Discrimination between infectious and non-infectious human norovirus using porcine gastric mucin

Model results indicated that the mean WWTP influent concentration of NoV GII (3.9 log 10 gc/liter; 95% credible interval [CI], 3.5, 4.3 log 10 gc/liter) is larger than the value for NoV GI (1.5 log 10 gc/liter; 95% CI, 0.4, 2.4 log 10 gc/liter), with large variations occurring from one WWTP to another. For WWTPs with mechanical systems and chlorine disinfection, mean log 10 reductions were ؊2.4 log 10 gc/liter (95% CI, ؊3.9, ؊1.1 log 10 gc/liter) for NoV GI, ؊2.7 log 10 gc/liter (95% CI, ؊3.6, ؊1.9 log 10 gc/liter) for NoV GII, and ؊2.9 log 10 PFU per liter (95% CI, ؊3.4, ؊2.4 log 10 PFU per liter) for MSCs. Comparable values for WWTPs with lagoon systems and chlorine disinfection were ؊1.4 log 10 gc/liter (95% CI, ؊3.3, 0.5 log 10 gc/liter) for NoV GI, ؊1.7 log 10 gc/liter (95% CI, ؊3.1, ؊0.3 log 10 gc/liter) for NoV GII, and ؊3.6 log 10 PFU per liter (95% CI, ؊4.8, ؊2.4 PFU per liter) for MSCs. Within WWTPs, correlations exist between mean NoV GI and NoV GII influent concentrations and between the mean log 10 reduction in NoV GII and the mean log 10 reduction in MSCs.H uman norovirus (NoV) is the leading cause of food-associated gastroenteritis in the United States (1) and Canada (2). U.S. residents are estimated to experience five episodes of norovirus gastroenteritis in their lifetimes (3). NoV is primarily spread via the fecal-oral route. However, attribution of a particular case of NoV illness to a specific source is complex. The transmission may be direct (person to person) or indirect (via contact with contaminated fomites) or may occur through the ingestion of contaminated food or water (4). Noroviruses are genetically diverse, comprising six genogroups (5), three of which (genogroup I [GI], GII, and GIV) are capable of causing illness in humans (6).Among foodborne NoV outbreaks, bivalve molluscs (e.g., clams, oysters, mussels), leafy vegetables, and fruits are the most frequently implicated (7). More than half of the norovirus outbreaks attributed to the consumption of bivalve molluscs in the United States during the years from 2001 to 2008 are believed to have originated from contamination during production or processing (7). Bivalve molluscan shellfish typically grow in estuaries, which may contain NoV-contaminated human fecal material from municipal wastewater outfalls, combined sewer overflow, or nonpoint sources of pollution, including human waste discharged from marine vessels (8, 9). Bivalve molluscan shellfish feed on algae from the surrounding water. During this feeding process, each bivalve mollusc may filter 20 to 90 liters of water per day and bioaccumulate a variety of microorganisms, including viruses and bacteria that are associated with pollution sources (8,(10)(11)(12). Significantly, molluscan shellfish have been found to retain viruses to a greater extent and for much longer periods than they do bacteria (8,13,14). Bivalve molluscs, therefore, may become contaminated with NoV when they are grown in harvesting areas contaminated with human wastes.In the United States and in Canada, ar...

Section: Discussionmentioning

confidence: 99%

Meta-Analysis of the Reduction of Norovirus and Male-Specific Coliphage Concentrations in Wastewater Treatment Plants

Pouillot

Doren

Woods

et al. 2015

“…Interestingly, it was found that porcine gastric mucin (PGM) contains HBGAs type A, type H1, and Lewis b and can be used as a source of HuNoV receptors (23). Based on this theory, a PGM magnetic bead (PGM-MB) binding assay was developed to detect intact HuNoV (25,26). It was found that HuNoVs GI.1 and GII.4 bound efficiently to PGM-MB (26,27).…”

mentioning

confidence: 99%

Variable High-Pressure-Processing Sensitivities for Genogroup II Human Noroviruses

Lou

DiCaprio

et al. 2016

Self Cite

Human norovirus (HuNoV) is a leading cause of foodborne diseases worldwide. High-pressure processing (HPP) is one of the most promising nonthermal technologies for the decontamination of viral pathogens in foods. However, the survival of HuNoVs after HPP is poorly understood because these viruses cannot be propagated in vitro. In this study, we estimated the survival of different HuNoV strains within genogroup II (GII) after HPP treatment using viral receptor-binding ability as an indicator. Four HuNoV strains (one GII genotype 1 [GII.1] strain, two GII.4 strains, and one GII.6 strain) were treated at high pressures ranging from 200 to 600 MPa. After treatment, the intact viral particles were captured by porcine gastric mucin-conjugated magnetic beads (PGM-MBs) that contained histo-blood group antigens, the functional receptors for HuNoVs. The genomic RNA copies of the captured HuNoVs were quantified by real-time reverse transcriptase PCR (RT-PCR). Two GII.4 HuNoVs had similar sensitivities to HPP. The resistance of HuNoV strains against HPP ranked as follows: GII.1 > GII.6 > GII.4, with GII.4 being the most sensitive. Evaluation of temperature and matrix effects on HPP-mediated inactivation of HuNoV GII.4, GII.1, and GII.6 strains showed that HuNoV was more easily inactivated at lower temperatures and at a neutral pH. In addition, phosphate-buffered saline (PBS) and minimal essential medium (MEM) can provide protective effects against HuNoV inactivation compared to H 2 O. Collectively, this study demonstrated that (i) different HuNoV strains within GII exhibited different sensitivities to high pressure, and (ii) HPP is capable of inactivating HuNoV GII strains by optimizing pressure parameters. IMPORTANCEHuman norovirus (HuNoV) is a leading cause of foodborne disease worldwide. Noroviruses are highly diverse, both antigenically and genetically. Genogroup II (GII) contains the majority of HuNoVs, with GII genotype 4 (GII.4) being the most prevalent. Recently, GII.1 and GII.6 have emerged and caused many outbreaks worldwide. However, the survival of these GII HuNoVs is poorly understood because they are uncultivable in vitro. Using a novel receptor-binding assay conjugated with real-time RT-PCR, we found that GII HuNoVs had variable susceptibilities to high-pressure processing (HPP), which is one of the most promising food-processing technologies. The resistance of HuNoV strains to HPP ranked as follows: GII.1 > GII.6 > GII.4. This study highlights the ability of HPP to inactivate HuNoV and the need to optimize processing conditions based on HuNoV strain variability and sample matrix.

“…Dancho et al demonstrated that the viral RNA signals derived from viral capture by PGM-conjugated magnetic beads were significantly reduced when HuNoV was treated by HPP and by heat inactivation (12). However, in the MNV model, when both cellular receptor and the ganglioside GD1a (receptor for MNV) were tested in a receptormediated capture qRT-PCR assay to evaluate the inactivation status of MNV, there was no correlation between the inactivation measured by tissue culture-based assay (plaque assay) and cellular receptor-based or ganglioside-based capture qRT-PCR (13).…”

Section: Discussionmentioning

confidence: 99%

“…Recently, receptor binding-based assays have been explored for inactivation studies. Dancho et al demonstrated that the viral RNA signals derived from HuNoV captured by PGM-conjugated magnetic beads were significantly reduced when HuNoV was treated by HPP and by heat inactivation (12). However, the results measured by this HBGA-conjugated capture qRT-PCR method for HuNoV could not be confirmed by tissue culture-based infectivity assays.…”

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confidence: 99%

New In Situ Capture Quantitative (Real-Time) Reverse Transcription-PCR Method as an Alternative Approach for Determining Inactivation of Tulane Virus

Wang

Yang

et al. 2014

We found that the ISC-qRT-PCR method could be used to evaluate virus inactivation deriving from damage to the capsid and study interactions between the capsid and viral receptor. Heat, chlorine, and ethanol treatment primarily affect the capsid structure, which in turns affects the ability of the capsid to bind to viral receptors. Inactivation of the virus by these methods could be reflected by the ISCqRT-PCR method and confirmed by TCID 50 assay. However, the loss of the infectivity caused by damage to the viral genome (such as that from UV irradiation) could not be effectively reflected by this method. Despite this limitation, the ISC-qRT-PCR provides an alternative approach to determine inactivation of Tulane virus. A particular advantage of the ISC-qRT-PCR method is that it is also a faster and easier method to effectively recover and detect the viruses, as there is no need to extract viral RNA or to transfer the captured virus from magnetic beads to PCR tubes for further amplification. Therefore, ISC-qRT-PCR can be easily adapted for use in automated systems for multiple samples.