Masters Theses

Date of Award

5-2013

Degree Type

Thesis

Degree Name

Master of Science

Major

Food Science and Technology

Major Professor

Doris H. D'Souza

Committee Members

Svetlana Zivanovic, Irene Hanning

Abstract

Human noroviruses (HNoVs) are considered the leading cause of acute non-bacterial gastroenteritis worldwide. Effective chemical disinfectants to inactivate HNoVs are needed. Since HNoVs cannot be cultivated in the lab, cultivable surrogates, feline calicivirus (FCV-F9) and murine norovirus (MNV-1), are used to determine inactivation using infectivity plaque assays. This study aimed to: 1) determine the ability of benzalkonium chloride (BAC) and potassium peroxymonosulfate (KPMS) to inactivate FCV-F9 and MNV-1 in vitro using suspension and carrier tests under clean and simulated dirty (5% fetal bovine serum) conditions over 1 h at room temperature; 2) determine inactivation of FCV-F9 and MNV-1 in suspension and carrier tests over 1 h at room temperature by sodium metasilicate (SMS). In suspension tests, BAC caused 1.94 and 2.59 log reductions of low and high FCV-F9 titers after 1 h, respectively. MNV-1 at low and high titers was reduced by > 3and 1.47 logs with BAC after 1 h, respectively. KPMS at 5 and 10 mg/mL reduced low titers of both viruses to non-detectable levels within 30 s. High FCV-F9 titers were non-detectable after 2 min with 5 mg/mL and within 30 s with 10 mg/mL of KPMS. KPMS at 5 mg/mL had little effect against high titers of MNV-1, but caused a 4.61 log reduction after 5 min with 10 mg/mL of KPMS. Using clean carrier tests, KPMS at 5 and 10 mg/mL reduced both tested viruses at low titers after 30 s and only high FCV-F9 titers after 10 min to undetectable levels. MNV-1 at high titers were reduced to non-detectable levels after 15 min with 10 mg/mL KPMS. BAC reduced low titers of both viruses to undetectable levels after 1 h using carrier tests with no significant reduction of high titers even after 2 h. The antiviral effect of both chemicals decreased under simulated dirty conditions. Both viruses were reduced within 15 s by 5% and 10% SMS using suspension tests. FCV-F9 and MNV-1 at high titers were reduced to undetectable levels after 2 min and 15 s, respectively with 2% SMS. KPMS and SMS appear suitable for the rapid control of HNoV transmission.

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