1. Occurrence and Proliferation of antibiotic resistance in biological wastewater treatment
Research Team: Daniel Gerrity, Majid Neyestani,
Funding Agencies and Partners:
Project Overview: The invention of antibiotics is considered as a turning point among all health-related
events. However the intensive use of these “wonder drugs” has led to the development of antibiotic resistance
(AR). Wastewater treatment plants seem to be among the hot spots for the development of AR specifically the
biological treatment process may be a suitable environment for resistance development. In spite of growing
interest in the fate of AR in biological treatment processes, the effects of operational conditions are still
unknown.
In this research, the effects of solids retention time (SRT) on the occurrence and proliferation of antibiotic
resistant bacteria (ARB) and antibiotic resistant genes (ARGs) are going to be evaluated. Four sequencing
batch reactors receiving the primary effluent of a local wastewater treatment facility in Las Vegas Valley will
be used to run with different SRTs in order to evaluate the fate of ARB and ARGs. Five different antibiotics,
including tetracycline, ampicillin, sulfamethoxazole, trimethoprim and vancomycin and also various
combinations are going to be used in this research. The sludge and the effluent from the reactors are going to
be tested for ARB and ARGs. In order to perform the test, a selective culture media supplemented with
antibiotics will be utilized to isolate the ARBs. Then, isolated ARBs are going to be tested for minimal
inhibitory concentration (MIC). Molecular analysis is going to be performed via quantitative polymerase chain
reaction (qPCR) in order to evaluate the ARGs in uncultured bacteria and also quantify the total pool of
resistance determinants.