Detection of mecA Gene in the Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

Abstract

Resistance coding in Staphylococcus aureus could be phenotypic or genotypic. In genotypic coding, mecA gene codes for the production of the altered penicillin-binding protein responsible for methicillin resistance. This study aimed at determining the nature of methicillin resistance observed in staphylococcal isolates. Ninety-six (48 each) clinical isolates of Staphylococcus aureus were collected from two health facilities in Sokoto namely Usmanu Danfodiyo University Teaching Hospital (UDUTH) and Specialist Hospital, and screened for Methicillin-resistant Staphylococcus aureus (MRSA) using Oxacillin-resistant screening agar base (ORSAB). Ten (5 each) of the 38 MRSA isolates obtained from the two health facilities were subjected to DNA extraction using DNA extraction mini-kit (Qiagen K.K., Tokyo, Japan). Polymerase Chain Reaction (PCR) was then carried out to amplify the extracted DNAs and the PCR products were subjected to agarose gel electrophoresis to detect the presence or absence of mecA gene. The result of ORSAB showed that 38 out of 96 clinical isolates were MRSA with 18 (37.5%) MRSA isolates from UDUTH and 20 (41.7%) MRSA isolates from Specialist Hospital. Agarose gel electrophoresis analysis of the PCR products showed that all isolates were mecA negative since no band showed the targeted DNA primer. The phenotypic methicillin resistance in the studied MRSA isolates were not coded by mecA gene.