Sialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in Haemophilus influenzae and its effect on virulence

Background. Sialic acid has been shown to be a major virulence determinant in the pathogenesis of otitis media caused by the bacterium Haemophilus influenzae. This study aimed to characterise the expression of genes required for the metabolism of sialic acid and to investigate the role of these gene...

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Main Authors: Jenkins, G, Figueira, M, Kumar, G, Sweetman, W, Makepeace, K, Pelton, S, Moxon, R, Hood, D
Format: Journal article
Language:English
Published: BioMed Central 2010
Subjects:
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author Jenkins, G
Figueira, M
Kumar, G
Sweetman, W
Makepeace, K
Pelton, S
Moxon, R
Hood, D
author_facet Jenkins, G
Figueira, M
Kumar, G
Sweetman, W
Makepeace, K
Pelton, S
Moxon, R
Hood, D
author_sort Jenkins, G
collection OXFORD
description Background. Sialic acid has been shown to be a major virulence determinant in the pathogenesis of otitis media caused by the bacterium Haemophilus influenzae. This study aimed to characterise the expression of genes required for the metabolism of sialic acid and to investigate the role of these genes in virulence. Results. Using qRT-PCR, we observed decreased transcriptional activity of genes within a cluster that are required for uptake and catabolism of 5-acetyl neuraminic acid (Neu5Ac), when bacteria were cultured in the presence of the sugar. We show that these uptake and catabolic genes, including a sialic acid regulatory gene (siaR), are highly conserved in the H. influenzae natural population. Mutant strains were constructed for seven of the nine genes and their influence upon LPS sialylation and resistance of the bacteria to the killing effect of normal human serum were assessed. Mutations in the Neu5Ac uptake (TRAP transporter) genes decreased virulence in the chinchilla model of otitis media, but the attenuation was strain dependent. In contrast, mutations in catabolism genes and genes regulating sialic acid metabolism (siaR and crp) did not attenuate virulence. Conclusion. The commensal and pathogenic behaviour of H. influenzae involves LPS sialylation that can be influenced by a complex regulatory interplay of sialometabolism genes. © 2010 Jenkins et al; licensee BioMed Central Ltd.
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spelling oxford-uuid:bf766a87-7691-468e-8721-3185eb45580d2022-03-27T05:47:41ZSialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in Haemophilus influenzae and its effect on virulenceJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:bf766a87-7691-468e-8721-3185eb45580dInfectious diseasesGenetics (medical sciences)PathologyEnglishSymplectic Elements at OxfordBioMed Central2010Jenkins, GFigueira, MKumar, GSweetman, WMakepeace, KPelton, SMoxon, RHood, DBackground. Sialic acid has been shown to be a major virulence determinant in the pathogenesis of otitis media caused by the bacterium Haemophilus influenzae. This study aimed to characterise the expression of genes required for the metabolism of sialic acid and to investigate the role of these genes in virulence. Results. Using qRT-PCR, we observed decreased transcriptional activity of genes within a cluster that are required for uptake and catabolism of 5-acetyl neuraminic acid (Neu5Ac), when bacteria were cultured in the presence of the sugar. We show that these uptake and catabolic genes, including a sialic acid regulatory gene (siaR), are highly conserved in the H. influenzae natural population. Mutant strains were constructed for seven of the nine genes and their influence upon LPS sialylation and resistance of the bacteria to the killing effect of normal human serum were assessed. Mutations in the Neu5Ac uptake (TRAP transporter) genes decreased virulence in the chinchilla model of otitis media, but the attenuation was strain dependent. In contrast, mutations in catabolism genes and genes regulating sialic acid metabolism (siaR and crp) did not attenuate virulence. Conclusion. The commensal and pathogenic behaviour of H. influenzae involves LPS sialylation that can be influenced by a complex regulatory interplay of sialometabolism genes. © 2010 Jenkins et al; licensee BioMed Central Ltd.
spellingShingle Infectious diseases
Genetics (medical sciences)
Pathology
Jenkins, G
Figueira, M
Kumar, G
Sweetman, W
Makepeace, K
Pelton, S
Moxon, R
Hood, D
Sialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in Haemophilus influenzae and its effect on virulence
title Sialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in Haemophilus influenzae and its effect on virulence
title_full Sialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in Haemophilus influenzae and its effect on virulence
title_fullStr Sialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in Haemophilus influenzae and its effect on virulence
title_full_unstemmed Sialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in Haemophilus influenzae and its effect on virulence
title_short Sialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in Haemophilus influenzae and its effect on virulence
title_sort sialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in haemophilus influenzae and its effect on virulence
topic Infectious diseases
Genetics (medical sciences)
Pathology
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