Genome characterization of piscine 'Scale drop and Muscle Necrosis syndrome'-associated strain of Vibrio harveyi focusing on bacterial virulence determinants.

Genomic characterization of Harveyi clade vibrio strain Y6 causing 'Scale drop and Muscle Necrosis syndrome' (SDMN) isolated from barramundi (Lates calcarifer) in Vietnam. A bacterial genome was sequenced using Illumina MiSeq platform. Multilocus sequence analysis confirmed that the bacterium belongs to Vibrio harveyi species. Further phylogenetic analysis inferred from core genome SNPs revealed a close relationship between our bacterium and the V. harveyi isolated from groupers in Taiwan and China. blastp results indicated that V. harveyi piscine strains carried numerous adhesin, secretion system, siderophore and toxin-related genes. Genome comparison between Y6 and 32 strains of V. harveyi from different origins showed that at least 17 potential virulence genes were present exclusively in the strain Y6. Many of these (six of 17 genes) were homologous to pyoverdine siderophore, a secreted high-affinity iron chelator, clusters originally found in Pseudomonas aeruginosa. Genome of V. harveyi Y6 was incorporated by a bacteriophage VHY6φ and replication protein of the phage was most similar to CTXφ described previously in Vibrio cholerae and Vibrio fischeri. However, the cholera toxin-encoding genes, namely ctxA and ctxB, were absent from VHY6φ, while the CTXφ-enterotoxin gene (zonula occludens toxin; zot) remained intact. Several putative virulence genes and a phage carrying toxin gene were identified in the genomes of SDMN-associated V. harveyi Y6. This study confers genomic information of the piscine pathogenic V. harveyi which recently caused widespread mortality. Such information is of importance to gain insight into bacterial molecular pathogenesis.

Kayansamruaj P ，Dong HT ，Hirono I ，Kondo H ，Senapin S ，Rodkhum C ... -  《-》

Delineating the key virulence factors and intraspecies divergence of Vibrio harveyi via whole-genome sequencing.

Fu S ，Ni P ，Yang Q ，Hu H ，Wang Q ，Ye S ，Liu Y ... -  《-》

Horizontal gene transfer contributes to virulence and antibiotic resistance of Vibrio harveyi 345 based on complete genome sequence analysis.

Deng Y ，Xu H ，Su Y ，Liu S ，Xu L ，Guo Z ，Wu J ，Cheng C ，Feng J ... -  《BMC GENOMICS》

Genomic insights of Vibrio harveyi RT-6 strain, from infected "Whiteleg shrimp" (Litopenaeus vannamei) using Illumina platform.

The pathogenicity of "Vibriosis" in shrimps imposes prominent menace to the sustainable growth of mariculture economy. Often the disease outbreak is associated speciously with Vibrio harveyi and its closely related species. The present study investigated the complete genome of the strain V. harveyi RT-6 to explore the molecular mechanism of pathogenesis. The genome of V. harveyi possesses a single chromosome of 6,374,398 bp in size, G + C content (44.7%) and 5730 protein coding genes. The reads of 1.3 Gb were retained from Illumina Hiseq 2500 sequencing method, assembled into 5912 predicted genes, 114 tRNAs genes, and 11 rRNAs genes. Unigenes were annotated by matching against Clusters of Orthologous Groups of proteins (COG)-5730, Gene ontology (GO)-1088, and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases-3401. Furthermore, 13 insertion sequences-(IS), virulence factors and prophage regions were also identified. A total of 94 pathogenic genes and 36 virulence factor genes were mainly identified using Virulence Factors Database (VFDB). Out of the 36 virulence factors, 23 genes responsible for encoding flagella-based motility protein were exclusively predicted to take part in pathogenic mechanism. The Whole Genome Sequencing (WGS) of the strain RT-6 (accession number: SRR5410471) highlighted the underlying genes and specifically accountable functional genes that were responsible for pathogenic infections in shrimps.

Thirugnanasambandam R ，Inbakandan D ，Kumar C ，Subashni B ，Vasantharaja R ，Stanley Abraham L ，Ayyadurai N ，Sriyutha Murthy P ，Kirubagaran R ，Ajmal Khan S ，Balasubramanian T ... -  《-》

Unique and conserved genome regions in Vibrio harveyi and related species in comparison with the shrimp pathogen Vibrio harveyi CAIM 1792.

Espinoza-Valles I ，Vora GJ ，Lin B ，Leekitcharoenphon P ，González-Castillo A ，Ussery D ，Høj L ，Gomez-Gil B ... -  《-》