Antibiogram and Multi-drug Resistance Profile of Escherichia coli Isolated from Retail Poultry Feeds

Abstract

Abstract High cost of poultry feeds necessitate feed retailing to small scale farmers. Retailing of feeds however, breaches feed biosecurity, enhances microbial contamination including antimicrobial resistant bacteria. The present study evaluated the antibiogram and multi-drug resistance profile of E. coli from retail poultry feeds in Southeastern Nigeria. A total of 390 feed samples from broiler starter, broiler finisher, chick grower, and layer ration belonging to various feed brands were collected for the study. Presumptive E. coli bacteria were isolated from samples following standard microbiological techniques and confirmed as E. coli using biochemical tests. Isolate antibiotic resistance was evaluated using 10 antibiotic agents. There was high prevalence of zero inhibition zone diameters among resistance zone diameters, and extensive antibiotic resistance by isolates. Of the 114 isolates, eight (7 %) were completely sensitive while 29 (25.4 %) were completely resistant (MDRI: 1.0). Feed brand J and broiler starter yielded the most resistant isolates. Resistance to cell wall inhibitors were the most prevalent (79.2 %) while nalidixic acid was the most resisted antibiotic (n = 99, 86.8 %). Antibiotic resistance status and source of isolates showed significant association across feed brands (χ2 = 49.085, p < 0.000), and feed types (χ2 = 25.429, p < 0.000); and for feed brands within states (χ2 = 16.518, p < 0.001; χ2 = 30.768, p < 0.000; and χ2 = 20.025, p < 0.006 for Abia, Ebonyi and Enugu States, respectively). Antibiotic agent and resistance status of isolates were significantly related across feed brands in Abia State. There were 41 multi-drug resistance patterns of which the most frequent involved eight antibiotics (n = 12, 29.3 %). In conclusion, retail poultry feeds harbor multi-drug resistant E. coli bacteria. Feed retailing should be outlawed, and feed companies made to bag graded small quantities for resource poor farmers.