Antimicrobial Resistance and Virulence of Methicillin-Resistant Staphylococcus aureus from Human, Chicken and
Flora Olubunmi Ogundipe1,2, Olufemi Ernest Ojo2,3, Andrea T Feßler2
1Department of Microbiology, College of Biosciences, Federal University of Agriculture, Abeokuta 110124, Nigeria.
Abstract:
Background: Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major threat to public health. This study investigated the occurrence of MRSA in humans, chickens, chicken meat and environmental samples within poultry farms and live bird markets in southwestern Nigeria. Methods: MRSA were isolated using selective culture and tested for antimicrobial susceptibility by broth microdilution. Selected isolates were characterized by whole genome sequencing (WGS). From WGS data, spa, dru, multilocus sequence typing (MLST) and SCCmec types, but also virulence and antimicrobial resistance genes, were identified. Results: Fifty-six MRSA isolates were detected in 734 samples. They showed resistance to β-lactams (100%), tetracycline (60.7%), ciprofloxacin (33.9%), erythromycin (28.6%), gentamicin (32.1%), and trimethoprim/sulfamethoxazole (10.7%). All 30 isolates investigated by WGS carried mecA, dfrG, and tet(38) genes. Other resistance genes detected were blaZ (83.3%), fosB (73.3%), tet(K) (60.0%), aacA-aphD (36.6%), aphA3 (33.3%), msr(A) (30.0%), mph(C) (30.0%), dfrS1 (3.3%), and sat4 (3.3%). Seven spa types (t091, t314, t657, t1476, t2331, t4690 and t12236), four known (dt9aw, dt10ao, dt10cj, and dt11a) and two novel (dt10dr and dt11dw) dru types, as well as five sequence types (ST8, ST121, ST152, ST772 and ST789) were found among the MRSA isolates. All ST121 isolates carried an SCCmec type IV cassette and were not dru-typeable. ST152 and ST121 were found only in specific sample categories within defined locations, while ST8 and ST772 were distributed across most sample categories and locations. Three SCCmec types, IVa, V and Vc, were identified. All MRSA isolates possessed virulence genes including aur, clpP, coa, fnbA, esaA, hly, hla, ica, isdA, srtB, sspA, and vWbp, among others. The toxic shock syndrome toxin gene (tst) was not detected in any isolate, whereas the Pantone-Valentine leukocidin genes lukF-PV/lukS-PV were present in all ST121, all ST772, and all but one ST152 isolates. Conclusion: The results of this study (i) showed that chicken meat is contaminated by MRSA and (ii) suggested that live bird markets may serve as focal points for the dissemination of MRSA within the community.
Insights
Methicillin-resistant Staphylococcus aureus (MRSA) was found in Nigerian poultry, including chicken meat. Live bird markets may be key hubs for MRSA spread in communities.
Area of Science:
- Microbiology
- Public Health
- Genomics
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant public health risk.
- MRSA surveillance is crucial in food production and market environments.
Purpose of the Study:
- To investigate the prevalence and characteristics of MRSA in poultry farms and live bird markets in southwestern Nigeria.
- To identify potential sources and transmission routes of MRSA in the region.
Main Methods:
- Isolation and antimicrobial susceptibility testing of MRSA from human, chicken, chicken meat, and environmental samples.
- Whole genome sequencing (WGS) for detailed characterization of MRSA isolates, including typing, virulence, and resistance genes.
Main Results:
- Fifty-six MRSA isolates were detected, exhibiting resistance to multiple antibiotics.
- WGS identified diverse spa, dru, MLST, and SCCmec types, along with numerous resistance and virulence genes.
- Specific sequence types (ST121, ST772, ST152) carried Panton-Valentine leukocidin genes, associated with severe infections.
Conclusions:
- Chicken meat is a potential source of MRSA contamination.
- Live bird markets may act as central points for MRSA dissemination within the community.
Related Concept Videos
01:28Antimicrobial Effectiveness
01:30Development of Antibiotic Resistance