scholarly journals Norovirus Persistence in Oysters to Prolonged Commercial Purification

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 944
Author(s):  
Roberta Battistini ◽  
Chiara Masotti ◽  
Valeria Listorti ◽  
Elisabetta Suffredini ◽  
Cristiana Maurella ◽  
...  

Depuration is generally the main treatment employed for bivalve mollusks harvested from contaminated sites. Commercial depuration has demonstrated to be effective for removal of bacterial pathogens, although it probably provides only limited efficacy against human enteric viruses. We evaluated the quantitative reduction of norovirus (NoV) genogroups I and II in naturally contaminated oysters after 1, 4, and 9 days of depuration. The process was conducted in an authorized depuration plant, and NoV concentration was determined by RT-qPCR according to ISO 15216-1:2017 method. Regardless of the NoV genogroup, our results showed no significant reduction in NoV concentration after 1 day of depuration. Higher mean reduction (68%) was obtained after 4 days of treatment, while no further increase was observed after 9 days. Overall, reduction was highly variable, and none of the trials showed statistically significant reduction in NoV RNA concentration at the end of each depuration period. Indeed, NoV concentration remained high in 70% of samples even after 9 days of depuration, with values ranging between 4.0 × 102 and 2.3 × 104 g.c./g. These results indicate that an extension of commercial depuration time does not appear to be effective for reducing or eliminating NoV in oysters.

2008 ◽  
Vol 54 (6) ◽  
pp. 472-478 ◽  
Author(s):  
Annie Locas ◽  
Christine Barthe ◽  
Aaron B. Margolin ◽  
Pierre Payment

To verify previous conclusions on the use of bacterial indicators suggested in regulations and to investigate virological quality of groundwater, a 1-year study was undertaken on groundwater used as a source of drinking water in 3 provinces in Canada. Raw water from 25 municipal wells was sampled during a 1-year period for a total of 167 samples. Twenty-three sites were selected on the basis of their excellent historical bacteriological water quality data, and 2 sites with known bacteriological contamination were selected as positive controls. Water samples were analyzed for general water quality indicators (aerobic endospores, total coliforms), fecal indicators ( Escherichia coli , enterococci, somatic and male-specific coliphages), total culturable human enteric viruses (determined by cell culture and immunoperoxidase), noroviruses (analyzed by reverse-transcriptase – polymerase chain reaction (RT–PCR)), adenovirus types 40 and 41 (analyzed by integrated cell culture (ICC) – PCR), and enteroviruses and reoviruses types 1, 2, and 3 (analyzed by ICC–RT–PCR). General water quality indicators were found very occasionally at the clean sites but were frequently present at the 2 contaminated sites. Only one of 129 samples from the 23 clean sites was positive for enterococci. These results confirm the value of raw water quality historical data to detect source water contamination affecting wells that are vulnerable. Samples from the 2 contaminated sites confirmed the frequent presence of fecal indicators: E. coli was found in 20/38 samples and enterococci in 12/38 samples. Human enteric viruses were not detected by cell culture on MA-104 cells nor by immunoperoxidase detection in any sample from the clean sites but were found at one contaminated site. By ICC–RT–PCR and ICC–PCR, viruses were found by cytopathic effect in one sample from a clean site and they were found in 3 samples from contaminated sites. The viruses were not detected by the molecular methods but were confirmed as picornaviruses by electron microscopy. Noroviruses were not detected in any samples. The results obtained reinforce the value of frequent sampling of raw water using simple parameters: sampling for total coliforms and E. coli remains the best approach to detect contamination of source water by fecal pollutants and accompanying pathogens. The absence of total coliforms at a site appears to be a good indication of the absence of human enteric viruses.


1978 ◽  
Vol 41 (9) ◽  
pp. 743-754 ◽  
Author(s):  
CHARLES P. GERBA ◽  
SAGAR M. GOYAL

During feeding, bivalve mollusks (oysters, mussels and clams) can accumulate pathogenic human enteric viruses when present in sewage-polluted seawater. It has been well established that infectious hepatitis virus is transmitted by consumption of raw or inadequately cooked shellfish. But because of the lack of epidemiologic techniques, transmission of other enteric viruses by shellfish has not been established. Other enteric viruses, such as polio, echo, coxsackie and reo, have been detected in shellfish. Enteroviruses have been detected in shellfish taken from both “open” and “closed” areas, based on bacteriological standards used at present in the United States. Field and laboratory studies have indicated that enteric viruses can survive for long periods in seawater and in shellfish. Recent advances in methodology have led to development of more rapid and less expensive methods for detection of a greater number of enteric viruses in shellfish.


2011 ◽  
Vol 84 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Kristen E. Gibson ◽  
Yayi Guo ◽  
James T. Schissler ◽  
Melissa C. Opryszko ◽  
Kellogg J. Schwab

2007 ◽  
Vol 53 (6) ◽  
pp. 688-694 ◽  
Author(s):  
Annie Locas ◽  
Christine Barthe ◽  
Benoit Barbeau ◽  
Annie Carrière ◽  
Pierre Payment

A 1 year study was undertaken on groundwater that was a source of drinking water in the province of Quebec, Canada. Twelve municipal wells (raw water) were sampled monthly during a 1 year period, for a total of 160 samples. Using historic data, the 12 sites were categorized into 3 groups: group A (no known contamination), group B (sporadically contaminated by total coliforms), and group C (historic and continuous contamination by total coliforms and (or) fecal coliforms). Bacterial indicators (total coliform, Escherichia coli , enteroccoci), viral indicators (somatic and male-specific coliphages), total culturable human enteric viruses, and noroviruses were analyzed at every sampling site. Total coliforms were the best indicator of microbial degradation, and coliform bacteria were always present at the same time as human enteric viruses. Two samples contained human enteric viruses but no fecal pollution indicators (E. coli, enterococci, or coliphages), suggesting the limited value of these microorganisms in predicting the presence of human enteric viruses in groundwater. Our results underline the value of historic data in assessing the vulnerability of a well on the basis of raw water quality and in detecting degradation of the source. This project allowed us to characterize the microbiologic and virologic quality of groundwater used as municipal drinking water sources in Quebec.


2018 ◽  
Vol 11 (1) ◽  
pp. 52-64 ◽  
Author(s):  
Laetitia Kaas ◽  
Leslie Ogorzaly ◽  
Gaël Lecellier ◽  
Véronique Berteaux-Lecellier ◽  
Henry-Michel Cauchie ◽  
...  

2010 ◽  
Vol 50 (5) ◽  
pp. 462-467 ◽  
Author(s):  
L. Serracca ◽  
M. Verani ◽  
R. Battistini ◽  
I. Rossini ◽  
A. Carducci ◽  
...  

2000 ◽  
Vol 66 (8) ◽  
pp. 3241-3248 ◽  
Author(s):  
F. Le Guyader ◽  
L. Haugarreau ◽  
L. Miossec ◽  
E. Dubois ◽  
M. Pommepuy

ABSTRACT The main pathogenic enteric viruses able to persist in the environment, such as hepatitis A virus (HAV), Norwalk-like virus (NLV), enterovirus (EV), rotavirus (RV), and astrovirus (AV), were detected by reverse transcription-PCR and hybridization in shellfish during a 3-year study. Oyster samples (n = 108), occasionally containing bacteria, were less frequently contaminated, showing positivity for AV (17%), NLV (23%), EV (19%), and RV (27%), whereas mussel samples, collected in areas routinely impacted by human sewage, were more highly contaminated: AV (50%), HAV (13%), NLV (35%), EV (45%), and RV (52%). Sequences obtained from HAV and NLV amplicons showed a great variety of strains, especially for NLV (strains close to Mexico, Snow Mountain Agent, or Norwalk virus). Viral contamination was mainly observed during winter months, although there were some seasonal differences among the viruses. This first study of virus detection over a fairly long period of time suggests that routine analysis of shellfish by a molecular technique is feasible.


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