Detection of Antibiotic-Resistant Escherichia coli in the Upper Citarum River Using a β-D-Glucuronidase Method

Background: Polluted rivers may become reservoirs of antibiotic-resistant Escherichia coli (AREc), raising concerns about environmental health. While monitoring is crucial for recognizing their incidence and evaluating mitigation solutions, current approaches are limited due to high costs, labor-intensive methods, and a lack of standardized indicators. This study aims to identify the priority AREc as the monitoring target and evaluate the applicability of the β-glucuronidase enzyme detection method (MPR Method) as an alternative rapid method for profiling AREc in the Upper Citarum River. Methods: River water sampling was conducted along the river during two periods with varying rainfall levels. Total Escherichia coli (TEc) and twelve types of antibiotic-resistant Escherichia coli (AREc) were measured simultaneously by the Agar Method and the β-D-Glucuronidase detection (MPR Method). Results: Statistical data analyses indicate that Total Escherichia coli (TEc) concentrations in the Upper Citarum River increase during periods of higher rainfall (𝓍 = 2558 ± 360 CFU/mL). Erythromycin-resistant Escherichia coli dominates in both periods (Period I 𝓍 = 57.6 ± 25.9%, Period II 𝓍 = 49.96 ± 29.5%). However, tetracycline-resistant Escherichia coli and Extended-Spectrum β-lactamase-producing Escherichia coli (ESBL-Ec) are the most suitable indicators for AREc concentration due to their consistency and correlation with other AREc types. The MPR method achieved an accuracy of up to 87.2%, a sensitivity of 67.4%, and a specificity of 94%. Conclusion: The MPR Method was considered a better alternative for the AREc screening method, particularly in a high bacterial load aquatic environment.