A Large-Scale Epidemiological Study to Identify Bacteria Pathogenic to Pacific Oyster Crassostrea gigas and Correlation Between Virulence and Metalloprotease-like Activity
A 4-year bacteriological survey (2003-2007) of four molluscs cultivated in France and faced with mortality episodes was performed by the French shellfish pathology network. The more abundant bacteria isolated during 92 mortality episodes, occurring mainly in Pacific oyster Crassostrea gigas, were identified by genotyping methods. It allowed us both to confirm the representativeness of Vibrio splendidus and Vibrio aestuarianus bacterial strains and to identify both a large number of Vibrio harveyi-related strains mainly detected during 2007 oyster mortality outbreaks and to a lesser extent bacterial strains identified as Shewanella colwelliana. Because metalloprotease has been reported to constitute a virulence factor in a few Vibrio strains pathogenic for C. gigas, several bacterial strains isolated in this study were screened to evaluate their pathogenicity in C. gigas spat by experimental infection and their ability to produce metalloprotease-like activity in the culture supernatant fluids. A high level (84%) of concordant results between azocaseinase activities and virulence of strains was obtained in this study. Because bacterial metalloprotease activities appeared as a common feature of pathogenic bacteria strains associated with mortality events of C. gigas reared in France, this phenotypic test could be useful for the evaluation of virulence in bacterial strains associated with such mortality episodes.
KeywordsVibrio Mortality Event Pacific Oyster Mollusc Species Vibrio Species
We thank Helen McCombie for her help with English editing.
- 7.Goulletquer P, Soletchnik P, Le Moine O, Razet D, Geairon P, Faury N (1998) Summer mortality of the Pacific cupped oyster Crassostrea gigas in the Bay of Marennes-Oleron (France). CM—Int Counc Explor Sea, Cascais (Portugal) 16–19:20Google Scholar
- 8.Samain JF, McCombie H (2008) Summer mortality of Pacific oyster Crassostrea gigas. The Morest Project, Editions Quae, 379pGoogle Scholar
- 12.Inamura H, Nakai T, Muroga K (1985) An extracellular protease produced by Vibrio anguillarum. Bulletin of the Japanese Society of Scientific Fisheries 51:1915–1920Google Scholar
- 16.Nottage AS, Birkbeck TH (1987) Production of proteinase during experimental infection of Ostrea edulis L. larvae with Vibrio alginolyticus NCMB 1339 and the antigenic relationship between proteinases produced by marine vibrios pathogenic for fish and shellfish. J Fish Dis 10:265–273CrossRefGoogle Scholar
- 29.Hall T (1999) BioitEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucl Acids Symp Ser 41:95–98Google Scholar
- 37.Guisande JA, Montes M, Farto R, Armada SP, Perez MJ, Nieto TP (2004) A set of tests for the phenotypic identification of culturable bacteria associated with Galician bivalve mollusc production. J Shellfish R 3:599–609Google Scholar
- 42.Ortigosa M, Garay E, Pujalte MJ (1994) Numerical taxonomy of Vibrionaceae isolated from oysters and seawater along an annual cycle. Syst Appl Microbiol 17:216–225Google Scholar
- 44.Labreuche Y (2006) Caractérisation de la virulence d'une souche de Vibrio aestuarianus, pathogène de l'huître creuse Crassostrea gigas. Université de Bretagne Occidentale, Brest, France, PhD, 277pGoogle Scholar
- 50.Chang AK, Kim HY, Park JE, Acharya P, Park IS, Yoon SM, You HJ, Hahm KS, Park JK, Lee JS (2005) Vibrio vulnificus secretes a broad-specificity metalloprotease capable of interfering with blood homeostasis through prothrombin activation and fibrinolysis. J Bacteriol 187:6909–6916CrossRefPubMedGoogle Scholar
- 56.Le Roux F, Mohamed Z, Chakroun N, Binesse J, Saulnier D, Bouchier C, Zidane N, Ma L, Rusniok C, Lajus A, Buchrieser C, Médigue C, Polz MF, Mazel D (2009) Genome sequence of Vibrio splendidus: an abundant planctonic marine species with a large genotypic diversity. Environ Microbiol 11:1959–1970CrossRefPubMedGoogle Scholar