Characterisation of norovirus contamination in an Irish shellfishery using real-time RT-qPCR and sequencing analysis

Rajko-Nenow, Paulina; Keaveney, Sinéad; Flannery, John; O'Flaherty, Vincent; Doré, William

doi:10.1016/j.ijfoodmicro.2012.10.001

Cited by 26 publications

(16 citation statements)

References 56 publications

(45 reference statements)

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“…In contrast, NoV GI.4 was the dominant genotype detected in effluent wastewater and oysters. This is consistent with a previous study by this laboratory in which NoV GI.4 was the predominant genotype detected in oysters originating from a commercial harvest area (47). In this study, the NoV GI.1 and GII.3 genotypes were absent in wastewater but were detected in oyster samples, and this could possibly be linked with their preferential accumulation in oyster tissues, which has been reported previously (48).…”

Section: Fig 2 Molecular Characterization Ofsupporting

confidence: 93%

Norovirus Genotypes Present in Oysters and in Effluent from a Wastewater Treatment Plant during the Seasonal Peak of Infections in Ireland in 2010

Rajko-Nenow

Waters

Keaveney

et al. 2013

Appl Environ Microbiol

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We determined norovirus (NoV) concentrations in effluent from a wastewater treatment plant and in oysters during the peak period of laboratory-confirmed cases of NoV infection in Ireland in 2010 (January to March). Weekly samples of influent, secondary treated effluent, and oysters were analyzed using real-time quantitative reverse transcription-PCR for NoV genogroup I (GI) and genogroup II (GII). The mean concentration of NoV GII (5.87 × 104genome copies 100 ml−1) in influent wastewater was significantly higher than the mean concentration of NoV GI (1.40 × 104genome copies 100 ml−1). The highest concentration of NoV GII (2.20 × 105genome copies 100 ml−1) was detected in influent wastewater during week 6. Over the study period, a total of 931 laboratory-confirmed cases of NoV GII infection were recorded, with the peak (n= 171) occurring in week 7. In comparison, 16 cases of NoV GI-associated illness were reported during the study period. In addition, the NoV capsid N/S domain was molecularly characterized for selected samples. Multiple genotypes of NoV GI (GI.1, GI.4, GI.5, GI.6, and GI.7) and GII (GII.3, GII.4, GII.6, GII.7, GII.12, GII.13, and GII.17), as well as 4 putative recombinant strains, were detected in the environmental samples. The NoV GII.4 variant 2010 was detected in wastewater and oyster samples and was the dominant strain detected in NoV outbreaks at that time. This study demonstrates the diversity of NoV genotypes present in wastewater during a period of high rates of NoV infection in the community and highlights the potential for the environmental spread of multiple NoV genotypes.

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Section: Fig 2 Molecular Characterization Ofsupporting

confidence: 93%

Norovirus Genotypes Present in Oysters and in Effluent from a Wastewater Treatment Plant during the Seasonal Peak of Infections in Ireland in 2010

Rajko-Nenow

Waters

Keaveney

et al. 2013

Appl Environ Microbiol

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“…Several studies have documented higher prevalences and levels of both NoV GI and NoV GII in commercially harvested shellfish during the winter (102,103,104,105,106,107), although some studies have reported no substantial summer-winter seasonality with respect to the prevalence of these genogroups in shellfish (108) and shellfish-growing waters (109). This discrepancy could be due to high fluxes of sewage contamination throughout the year in the latter study sites.…”

Section: Seasonal and Environmental Influencesmentioning

confidence: 86%

Environmental Transmission of Human Noroviruses in Shellfish Waters

Campos

Lees

2014

Appl Environ Microbiol

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Human noroviruses (NoV) are the most common cause of epidemic gastroenteritis following consumption of bivalve shellfish contaminated with fecal matter. NoV levels can be effectively reduced by some sewage treatment processes such as activated sludge and membrane bioreactors. However, tertiary sewage treatment and substantial sewage dilution are usually required to achieve low concentrations of virus in shellfish. Most outbreaks have been associated with shellfish harvested from waters affected by untreated sewage from, for example, storm overflows or overboard disposal of feces from boats. In coastal waters, NoV can remain in suspension or associate with organic and inorganic matter and be accumulated by shellfish. Shellfish take considerably longer to purge NoV than fecal indicator bacteria when transferred from sewage-polluted estuarine waters to uncontaminated waters. The abundance and distribution of NoV in shellfish waters are influenced by the levels of sewage treatment, proximity of shellfish beds to sewage sources, rainfall, river flows, salinity, and water temperature. Detailed site-specific information on these factors is required to design measures to control the viral risk.

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“…A previously described RT-qPCR was performed using RNA Ultrasense™ one-step quantitative RT-PCR system (Invitrogen, USA) on an AB7500 real-time PCR instrument (Applied Biosystems, USA) [14]. For NoV GI analysis, forward primer QNIF4 [15], reverse primer NV1LCR, and probe NVGG1p [16] were used, and for NoV GII, forward primer QNIF2 [17], reverse primer COG2R [18], and probe QNIFS [17] were used.…”

Section: Methodsmentioning

confidence: 99%

Norovirus genotypes implicated in two oyster-related illness outbreaks in Ireland

et al. 2013

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We investigated norovirus (NoV) concentrations and genotypes in oyster and faecal samples associated with two separate oyster-related outbreaks of gastroenteritis in Ireland. Quantitative analysis was performed using real-time quantitative reverse transcription polymerase chain reaction and phylogenetic analysis was conducted to establish the NoV genotypes present. For both outbreaks, the NoV concentration in oysters was >1000 genome copies/g digestive tissue and multiple genotypes were identified. In faecal samples, GII.13 was the only genotype detected for outbreak 1, whereas multiple genotypes were detected in outbreak 2 following the application of cloning procedures. While various genotypes were identified in oyster samples, not all were successful in causing infection in consumers. In outbreak 2 NoV GII.1 was identified in all four faecal samples analysed and NoV GII concentrations in faecal samples were >108 copies/g. This study demonstrates that a range of NoV genotypes can be present in highly contaminated oysters responsible for gastroenteritis outbreaks.

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Characterisation of norovirus contamination in an Irish shellfishery using real-time RT-qPCR and sequencing analysis

Cited by 26 publications

References 56 publications

Norovirus Genotypes Present in Oysters and in Effluent from a Wastewater Treatment Plant during the Seasonal Peak of Infections in Ireland in 2010

Norovirus Genotypes Present in Oysters and in Effluent from a Wastewater Treatment Plant during the Seasonal Peak of Infections in Ireland in 2010

Environmental Transmission of Human Noroviruses in Shellfish Waters

Norovirus genotypes implicated in two oyster-related illness outbreaks in Ireland

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