Load and Prevalence of Antimicrobial-Resistant Escherichia coli from Fresh Goat Meat in Arusha, Tanzania

Abstract

Given the potential public health risks associated with a burgeoning goat meat industry in Tanzania, we estimated the load of Escherichia coli and the prevalence of antibiotic-resistant strains for goat meat by using a cross-sectional study design (June to July 2015). Five large (n¼60 samples) and five small (n¼64 samples) slaughterhouses were sampled over a period of four to six visits each. Meat rinsate was prepared and plated onto MacConkey agar, and presumptive E. coli colonies were enumerated and reported as CFU per milliliter of rinsate. In total, 2,736 presumptive E. coli isolates were tested for antibiotic drug sensitivity by using breakpoint assays against 11 medically important antibiotics. E. coli was recovered from almost all the samples (96.8%), with counts ranging from 2 to 4 log CFU ml 1, and there was no significant difference (P¼0.43) in recovery according to facility size (average, 3.37 versus 3.13 log CFU ml 1, large and small, respectively). Samples from large facilities had relatively higher prevalence (P ¼ 0.026) of antibiotic-resistant E. coli compared with small facilities. This was mostly explained by more ampicillin (30.1 versus 12.8%) and amoxicillin (17.6 versus 4.5%) resistance for large versus small facilities, respectively, and more tetracycline resistance for small facilities (5.6 versus 10.6%, respectively). Large slaughter operations may serve as foci for dissemination of antibiotic-resistant bacteria via food products. More effective hygiene practices during slaughter and meat handling would limit the probability of transmitting antibiotic-resistant E. coli in goat meat.