Humboldt Journal of Microbiology
Abstract
Limited studies have been conducted regarding the fecal contamination and microbial dispersal through rainwater, with no known studies investigating the potential connection between antibiotic resistant microbes and water quality in rainwater. This study seeks to identify the presence of a correlation between water quality and incidence of antibiotic resistance in rainwater microbes. We hypothesize that there will be a correlation between these two variables. We additionally anticipate a high incidence of fecal contamination across rural and urban collection sites alike, with fecal contamination being more prevalent in rural areas than urban locals. To determine water quality, we measured the concentration of fecal coliforms in four rainwater samples collected throughout western Humboldt County using selective and differential media. We determined the levels of antibiotic resistance using microtiter plates and bacterial growth scoring, quantifying antibiotic resistance by calculating the MIC of each isolate across a concentration gradient of ampicillin. We found no relationship between fecal coliform abundance and the incidence of ampicillin resistance. Each sample contained at least one fecal coliform, denoting fecal contamination of rainwater across all collection sites. Therefore, rainwater should not be consumed or used for domestic use without proper filtration and water treatment. With a high concentration of fecal coliforms in our samples, public health may be compromised, as their presence in rainwater indicates the potential for pathogenic microorganisms to disperse via rain events. Further studies elucidating the role of horizontal gene transfer in rain-dispersed microbes is required to fully understand the impacts rainwater has in the geographic distribution of antibiotic resistant microbes in contaminated water.
Recommended Citation
Murphy, Theo P.; Wendley, Eve; Laskowski, Justice; and Paredes, Tyler
(2025)
"Elucidating the Relationship Between Water Quality and Antibiotic Resistance of Rainwater Microbes Across Western Humboldt County,"
Humboldt Journal of Microbiology: Vol. 24, Article 3.
Available at:
https://digitalcommons.humboldt.edu/hjm/vol24/iss1/3
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