Mechanistic Study of Coxsackievirus B5 Inactivation by Chlorine
Advisor: Professor Benito J. Mariñas
Date: Friday Oct 14th, 1 pm.
Location: Hydro 2015
Zoom: https://illinois.zoom.us/j/87955158437?pwd=amxZQmd3ZEY0cll6YldNanRGanBWZz09 (Meeting ID: 879 5515 8437. Password: 106823)
Abstract: Disinfection is the most important water treatment technology to achieve safe drinking water. Waterborne viruses have significant implications on public health. US Environmental Protection Agency (USEPA) requires 4-log removal of enteric viruses. Chlorine, including free chlorine and chloramine (mainly monochloramine), are two commonly used disinfectants for their relatively low price and disinfection efficiency. Coxsackievirus B5 (CVB5), a single-stranded RNA virus, is one of the most resistant viruses to free chlorine treatment and is also resistant to monochloramine treatment. Human Adenovirus Serotype 2 (HAdV-2), a double-stranded DNA virus, is the most resistant virus to monochloramine treatment while having low resistance to free chlorine. On the basis of available HAdV-2 studies, studies of CVB5 inactivation by free chlorine or monochloramine were performed on the kinetics and molecular mechanism levels. Inactivation kinetics of CVB5 inactivation by free chlorine and monochloramine at various pH and temperature conditions were examined and dependence of the inactivation rates on water temperature and pH was found. Mathematical models were built based on the CVB5 free chlorine and monochloramine inactivation data to predict the CVB5 inactivation kinetics in pH and temperature ranges relevant to water treatment and comparison was made to data available in the literature. The gene integrity damage of CVB5 by free chlorine or monochloramine was examined by reverse transcriptase quantitative PCR with approximately 100 or 1000-base amplicons, and the effect of free chlorine or monochloramine treatment on several CVB5 replication cycle events was also investigated. It was found that after chlorine treatment, CVB5 gene integrity was partially damaged, the attachment to BGMK cells were partially inhibited, and the gene replication in BGMK cells were completely inhibited. The results were compared to previous HAdV-2 studies to provide a comprehensive picture of CVB5 and HAdV-2 inactivation by free chlorine and monochloramine in the aspect of kinetics, genome damage, and replication cycle events. Future legislation on water disinfection will benefit from these studies. Furthermore, a previous study successfully developed an aptamer sensor that selectively detected infectious HAdV-2 only. The results of this dissertation support the development of an aptamer sensor for CVB5.