Antimicrobial Resistance in Food Animals and the Environment in Nigeria: A Review

Abstract

Antimicrobial resistance (AMR) has emerged as a global health threat, which has elicited a high-level political declaration at the United Nations General Assembly, 2016. In response, member countries agreed to pay greater attention to the surveillance and implementation of antimicrobial stewardship. The Nigeria Centre for Disease Control called for a review of AMR in Nigeria using a “One Health approach”. As anecdotal evidence suggests that food animal health and production rely heavily on antimicrobials, it becomes imperative to understand AMR trends in food animals and the environment. We reviewed previous studies to curate data and evaluate the contributions of food animals and the environment (2000⁻2016) to the AMR burden in Nigeria using a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart focused on three areas: Antimicrobial resistance, residues, and antiseptics studies. Only one of the 48 antimicrobial studies did not report multidrug resistance. At least 18 bacterial spp. were found to be resistant to various locally available antimicrobials. All 16 residue studies reported high levels of drug residues either in the form of prevalence or concentration above the recommended international limit. Fourteen different “resistotypes” were found in some commonly used antiseptics. High levels of residues and AMR were found in food animals destined for the human food chain. High levels of residues and antimicrobials discharged into environments sustain the AMR pool. These had evolved into potential public health challenges that need attention. These findings constitute public health threats for Nigeria’s teeming population and require attention.

Keywords: Nigeria; antibiotics residue; antimicrobial resistance; bacteria; environment; food animals.

Figure 1

Distribution of organisms studied in the antimicrobial resistance studies based on reports.

Figure 2

Number of reports yearly per organism for the geopolitical zones of Nigeria. NC = North central, NE = North east, NW = North West, SE = South East, SS = South South, SW = South West.

Figure 3

Number of reports of antimicrobial resistance levels of (a) β-lactam derivatives; (b) Quinolones, (c) Aminiglycosides; (d) Macrolides, Phenicols, and Tetracyclines; and (e) Sulfonamides derivatives antimicrobials.

Figure 3

Number of reports of antimicrobial resistance levels of (a) β-lactam derivatives; (b) Quinolones, (c) Aminiglycosides; (d) Macrolides, Phenicols, and Tetracyclines; and (e) Sulfonamides derivatives antimicrobials.

Figure 4

Number of reports of antimicrobial resistance categories for (a) Escherichia coli; (b) Salmonella; (c) Staphylococcus; (d) Pseudomonas; (e) Klebsiella; and (f) other bacteria.

Figure 4

Number of reports of antimicrobial resistance categories for (a) Escherichia coli; (b) Salmonella; (c) Staphylococcus; (d) Pseudomonas; (e) Klebsiella; and (f) other bacteria.

Figure 5

(a) Test procedure for each antibiotic tested in antimicrobial residue studies; (b) Relative level of antimicrobial residue. Tetracycline: Very high residue (n = 3), High (n = 1), Low (n = 4); Chloramphenicol: Very high (n = 1), High (n = 1), Low (n = 1); Amoxicillin No: (n = 1); Penicillin: Very high (n = 1), Slight high (n = 1), Low (n = 1); and Antimicrobial residue generally: Very high (n = 1), Slightly high (n = 2), Low (n = 1).