Occurrence of virulence genes among Vibrio cholerae and Vibrio parahaemolyticus strains from treated wastewaters.

Pathogenic Vibrio species are an important cause of foodborne illnesses. The aim of this study was to describe the occurrence of potentially pathogenic Vibrio species in the final effluents of a wastewater treatment plant and the risk that they may pose to public health. During the 1-year monitoring, a total of 43 Vibrio strains were isolated: 23 Vibrio alginolyticus, 1 Vibrio cholerae, 4 Vibrio vulnificus, and 15 Vibrio parahaemolyticus.

Development of a colony hybridization method for the enumeration of total and potentially enteropathogenic Vibrio parahaemolyticus in shellfish.

Vibrio parahaemolyticus is a marine microorganism, recognized as cause of gastroenteritis outbreaks associated with seafood consumption. In this study the development and the in-house validation of a colony hybridization method for the enumeration of total and potentially pathogenic V. parahaemolyticus is reported.

Detection and quantification of Vibrio parahaemolyticus in shellfish from Italian production areas.

Vibrio parahaemolyticus is a marine microorganism, recognized as an important cause of foodborne illness particularly in Asia, South America and United States. Outbreaks are rarely reported in Europe, but they can occur unexpectedly in relation, among other reasons, to the spread of highly virulent strains. It is known that the risk is proportional to exposure levels to pathogenic V.

Qualitative and quantitative assessment of viral contamination in bivalve molluscs harvested in Italy.

Bivalve molluscs are a well documented source of viral infection. Further data on shellfish viral contamination are needed to implement European Regulations with sanitary measures more effective against viral pathogens. To this aim, 336 samples of bivalve molluscs (185 mussels, 66 clams, 23 oysters and 62 samples from other species) collected in harvesting areas of class A and B of four Italian Regions were analyzed for qualitative and quantitative determination of hepatitis A virus (HAV) and Norovirus (NoV) GI and GII, using real time RT-PCR.

Noroviruses in seafood: a 9-year monitoring in Italy.

Norovirus (NoV) are increasingly important as etiological agents of gastrointestinal infections. Consumption of bivalve molluscs and ready-to-eat fishery products is one of the most common ways of acquiring NoV foodborne infections, and the rise of outbreaks of viral gastroenteritis represents an important health problem that is also responsible for economic losses. The aim of this work was to define the prevalence of NoV contamination in preserved fishery products and in shellfish commercialized in Italy, taking into account the results obtained during 9 years of survey (2003-2011) and paying special attention to the regions more involved in national production.

Presence of pathogenic Vibrio parahaemolyticus in waters and seafood from the Tunisian Sea.

The occurrence of the hemolysin genes, tdh and trh, in Vibrio parahaemolyticus strains isolated from environmental samples collected from various exported seafood products comprising of fishes and shellfish (Mytilus edulis and Crassostrea gigas) or seawater, was studied. Eight strains were confirmed as V. parahaemolyticus by toxR -based polymerase chain reaction and only one strain out of these 8 strains was positive for tdh and trh genes.

Norovirus monitoring in bivalve molluscs harvested and commercialized in southern Italy.

Norovirus (NoV) is the main cause of human nonbacterial gastroenteritis throughout the world. NoVs are classified into five genogroups: GI, GII, GIII, GIV, and GV. NoVs from GI and GII are the most commonly reported NoVs associated with human infections, and raw or undercooked shellfish have been identified as the main potential infection vehicle.

Phylogenetic and evolutionary analysis of Vibrio parahaemolyticus and Vibrio alginolyticus isolates based on toxR gene sequence.

The Vibrio genus contains a large number of closely related bacterial species differing, in some cases, less than 1% in 16S rRNA gene sequence. The present study evaluated the usefulness of toxR gene for phylogenetic and evolution analysis on Vibrio isolates of environmental or clinical origin belonging to the two closely related species V. parahaemolyticus and V.

Duplex Real Time PCR for the detection of hepatitis A virus in shellfish using Feline Calicivirus as a process control.

The consumption of bivalve shellfish is a common cause of foodborne outbreaks of viral origin. The evaluation of the sanitary quality of these products, however, is still based on bacterial indicators of fecal contamination (Reg. (EC) No.

Evaluation of different polymerase chain reaction methods for the identification of Vibrio parahaemolyticus strains isolated by cultural methods.

Control of contamination by Vibrio parahaemolyticus in fishery products is often hampered by the lack of standardized methods and by the uncertainty associated with biochemical identification of the isolates. In this study, 5 polymerase chain reaction (PCR) methods for the identification of V. parahaemolyticus to the species level were evaluated by using 25 Vibrio reference strains and 163 isolates from fishery products, environmental sources, and clinical samples.

Assessment of human enteric viruses in shellfish from the northern Adriatic sea.

Incidence and circulation of different strains of hepatitis A and Norovirus in shellfish were studied on 235 samples (Tapes philippinarum, Mytilus galloprovincialis, Ostrea spp. and Chlamys spp.) obtained from different sites, representing the shellfish production areas of the northern Adriatic sea.

Resistance of hepatitis A virus in mussels subjected to different domestic cookings.

Hepatitis A is a worldwide infectious disease. Shellfish consumption has always been one of the major risk factors for hepatitis A infection, especially when these products are eaten raw or slightly cooked. Moreover, the cooking does not always guarantee the harmlessness of shellfish.

Round-robin comparison of methods for the detection of human enteric viruses in lettuce.

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 calicivirus strains at different concentrations. Nucleic acid extractions were done at the same time in the same laboratory to reduce assay-to-assay variability.

Reverse transcription-booster PCR for detection of noroviruses in shellfish.

The methods commonly used for norovirus (NV) detection are based on reverse transcription-PCR (RT-PCR) followed by confirmation of the amplified sequence. To increase sensitivity, an RT-booster PCR was developed. The proposed method showed an increase in sensitivity at least 2 log units for all the NV strains tested compared with the standard RT-PCR method.

Multicenter validation of PCR-based method for detection of Salmonella in chicken and pig samples.

As part of a standardization project, an interlaboratory trial including 15 laboratories from 13 European countries was conducted to evaluate the performance of a noproprietary polymerase chain reaction (PCR)-based method for the detection of Salmonella on artificially contaminated chicken rinse and pig swab samples. The 3 levels were 1-10, 10-100, and 100-1000 colony-forming units (CFU)/100 mL. Sample preparations, including inoculation and pre-enrichment in buffered peptone water (BPW), were performed centrally in a German laboratory; the pre-PCR sample preparation (by a resin-based method) and PCR assay (gel electrophoresis detection) were performed by the receiving laboratories.

Comparison of PCR, electrochemical enzyme-linked immunosorbent assays, and the standard culture method for detecting salmonella in meat products.

An electrochemical enzyme-linked immunosorbent assay (ELISA) coupled with flow injection analysis (ELISA-FIA) and a PCR-based method using ST11 and ST15 primers for detecting salmonellae in meat were evaluated in comparison with the International Organization for Standardization (ISO) culture method. The methods were applied to experimentally contaminated and naturally contaminated meat samples. The results showed that both ELISA-FIA and PCR allowed detection of salmonella in a product contaminated with a low number of the microorganisms (1 to 10 salmonellae/25 g) after only 5 h of incubation of preenrichment broth, and they were just as effective as the ISO method.

[Microbiological risk associated with seafood consumption].

Seafood has always been an important source for human nutrition. The increase of its consumption, however, and the epidemiological data, confirming the role of seafood, especially shellfish, as a carrier of foodborne toxinfections, has brought the need of a greater control of his microbiological characteristics. In this review we considered the main pathogenous microorganisms associated to such products, with a special attention towards the emerging pathogens not yet considered in the legislation (autochthonous pathogens, e.

Evaluation of DNA extraction methods for use in combination with SYBR green I real-time PCR to detect Salmonella enterica serotype enteritidis in poultry.

The objective of this study was to develop a rapid, reproducible, and robust method for detecting Salmonella enterica serotype Enteritidis in poultry samples. First, for the extraction and purification of DNA from the preenrichment culture, four methods (boiling, alkaline lysis, Nucleospin, and Dynabeads DNA Direct System I) were compared. The most effective method was then combined with a real-time PCR method based on the double-stranded DNA binding dye SYBR Green I used with the ABI Prism 7700 system.

The survival of hepatitis A virus in fresh produce.

Fresh produce has been repeatedly implicated as the source of human viral infections, including infection with hepatitis A virus (HAV). The objective of the present study was to evaluate the HAV adsorption capacity of the surface of various fresh vegetables that are generally eaten raw and the persistence of the HAV. To this end, the authors experimentally contaminated samples of lettuce, fennel, and carrot by immersing them in sterile distilled water supplemented with an HAV suspension until reaching a concentration of 5 log tissue culture infectious dose (TCID50)/ml.

Effects of depuration of molluscs experimentally contaminated with Escherichia coli, Vibrio cholerae 01 and Vibrio parahaemolyticus.

Aims: The aim of the present study was to investigate the behaviour of two pathogenic vibrios (Vibrio cholerae O1 and Vibrio parahaemolyticus) during depuration and to compare it with that of Escherichia coli, used as an indicator of suitability for consumption.

Methods And Results: Samples of Mytilus galloprovincialis were experimentally contaminated with E. coli, V.