Prevalence of Inducible Clindamycin Resistance Staphylococcus aureus Associated with Wound Infection in Central Nepal

Abstract

Background: To determine the prevalence of inducible clindamycin resistance among methicillin-resistance Staphylococcus aureus (MRSA), and to detect the presence of mecA and ermC genes among MRSA recovered from hospital patients in central Nepal.
Methods: Staphylococcus aureus isolated from a total of 289 clinical specimens consisting of pus and wound swabs were analyzed and identified. The MRSA strains were screened using a cefoxitin (30 µg) disc following the CLSI procedure and a double-disc test (D-test) was applied to investigate iMLSB-resistant phenotypes among the MRSA isolates. The bacterial genomic DNA was extracted and mecA and ermC genes were detected using specific primer pairs.
Results: Among the 64 S. aureus strains, 39.1% of the isolates were MRSA. The prevalence of inducible clindamycin resistance among MRSA was observed to be 48%. All MRSA (100%) isolates were resistant to penicillin and amoxicillin, whereas all strains were susceptible to linezolid, vancomycin, teicoplanin, and tigecycline. Among MRSA isolates, 8% carried the mecA gene and 13.3% of iMLSB isolates were positive for the ermC gene.
Conclusions: A high rate of inducible clindamycin resistance among MRSA was observed. To identify the status of antibiotic resistance among S. aureus, further genomic-based studies are required.
Keywords: Aureus; ermC gene; inducible clindamycin resistance; mecA gene; methicillin-resistant S.