Molecular Characterization And Antibiogram Of Methicillin And Vancomycin Resistant Staphylococcus Aureus From Clinical And Community Isolates In Abakaliki, Nigeria

This study was aimed at isolating and molecularly characterizing Staphylococcus aureus exhibiting methicillin and vancomycin-resistance traits from clinical and community samples in Abakaliki, South Eastern Nigeria. Exactly 303 clinical samples from wounds, pus, urine, HVS (high vaginal swab), ear swabs, sputum and semen of hospital patients; and 406 community samples (nasal and ear swabs) were obtained for this study. Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Staphylococcus aureus (VRSA) isolates were detected using Kirby-Bauer disc diffusion method. Multiplex PCR was used to detect mecA, SCCmec, and PVL genes in the HA-MRSA and CA-MRSA isolates. A total of 84 (27.7 %) and 120 (29.5 %) Staphylococcus aureus isolates were obtained from the clinical and community samples respectively using standard microbiological techniques. Results showed that MRSA and VRSA were highly prevalent in wound samples and less prevalent in HVS, pus and sputum samples while none was observed in semen samples. The MRSA and VRSA isolates exhibited high resistance to nitrofurantoin, tetracycline, penicillin, clindamycin, sulphamethoxazole and ceftazidime. Gentamycin was the most effective antibiotic against the MRSA and VRSA isolates obtained from hospitals samples while ciprofloxacin was the most effective against MRSA and VRSA isolates obtained from community samples. Our study has shown that mecA and SCCmec IVa genes are present in the HA-MRSA and CA-MRSA isolates from our study area. In contrast, PVL genes were detected only in CA-MRSA. The high resistance of the clinical and community isolates to most of the antibiotics used in this study shows that such antibiotics are now ineffective in treating people with MRSA and VRSA infections. This situation is very worrisome and could result in grave public health problem if not quickly addressed. Therefore, it is pertinent to closely monitor MRSA and VRSA emerging from Abakaliki, Nigeria.