Hospitals in Katsina Metropolis

Study’s Novelty Excerpt • This study provides a novel assessment of inducible clindamycin resistance in Staphylococcus aureus clinical isolates within Katsina Metropolis, Nigeria, filling a critical gap in regional data. • By employing both phenotypic (D-test) and genotypic (PCR) methods, the research uniquely identifies the prevalence of resistance phenotypes and the predominance of the ermC gene among isolates, highlighting the mechanisms behind this resistance. • The findings emphasize the need for tailored antibiotic treatment strategies and continuous surveillance to effectively combat the growing challenge of antimicrobial resistance in the region. Full Abstract The emergence of inducible clindamycin resistance presents a significant challenge in treating Staphylococcus aureus (S. aureus) infections. This phenotype, evading routine susceptibility testing, compromises treatment efficacy and prolongs patient illness. Despite its clinical importance, limited data exist on its prevalence in Katsina Metropolis, Nigeria. This study aims to assess its prevalence and evaluate the phenotypic and genotypic characteristics among clinical isolates collected from selected hospitals in Katsina Metropolis. S. aureus isolates from various clinical specimens were obtained from three hospitals and identified using standard bacteriological methods. Antibiogram profiles were determined following CLSI guidelines, revealing varying efficacy among commonly prescribed antibiotics. Notably, chloramphenicol (87.8%), clindamycin (79.6%), tetracycline (69.4%), and azithromycin (67.3%) demonstrated high efficacy rates, while cefoxitin, ciprofloxacin, and trimethoprim-sulfamethoxazole exhibited the highest resistance level of (44.9%), (42.9%), and (40.8%) respectively. Prevalence of Macrolide Lincosamide Streptogramin B (MLSB) phenotypes was assessed using the D-test, unveiling specific resistance phenotypes among the isolates. Polymerase chain reaction detected the ermC gene as predominant among D-test-positive isolates, all expressing the iMLSB phenotype. These findings shed light on the prevalence and mechanisms of inducible clindamycin resistance in S. aureus clinical isolates in Katsina Metropolis, emphasizing the importance of tailored treatment strategies and ongoing surveillance in combating antimicrobial resistance effectively