Ngo Thao P H, Bartie Kerry L, Thompson Kim D, Verner-Jeffreys David W, Hoare Rowena, Adams Alexandra
Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, UK.
Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, UK.
Vet Microbiol. 2017 Mar;201:216-224. doi: 10.1016/j.vetmic.2017.01.032. Epub 2017 Jan 31.
Flavobacterium psychrophilum is one of the most important bacterial pathogens affecting cultured rainbow trout (Oncorhynchus mykiss) and is increasingly causing problems in Atlantic salmon (Salmo salar L.) hatcheries. Little is known about the heterogeneity of F. psychrophilum isolates on UK salmonid farms. A total of 315 F. psychrophilum isolates, 293 of which were collected from 27 sites within the UK, were characterised using four genotyping methods and a serotyping scheme. A high strain diversity was identified among the isolates with 54 pulsotypes, ten (GTG)-PCR types, two 16S rRNA allele lineages, seven plasmid profiles and three serotypes. Seven PFGE groups and 27 singletons were formed at a band similarity of 80%. PFGE group P (n=75) was found to be numerically predominant in eight sites within the UK. Two major PFGE clusters and 13 outliers were found at the band similarity of 40%. The predominant profileobserved within the F. psychrophilum isolates examined was PFGE cluster II - (GTG)-PCR type r1-16S rRNA lineage II - serotype Th (70/156 isolates examined, 45%). Co-existence of genetically and serologically heterogeneous isolates within each farm was detected, confounding the ability to control RTFS outbreaks. The occurrence over time (up to 11 years) of F. psychrophilum pulsotypes in three representative sites (Scot I, Scot III and Scot V) within Scotland was examined, potentially providing important epidemiological data for farm management and the development of site-specific vaccines.
嗜冷黄杆菌是影响养殖虹鳟（Oncorhynchus mykiss）的最重要细菌病原体之一，并且在大西洋鲑（Salmo salar L.）孵化场中引发的问题日益增多。关于英国鲑鱼养殖场中嗜冷黄杆菌分离株的异质性，人们了解甚少。使用四种基因分型方法和一种血清分型方案，对总共315株嗜冷黄杆菌分离株进行了特征分析，其中293株是从英国境内的27个地点采集的。在这些分离株中鉴定出了高度的菌株多样性，包括54种脉冲型、10种（GTG）-PCR型、2个16S rRNA等位基因谱系、7种质粒图谱和3种血清型。在条带相似度为80%时，形成了7个PFGE组和27个单株。发现PFGE组P（n = 75）在英国的8个地点在数量上占主导地位。在条带相似度为40%时，发现了2个主要的PFGE簇和13个异常值。在所检测的嗜冷黄杆菌分离株中观察到的主要谱型是PFGE簇II - （GTG）-PCR型r1 - 16S rRNA谱系II - 血清型Th（在所检测的156株分离株中有70株，占45%）。在每个养殖场内都检测到了遗传和血清学上异质的分离株共存，这使得控制虹鳟鱼细菌性冷水病（RTFS）疫情的能力受到影响。研究了苏格兰境内三个代表性地点（苏格兰I、苏格兰III和苏格兰V）中嗜冷黄杆菌脉冲型随时间（长达11年）的出现情况，这可能为养殖场管理和开发针对特定地点的疫苗提供重要的流行病学数据。
