Antimicrobial Resistance In Extended Spectrum Beta Lactamase Producing Escherichia Coli Triggered By Pesticides

Abstract

Background: Antimicrobial resistance (AMR), especially those caused by Extended-Spectrum Beta-Lactamase-producing E. coli (ESBL-producing E. coli), are a major global health problem. Knowing that misuse of antibiotics is a key driver in the development of resistance to these microbial agents, the effects of environmental non-antibiotic stressors such as pesticides in agriculture is, however, critically understudied. Objective: Pesticides like Glyphosate, used widely in agriculture for pest control, have been indicated to enhance efflux pump activity, beta-lactamase production and are targets of plasmids that carry antibiotic resistant genes. Thus, such chemicals are increasing AMR in gram-negative bacteria. Materials and Methods: This comparative experimental study analyzed 70 E. coli isolates from three groups: Non-Exposed Control (n = 10), Glyphosate-Exposed (n = 40), Mixed Pesticide-Exposed (n = 20). Isolates were biochemically confirmed. Antibiogram (ABG) was carried out using the Kirby-Bauer method against six agents, including the key ESBL markers Ceftazidime and Cefotaxime, and last-resort antibiotics Imipenem. Results were interpreted according to CLSI guidelines, with the Double-Disk Synergy Test (DDST) being used to phenotypically confirm ESBL production in resistant isolates. Results: susceptibility testing throughout three cohorts illustrates a clear link between chemical stress and resistance. Non-Exposed Control isolates (n = 10) displayed 0% resistance to all of the drugs used in testing. In contrast, the Glyphosate-Exposed group (n = 40) exhibited a surge in Cefotaxime (CTX) resistance of 70.0% (a hallmark ESBL activity), while retaining full Imipenem susceptibility. Resistance was greatest in the Mixed Pesticide-Exposed group (n = 20), where CTX resistance reached 90.0% (and showed 0% sensitivity) demonstrating DRE-driven chemical stress. This group also developed multi-drug resistance (MDR) characteristics, with elements including Gentamicin (30.0%), importantly Imipenem resistance at 10.0% (n=2). Conclusion: Pesticide exposure serves as an environmental selective agent promoting the formation of clinically relevant ESBL resistant mechanisms. These results do not point to any species barrier but can happen across different organisms. The authors argue that these findings require environmental chemical surveillance to be built-into AMR stewardship policy under the "One Health" framework.