Abstract

This study aims to assess the interactions between antibiotic resistance and the ability of heterotrophs effected by highly polluted environments to remediate antibiotics from soil via biodegradation. These findings would reveal whether a self-cleaning process is occurring in the waters of Western NY. Water and sediment heterotrophs were obtained from wastewater contaminated environments to understand the factors influencing metabolism. A total of 113 isolates from Charlotte, Durand, and Payne Beaches, the Genesee River, and Hemlock Lake were cultured and detected for antibiotic resistance to 24 different antibiotics. Of these, seven robust bacteria from sediments were considered for their ability to use a single antibiotic as their sole carbon source — available carbon limited substrate utilization. Microbes were able to remediate antibiotic substrates from soil between 18.1-42.1% at one-times the concentration, whereas two and three times the original concentration was impotently degraded by 13.4-24.0% and 5.7-18.2%, separately. Heterotrophs also demonstrated unique substrate binding affinity for alternative substrates, which were discovered to be degraded between 1.05% to 72.96%. We found the best alternative substrates with enzyme activity to be tetracycline (70.26-72.96%), chloramphenicol (49.28-66.78%), and trimethoprim (54.51-57.22%). An assessment of antimicrobial susceptibility revealed that the highest resistance was observed to aminoglycoside antibiotics, followed by cephalosporins, beta-lactams, and fluoroquinolones. A robust isolate from Durand Beach was resistant to 19 out of the 24 antibiotics under evaluation. We posit that heterotrophs of highly polluted environments are restricted by carbon-availability, have unique binding affinity for alternative substrates, and are multidrug-resistant.

Publication Date

4-10-2019

Document Type

Thesis

Student Type

Graduate

Degree Name

Environmental Science (MS)

Department, Program, or Center

Thomas H. Gosnell School of Life Sciences (COS)

Advisor

Jeffrey Lodge

Advisor/Committee Member

Carrie McCalley

Advisor/Committee Member

Robert Osgood

Campus

RIT – Main Campus

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