Risk Factors for ESBL-Producing Enterobacteriaceae in Wastewater of Dairy Farms in East Java, Indonesia

The proliferation of Enterobacteriaceae with extended-spectrum beta-lactamase (ESBL), including Escherichia coli and Klebsiella pneumoniae, poses a significant threat to public health due to their resistance to β-lactam antibiotics. This study focuses on the risk factors of ESBL-producing Enterobacteriaceae in the wastewater of dairy farms in East Java, Indonesia, a major milk-producing region. Utilizing an observational cross-sectional design, data were collected from 342 wastewater samples across six regions with high dairy cattle populations in East Java. Risk factors were assessed through questionnaires addressing variables related to farmers and farm management. Univariate analysis by regency/city identified several significant risk factors for the occurrence of ESBL-producing Enterobacteriaceae in dairy farm wastewater in East Java, and it differed between regencies/cities. Multivariate analysis of risk factors that significantly correlated with ESBL-producing Enterobacteriaceae showed a distance of ≤ 10 m between septic tanks and wells that significantly increased the risk of ESBL-producing Enterobacteriaceae occurrence (OR 3.24, 95% CI: 1.07-9.80), as did not using detergent for barn cleaning (OR 2.67, 95% CI: 1.23-5.67). Conversely, the use of water storage tanks and a distance of ≤ 500 m from other dairy farms appeared to reduce the risk. This study provides critical insights for developing strategies to control and prevent antibiotic resistance in the dairy farming sector, such as improved wastewater management, stricter regulations on antibiotic usage, and enhanced farmer education programs. Implementing these strategies is crucial to mitigating the spread of ESBL-producing Enterobacteriaceae, thereby improving public and environmental health in East Java.