title: Evaluation of the porcine gastric mucin binding assay for high-pressure-inactivation studies using murine norovirus and tulane virus.
abstract: We compared the results of high-hydrostatic-pressure (HHP) inactivation of murine norovirus type 1 (MNV-1) and Tulane virus (TV) obtained by a porcine gastric mucin binding assay followed by quantitative reverse transcription-PCR (referred to here as the PGM-MB/PCR assay) and a plaque assay and evaluated HHP inactivation of a human norovirus (HuNoV) genogroup I genotype 1 (GI.1) strain and a HuNoV GII.4 strain by using the PGM-MB/PCR assay. Viruses were treated at different pressure levels for 2 min at 4 or 21°C in culture medium of neutral pH and in culture medium of pH 4 at 21°C. The log reductions of infectious MNV-1 and TV particles caused by HHP were assessed using the PGM-MB/PCR and plaque assays, while the log reductions of HuNoVs were assessed by the PGM-MB/PCR assay only. For TV and MNV-1, the two pressure inactivation curves obtained using the plaque and PGM-MB/PCR assays were almost identical at ≤2-log-reduction levels regardless of the treatment temperature and pH. Further increasing the pressure over the 2-log-reduction level resulted in higher log reductions of TV and MNV-1, as assessed by the plaque assay, but did not increase the log reductions, as assessed by the PGM-MB/PCR assay. HHP treatments could achieve maximum reductions of ∼3 and 3.5 log units for GI.1 and GII.4, respectively, as assessed by the PGM-MB/PCR assay. On the basis of these results, it can reasonably be concluded that the PGM-MB/PCR assay would very likely be able to estimate HHP inactivation of HuNoV at ≤2-log-reduction levels. It would also likely conservatively quantify HHP inactivation of the GI.1 strain at 2- to 3-log-reduction levels and the GII.4 strain at 2- to 3.5-log-reduction levels.
authors.affiliation: Department of Animal and Food Sciences, University of Delaware, Newark, Delaware, USA.
authors.forename: Xinhui
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Animal and Food Sciences, University of Delaware, Newark, Delaware, USA haiqiang@udel.edu.
authors.forename: Haiqiang
authors.initials: H
authors.lastname: Chen
mesh_terms: D000818:Animals; D002139:Caliciviridae / Q000502:physiology*; D004203:Disinfection / Q000379:methods*; D005752:Gastric Mucins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006874:Hydrostatic Pressure; D050296:Microbial Viability; D060888:Real-Time Polymerase Chain Reaction; D013552:Swine; D013696:Temperature; D010948:Viral Plaque Assay; D014773:Virology / Q000379:methods*
chemical_list: D005752:Gastric Mucins