Sil: A Streptococcus iniae Bacteriocin with Dual Role as an Antimicrobial and an Immunomodulator That Inhibits Innate Immune Response and Promotes S. iniae Infection
Streptococcus iniae is a Gram-positive bacterium and a severe pathogen to a wide range of economically important fish species. In addition, S. iniae is also a zoonotic pathogen and can cause serious infections in humans. In this study, we identified from a pathogenic S. iniae strain a putative bacte...
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ftpubmed:oai:pubmedcentral.nih.gov:4004548 2023-05-15T18:15:52+02:00 Sil: A Streptococcus iniae Bacteriocin with Dual Role as an Antimicrobial and an Immunomodulator That Inhibits Innate Immune Response and Promotes S. iniae Infection Li, Mo-fei Zhang, Bao-cun Li, Jun Sun, Li 2014-04-29 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004548 http://www.ncbi.nlm.nih.gov/pubmed/24781647 https://doi.org/10.1371/journal.pone.0096222 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC http://www.ncbi.nlm.nih.gov/pubmed/24781647 http://dx.doi.org/10.1371/journal.pone.0096222 This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. CC-BY Research Article Text 2014 ftpubmed https://doi.org/10.1371/journal.pone.0096222 2014-05-04T01:15:13Z Streptococcus iniae is a Gram-positive bacterium and a severe pathogen to a wide range of economically important fish species. In addition, S. iniae is also a zoonotic pathogen and can cause serious infections in humans. In this study, we identified from a pathogenic S. iniae strain a putative bacteriocin, Sil, and examined its biological activity. Sil is composed of 101 amino acid residues and shares 35.6% overall sequence identity with the lactococcin 972 of Lactococcus lactis. Immunoblot analysis showed that Sil was secreted by S. iniae into the extracellular milieu. Purified recombinant Sil (rSil) exhibited a dose-dependent inhibitory effect on the growth of Bacillus subtilis but had no impact on the growths of other 16 Gram-positive bacteria and 10 Gram-negative bacteria representing 23 different bacterial species. Treatment of rSil by heating at 50°C abolished the activity of rSil. rSil bound to the surface of B. subtilis but induced no killing of the target cells. Cellular study revealed that rSil interacted with turbot (Scophthalmus maximus) head kidney monocytes and inhibited the innate immune response of the cells, which led to enhanced cellular infection of S. iniae. Antibody blocking of the extracellular Sil produced by S. iniae significantly attenuated the infectivity of S. iniae. Consistent with these in vitro observations, in vivo study showed that administration of turbot with rSil prior to S. iniae infection significantly increased bacterial dissemination and colonization in fish tissues. Taken together, these results indicate that Sil is a novel virulence-associated bacteriostatic and an immunoregulator that promotes S. iniae infection by impairing the immune defense of host fish. Text Scophthalmus maximus Turbot PubMed Central (PMC) PLoS ONE 9 4 e96222 |
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Research Article Li, Mo-fei Zhang, Bao-cun Li, Jun Sun, Li Sil: A Streptococcus iniae Bacteriocin with Dual Role as an Antimicrobial and an Immunomodulator That Inhibits Innate Immune Response and Promotes S. iniae Infection |
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Research Article |
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Streptococcus iniae is a Gram-positive bacterium and a severe pathogen to a wide range of economically important fish species. In addition, S. iniae is also a zoonotic pathogen and can cause serious infections in humans. In this study, we identified from a pathogenic S. iniae strain a putative bacteriocin, Sil, and examined its biological activity. Sil is composed of 101 amino acid residues and shares 35.6% overall sequence identity with the lactococcin 972 of Lactococcus lactis. Immunoblot analysis showed that Sil was secreted by S. iniae into the extracellular milieu. Purified recombinant Sil (rSil) exhibited a dose-dependent inhibitory effect on the growth of Bacillus subtilis but had no impact on the growths of other 16 Gram-positive bacteria and 10 Gram-negative bacteria representing 23 different bacterial species. Treatment of rSil by heating at 50°C abolished the activity of rSil. rSil bound to the surface of B. subtilis but induced no killing of the target cells. Cellular study revealed that rSil interacted with turbot (Scophthalmus maximus) head kidney monocytes and inhibited the innate immune response of the cells, which led to enhanced cellular infection of S. iniae. Antibody blocking of the extracellular Sil produced by S. iniae significantly attenuated the infectivity of S. iniae. Consistent with these in vitro observations, in vivo study showed that administration of turbot with rSil prior to S. iniae infection significantly increased bacterial dissemination and colonization in fish tissues. Taken together, these results indicate that Sil is a novel virulence-associated bacteriostatic and an immunoregulator that promotes S. iniae infection by impairing the immune defense of host fish. |
format |
Text |
author |
Li, Mo-fei Zhang, Bao-cun Li, Jun Sun, Li |
author_facet |
Li, Mo-fei Zhang, Bao-cun Li, Jun Sun, Li |
author_sort |
Li, Mo-fei |
title |
Sil: A Streptococcus iniae Bacteriocin with Dual Role as an Antimicrobial and an Immunomodulator That Inhibits Innate Immune Response and Promotes S. iniae Infection |
title_short |
Sil: A Streptococcus iniae Bacteriocin with Dual Role as an Antimicrobial and an Immunomodulator That Inhibits Innate Immune Response and Promotes S. iniae Infection |
title_full |
Sil: A Streptococcus iniae Bacteriocin with Dual Role as an Antimicrobial and an Immunomodulator That Inhibits Innate Immune Response and Promotes S. iniae Infection |
title_fullStr |
Sil: A Streptococcus iniae Bacteriocin with Dual Role as an Antimicrobial and an Immunomodulator That Inhibits Innate Immune Response and Promotes S. iniae Infection |
title_full_unstemmed |
Sil: A Streptococcus iniae Bacteriocin with Dual Role as an Antimicrobial and an Immunomodulator That Inhibits Innate Immune Response and Promotes S. iniae Infection |
title_sort |
sil: a streptococcus iniae bacteriocin with dual role as an antimicrobial and an immunomodulator that inhibits innate immune response and promotes s. iniae infection |
publisher |
Public Library of Science |
publishDate |
2014 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004548 http://www.ncbi.nlm.nih.gov/pubmed/24781647 https://doi.org/10.1371/journal.pone.0096222 |
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Scophthalmus maximus Turbot |
genre_facet |
Scophthalmus maximus Turbot |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC http://www.ncbi.nlm.nih.gov/pubmed/24781647 http://dx.doi.org/10.1371/journal.pone.0096222 |
op_rights |
This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
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CC-BY |
op_doi |
https://doi.org/10.1371/journal.pone.0096222 |
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PLoS ONE |
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9 |
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4 |
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e96222 |
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1766189099010490368 |