Activities and influence of veterinary drug marketers on antimicrobial usage in livestock production in Oyo and Kaduna States, Nigeria

Antimicrobial usage in animals contributes to the emergence of antimicrobial resistant bacterial strains. Investigations were carried out on how the characteristics, knowledge, attitude and practices of antimicrobial marketers influenced antimicrobials usage in animal production in Oyo and Kaduna States, Nigeria. Focus group discussions, in-depth interviews and structured questionnaires were used to gather information about the characteristics and activities of antimicrobial marketers. Overall, 70 (56.9 %) of 123 marketers had post-secondary education while 76 (61.8 %) were trained on the use of antimicrobials. Eighteen (14.6 %) of the marketers were licensed veterinarians. Only 51 (41.5 %) marketers displayed adequate knowledge about antimicrobials and antimicrobial usage. Sixty-seven (54.6 %) marketers requested a prescription before selling antimicrobials while 113 (91.9 %) marketer recommended antimicrobials for use in animals. Two-third of the marketers (66.7 %) prescribed antimicrobials without physically examining sick animals but based their prescriptions on verbal reports of clinical signs by farmers and on their personal experience. Marketers with higher educational qualification displayed more adequate knowledge of antimicrobials and antimicrobial usage than those with basic education background only. More years of experience in antimicrobial marketing did not translate to better knowledge on antimicrobial usage. Only 45 (36.6 %) respondents were aware of the existence of regulatory agencies monitoring the use of antimicrobials in animals. Farmers ignored the services of veterinarians in the diagnosis and control of animal diseases but resorted to drug marketers for help. Effective communication of existing legislations on antimicrobial usage, improved access to veterinary services and strict enforcement of regulatory policies are recommended for checking non-judicious use of antimicrobial agents in animal production. Sales of antimicrobial agents for animal use without veterinarian’s prescription must be prohibited

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

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