Abstract:
Skin conditions associated with Tenacibaculum spp. constitute a significant threat to the health and welfare of sea-farmed Atlantic salmon (Salmo salar L.) in Norway. Fifteen presumptive tenacibaculosis outbreaks distributed along the Norwegian coast during the late winter and spring of 2018 were investigated. Bacteriological culture confirmed the presence of Tenacibaculum spp. Seventy-six isolates cultured from individual fish were selected and subjected to whole-genome sequencing and MALDI-TOF MS analysis. Average nucleotide identity and MALDI-TOF analyses confirmed the presence of T. finnmarkense and T. dicentrarchi, with further division of T. finnmarkense into genomovars (gv.) finnmarkense and ulcerans. Core genome multilocus sequence typing (cgMLST) and single-nucleotide polymorphism (SNP) analyses identified the presence of a genetically conserved cluster of gv. finnmarkense isolates against a background of relatively genetically diverse gv. finnmarkense and gv. ulcerans isolates in 13 of the 15 studied cases. This clustering strongly suggests a link between T. finnmarkense gv. finnmarkense and development of clinical tenacibaculosis in sea-farmed Norwegian salmon in the late winter and spring. Analysis of 25 Tenacibaculum isolates collected during the spring of 2019 from similar cases identified a similar distribution of genotypes. Low water temperatures were common to all cases, and most incidences involved relatively small fish shortly after sea transfer, suggesting that these fish are particularly predisposed to Tenacibaculum infection.
摘要:
与Tenacibaculumspp相关的皮肤状况。对挪威的海洋养殖大西洋鲑鱼(SalmosalarL.)的健康和福利构成重大威胁。调查了2018年冬末和春季在挪威海岸分布的15起推定性肌腱病暴发。细菌学培养证实了Tenacibaculumspp的存在。选择从个体鱼培养的76个分离物,并进行全基因组测序和MALDI-TOFMS分析。平均核苷酸同一性和MALDI-TOF分析证实了T.finnmarkense和T.dicentrarchi的存在,将T.finnmarkense进一步划分为genomovars(gv.)芬兰人和溃疡。核心基因组多位点序列分型(cgMLST)和单核苷酸多态性(SNP)分析确定了遗传保守的gv簇的存在。finnmarkense分离株的背景是基因相对不同的gv。finnmarkense和gv.在15例研究病例中,有13例分离出溃疡。这种聚类强烈表明T.finnmarkensegv之间存在联系。冬季末和春季,海上养殖的挪威鲑鱼中的临床tenacibacusis的发展和发展。对2019年春季从类似病例中收集的25株Tenacibaculum分离株进行分析,发现基因型分布相似。低水温在所有情况下都很常见,大多数事件涉及海上转移后不久的相对较小的鱼,这表明这些鱼特别容易感染Tenacibaculum。