Antimicrobial Resistance and Virulence of Methicillin-Resistant Staphylococcus aureus from Human, Chicken and Environmental Samples within Live Bird Markets in Three Nigerian Cities

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.

Phenotypic detection, antimicrobial susceptibility and virulence profile of staphylococci in the pig production setting, Makurdi, Nigeria

“…All the isolates phenotypically multidrug-resistant (MDR), had an MAR index of ≥0.2, which suggests that the isolates originated from a source where antibiotics are used frequently [ 23 ]. The high rates of resistance observed towards the β-lactams, penicillins, tetracyclines and macrolides are consistent with the findings from previous studies in animals and animal products, including pigs and pork [ 10, 21, 22, 24 ], poultry [ 25 ], cattle [ 26 ], camels [ 27 ] and humans [ 11, 21, 25 ] in Nigeria. This high rate of resistance may not be coincidental, as we hypothesize that it is linked to the well-documented widespread, heavy and unregulated use of these agents in pig production across the country for prophylaxis and therapy [ 28 ].…”

A 6-Year Update on the Diversity of Methicillin-Resistant Staphylococcus aureus Clones in Africa: A Systematic Review

“…PVL-positive t590-ST1-V [5C2] was documented from nasal samples both in hospitalized patients and health care workers (HCWs) in São Tomé and Príncipe ( Conceição et al, 2015a , b ). Another PVL-positive lineage: t657-ST772-V [5C2] (Bengal Bay Clone), was detected from human nasal samples in the community setting in Nigeria ( Ogundipe et al, 2020 ). Moreover, PVL-negative t127-ST1-IV [2B] was described in a nasal sample of a non-hospitalized individual in Morocco ( Mourabit et al, 2017 ), while it’s variant (t127-ST1-V [5C2]) was identified from non-human specimens (milk products) in Uganda ( Asiimwe et al, 2017b ).…”

“…The PVL-negative ST8-V/VII (largely t1476) was the major clone in the DRC ( Lebughe et al, 2017 ; Vandendriessche et al, 2017 ), and Angola ( Aires-de-Sousa et al, 2018 ). Two countries, i.e., Morocco ( Mourabit et al, 2017 ) and Nigeria ( Ogundipe et al, 2020 ), described ST8-V [5C2] with different spa types (t2231, t2658, and t12236) in non-clinical settings. The t456-ST8-I [1B] was only identified in South Africa ( Mahomed et al, 2018 ).…”

Multi-Drug Resistant Escherichia coli, Biosecurity and Anti-Microbial Use in Live Bird Markets, Abeokuta, Nigeria

“…In the Nigerian’ poultry value chain, live bird markets (LBMs) are essential to the farmers for the preferential sales and marketing of poultry and poultry products for human consumption [ 1 ]. The LBMs are typically in urban, peri-urban, and rural settings and typified by permanently placed pen-like structures in which the chickens can be temporarily housed until they are sold [ 2 ]. The LBMs bring together a variety of multi-farmed, multi-sourced, and multi-aged poultry species to meet the preferences of various customers [ 3 ].…”