title: Analysis of the viral replication cycle of adenovirus serotype 2 after inactivation by free chlorine.
abstract: Free chlorine is effective at inactivating a wide range of waterborne viral pathogens including human adenovirus (HAdV), but the mechanisms by which free chlorine inactivates HAdV and other human viruses remain to be elucidated. Such advances in fundamental knowledge are key for development of new disinfection technologies and novel sensors to detect infectious viruses in drinking water. We developed and tested a quantitative assay to analyze several steps in the HAdV replication cycle upon increasing free chlorine exposure. We used quantitative polymerase chain reaction (qPCR) to detect HAdV genomic DNA as a means to quantify attachment and genome replication of untreated and treated virions. Also, we used quantitative reverse-transcription PCR (RT-qPCR) to quantify the transcription of E1A (first early protein) and hexon mRNA. We compared these replication cycle events to virus inactivation kinetics to determine what stage of the virus replication cycle was inhibited as a function of free chlorine exposure. We observed that adenovirus inactivated at levels up to 99.99% by free chlorine still attached to host cells; however, viral DNA synthesis and early E1A and late hexon gene transcription were inhibited. We conclude that free chlorine exposure interferes with a replication cycle event occurring postbinding but prior to early viral protein synthesis.
authors.affiliation: †Department of Civil and Environmental Engineering, ‡Department of Microbiology and College of Medicine, and §Safe Global Water Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
authors.forename: Aimee M
authors.initials: AM
authors.lastname: Gall
authors.affiliation: †Department of Civil and Environmental Engineering, ‡Department of Microbiology and College of Medicine, and §Safe Global Water Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
authors.forename: Joanna L
authors.initials: JL
authors.lastname: Shisler
authors.affiliation: †Department of Civil and Environmental Engineering, ‡Department of Microbiology and College of Medicine, and §Safe Global Water Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
authors.forename: Benito J
authors.initials: BJ
authors.lastname: Mariñas
mesh_terms: D000257:Adenoviridae Infections / Q000517:prevention & control* / Q000821:virology; D000260:Adenoviruses, Human / Q000187:drug effects* / Q000502:physiology; D002713:Chlorine / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D006801:Humans; D060888:Real-Time Polymerase Chain Reaction; D038301:Virus Inactivation / Q000187:drug effects*; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D004202:Disinfectants; D002713:Chlorine