Detection of mecA and mecC genes among Methicillin-Resistant Staphylococcus aureus from Wounds of Patients Attending Selected Hospitals in Kaduna, Nigeria

Abstract

Phenotypically identified Methicillin-Resistant Staphylococcus aureus (MRSA) that lacks mecA or mecC raises questions about the molecular basis of the observed resistance and the reliability of molecular detection. The present study detects mecA and mecC genes among MSRA from wounds of patients attending selected hospitals in Kaduna State, Nigeria. A cross-sectional, laboratory-based study was conducted between May and December 2025. Two hundred wound swab samples comprising surgical, ulcer, scald and burn wounds were collected from consenting patients attending the selected hospitals. S. aureus was isolated and identified based on standard morphological and biochemical procedures. Phenotypic detection of MRSA was performed by disk diffusion method using cefoxitin (30 µg). Ten (10) MRSA isolates were randomly selected for detection of mecA and mecC genes. A total of 78 S. aureus were recovered from 200 wound swabs, with ulcer wounds having the highest occurrence of S. aureus (52.27%), followed by surgical wounds (42.35%), scald wounds (28.57%) and burn wounds (25.58%). There is a significant statistical association (p = 0.04216) between the occurrence of S. aureus and type of wound. Of the 78 S. aureus isolates, 61 (78.21%) were phenotypically identified as MRSA. PCR results showed that 7 of 10 MRSA isolates screened carried mecA gene and none of the 10 MRSA screened carried mecC. The fact that 3 phenotypically identified MRSA lacked mecA and no isolates had mecC shows that methicillin resistance cannot always be explained by these two genes. A combination of phenotypic and molecular methods is recommended for accurate detection of MRSA.