Antibiotic Resistance pattern of Methicillin-Resistant Staphylococcus aureus (MRSA) from Selected Pharmaceutical Company Effluents in Ogun State, Nigeria
1 Department of Microbiology, Faculty of Biological Sciences, Alex Ekwueme Federal University, Ndufu-Alike Ikwo Ebonyi state
2 Department of Microbiology, Faculty of Basic Medical Sciences, Federal University of Allied Health Science, Enugu.
3 Department of Microbiology, Faculty of Sciences, Ebonyi State University, Abakaliki.
Research Article
International Journal of Biological and Pharmaceutical Sciences Archive, 2026, 12(01), 100–110
Article DOI: 10.53771/ijbpsa.2026.12.1.0075
Publication history:
Received on 28 June 2026; revised on 06 August 2026; accepted on 08 August 2026
Abstract:
Background: Pharmaceutical manufacturing effluents have emerged as significant environmental reservoirs of antibiotic-resistant bacteria, posing serious public health threats. Methicillin-resistant Staphylococcus aureus (MRSA) is a major healthcare-associated pathogen, and its presence in industrial wastewater represents a critical pathway for environmental dissemination of resistance determinants. This study investigated the antibiotic resistance patterns of MRSA isolated from wastewater effluents of selected pharmaceutical companies in Ogun State, Nigeria.
Objective: To determine the phenotypic antibiotic resistance profiles of MRSA isolates from pharmaceutical company effluents.
Methods: A total of 164 Staphylococcus aureus isolates were recovered from pretreated wastewater samples collected from three pharmaceutical companies (A, B, and C) in Ogun State, Nigeria. MRSA was phenotypically identified using cefoxitin disk diffusion (30 µg) according to CLSI guidelines. Antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method against 10 antibiotics from multiple classes, including β-lactams, glycopeptides, aminoglycosides, fluoroquinolones, and lincosamides.
Results: The overall MRSA prevalence among S. aureus isolates was 35 (49.3%) in Pharma A, 29 (48.3%) in Pharma B, and 15 (45.5%) in Pharma C. Alarmingly, all MRSA isolates (100%) exhibited resistance to aztreonam, cefoxitin, clindamycin, ceftriaxone, imipenem, trimethoprim-sulfamethoxazole, and vancomycin. High resistance rates were also observed for gentamicin (55.2-71.4%), ofloxacin (72.4-80.0%), and levofloxacin (85.7-86.7%).
Conclusion: This study reveals an alarmingly high prevalence of multidrug-resistant MRSA in pharmaceutical wastewater, including complete resistance to vancomycin, a last-resort antibiotic. These findings highlight pharmaceutical effluents as critical hotspots for the environmental dissemination of highly resistant MRSA strains, necessitating urgent regulatory interventions and enhanced wastewater treatment protocols.
Keywords:
MRSA; Antibiotic resistance; Pharmaceutical wastewater; Environmental contamination.
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