1
|
Jarke C, Petereit A, Fehlhaber K, Braun PG, Truyen U, Albert T. Impact of Sodium Chloride, Sucrose and Milk on Heat Stability of the Murine Norovirus and the MS2 Phage. FOOD AND ENVIRONMENTAL VIROLOGY 2013; 5:135-143. [PMID: 23625486 DOI: 10.1007/s12560-013-9112-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 04/15/2013] [Indexed: 06/02/2023]
Abstract
Until now, little is known about the influence of food additives on heat inactivation of noroviruses. Only a few studies have shown a protective or inhibiting effect on virus infectivity caused by the food matrix. Therefore, the aim of this study was to examine the influence of sodium chloride, sucrose and milk on heat stability of the surrogates murine norovirus (MNV) and MS2 phage at 60 °C for 1-5 min in PBS for MNV and for 5-120 min in suspension medium buffer for MS2 phage. Different concentrations of sodium chloride (5, 10 %) and sucrose (5, 50 %) were added to the respective buffers. In addition, commercially available milk with different fat concentrations (0.3, 1.5, 3.5 %) was investigated in this study. In general, a linear titre reduction for MNV and MS2 phage could be observed, except for the heat treatment of MNV in PBS with 50 % sucrose. A protective effect of PBS with 50 % sucrose and of the matrix milk on MNV could be concluded. All other tested conditions did not show any influence on virus inactivation. However, MS2 phage did show a higher heat resistance throughout the experiments compared to MNV. In future investigations, it should be tested, whether the achieved data may be considered in risk assessments of heat-treated food products with high concentrations of sugar. Furthermore, it should be clarified, whether these results can also be referred to complex food matrices.
Collapse
Affiliation(s)
- Christina Jarke
- Faculty of Veterinary Medicine, Centre of Veterinary Public Health, Institute of Food Hygiene, Leipzig University, An den Tierkliniken 1, 04103, Leipzig, Germany,
| | | | | | | | | | | |
Collapse
|
2
|
Ajami N, Koo H, Darkoh C, Atmar RL, Okhuysen PC, Jiang ZD, Flores J, Dupont HL. Characterization of norovirus-associated traveler's diarrhea. Clin Infect Dis 2010; 51:123-30. [PMID: 20540620 DOI: 10.1086/653530] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Traveler's diarrhea is the most common medical complaint of international visitors to developing regions. Previous findings suggested that noroviruses (NoVs) are an underappreciated cause of traveler's diarrhea. METHODS. In the present study, we sought to define the presence of NoVs in 320 acute diarrheic stool samples collected from 299 US students who traveled to Guadalajara, Cuernavaca, or Puerto Vallarta, Mexico, during the period from 2007 through 2008. Conventional and quantitative real-time polymerase chain reaction assays were used to detect and determine NoV loads in stool samples. NoV strains were characterized by purification of viral RNA followed by sequencing of the viral capsid protein 1 gene. Sequences were compared using multiple sequence alignment, and phylogenetic trees were generated to evaluate the evolutionary relatedness of the viral strains associated with cases of traveler's diarrhea. RESULTS NoV RNA was detected in 30 (9.4%) of 320 samples. Twelve strains belonged to genogroup I, and 18 strains belonged to genogroup II. NoV prevalence was higher in the winter season than in the summer season (23% vs 7%, respectively; P = .001). The cDNA viral loads of genogroup I viruses were found to be 500-fold higher than those of genogroup II strains. Phylogenetic analysis revealed a diverse population of NoV strains over different locations and years. CONCLUSIONS NoV strains are important causes of traveler's diarrhea in Mexico, especially during the wintertime, and US students in Mexico may represent a suitable group for future NoV vaccine efficacy trials.
Collapse
Affiliation(s)
- N Ajami
- Department of Molecular Virology and Microbiology and Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
| | | | | | | | | | | | | | | |
Collapse
|
3
|
Appleton H. Small round viruses: classification and role in food-borne infections. CIBA FOUNDATION SYMPOSIUM 2007; 128:108-25. [PMID: 3036438 DOI: 10.1002/9780470513460.ch7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Since the first observation of Norwalk virus in the electron microscope in 1972, many different small virus particles in the size range 20-40 nm have been described world-wide in association with outbreaks of gastroenteritis. Progress characterizing these agents has been hampered by the relatively small numbers of particles present in clinical material and the lack of success in culturing them. Although the relationship between some of these viruses remains confusing, a number of distinct groups has emerged, based on morphological features and limited physical data. Immuno-electron microscopy has proved valuable in detecting viruses but the addition of antibody can mask surface morphological features. Examination of viruses in negatively stained preparations without added antibody has revealed distinct morphological differences and viruses previously thought to be simply antigenic variants within the Norwalk group of viruses clearly belong to other groups. Preliminary evidence suggests that one human virus unrelated to Norwalk has a single-stranded DNA genome and is a parvovirus. Some groups have been implicated in outbreaks of food-borne gastroenteritis, particularly after the consumption of shellfish, and their role in other food-borne and water-borne outbreaks is being increasingly recognized.
Collapse
|
4
|
|
5
|
Parashar UD, Monroe SS. "Norwalk-like viruses" as a cause of foodborne disease outbreaks. Rev Med Virol 2001; 11:243-52. [PMID: 11479930 DOI: 10.1002/rmv.321] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
While outbreaks of foodborne disease remain an important public health concern, their aetiology is not identified in a majority of instances. In targeted studies, the application of newly developed molecular assays has demonstrated that a large proportion of these outbreaks may be caused by the "Norwalk-like viruses" (NLV), a genus of genetically related viruses belonging to the family Caliciviridae. NLV outbreaks associated with consumption of faecally contaminated oysters are frequently reported and can best be controlled by preventing contamination of oyster-harvesting waters. Infectious foodhandlers are another frequent source of contamination, and such transmission can be minimised by exclusion of ill foodhandlers and the maintenance of strict personal hygiene. Molecular assays have greatly refined the epidemiological investigation of foodborne NLV outbreaks, allowing the linking of outbreaks in different locations and permitting the identification of the virus in the implicated vehicle. The development of simpler and more sensitive assays and their use on a broader scale will assist in defining the true burden of foodborne NLV outbreaks and improve strategies for their prevention and control.
Collapse
Affiliation(s)
- U D Parashar
- Respiratory and Enteric Viruses Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA.
| | | |
Collapse
|
6
|
Vipond IB, Pelosi E, Williams J, Ashley CR, Lambden PR, Clarke IN, Caul EO. A diagnostic EIA for detection of the prevalent SRSV strain in United Kingdom outbreaks of gastroenteritis. J Med Virol 2000; 61:132-7. [PMID: 10745245 DOI: 10.1002/(sici)1096-9071(200005)61:1<132::aid-jmv21>3.0.co;2-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Small round structured viruses (SRSVs) are the major cause of outbreaks of gastroenteritis in the UK. Diagnosis is problematic due to insensitive electron microscopy (EM) or technically demanding reverse transcription polymerase chain reaction (RT-PCR) techniques. We have studied outbreaks of non-bacterial gastroenteritis using an EIA based upon recombinant capsid protein from the currently prevalent circulating strain of SRSV (Lordsdale Genotype II) and compared its performance against EM and RT-PCR assays. Faecal specimens sent to the Bristol Public Health Laboratory for outbreak investigation from December 1996 to December 1997 were applied retrospectively to the SRSV EIA and results compared with the routine EM and RT-PCR that had been carried out prospectively. Overall, the three tests identified SRSVs in specimens from 70% of the outbreaks (213/305) investigated. Of the 213 total positive outbreaks, the EIA identified 71%, that compared favourably with EM (63%) and RT-PCR (84%). The Lordsdale Genotype II SRSV EIA provides a simple cost-effective assay that will for the first time make detection of currently circulating SRSV strains associated with UK outbreaks available to all routine laboratories. The EIA format makes the assay widely applicable to non-specialist laboratories, unlike the RT-PCR assay, and the improved sensitivity over EM will allow successful screening of UK outbreaks alongside commercial EIAs currently available for adenovirus, astrovirus and rotavirus. Furthermore, the assay will allow rapid identification of emerging SRSV strains.
Collapse
Affiliation(s)
- I B Vipond
- Regional Virus Laboratory, Public Health Laboratory, Bristol, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
7
|
Chadwick PR, Beards G, Brown D, Caul EO, Cheesbrough J, Clarke I, Curry A, O'Brien S, Quigley K, Sellwood J, Westmoreland D. Management of hospital outbreaks of gastro-enteritis due to small roundstructured viruses. J Hosp Infect 2000; 45:1-10. [PMID: 10833336 DOI: 10.1053/jhin.2000.0662] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Small round structured viruses (SRSVs, Norwalk-like viruses, NLVs) are the most common cause of outbreaks of gastro-enteritis in hospitals and also cause outbreaks in other settings such as schools, hotels, nursing homes and cruise ships. Hospital outbreaks often lead to ward closure and major disruption in hospital activity. Outbreaks usually affect both patients and staff, sometimes with attack rates in excess of 50%. For this reason, staff shortages can be severe, particularly if several wards are involved at the same time. SRSVs may be spread by several routes: faecal-oral; vomiting/aerosols; food and water. Viruses may be introduced into the ward environment by any of these routes and then propagated by person-to-person spread. In an outbreak setting, the diagnosis can usually be made rapidly and confidently on clinical and epidemiological grounds, particularly if vomiting is a prominent symptom. By the time an SRSV outbreak has been recognized at ward level, most susceptible individuals will have been exposed to the virus and infection control efforts must prioritize the prevention of spread of infection to other clinical areas bycontainment of infected/exposed individuals (especially the prevention of patient and staff movements to other areas), hand-hygiene and effective environmental decontamination. This report of the Public Health Laboratory Service Viral Gastro-enteritis Working Group reviews the epidemiology of outbreaks of infection due to SRSVs and makes recommendations for their management in the hospital setting. The basic principles which underpin these recommendations will also be applicable to the management of some community-based institutional outbreaks.
Collapse
Affiliation(s)
- P R Chadwick
- Salford Royal Hospitals NHS Trust, Hope Hospital, Salford
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
McCaughey C, O'Neill HJ, Wyatt DE, Coyle PV. Rationalised virological electron microscope specimen testing policy. J Clin Pathol 2000; 53:163. [PMID: 10767838 PMCID: PMC1763280 DOI: 10.1136/jcp.53.2.163] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
9
|
|
10
|
Curry A, Bryden A, Morgan-Capner P, Fox A, Guiver M, Martin L, Mutton K, Wright P, Mannion P, Westwell A, Cheesbrough J, Ashton I, Blackley A. A rationalised virological electron microscope specimen testing policy. PHLS North West Viral Gastroenteritis and Electron Microscopy Subcommittee. J Clin Pathol 1999; 52:471-4. [PMID: 10562819 PMCID: PMC501438 DOI: 10.1136/jcp.52.6.471] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The aim of this project was to produce guidance for a rationalised virological electron microscopy specimen testing policy for PHLS North West, to facilitate centralisation of a groupwide diagnostic electron microscopy service on a single site. Careful specimen selection to limit numbers and the groupwide use of commercially available enzyme immunoassays has allowed PHLS North West to reduce the number of specimens prepared for electron microscopy. The rationalised virological electron microscopy specimen testing policy has enabled a diagnostic electron microscopy service to be provided from a single site with a manageable workload. Implementation of this specimen testing policy by PHLS North West has been successful and may be applicable to other laboratories (or groups of laboratories) to maximise the use of expensive electron microscopy facilities.
Collapse
Affiliation(s)
- A Curry
- Public Health Laboratory, Withington Hospital, Manchester, UK
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Stolle A, Sperner B. Viral infections transmitted by food of animal origin: the present situation in the European Union. ARCHIVES OF VIROLOGY. SUPPLEMENTUM 1997; 13:219-228. [PMID: 9413541 DOI: 10.1007/978-3-7091-6534-8_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The goal of this presentation was to clarify which foods are involved in viral diseases, which viruses are transmitted via food and how to evaluate the risk of a foodborne viral infection. Food items frequently identified as cause of viral disease outbreaks were shellfish harvested in sewage-contaminated water. Another common source of foodborne viral illness was cold food contaminated by infected food handlers. In the European Union the viruses most frequently associated with foodborne illness were hepatitis A virus and the SRSV's. A few isolated cases of foodborne hepatitis E were reported in Mediterranean countries. Compared to other foodborne diseases, those caused by viruses are less severe and seldom fatal. This might be a reason why the problem of viral contamination of food has been neglected. Yet, because many foodborne viral diseases are not recognized either as foodborne or as caused by viruses, the actual number of cases must be assumed to be significantly higher than the reported number. Consequently, food associated diseases of viral origin should be granted more attention.
Collapse
Affiliation(s)
- A Stolle
- Institute for Hygiene and Technology of Food of Animal Origin, Veterinary Faculty, Ludwig-Maximilians-University, Munich, Federal Republic of Germany
| | | |
Collapse
|
12
|
Chadwick PR, McCann R. Transmission of a small round structured virus by vomiting during a hospital outbreak of gastroenteritis. J Hosp Infect 1994; 26:251-9. [PMID: 7915285 DOI: 10.1016/0195-6701(94)90015-9] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An outbreak of gastroenteritis due to a small round structured virus (SRSV) (Norwalk-like virus) occurred in an elderly care unit, affecting a total of 126 patients and staff. The outbreak caused major disruption to the provision of health care services by the unit over a 3-week period. Following the outbreak a study was undertaken to explore risk factors for acquisition of SRSV infection by health care workers on the unit. Exposure to patients nearby who were vomiting and the number of close contacts with ill patients were significantly related to the risk of developing gastroenteritis (P < 0.05). No significant increase in risk of developing gastroenteritis was found in nurses who cleaned vomit or faeces from affected patients. The findings suggest that aerosolization of vomit was of major importance in transmission of infection during the outbreak; the implications for infection control are discussed.
Collapse
Affiliation(s)
- P R Chadwick
- Department of Microbiology, Hope Hospital, Salford, UK
| | | |
Collapse
|
13
|
|
14
|
Oishi I, Yamazaki K, Kimoto T, Minekawa Y. Demonstration of low molecular weight polypeptides associated with small, round-structured viruses by western immunoblot analysis. Microbiol Immunol 1992; 36:1105-12. [PMID: 1282654 DOI: 10.1111/j.1348-0421.1992.tb02114.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Small, round-structured viruses (SRSV) were detected in 14 of 300 fecal specimens obtained from patients with acute gastroenteritis by electron microscopy. These SRSV strains were morphologically indistinguishable from one another. While 11 of these strains had a single usual major structural protein with molecular weight of 63,000 (63K) daltons (p63), interestingly, three strains possessed a single major structural protein with molecular weight of 33K daltons (p33). Treatments of p63-SRSV with proteolytic enzymes or denaturating reagents did not affect the molecular weight of p63, and the p33 was not detectable by Western immunoblot in the ultracentrifugal supernatant of the p63-SRSV suspension. These results suggest that the p33 is neither a definitive subunit of p63 nor disintegrated component derived from the p63-SRSV but a novel polypeptide of SRSV. Immune electron microscopy and Western immunoblot analyses indicated that p63- and p33-SRSVs may share an antigenic determinant(s).
Collapse
Affiliation(s)
- I Oishi
- Laboratory of Virology, Osaka Prefectural Institute of Public Health, Japan
| | | | | | | |
Collapse
|
15
|
Kobayashi S, Morishita T, Yamashita T, Sakae K, Nishio O, Miyake T, Ishihara Y, Isomura S. A large outbreak of gastroenteritis associated with a small round structured virus among schoolchildren and teachers in Japan. Epidemiol Infect 1991; 107:81-6. [PMID: 1879493 PMCID: PMC2272036 DOI: 10.1017/s0950268800048706] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In March 1989 a large outbreak of acute gastroenteritis occurred simultaneously among schoolchildren and teachers at nine elementary schools in Toyota City, Japan. Illness was observed in 3236 (41.5%) of 7801 schoolchildren and 117 (39.4%) of 297 teachers. The main clinical symptoms were diarrhoea, vomiting, nausea and abdominal pain. Gastroenteritis was significantly associated with the consumption of school lunch served by one particular lunch preparation centre. One food handler at the centre suffered from gastroenteritis during the outbreak. Small round structured virus (SRSV) was detected in 4 of 8 stool specimens from sick persons. The school lunch contaminated by the infected food handler is the most probable source of this outbreak due to SRSV.
Collapse
Affiliation(s)
- S Kobayashi
- Aichi Prefectural Institute of Public Health, Nagoya, Japan
| | | | | | | | | | | | | | | |
Collapse
|
16
|
|
17
|
|
18
|
Riordan T, Wills A. An outbreak of gastroenteritis in a psycho-geriatric hospital associated with a small round structured virus. J Hosp Infect 1986; 8:296-9. [PMID: 2878035 DOI: 10.1016/0195-6701(86)90126-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
An outbreak of gastroenteritis in a psycho-geriatric hospital is described. Small round structured viruses, morphologically similar to Norwalk agent, were seen in stool samples from four patients. Although the illness was mild, 67 patients and 30 nurses on four wards were affected over a period of 4 weeks. Because of shortage of staff and isolation facilities, difficulty was experienced in introducing effective control measures.
Collapse
|
19
|
|
20
|
Mossel DA, Dijkmann KE. A centenary of academic and less learned food microbiology. Pitfalls of the past and promises for the future. Antonie Van Leeuwenhoek 1984; 50:641-63. [PMID: 6397133 DOI: 10.1007/bf02386231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A review is presented of the development of Food Microbiology from its roots in different disciplines - including human and animal medicine, general microbiology, agricultural science and food chemistry - to an autonomous science with the main vocation to provide the knowledge allowing providing food that is wholesome, of high quality and acceptable in the microbiological sense. This evolution entailed a change in approach from mere, and often rather primitive inspection of end-products to intervention by (i) identification of hazard points ("critical points" or CPs) by ecological studies; (ii) elimination of CPs by elaboration of Good Manufacturing and Distribution Practices (GMPs); (iii) validation of GMPs by monitoring production lines and final products at point of sale and gauging the results by Risk Analysis. It is emphasized, that although advanced and ecologically sound techniques have become available, it will still require extensive education and training at all levels before the scientific advances outlined in this review will have been fully integrated in day-to-day food production and catering in developed as well developing areas of the world. Interdisciplinary instruction and co-operation cannot be missed in attempts to reach this goal.
Collapse
|