Round-Robin Comparison of Methods for the Detection of Human Enteric Viruses in Lettuce

2004 ◽  
Vol 67 (10) ◽  
pp. 2315-2319 ◽  
Author(s):  
FRANÇOISE S. LE GUYADER ◽  
ANNA-CHARLOTTE SCHULTZ ◽  
LARISSA HAUGARREAU ◽  
LUCIANA CROCI ◽  
LEENA MAUNULA ◽  
...  
Keyword(s):  
Low Cost ◽  
Enteric Virus ◽  
Virus Contamination ◽  
Human Enteric Virus ◽  
Sewage Contamination ◽  
Concentration Step ◽  
Human Enteric Viruses ◽  
Reliable Methods ◽  
Virus Strains ◽  
Commercial Kit

Five methods that detect human enteric virus contamination in lettuce were compared. To mimic multiple contaminations as observed after sewage contamination, artificial contamination was with human calicivirus and poliovirus and animal calici-virus strains at different concentrations. Nucleic acid extractions were done at the same time in the same laboratory to reduce assay-to-assay variability. Results showed that the two critical steps are the washing step and removal of inhibitors. The more reliable methods (sensitivity, simplicity, low cost) included an elution/concentration step and a commercial kit. Such development of sensitive methods for viral detection in foods other than shellfish is important to improve food safety.

Demonstration of Viral Contamination of Oysters Responsible for an Outbreak of Viral Gastroenteritis

1981 ◽  
Vol 44 (4) ◽  
pp. 294-296 ◽  
Author(s):  
M. J. EYLES ◽  
G. R. DAVEY ◽  
E. J. HUNTLEY
Keyword(s):  
Causative Agent ◽  
Enteric Virus ◽  
Fecal Specimen ◽  
Viral Gastroenteritis ◽  
Norwalk Virus ◽  
Viral Contamination ◽  
Virus Contamination ◽  
Human Enteric Virus ◽  
Viral Illness ◽  
Echovirus Type

Two viruses, echovirus type 8 and a reovirus, were isolated from a batch of oysters responsible for an outbreak of gastroenteritis. Characteristics of the illness, detection of Norwalk virus in the feces of one of the victims and other factors indicated strongly that the illness was due to infection with Norwalk virus. Examination of the implicated oysters and a fecal specimen from a victim failed to provide evidence of the involvement of any other causative agent. Thus laboratory evidence of human enteric virus contamination of a batch of food responsible for a viral illness has been provided.

Specific interactions of rotavirus HAL1166 with Enterobacter cloacae SENG-6 and their contribution on rotavirus HAL1166 removal

2019 ◽  
Vol 79 (2) ◽  
pp. 342-348 ◽  
Author(s):  
Mohan Amarasiri ◽  
Hiroki Kawai ◽  
Masaaki Kitajima ◽  
Satoshi Okabe ◽  
Daisuke Sano
Keyword(s):  
Suspended Solids ◽  
Cross Flow ◽  
Enteric Viruses ◽  
Enteric Virus ◽  
Enterobacter Cloacae ◽  
Specific Interactions ◽  
Virus Removal ◽  
Human Enteric Virus ◽  
Cake Layer ◽  
Human Enteric Viruses

Abstract Contribution of specific interactions between human enteric viruses and wastewater suspended solids on human enteric virus removal by microfiltration was studied. A cross-flow microfiltration system was used with rotavirus HAL1166 and Enterobacter cloacae SENG-6 as the model virus and wastewater suspended solid. Cleavage of rotavirus HAL1166 protein VP4 by trypsin produces the VP8* subunit, which specifically interacts with histo-blood group antigen (HBGA). In the presence of Enterobacter cloacae SENG-6, the trypsin-treated rotavirus concentration reduced with time (R2 > 0.6) compared to the reduction of non-trypsin treated rotavirus. Calculation of the gel/cake layer deposited on the membrane, consisting of Enterobacter cloacae SENG-6 and either trypsin-treated or non-trypsin treated rotavirus HAL1166, revealed that the microflocs consisting of trypsin-treated rotavirus and Enterobacter cloacae SENG-6 have lower porosity and permeability, displaying higher resistance to virus passage through the membrane. The results provide evidence that specific wastewater suspended solids–human enteric virus interaction can contribute to increasing the removal of human enteric viruses by microfiltration.

Monitoring the marine environment for small round structured viruses (SRSVS): a new approach to combating the transmission of these viruses by molluscan shellfish

1998 ◽  
Vol 38 (12) ◽  
pp. 51-56 ◽  
Author(s):  
K. Henshilwood ◽  
J. Green ◽  
D. N. Lees
Keyword(s):  
Enteric Virus ◽  
Winter Period ◽  
Rt Pcr ◽  
Cloning And Sequencing ◽  
New Approach ◽  
Human Enteric Virus ◽  
Different Strains ◽  
The Uk ◽  
Public Health Protection

This study investigates human enteric virus contamination of a shellfish harvesting area. Samples were analysed over a 14-month period for Small Round Structured Viruses (SRSVs) using a previously developed nested RT-PCR. A clear seasonal difference was observed with the largest numbers of positive samples obtained during the winter period (October to March). This data concurs with the known winter association of gastroenteric illness due to oyster consumption in the UK and also with the majority of the outbreaks associated with shellfish harvested from this area during the study period. RT-PCR positive amplicons were further characterised by cloning and sequencing. Sequence analysis of the positive samples identified eleven SRSV strains, of both Genogroup I and Genogroup II, occurring throughout the study period. Many shellfish samples contained a mixture of strains with a few samples containing up to three different strains with both Genogroups represented. The observed common occurrence of strain mixtures may have implications for the role of shellfish as a vector for dissemination of SRSV strains. These results show that nested RT-PCR can identify SRSV contamination in shellfish harvesting areas. Virus monitoring of shellfish harvesting areas by specialist laboratories using RT-PCR is a possible approach to combating the transmission of SRSVs by molluscan shellfish and could potentially offer significantly enhanced levels of public health protection.

scholarly journals Detection of multiple enteric virus strains within a foodborne outbreak of gastroenteritis: an indication of the source of contamination

2004 ◽  
Vol 133 (1) ◽  
pp. 41-47 ◽  
Author(s):  
C. I. GALLIMORE ◽  
C. PIPKIN ◽  
H. SHRIMPTON ◽  
A. D. GREEN ◽  
Y. PICKFORD ◽  
...  
Keyword(s):  
Arabian Gulf ◽  
Enteric Virus ◽  
Multiple Infections ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Epidemiological Analysis ◽  
Viral Aetiology ◽  
Polymerase Chain ◽  
Most Probable Explanation ◽  
Virus Strains

An outbreak of acute gastroenteritis of suspected viral aetiology occurred in April 2003 in the British Royal Fleet Auxillary ship (RFA) Argus deployed in the Northern Arabian Gulf. There were 37 cases amongst a crew of 400 personnel. Of 13 samples examined from cases amongst the crew, six enteric viruses were detected by reverse transcriptase polymerase chain reaction (RT–PCR). Five different viruses were identified including, three norovirus genotypes, a sapovirus and a rotavirus. No multiple infections were detected. A common food source was implicated in the outbreak and epidemiological analysis showed a statistically significant association with salad as the source of the outbreak, with a relative risk of 3·41 (95% confidence interval of 1·7–6·81) of eating salad on a particular date prior to the onset of symptoms. Faecal contamination of the salad at source was the most probable explanation for the diversity of viruses detected and characterized.

Outbreaks of Shellfish-Associated Enteric Virus Illness in the United States: Requisite for Development of Viral Guidelines

1985 ◽  
Vol 48 (9) ◽  
pp. 815-823 ◽  
Author(s):  
GARY P. RICHARDS
Keyword(s):  
United States ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Enteric Virus ◽  
The United States ◽  
Viral Gastroenteritis ◽  
Norwalk Virus ◽  
Virus Contamination ◽  
Pathogenic Viruses

Outbreaks of hepatitis A, Norwalk illness, and nonspecific viral gastroenteritis are associated with consumption of sewage-contaminated shellfish. Over 100 outbreaks have been reported in the United States during the past 50 years. Reported cases of shellfish-associated enteric virus illness are on the increase, whereas bacterial illness from shellfish is on the decline. As yet, there are no procedures for detecting hepatitis A virus, Norwalk virus and numerous other pathogenic viruses in environmental samples, but virus extraction and assay procedures for water and shellfish are available for the more easily cultivated enteric viruses. Current standards rely on bacterial indicators as a means to evaluate the sanitary quality of shellfish and their growing waters, but the adequacy of using bacteria as indicators of possible virus contamination is questionable. The feasibility of employing enteroviruses or rotaviruses as possible viral indiators is discussed. It is proposed that easily cultivated enteroviruses, such as poliovirus, be used as an interim indicator for the possible presence of human pathogenic viruses in seafoods, with the subsequent formulation of guidelines to limit the levels of virus contamination in shellfish.

Microbial Purification of Shellfish: A Review of Depuration and Relaying

1988 ◽  
Vol 51 (3) ◽  
pp. 218-251 ◽  
Author(s):  
GARY P. RICHARDS
Keyword(s):  
Enteric Virus ◽  
Intestinal Cells ◽  
Review Of The Literature ◽  
Indicator Microorganisms ◽  
Virus Contamination ◽  
Pathogenic Viruses ◽  
Proper Design ◽  
Flow Through ◽  
Low Levels ◽  
Vibrio Spp

A review of the literature on shellfish depuration and relaying revealed wide diversity in microbial uptake and elimination among shellfish species and for different microorganisms. Information on relaying of five commercial shellfish species and on controlled purification (depuration) of 11 species indicates that such processes are effective in reducing the levels of bioconcentrated bacteria and viruses from shellfish. The degree of bacterial and viral bioconcentration varies with shellfish species; however, the primary sites of bioconcentration are the hepatopancreas and digestive diverticula. Low levels of enteric viruses and coliphage may be sequestered in shellfish hemolymph and tissues, thus protecting them from elimination through depurative processes. Vibrio spp. appear to proliferate when closely associated with intestinal cells of shellfish. Shellfish relaying techniques offer effective microbial depletion provided water quality is acceptable and shellfish remain physiologically active. The current body of literature on controlled purification demonstrates a broad spectrum of conditions under which shellfish are depurated. Optimal times, temperatures and salinities for effective depuration vary among shellfish species. Proper design and operation of depuration plants is crucial to insure process integrity. Recirculating and flow-through purification systems are effective in reducing the levels of pathogenic and indicator microorganisms from shellfish, but the extent to which they reduce viruses from shellfish is uncertain. Studies are needed to validate the effectiveness of depuration processes in eliminating pathogenic viruses and to address the adequacy of indicator bacteria as measures of enteric virus contamination.

Bacteriophages and bacteria as indicators of enteric viruses in oysters and their harvest waters

1998 ◽  
Vol 38 (12) ◽  
pp. 37-44 ◽  
Author(s):  
H. Chung ◽  
L.-A. Jaykus ◽  
G. Lovelace ◽  
M. D. Sobsey
Keyword(s):  
Enteric Viruses ◽  
Enteric Virus ◽  
Indicator Bacteria ◽  
Faecal Coliforms ◽  
Rt Pcr ◽  
E Coli ◽  
Virus Contamination ◽  
Receiving Waters ◽  
Male Specific ◽  
Receiving Water

Reliable indicators are needed to detect enteric virus contamination of bivalve molluscan shellfish and their harvest waters. Concentrations of male-specific (F+) coliphages, Bacteroides fragilis phages, Salmonella phages and several indicator bacteria in wastewater, estuarine receiving water and its oysters were examined for their ability to predict the presence and levels of faecal contamination and enteric viruses in oysters. Enteric viruses in oysters were detected by cell culture and RT-PCR methods. F+ coliphages, Salmonella phages, B fragilis phages and faecal indicator bacteria (faecal coliforms, E coli, enterococci and Clostridium perfringens) were generally positively associated and were highest in raw sewage and progressively lower in sewage effluent and in receiving waters at increasing distance from the wastewater discharge. Indicator levels in oysters were highest for F+ coliphages and C perfringens. One F+ RNA coliphage serotype (Group II) predominated in the wastewater, receiving water and oysters. Human enteric viruses were detected in 17/31 oyster samples. The levels of most indicators in oysters and water were higher when oysters were enteric virus-positive and lower when oysters were enteric virus-negative. F+ coliphages and C perfringens were the only indicators significantly associated with the presence of enteric viruses in oysters. F+ coliphages and their serotypes are promising indicators of human enteric virus contamination in oysters and their harvest waters.

scholarly journals EVALUATION OF DIFFERENT TECHNIQUES FOR DNA DIRECT EXTRACTION FROM BRAZILIAN AGRICULTURAL SOIL

2010 ◽  
Vol 10 (1) ◽  
pp. 12 ◽  
Author(s):  
Márcia Maria Rosa ◽  
Sâmia Maria Tauk-Tornisielo ◽  
Sandra Regina Ceccato-Antonini
Keyword(s):  
Low Cost ◽  
Temperate Climate ◽  
Direct Extraction ◽  
Soil Biodiversity ◽  
Soil Dna ◽  
Dna Yield ◽  
Sugarcane Crop ◽  
Brazilian Soils ◽  
Great Complexity ◽  
Commercial Kit

Soil is an ecosystem characterized by a great complexity and hard to study due to its heterogeneity, especially the soil microorganism’s community. Currently, molecular biology tools have been used to study the soil biodiversity mainly through microbial genes. DNA Direct Extraction from soil is an important step in this kind of study, however the majority of techniques were developed for soils from temperate climate and just a few can be applied efficiently to Brazilian soils. This work aimed to evaluate nine different techniques for soil DNA direct extraction from sugarcane crop areas under organic and conventional managements and also to propose modifications which might result in higher DNA yield and low cost. DNA bands were observed only for three techniques (Selbach´s, Direito´s and commercial kit), two of them already tested for tropical climate soils. The best results for DNA yield (µg.g-1 soil) were obtained through Selbach´s and commercial kit techniques, however not differing statistically from those results through a protocol here proposed. This modified protocol showed the best results for DNA yield whatever soil was used. The best DNA yields were found in soil under organic management probably due to higher microbial biomass. This protocol showed better results in yield of DNA regardless of the soil used and was easier to perform and less costly.

Viable virus aerosol propagation by positive airway pressure (PAP) circuit leak and mitigation with a ventilated patient hood

2020 ◽  
pp. 2003666
Author(s):  
Shane A. Landry ◽  
Jeremy J. Barr ◽  
Martin I. MacDonald ◽  
Dinesh Subedi ◽  
Darren Mansfield ◽  
...  
Keyword(s):  
Airway Pressure ◽  
Respiratory Diseases ◽  
High Efficiency ◽  
Positive Airway Pressure ◽  
Low Cost ◽  
Dependent Manner ◽  
Virus Propagation ◽  
Infectious Risk ◽  
Virus Contamination ◽  
Dose Dependent

IntroductionNosocomial transmission of SARS-CoV-2 has been a major feature of the COVID-19 pandemic. Evidence suggests patients can auto-emit aerosols containing viable viruses, these aerosols could be further propagated when patients undergo certain treatments including continuous positive airway pressure (PAP) therapy. Our aim was to assess i) the degree of viable virus propagated from PAP circuit mask leak, ii) the efficacy of a ventilated plastic canopy to mitigate virus propagation.MethodsBacteriophage PhiX174 (108 copies·mL−1) was nebulised into a custom PAP circuit. Mask leak was systematically varied at the mask interface. Plates containing Escherichia coli host quantified viable virus (via plaque forming unit) settling on surfaces around the room. The efficacy of a low-cost ventilated headboard created from a tarpaulin hood and a high efficiency particulate air (HEPA) filter was tested.ResultsMask leak was associated with virus contamination in a dose-dependent manner (χ2=58.24, df=4, p<0.001). Moderate mask leak (≥21 L·min−1) was associated with virus counts equivalent to using PAP with a vented mask. The highest frequency of viruses was detected on surfaces 1 m away, however, viable viruses were recorded up to 3.86 m from the source. A plastic hood with HEPA filtration significantly reduced viable viruses on all plates. HEPA exchange rates ≥170 m3·hr−1 eradicated all evidence of virus contamination.ConclusionMask leak from PAP may be a major source of environmental contamination and nosocomial spread of infectious respiratory diseases. Subclinical mask leak levels should be treated as an infectious risk. Low-cost patient hoods with HEPA filtration are an effective countermeasure.

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