title: Clonal structure in Ichthyobacterium seriolicida, the causative agent of bacterial haemolytic jaundice in yellowtail, Seriola quinqueradiata, inferred from molecular epidemiological analysis.
abstract: Bacterial haemolytic jaundice caused by Ichthyobacterium seriolicida has been responsible for mortality in farmed yellowtail, Seriola quinqueradiata, in western Japan since the 1980s. In this study, polymorphic analysis of I. seriolicida was performed using three molecular methods: amplified fragment length polymorphism (AFLP) analysis, multilocus sequence typing (MLST) and multiple-locus variable-number tandem repeat analysis (MLVA). Twenty-eight isolates were analysed using AFLP, while 31 isolates were examined by MLST and MLVA. No polymorphisms were identified by AFLP analysis using EcoRI and MseI, or by MLST of internal fragments of eight housekeeping genes. However, MLVA revealed variation in repeat numbers of three elements, allowing separation of the isolates into 16 sequence types. The unweighted pair group method using arithmetic averages cluster analysis of the MLVA data identified four major clusters, and all isolates belonged to clonal complexes. It is likely that I. seriolicida populations share a common ancestor, which may be a recently introduced strain.
authors.affiliation: National Research Institute of Aquaculture, Fisheries Research Agency, Research Center for Fish Diseases, Minami-Ise, Mie, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsuyama
authors.affiliation: Fisheries Research Institute, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Kamiura, Oita, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fukuda
authors.affiliation: National Research Institute of Aquaculture, Fisheries Research Agency, Research Center for Fish Diseases, Minami-Ise, Mie, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sakai
authors.affiliation: Fisheries Technology Department, Kyoto Prefectural Agriculture, Forestry and Fisheries Technology Center, Miyazu, Kyoto, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Tanimoto
authors.affiliation: Fisheries Technology Department, Kyoto Prefectural Agriculture, Forestry and Fisheries Technology Center, Miyazu, Kyoto, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nakanishi
authors.affiliation: National Research Institute of Fisheries Science, Fisheries Research Agency, Research Center for Bioinformatics and Biosciences, Yokohama, Kanagawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: National Research Institute of Aquaculture, Fisheries Research Agency, Research Center for Fish Diseases, Minami-Ise, Mie, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takano
authors.affiliation: National Research Institute of Aquaculture, Fisheries Research Agency, Research Center for Fish Diseases, Minami-Ise, Mie, Japan.
authors.forename: C
authors.initials: C
authors.lastname: Nakayasu
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis / Q000662:veterinary; D000818:Animals; D001424:Bacterial Infections / Q000382:microbiology / Q000662:veterinary*; D041963:Bacteroidetes / Q000235:genetics / Q000502:physiology*; D005393:Fish Diseases / Q000382:microbiology*; D007564:Japan; D007565:Jaundice / Q000382:microbiology / Q000662:veterinary*; D018598:Minisatellite Repeats; D058885:Multilocus Sequence Typing / Q000662:veterinary; D010473:Perciformes; D010802:Phylogeny
keywords: 
  Ichthyobacterium seriolicida
  ; amplified fragment length polymorphism; multilocus sequence typing; multiple-locus variable-number tandem repeat analysis; polymorphism