Antimicrobial susceptibility of Escherichia coli, Klebsiella pneumoniae, and Enterococcus species and the associated risk factors in poultry farms in Blantyre City: a wake-up call to the one health approach.

Abstract

BACKGROUND: Small scale poultry farming often involves intensive farming which includes the extensive use of antibiotics for growth promotion and disease prevention. This can be used as a focal point for understanding the spread of resistant bacteria among the livestock, human and the environment interface. This study aimed at unravelling the antimicrobial use and resistance in small scale poultry farmers in Blantyre, Malawi. METHODS: Samples from chickens, humans and the environment were collected from various poultry farms to assess resistant profiles for,, andspecies. Bacterial culturing and disc diffusion methods were used to isolate and assess the antimicrobial resistance (AMR) profiles of the isolated bacteria respectively. Logistic and linear regression tests were used to assess potential risk factors for the AMR. RESULTS: The study revealed uniform resistance profiles ofto ampicillin, cefotaxime, ciprofloxacin, gentamicin and sulfamethoxazole trimethoprim across samples from humans, chickens and their shared environment. Theresistance profiles to sulfamethoxazole trimethoprim were higher in chicken and environmental samples compared to the human samples. The resistance profiles forspecies to vancomycin, linezolid, ciprofloxacin and tigecycline were similar across the three sample types. Nevertheless,andshowed 100% sulfamethoxazole trimethoprim, while theshowed 80% resistance to vancomycin from all the three sample types. Farms that did not observe withdrawal periods were five times more likely to experience AMR (OR = 5.32, 95% CI: 1.89–14.94, = 0.013) than the farms that observed withdrawal periods. Farms that had inadequate waste management practices were three times more likely to experience AMR (OR = 3.42, 95% CI: 1.22–9.59, = 0.037) than the farms that had adequate waste management practices. CONCLUSIONS: The study confirms occurrence of AMR in the poultry farming, humans and the environment influenced by both biological and management factors. The similar resistance patterns across three sample types suggest a dynamic transmission of resistant bacteria at the human-animal-environment interface, hence emphasizing the need for a One health approach to mitigate AMR. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12917-025-05189-7.