BMC Microbiol. 2025 Dec 20. doi: 10.1186/s12866-025-04643-8. Online ahead of print.
ABSTRACT
BACKGROUND: Antimicrobial resistance (AMR) in animal-derived food is a significant global health issue, especially in low- and middle-income countries where sanitation, responsible antibiotic use, and surveillance remain weak. In dairy farming, Escherichia coli (E. coli) and Klebsiella species are of particular concern as they frequently exhibit multidrug resistance and produce extended-spectrum β-lactamase (ESBL). Despite their growing public health significance, limited data exist on their distribution in Ethiopia, particularly in the Tigray region. Therefore, this study aimed to determine the prevalence and antimicrobial resistance profiles of E. coli and Klebsiella spp. in dairy farm environments in the Tigray region of northern Ethiopia.
METHODS: A cross-sectional study was conducted between December 2024 and May 2025, analyzing 712 samples from raw bulk tank milk, milk-container swabs, water, and milkers’ stool, each 178. Escherichia coli and Klebsiella spp. were isolated and identified using standard culture and biochemical tests. Antimicrobial susceptibility was determined by the disk diffusion method according to CLSI (2024), and ESBL production was confirmed using the phenotypic double-disk synergy test (DDST). Isolates resistant to one or more antibiotics in three or more antimicrobial classes were classified as Multi-Drug Resistant (MDR). Data were processed and analyzed using SPSS version 26.
RESULTS: Out of 712 samples, 494 (69.4%) were positive for either E. coli or Klebsiella spp., with E. coli (49.6%) predominating over K. pneumoniae (10.3%) and K. oxytoca (9.6%). High resistance levels were observed to tetracycline (62.9%), amoxicillin/clavulanic acid (31.2%), and trimethoprim-sulfamethoxazole (27.7%), while resistance to meropenem remained low (2.4%). Overall, 32.4% of isolates were MDR, with the highest rates in E. coli (32.0%). ESBL production was detected in 53 (10.7%) of isolates, across all sample types and locations.
CONCLUSION: The study revealed a high prevalence of E. coli and Klebsiella spp. in dairy farm environments, with a considerable proportion of MDR and ESBL producers. This poses a serious concern for food safety and public health. These findings highlight the urgent need to enhance hygiene, antimicrobial stewardship, and integrated One Health-based surveillance along the dairy value chain.
PMID:41422193 | DOI:10.1186/s12866-025-04643-8
