Antimicrobial sensitivity of faecal Escherichia coli isolated from backyard broiler chickens in Chitungwiza, Zimbabwe

Abstract

Antimicrobial resistance (AMR) is currently one of the greatest public health threats being faced by humanity. Although a lot of funding for research is being availed there are still a lot of gaps in understanding its dynamics as well as the actual degree of this problem. There is also the concept of using the One Health approach to fully understand this threat.

The aims of this study were to isolate E. coli from backyard broiler chickens from selected households in Chitungwiza, Zimbabwe, to determine the antimicrobial sensitivity of the isolates and to assess the level of knowledge of the backyard poultry keepers with regards to AMR. One hundred and thirty-eight (138) cloacal samples were randomly collected from backyard poultry from randomly selected households. Escherichia coli isolation was done on MacConkey agar and biochemical tests were carried out to identify the isolates. Antibiotic sensitivity analysis was carried out on Mueller Hinton agar and the zones of inhibition were measured and interpreted in line with CLSI guidelines.

A total of 98 (68%) of E. coli isolates were obtained. Antimicrobial susceptibility analysis revealed four (4%) isolates that were resistant to all six (6) antibiotics. Escherichia coli resistance to tetracycline was 93.6%, ciprofloxacin 44.7%, ampicillin 59.6%, ceftriaxone 9.6%, trimethoprim / sulphamethoxazole 79.8% and colistin sulphate 4.3%. Isolates were most often resistant to tetracycline.

Fifteen (15) people answered the questionnaire and of these only two (13.3%) knew about withdrawal periods and practiced them. The overuse of poultry drugs and their wide availability could be the main driver of AMR in poultry. The results obtained in this study indicated that there is indeed AMR in E. coli from backyard broiler birds and the greater population is not aware of this. This poses a great public health threat since some of the drugs are used as first line drugs in the treatment of human infections.