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ARS Home » Plains Area » Lincoln, Nebraska » Agroecosystem Management Research » Research » Publications at this Location » Publication #417732
Research Project: Managing Manure as a Soil Resource for Improved Biosecurity, Nutrient Availability, and Soil Sustainability

Location: Agroecosystem Management Research

Title: Evaluation of compartment bag test and membrane filtration for detection and quantification of ESBL E.coli across agriculturally dominated Shell Creek watershed

Author
item HAZRA, MOUSHUMI - University Of Nebraska
item Durso, Lisa
item BARTELT-HUNT, SHANNON - University Of Nebraska
item BROWN, MORIAH - University Of Nebraska

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Antibiotic resistance in water systems poses a concern to human and environmental health. Polluted water bodies such as lakes, creeks and rivers harbor resistant bacteria/genes with the potential to alter ecosystem function of aquatic ecosystems and serve as a vector of antibiotic resistant bacteria capable of infecting animals and humans. The World Health Organization Tricycle Protocol (WHO TP) monitors global antimicrobial resistance (AMR) considering a single indicator organism, the extended-spectrum-ß-lactamase E.coli. The traditional method involves quantifying plating/culturing E.coli bacteria using membrane filtration (MF) on TBX agar supplemented with cefotaxime, which requires lab facilities and trained personnel, limiting its field application. These resources are not available in lower-resource settings. In response, we evaluated a modified compartment bag test (CBT) to quantify the most probable numbers (MPN) of ESBL E.coli. This study compared the modified CBT against the standard method of membrane filtration. We collected four surface water samples from the agriculturally dominated Shell Creek watershed over 6 months. E.coli were quantified using CBT with chromogenic E.coli medium, and by MF on tryptone bile glucuronic agar supplemented with cefotaxime and tetracycline with the same antibiotic. Isolated E.coli were confirmed through indole test and characterized for antibiotic sensitivity by Kirby Bauer disk diffusion test. Results showed a higher proportion of ESBL-E.coli during the rainy season, indicating runoff and sediments as a source of contamination. While the CBT and MF yielded different results, CBT offers a viable alternative approach for surface water monitoring that can provide valuable information for surveillance where other methods are not feasible.