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ARS Home » Plains Area » Lincoln, Nebraska » Agroecosystem Management Research » Research » Publications at this Location » Publication #429897
Research Project: Managing Manure as a Soil Resource for Improved Biosecurity, Nutrient Availability, and Soil Sustainability

Location: Agroecosystem Management Research

Title: Agriculturally Sourced Multidrug-Resistant Escherichia coli for Use as Control Strains

Author
item Wells, James
item Durso, Lisa
item Ibekwe, Abasiofiok
item Frye, Jonathan
item Sharma, Manan
item Williams, Clinton
item Shamimuzzaman, Md

Submitted to: Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/19/2025
Publication Date: 4/25/2025
Citation: Wells, J., Durso, L.M., Ibekwe, A.M., Frye, J.G., Sharma, M., Williams, C.F., Shamimuzzaman, M. 2025. Agriculturally Sourced Multidrug-Resistant Escherichia coli for Use as Control Strains. Pathogens. 14(5):417. https://doi.org/10.3390/pathogens14050417.
DOI: https://doi.org/10.3390/pathogens14050417

Interpretive Summary: Antibiotic resistance is a global health threat. The first step in controlling it, is to track where and when it is found. There are established programs already underway to track antibiotic resistance in people, but efforts to track antibiotic resistance in the environment are lacking. Many efforts focus on tracking antibiotic resistance in E. coli, and use control strains that come from humans. Since human-associated E. coli have been shown to be different from other non-human E. coli, we isolated and characterized two agriculturally-associated E. coli to serve as control strains for future environmental antibiotic resistance tracking efforts.

Technical Abstract: Bacteriological control strains with known characteristics ensure consistency and reproducibility of assay performance across different laboratories and are an important cornerstone of quality control in the microbiology laboratory. Ideally, control strains should be representative of the assay target and be widely available from reputable sources. However, for work involving antibiotic resistance most controls come from human and veterinary clinical sources and are not optimized for work in agriculturally impacted environments or not widely available. The objective of this work was to identify and make widely available two E. coli isolates sourced from agricultural production settings that could be used as external controls supporting method development, research and environmental monitoring for extended spectrum ß-lactamase producing (ESBL) and tetracycline resistant Escherichia coli. Previously collected E. coli suspects were screened based on antimicrobial susceptibility testing data, then confirmed as E. coli and characterized both phenotypically and genotypically. The positive control strain, ARS-C301 was ESBL positive and contained the CTX-M-55 and tet(A) genes, and the negative control strain, ARS-C101 was negative for both targets. Here we introduce two agriculturally sourced, fully characterized, and genetically sequenced control strains for use as laboratory controls in research involving extended-spectrum ß-lactamase producing (ESBL) and tetracycline-resistant Escherichia coli isolated from the environment, available via publicly accessible culture collections, and commercially as a quantitative pellet.