Identification and Characterization of a Repeat-in-Toxin Gene Cluster in Vibrio anguillarum
ABSTRACT Vibrio anguillarum is the causative agent of vibriosis in fish. Hemolysins of V. anguillarum have been considered virulence factors during infection. One hemolysin gene, vah1 , has been previously identified but does not account for all hemolytic activity. The mini-Tn 10 Km mutagenesis perf...
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American Society for Microbiology
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crasmicro:10.1128/iai.01308-07 2024-06-23T07:51:20+00:00 Identification and Characterization of a Repeat-in-Toxin Gene Cluster in Vibrio anguillarum Li, Ling Rock, Jessica L. Nelson, David R. 2008 http://dx.doi.org/10.1128/iai.01308-07 https://journals.asm.org/doi/pdf/10.1128/IAI.01308-07 en eng American Society for Microbiology https://journals.asm.org/non-commercial-tdm-license Infection and Immunity volume 76, issue 6, page 2620-2632 ISSN 0019-9567 1098-5522 journal-article 2008 crasmicro https://doi.org/10.1128/iai.01308-07 2024-06-03T08:10:52Z ABSTRACT Vibrio anguillarum is the causative agent of vibriosis in fish. Hemolysins of V. anguillarum have been considered virulence factors during infection. One hemolysin gene, vah1 , has been previously identified but does not account for all hemolytic activity. The mini-Tn 10 Km mutagenesis performed with a vah1 mutant resulted in a hemolysin-negative mutant. The region surrounding the mutation was cloned and sequenced, revealing a putative rtx operon with six genes ( rtxACHBDE ), where rtxA encodes an exotoxin, rtxC encodes an RtxA activator, rtxH encodes a conserved hypothetical protein, and rtxBDE encode the ABC transporters. Single mutations in rtx genes did not result in a hemolysin-negative phenotype. However, strains containing a mutation in vah1 and a mutation in an rtx gene resulted in a hemolysin-negative mutant, demonstrating that the rtx operon is a second hemolysin gene cluster in V. anguillarum M93Sm. Reverse transcription-PCR analysis revealed that the rtxC and rtxA genes are cotranscribed, as are the rtxBDE genes. Additionally, Vah1 and RtxA each have cytotoxic activity against Atlantic salmon kidney (ASK) cells. Single mutations in vah1 or rtxA attenuate the cytotoxicity of V. anguillarum M93Sm. A vah1 rtxA double mutant is no longer cytotoxic. Moreover, Vah1 and RtxA each have a distinct cytotoxic effect on ASK cells, Vah1 causes cell vacuolation, and RtxA causes cell rounding. Finally, wild-type and mutant strains were tested for virulence in juvenile Atlantic salmon. Only strains containing an rtxA mutation had reduced virulence, suggesting that RtxA is a major virulence factor for V. anguillarum . Article in Journal/Newspaper Atlantic salmon ASM Journals (American Society for Microbiology) Infection and Immunity 76 6 2620 2632 |
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English |
description |
ABSTRACT Vibrio anguillarum is the causative agent of vibriosis in fish. Hemolysins of V. anguillarum have been considered virulence factors during infection. One hemolysin gene, vah1 , has been previously identified but does not account for all hemolytic activity. The mini-Tn 10 Km mutagenesis performed with a vah1 mutant resulted in a hemolysin-negative mutant. The region surrounding the mutation was cloned and sequenced, revealing a putative rtx operon with six genes ( rtxACHBDE ), where rtxA encodes an exotoxin, rtxC encodes an RtxA activator, rtxH encodes a conserved hypothetical protein, and rtxBDE encode the ABC transporters. Single mutations in rtx genes did not result in a hemolysin-negative phenotype. However, strains containing a mutation in vah1 and a mutation in an rtx gene resulted in a hemolysin-negative mutant, demonstrating that the rtx operon is a second hemolysin gene cluster in V. anguillarum M93Sm. Reverse transcription-PCR analysis revealed that the rtxC and rtxA genes are cotranscribed, as are the rtxBDE genes. Additionally, Vah1 and RtxA each have cytotoxic activity against Atlantic salmon kidney (ASK) cells. Single mutations in vah1 or rtxA attenuate the cytotoxicity of V. anguillarum M93Sm. A vah1 rtxA double mutant is no longer cytotoxic. Moreover, Vah1 and RtxA each have a distinct cytotoxic effect on ASK cells, Vah1 causes cell vacuolation, and RtxA causes cell rounding. Finally, wild-type and mutant strains were tested for virulence in juvenile Atlantic salmon. Only strains containing an rtxA mutation had reduced virulence, suggesting that RtxA is a major virulence factor for V. anguillarum . |
format |
Article in Journal/Newspaper |
author |
Li, Ling Rock, Jessica L. Nelson, David R. |
spellingShingle |
Li, Ling Rock, Jessica L. Nelson, David R. Identification and Characterization of a Repeat-in-Toxin Gene Cluster in Vibrio anguillarum |
author_facet |
Li, Ling Rock, Jessica L. Nelson, David R. |
author_sort |
Li, Ling |
title |
Identification and Characterization of a Repeat-in-Toxin Gene Cluster in Vibrio anguillarum |
title_short |
Identification and Characterization of a Repeat-in-Toxin Gene Cluster in Vibrio anguillarum |
title_full |
Identification and Characterization of a Repeat-in-Toxin Gene Cluster in Vibrio anguillarum |
title_fullStr |
Identification and Characterization of a Repeat-in-Toxin Gene Cluster in Vibrio anguillarum |
title_full_unstemmed |
Identification and Characterization of a Repeat-in-Toxin Gene Cluster in Vibrio anguillarum |
title_sort |
identification and characterization of a repeat-in-toxin gene cluster in vibrio anguillarum |
publisher |
American Society for Microbiology |
publishDate |
2008 |
url |
http://dx.doi.org/10.1128/iai.01308-07 https://journals.asm.org/doi/pdf/10.1128/IAI.01308-07 |
genre |
Atlantic salmon |
genre_facet |
Atlantic salmon |
op_source |
Infection and Immunity volume 76, issue 6, page 2620-2632 ISSN 0019-9567 1098-5522 |
op_rights |
https://journals.asm.org/non-commercial-tdm-license |
op_doi |
https://doi.org/10.1128/iai.01308-07 |
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Infection and Immunity |
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76 |
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6 |
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2620 |
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2632 |
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1802642400519127040 |