One-Health Approach to Determine and Tackle Antimicrobial Resistance in the Human Dairy Interface: A Case of Non-Typhoidal Salmonella and Lactose-Fermenting Enterobacteriaceae

Background Antimicrobial resistance (AMR) is among the top public health concerns globally. Determining the susceptibility pattern of pathogens is important in designing strategies to combat AMR. Thus, this study was designed to determine the AMR pattern of non-typhoidal Salmonella (NTS) and lactose fermenting Enterobacteriaceae (LFE) isolated from the human-dairy interface in the northwestern part of Ethiopia, where such information is lacking. Methods The study analysed 362 samples collected from humans, animals, food (milk) and the environment (sewage). The bacteria were isolated from the samples using standardized bacteriological methods. The antimicrobial susceptibility patterns and extended-spectrum beta-lactamase (ESBL) production ability were screened and confirmed by using the Kirby-Bauer disk diffusion method. The isolates were further characterized genotypically using multiplex polymerase chain reaction targeting the three ESBL-encoding genes. Results A total of 28 and 375 NTS and LFE bacterial isolates were identified. Isolates were more resistant to ampicillin and tetracycline. Forty-six point four and 70.7% of NTS and LFE were multidrug resistant (MDR), respectively. None of NTS and 21.3% of LFE were ESBL-producing. Genotypically, the majority of the isolates (97.5%), which were positive on the phenotypic test, were carrying one or more ESBL encoding genes. In conclusion, a high proportion of the bacterial isolates were resistant to commonly used antimicrobials, MDR, and were positive for ESBL production. Conclusion The findings provide evidence that the human-dairy interface is one of the important reservoirs of AMR traits and intervention points to reduce AMR. Therefore, the implementation of AMR mitigation strategies in a one-health approach is highly needed in the area.