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rpoB mutations conferring rifampicin-resistance affect growth, stress response and motility in Vibrio vulnificus

Rifampicin is a broad-spectrum antibiotic that binds to the bacterial RNA polymerase (RNAP), compromising DNA transcription. Rifampicin resistance is common in several microorganisms and it is typically caused by point mutations in the gene encoding the β subunit of RNA polymerase, rpoB. Different r...

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Autores principales: Cutugno, Laura, Mc Cafferty, Jennifer, Pané-Farré, Jan, O’Byrne, Conor, Boyd, Aoife
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Microbiology Society 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7819355/
https://www.ncbi.nlm.nih.gov/pubmed/33186092
http://dx.doi.org/10.1099/mic.0.000991
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author Cutugno, Laura
Mc Cafferty, Jennifer
Pané-Farré, Jan
O’Byrne, Conor
Boyd, Aoife
author_facet Cutugno, Laura
Mc Cafferty, Jennifer
Pané-Farré, Jan
O’Byrne, Conor
Boyd, Aoife
author_sort Cutugno, Laura
collection PubMed
description Rifampicin is a broad-spectrum antibiotic that binds to the bacterial RNA polymerase (RNAP), compromising DNA transcription. Rifampicin resistance is common in several microorganisms and it is typically caused by point mutations in the gene encoding the β subunit of RNA polymerase, rpoB. Different rpoB mutations are responsible for various levels of rifampicin resistance and for a range of secondary effects. rpoB mutations conferring rifampicin resistance have been shown to be responsible for severe effects on transcription, cell fitness, bacterial stress response and virulence. Such effects have never been investigated in the marine pathogen Vibrio vulnificus , even though rifampicin-resistant strains of V. vulnificus have been isolated previously. Moreover, spontaneous rifampicin-resistant strains of V. vulnificus have an important role in conjugation and mutagenesis protocols, with poor consideration of the effects of rpoB mutations. In this work, effects on growth, stress response and virulence of V. vulnificus were investigated using a set of nine spontaneous rifampicin-resistant derivatives of V. vulnificus CMCP6. Three different mutations (Q513K, S522L and H526Y) were identified with varying incidence rates. These three mutant types each showed high resistance to rifampicin [minimal inhibitory concentration (MIC) >800 µg ml(−1)], but different secondary effects. The strains carrying the mutation H526Y had a growth advantage in rich medium but had severely reduced salt stress tolerance in the presence of high NaCl concentrations as well as a significant reduction in ethanol stress resistance. Strains possessing the S522L mutation had reduced growth rate and overall biomass accumulation in rich medium. Furthermore, investigation of virulence characteristics demonstrated that all the rifampicin-resistant strains showed compromised motility when compared with the wild-type, but no major effects on exoenzyme production were observed. These findings reveal a wide range of secondary effects of rpoB mutations and indicate that rifampicin resistance is not an appropriate selectable marker for studies that aim to investigate phenotypic behaviour in this organism.
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spelling pubmed-78193552021-01-22 rpoB mutations conferring rifampicin-resistance affect growth, stress response and motility in Vibrio vulnificus Cutugno, Laura Mc Cafferty, Jennifer Pané-Farré, Jan O’Byrne, Conor Boyd, Aoife Microbiology (Reading) Research Article Rifampicin is a broad-spectrum antibiotic that binds to the bacterial RNA polymerase (RNAP), compromising DNA transcription. Rifampicin resistance is common in several microorganisms and it is typically caused by point mutations in the gene encoding the β subunit of RNA polymerase, rpoB. Different rpoB mutations are responsible for various levels of rifampicin resistance and for a range of secondary effects. rpoB mutations conferring rifampicin resistance have been shown to be responsible for severe effects on transcription, cell fitness, bacterial stress response and virulence. Such effects have never been investigated in the marine pathogen Vibrio vulnificus , even though rifampicin-resistant strains of V. vulnificus have been isolated previously. Moreover, spontaneous rifampicin-resistant strains of V. vulnificus have an important role in conjugation and mutagenesis protocols, with poor consideration of the effects of rpoB mutations. In this work, effects on growth, stress response and virulence of V. vulnificus were investigated using a set of nine spontaneous rifampicin-resistant derivatives of V. vulnificus CMCP6. Three different mutations (Q513K, S522L and H526Y) were identified with varying incidence rates. These three mutant types each showed high resistance to rifampicin [minimal inhibitory concentration (MIC) >800 µg ml(−1)], but different secondary effects. The strains carrying the mutation H526Y had a growth advantage in rich medium but had severely reduced salt stress tolerance in the presence of high NaCl concentrations as well as a significant reduction in ethanol stress resistance. Strains possessing the S522L mutation had reduced growth rate and overall biomass accumulation in rich medium. Furthermore, investigation of virulence characteristics demonstrated that all the rifampicin-resistant strains showed compromised motility when compared with the wild-type, but no major effects on exoenzyme production were observed. These findings reveal a wide range of secondary effects of rpoB mutations and indicate that rifampicin resistance is not an appropriate selectable marker for studies that aim to investigate phenotypic behaviour in this organism. Microbiology Society 2020-11-13 /pmc/articles/PMC7819355/ /pubmed/33186092 http://dx.doi.org/10.1099/mic.0.000991 Text en © 2020 The Authors https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License. This article was made open access via a Publish and Read agreement between the Microbiology Society and the corresponding author’s institution.
spellingShingle Research Article
Cutugno, Laura
Mc Cafferty, Jennifer
Pané-Farré, Jan
O’Byrne, Conor
Boyd, Aoife
rpoB mutations conferring rifampicin-resistance affect growth, stress response and motility in Vibrio vulnificus
title rpoB mutations conferring rifampicin-resistance affect growth, stress response and motility in Vibrio vulnificus
title_full rpoB mutations conferring rifampicin-resistance affect growth, stress response and motility in Vibrio vulnificus
title_fullStr rpoB mutations conferring rifampicin-resistance affect growth, stress response and motility in Vibrio vulnificus
title_full_unstemmed rpoB mutations conferring rifampicin-resistance affect growth, stress response and motility in Vibrio vulnificus
title_short rpoB mutations conferring rifampicin-resistance affect growth, stress response and motility in Vibrio vulnificus
title_sort rpob mutations conferring rifampicin-resistance affect growth, stress response and motility in vibrio vulnificus
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7819355/
https://www.ncbi.nlm.nih.gov/pubmed/33186092
http://dx.doi.org/10.1099/mic.0.000991
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