Phenotypic and genotypic characterisation of methicillin and inducible clindamycin co-resistant <i>Staphylococcus aureus</i> isolated from clinical samples

Abstract

The increase in microbial resistance to antibiotics is emerging as a challenge globally in the treatment of infections. The emergence of multiple drug-resistant microbial infections has created a severe concern for public health. Phenotypic and genotypic estimation of these resistant genes will assist in mitigating measures to curb the rising incidence The aim of this study is to isolate and characterize inducible clindamycin and methicillin co-resistant Staphylococcus aureus from clinical samples phenotypical and genotypically. Clinical samplescollected from the various hospitals were cultured on mannitol salt agar, blood agar and incubated overnight at 37oC. Colonial morphology, API identification system and standard identifications including Gram stain reaction, catalase, and coagulase were used to identify the isolates. he antibiotic susceptibility and D tests were carried out on Mueller- Hinton agar using the modified Kirby-Bauer method according to the guidelines of the Clinical Laboratory Standard Institute (CLSI). The overall occurrence of S. aureus was 75% (160/214). Multiple drug-resistant, S. aureus was 50% (81/160), methicillin resistance was 32%, (51/160), and inducible clindamycin resistance was 29.38% (47/160). The prevalence of co-resistance of inducible clindamycin and Methicillin resistance was 23.75%. The prevalence of resistance genes among the isolates with co-resistance of inducible clindamycin and methicillin resistance genes were 13.7%, 17.6, 5.9, 5.9, for Mec A, Mec C, Erm B and Erm C respectively. The highest incidence of inducible clindamycin and methicillin co-resistance was seen in urine samples. This study reveals a high level prevalence of methicillin and inducible clindamycin co- resistance among the isolates from the clinical samples studied which is a public health threat.