Data/hora: 07/06/2024 02:16:37

Provedor de dados: | 5
País: | France
Título: | Identification de marqueurs génétiques de la virulence chez Vibrio nigripulchritudo, un pathogène de crevettes pénéides en Nouvelle-Calédonie
Autores: | Reynaud, Yann.
Data: | 2008-04-08
Ano: | 2008
Palavras-chave: | Plasmide; SSH; Épidémiology; Virulence; Shrimp; Vibriosis; Vibrio nigripulchritudo; Plasmide; SSH; Épidémiologie; Virulence; Crevette; Vibriose; Vibrio nigripulchritudo.
Resumo: | Since 1997, a new pathology seasonally occurs in new caledonian shrimp farms during the warm season and was named Summer Syndrome. Diseased Litopenaeus stylirostris shrimp suffer from a septicemic vibriosis which was attributed to V. nigripulchritudo. Preliminary studies based on a collection of V. nigripulchritudo strains have brought to light different virulence levels according to experimental infections results; three virulence statuses were defined: highly (HP), moderately (MP) and non pathogenic (NP). The aim of this work was to genetically characterize virulent V. nigripulchritudo strains. In a first step the genetic diversity of 58 V. nigripulchritudo strains was analyzed by MLST and AP-PCR, revealing a cluster of HP and MP strains, characterized by a low genetic variability and that includes all Summer Syndrome-associated isolates. This confirms the emergence of one cluster of pathogenic V. nigripulchritudo simultaneously with the emergence of the Summer Syndrome ; in a second step, 368 genetic markers of virulence were identified by a Suppressive Subtractive Hybridization performed between the genomes of a HP strain and a genetically close, NP isolate; the distribution of the screened SSH fragments was studied in 58 V. nigripulchritudo isolates by macro-array: 78 DNA fragments were selected, allowing to characterize clusters identified and pathogenic statuses; 13 are specific of the HP strains involved in Summer Syndrome. Interestingly, 10 of these markers are carried by a plasmid pSFn1 that contains sequences highly similar to those of a plasmid pAK1, detected in Vibrio shilonii, a coral pathogen. The origin and consequences of this plasmid acquisition are discussed.
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/2008/these-3906.pdf
Editor: | Université de Paris 6 – Pierre et Marie Curie
Relação: | http://archimer.ifremer.fr/doc/00000/3906/
Formato: | application/pdf