Publications (49) View all
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Article: Comparative analysis and distribution of pP9014, a novel drug resistance IncP-1 plasmid from Photobacterium damselae subsp. piscicida.
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ABSTRACT: Photobacterium damselae subsp. piscicida, a causative agent of pseudotuberculosis, often harbours resistance plasmids (R plasmids) that facilitate horizontal gene transfer of drug resistance genes. R plasmid pP9014 was isolated from P. damselae subsp. piscicida and its complete nucleotide sequence was determined using Next Generation Sequencing technology. A protein network analysis was conducted to determine the relatedness of protein coding sequences, and ClustalW was used for the full nucleotide sequences. The occurrence of pP9014-like plasmids compared with pP99-018-like plasmids in a specific region was determined using probes for their transfer regions. pP9014 is 55851bp long with an overall GC content of 44.4% encoding 61 open reading frames (ORFs) including antimicrobial resistance genes and two conjugative transfer regions (Tra and Trb). The backbone showed highest similarity to Marinobacter adhaerens pHP-42 and Methylophaga sp. JAM7. pP9014 is similar to several IncP plasmids but forms a different subgroup. pP9014 is a unique plasmid in P. damselae subsp. piscicida and was not commonly found in drug-resistant P. damselae subsp. piscicida isolated from different areas and years in Japan. Plasmids similar to the previously reported pP99-018 are more widely distributed. This rarity suggests that plasmids similar to pP99-018 are more compatible with γ-proteobacteria. pP9014 is the first reported IncP-1 plasmid from fish pathogens. Its similarity to other IncP plasmids isolated from soil and human pathogens suggests that plasmids of the IncP-1 incompatibility group are vectors for the transfer of drug resistance genes among diverse environments.International journal of antimicrobial agents 04/2013; · 3.03 Impact Factor -
Article: Heat shock protein profiles on the protein and gene expression levels in olive flounder kidney infected with Streptococcus parauberis.
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ABSTRACT: Heat shock proteins (HSPs) have been observed in cells exposed to a variety of stresses, including infectious pathogens. This study used a label-free, quantitative proteomic approach and transcriptional gene expression analysis to investigate infection-related HSP proteins and their encoding genes in whole kidneys from olive flounder (Paralichthys olivaceus). During Streptococcus parauberis infection in the flounder, the genes encoding Hsp10, Hsp40A4, Hsp40B6, Hsp40B11, Hsp60, Hsp70, glucose regulated protein 78 (Grp78), Hsp90α, Hsp90β and Grp94 were induced, and the protein levels of Hsp60, Hsp70, Hsp90α, Hsp90β and Grp94 were differentially regulated over time. Subsequent results also revealed that Hsp60, Hsp70, Hsp90α, Hsp90β and Grp94 appear to be the dominant and critical HSPs in olive flounder during bacterial infection. This is the first estimation of the differential involvement of HSPs in the immune response of olive flounder exposed to bacterial infection.Fish & Shellfish Immunology 03/2013; · 3.32 Impact Factor -
Article: Innate immunity of finfish: Primordial conservation and function of viral RNA sensors in teleosts.
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ABSTRACT: During the past decade, huge progress has been made in research into teleost PAMPs (pathogen-associated molecule patterns) recognition receptors (PRRs). Numerous fish PRR genes have been identified, and the primordial functions of PRRs involved in the innate immune response to viral infection (especially those responsible for sensing viral RNA) have been increasingly clarified in teleosts. Particular progress has been made in our understanding of Toll-like receptors (TLRs) and retinoic acid inducible gene I (RIG-I)-like receptors (RLRs). However, there are important evolutionary differences between teleosts and mammals; for instance, seven TLR repertoires (TLR5S, -14, -19, -20, -21, -22 and -23) are present in teleosts but not in mammals, indicating that some TLRs likely possess different functions. Thus, comparison of PRRs in teleosts and mammals may help us understand the immune responses triggered by host-pathogen interactions in teleosts. In this article, the evolutionary conservations and divergences in the PRR mechanisms of teleosts and mammals are examined, with a focus on their molecular features and the recognition of viral RNA by fish TLRs and RLRs. In addition, the mechanism of type I interferon gene expression in teleosts, which is enhanced after the recognition of viral RNA by fish TLRs and RLRs, is also introduced.Fish & Shellfish Immunology 02/2013; · 3.32 Impact Factor -
Article: RNA-Seq-Based Metatranscriptomic and Microscopic Investigation Reveals Novel Metalloproteases of Neobodo sp. as Potential Virulence Factors for Soft Tunic Syndrome in Halocynthia roretzi
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ABSTRACT: Bodonids and trypanosomatids are derived from a common ancestor with the bodonids being a more primitive lineage. The Neobodonida, one of the three clades of bodonids, can be free-living, commensal or parasitic. Despite the ecological and evolutionary significance of these organisms, however, many of their biological and pathological features are currently unknown. Here, we employed metatranscriptomics using RNA-seq technology combined with field-emission microscopy to reveal the virulence factors of a recently described genus of Neobodonida that is considered to be responsible for ascidian soft tunic syndrome (AsSTS), but whose pathogenesis is unclear. Our microscopic observation of infected tunic tissues suggested putative virulence factors, enabling us to extract novel candidate transcripts; these included cysteine proteases of the families C1 and C2, serine proteases of S51 and S9 families, and metalloproteases grouped into families M1, M3, M8, M14, M16, M17, M24, M41, and M49. Protease activity/inhibition assays and the estimation of expression levels within gene clusters allowed us to identify metalloprotease-like enzymes as potential virulence attributes for AsSTS. Furthermore, a multimarker-based phylogenetic analysis using 1,184 concatenated amino acid sequences clarified the order Neobodo sp. In sum, we herein used metatranscriptomics to elucidate the in situ expression profiles of uncharacterized putative transcripts of Neobodo sp., combined these results with microscopic observation to select candidate genes relevant to pathogenesis, and used empirical screening to define important virulence factors.PLoS ONE 12/2012; 7(12):e52379. · 4.09 Impact Factor -
Article: Variable domain antibodies specific for viral hemorrhagic septicemia virus (VHSV) selected from a randomized IgNAR phage display library.
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ABSTRACT: Phage display libraries are used to screen for nucleotide sequences that encode immunoglobulin variable (V) regions that are specific for a target antigen. We previously constructed an immunoglobulin new antigen receptor (IgNAR) phage display library. Here we used this library to obtain an IgNAR V region that is specific for viral hemorrhagic septicemia virus (VHSV). A phage clone (clone 653) was found to be specific for VHSV by the biopanning method. The V region of clone 653 was used to construct a 6×His tagged recombinant IgNAR-653 V protein (rIgNAR-653) using the Escherichia coli pET system. The rIgNAR-653 protein bound specifically to VHSV, confirming its activity.Fish & Shellfish Immunology 12/2012; · 3.32 Impact Factor
