title: Occurrence and molecular characterisation of Vibrio parahaemolyticus in crustaceans commercialised in Venice area, Italy.
abstract: Infections due to the pathogenic human vibrios, Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus, are mainly associated with consumption of raw or partially cooked bivalve molluscs. At present, little is known about the presence of Vibrio species in crustaceans and the risk of vibriosis associated with the consumption of these products. The aim of the present study was to evaluate the prevalence and concentration of the main pathogenic Vibrio spp. in samples of crustaceans (n=143) commonly eaten in Italy, taking into account the effects of different variables such as crustacean species, storage conditions and geographic origin. Subsequently, the potential pathogenicity of V. parahaemolyticus strains isolated from crustaceans (n=88) was investigated, considering the classic virulence factors (tdh and trh genes) and four genes coding for relevant proteins of the type III secretion systems 2 (T3SS2α and T3SS2β). In this study, the presence of V. cholerae and V. vulnificus was never detected, whereas 40 samples (28%) were positive for V. parahaemolyticus with an overall prevalence of 41% in refrigerated products and 8% in frozen products. The highest prevalence and average contamination levels were detected in Crangon crangon (prevalence 58% and median value 3400 MPN/g) and in products from the northern Adriatic Sea (35%), with the samples from the northern Venetian Lagoon reaching a median value of 1375 MPN/g. While genetic analysis confirmed absence of the tdh gene, three of the isolates contained the trh gene and, simultaneously, the T3SS2β genes. Moreover three possibly clonal tdh-negative/trh-negative isolates carried the T3SS2α apparatus. The detection of both T3SS2α and T3SS2β apparatuses in V. parahaemolyticus strains isolated from crustaceans emphasised the importance of considering new genetic markers associated with virulence besides the classical factors. Moreover this study represents the first report dealing with Vibrio spp. in crustaceans in Italy, and it may provide useful information for the development of sanitary surveillance plans to prevent the risk of vibriosis in seafood consumers.
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale Dell'Università 10, 35020 Legnaro, Padua, Italy. Electronic address: grethel76@gmail.com.
authors.forename: Greta
authors.initials: G
authors.lastname: Caburlotto
authors.affiliation: Istituto Superiore di Sanità, Department of Veterinary Public Health and Food Safety, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Suffredini
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale Dell'Università 10, 35020 Legnaro, Padua, Italy.
authors.forename: Marica
authors.initials: M
authors.lastname: Toson
authors.affiliation: University of Padova, Department of Comparative Biomedicine and Food Science, Viale dell'Università 16, 35020 Legnaro, Padua, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Fasolato
authors.affiliation: Azienda Ulss 12 Veneziana, Department of Prevention - Veterinary Service, P.le San Lorenzo Giustiniani 11/d, 30174 Venezia Mestre, VE, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Antonetti
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale Dell'Università 10, 35020 Legnaro, Padua, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Zambon
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale Dell'Università 10, 35020 Legnaro, Padua, Italy.
authors.forename: Amedeo
authors.initials: A
authors.lastname: Manfrin
mesh_terms: D000818:Animals; D003445:Crustacea / Q000382:microbiology*; D005516:Food Microbiology; D006801:Humans; D007558:Italy; D017747:Seafood / Q000382:microbiology; D014736:Vibrio parahaemolyticus / Q000235:genetics / Q000502:physiology*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors
keywords: Enumeration; Most probable number (MPN); Prevalence; T3SS2; tdh; trh