Extended-Spectrum Beta-Lactamase Producing Escherichia coli in Raw Cow Milk At Selling Points and Determinants of Contamination in and Around Chencha, Southern Ethiopia.

Introduction: Bacterial foodborne infections are a major public health concern globally, and the emergence of antimicrobial-resistant bacteria in food worsens the associated problems which are alarming issues. The current study aimed to isolate E. coli, determine antimicrobial resistance patterns, estimate the prevalence of extended-spectrum beta-lactamase-producing E. coli, and determinants of raw cow milk contamination at selling points in and around Chencha, Southern Ethiopia from January 2021 to April, 2022.

Methods: A total of 384 milk samples were collected randomly using a cross-sectional study and processed in the laboratory for evaluation of microbial load, bacterial isolation, and antimicrobial susceptibility patterns. The determinants were assessed through a prepared questionnaire, and descriptive statistics and multivariable logistic regression analysis were performed using SPSS version 21.

Results: Out of 384 milk samples analyzed for microbial loads, 5.3±1.68 log and 2.17±1.51 log CFU/mL respectively were the mean values of total viable count and total coliform count. A total of 118 (30.7%) samples were contaminated with E. coli of about 11.8% extended-spectrum beta-lactamase producers. Notably, 91 (77.1%) of isolates were multiple drug-resistant isolates. The multivariable logistic regression showed that variables of educational status of milk handlers, hand washing activities, nose picking habit of milk handlers, milk container cleaning activity, milk container type, physical abnormal milk checking status, and attended training on hygienic food handling practices type were significantly associated with the milk contamination in the study area.

Conclusion: The results implied that the raw milk samples served in the study area contained bacterial pathogens and a higher microbial load than recommended standards. Our data also confirmed the presence of multiple drug resistant and extended-spectrum beta-lactamase producing E. coli. Therefore, a close follow-up and training of milk handlers is needed. Besides, consumers should be made aware of the risks of consuming raw milk.