ABSTRACT
Background: The irrational use of antibiotics in humans and livestock has contributed to the emergence of antimicrobial resistance (AMR). This study investigated the commonly sold and dispensed antibiotics for prophylaxis in broiler chickens in pharmacy and agro-veterinary shop personnel in the Lusaka District of Zambia. Methods: This cross-sectional study was conducted from August 2023 to October 2023 among 200 veterinary medicine dispensers in the Lusaka District of Zambia using a simulated farmer or mystery shopper approach. Data analysis was performed using IBM Statistical Package for Social Sciences version 23.0. Results: Out of the 200 medicine outlets investigated, 23 (11.5%) were agro-veterinary shops, while 177 (88.5%) were community pharmacies. A total of 165 community pharmacies and agro-veterinary shops provided veterinary services in the Lusaka District and sold medicines without prescription giving a 100% non-prescription sale. Of the 178 medicines dispensed for prophylaxis, 88.5% were antibiotics, while 13.5% were vitamins. The most dispensed antibiotic drug for prophylaxis in broiler chickens was oxytetracycline (30.34%), amoxicillin (17.98%) and gentamicin/doxycycline (10.67%). Conclusions: This study revealed a high sale and dispensing of antibiotics for prophylaxis in broiler chickens of which oxytetracycline, amoxicillin and gentamicin/doxycycline were commonly dispensed. There is a need for increased regulatory enforcement of selling antibiotics without a prescription as this may predispose poultry to the development of AMR and possible transmission of superbugs to humans and the environment. Educational interventions should be provided to community pharmacy and agro-veterinary personnel on adhering to antimicrobial stewardship practices when dispensing poultry antibiotics.
ABSTRACT
Poultry products in Zambia form an integral part of the human diet in many households, as they are cheap and easy to produce. The burden of poultry diseases has, however, remained a major challenge. Growing consumer demand for poultry products in Zambia has resulted in non-prudent antimicrobial use on farms, intending to prevent and treat poultry diseases for growth optimisation and maximising profits. This cross-sectional study aimed to identify the different types of bacteria causing diseases in chickens in Lusaka and to detect the extended-spectrum lactamase (ESBL)-encoding genes. We collected 215 samples from 91 diseased chickens at three post-mortem facilities and screened them for Gram-negative bacteria. Of these samples, 103 tested positive for various clinically relevant Enterobacteriaceae, including Enterobacter (43/103, 41.7%), Escherichia coli (20/103, 19.4%), Salmonella (10/103, 9.7%), and Shigella (8/103, 7.8%). Other isolated bacteria included Yersinia, Morganella, Proteus, and Klebsiella, which accounted for 21.4%. E. coli, Enterobacter, Salmonella, and Shigella were subjected to antimicrobial susceptibility testing. The results revealed that E. coli, Enterobacter, and Shigella were highly resistant to tetracycline, ampicillin, amoxicillin, and trimethoprim-sulfamethoxazole, while Salmonella showed complete susceptibility to all tested antibiotics. The observed resistance patterns correlated with antimicrobial usage estimated from sales data from a large-scale wholesale and retail company. Six (6/14, 42.9%) E. coli isolates tested positive for blaCTX-M, whilst eight (8/14, 57.1%) Enterobacter samples tested positive for blaTEM. Interestingly, four (4/6, 66.7%) of the E. coli isolates carrying blaCTX-M-positive strains were also positive for blaTEM. Sanger sequencing of the PCR products revealed that five (5/6, 83.3%) of the abovementioned isolates possessed the blaCTX-M-15 allele. The results suggest the presence of potentially pathogenic ESBL-producing Enterobacteriaceae in poultry, threatening public health.
