Characterization by numerical taxonomy and ribotyping ofVibrio splendidusbiovar I andVibrio scophthalmistrains associated with turbot cultures

Abstract

R. FARTO, M. MONTES, M.J. PÉ RE Z , T .P . NI ET O , J .L . LA RS E N A ND K . P ED E RS EN . 1999. TwelveVibrio strains were examined phenotypically in 91 biochemical characters and genotypically by ribotyping. Ten were isolated from sea water and two from diseased turbot (Scophthalmus maximus). All isolates originated from one experimental system located in Ría de Vigo (Galicia, north-west Spain). Different type strains were used for comparative purposes. The taxonomic position was analysed with the NTSYST-pc and similarities among strains were calculated by the Simple Matching coefficient (S SM ). rRNA gene restriction patterns were performed with the HindIII enzyme. The S SM coefficient separated the 12 Vibrio strains into two groups which included strains that showed a S SM coefficient quite similar to V. splendidus biovar I (ATCC 33125) and V. scophthalmi (CECT 4638). None of 91 phenotypical characters were specific in distinguishing both species. The ribotyping confirmed the taxonomic classification of strains. The pathogenicity of each strain was evaluated; 10 environmental strains were avirulent and two, isolated from diseased turbot, were virulent. Different biotypes and ribotypes were found among the avirulent isolates. This work showed ribotyping to be a valuable tool for identification and confirmed the necessity of extending the ribotype database within closely related Vibrio species in order to clarify the taxonomic position.

Screening of Vibrio isolates to develop an experimental infection model in the Pacific oyster Crassostrea gigas

“…Independently of the host they infect, these strains could share a common mechanism -genetic and/or metabolic -providing potential for pathogenicity. The strains related to Vibrio splendidus are widely distributed in various environments (Nealson et al 1993, Farto et al 1999, they display an elevated genetic diversity and, according to the literature, may be associated with mortality in a broad range of aquatic animals (Nicolas et al 1996, Sugumar et al 1998, Gatesoupe et al 1999, Lacoste et al 2001, Farto et al 2003). In contrast, various Vibrio species, including V. pectinicida, V. tapetis, and V. penaecida, have a narrower host specificity and consistent pathogenicity.…”

Comparative analysis of Vibrio splendidus-related strains isolated during Crassostrea gigas mortality events

“…Therefore, we do not yet have any phenotypic or genotypic feature to distinguish pathogenic V. splendidus strains from nonpathogenic ones. Vibrio splendidus is widely distributed in marine ecosystems (Nealson et al, 1993;Farto et al, 1999;Macian et al, 2000). Different strains have been associated with mortalities of C. gigas larvae (Sugumar et al, 1998), scallops larvae Pecten maximus (Nicolas et al, 1996), and fish larvae (Gatesoupe et al, 1999).…”

Two Vibrio splendidus related strains collaborate to kill Crassostrea gigas: taxonomy and host alterations

“…Therefore, taxonomic identification of V. splendidus related strains should be conducted using a polyphasic approach employing new phenotypic tests and molecular techniques (Thompson et al 2001, Stackenbrandt et al 2002. A wide range of virulence among strains related to Vibrio splendidus has been observed by experimental exposure on different animal models (Sugumar et al 1998, Farto et al 1999, Gatesoupe et al 1999). Studies of ribosomal and gyrB gene polymorphisms or RAPD have not led to the identification of markers associated with pathogenicity.…”

“…Vibrio splendidus (Baumann et al 1980, Baumann & Schubert 1984) is widely distributed in marine ecosystems (Nealson et al 1993, Farto et al 1999. It has long been considered an environmental organism with no pathogenic significance (Baticados et al 1990, Paillard & Maes 1990, Myhr et al 1991, Castro et al 1992.…”