541 - Producing Antibiotic Free Chicken Meat in Developing Countries: What We Learned from Nigeria

The removal of antibiotics has been the main approach adopted by developed countries to curtail antimicrobial resistance (AMR) spread in food animals, however there is a paucity of data on the preharvest control points that are relevant to developing countries in sub-Saharan Africa. To provide new insights on the AMR problem faced by these nations, we raised 1-day old broiler chickens in Nigeria on three different feeds given as a single diet. Two of the feed were locally sourced (local 1 and local 2) and one was donated from North America (foreign). Day-old chicks were bought from a commercial hatchery and randomly assigned to 1 of the 3 feed types and raised for 49 days. We used TaqMan-based qPCR to assess the abundance of antibiotic resistance genes (ARG). ARG in the meconium, and in the ceca of broiler chicks at 4 and 49 days old. Additionally, we used E. coli and Salmonella isolates (n = 96) recovered from the meconium, ceca, and fecal droppings to surveil the classes of antibiotic resistance that are prevalent during preharvest broiler production. Cecal samples carried higher levels of ARG compared to meconium samples and ARG abundance was higher at day 4 compared to day 49. Beta-lactam resistance gene (blaTEM) was the ARG with the highest abundance (Log 9.41±0.79 gene copies/g ceca), while ARG for macrolides (ermB), sulfonamides (sul1), tetracycline (tetM) and aminoglycosides (aadA) were Log 9.03± 0.9, Log 9.30±0.69, Log 8.61±1.05 and Log 8.79±0.95 gene copies/g ceca, respectively. Fifty percent of the isolates recovered from the meconium were classified as multidrug resistance (MDR) (i.e., resistance to 3 or more antibiotic class), while the number of isolates classified as MDR from the ceca and feces differed by source of feed (range = 67 – 83%). The elevated levels of ARG and MDR bacteria found in this study suggests that a directed multipronged “One Health” approach will be required to curtail the spread of AMR in food animals grown in developing nations.