Titre
M-protein and other intrinsic virulence factors of Streptococcus pyogenes are encoded on an ancient pathogenicity island.
Type
article
Institution
UNIL/CHUV/Unisanté + institutions partenaires
Périodique
Auteur(s)
Panchaud, A.
Auteure/Auteur
Guy, L.
Auteure/Auteur
Collyn, F.
Auteure/Auteur
Haenni, M.
Auteure/Auteur
Nakata, M.
Auteure/Auteur
Podbielski, A.
Auteure/Auteur
Moreillon, P.
Auteure/Auteur
Roten, C.A.
Auteure/Auteur
Liens vers les personnes
Liens vers les unités
ISSN
1471-2164[electronic]
Statut éditorial
Publié
Date de publication
2009
Volume
10
Première page
198
Peer-reviewed
Oui
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't Publication Status: epublish
Résumé
BACKGROUND: The increasing number of completely sequenced bacterial genomes allows comparing their architecture and genetic makeup. Such new information highlights the crucial role of lateral genetic exchanges in bacterial evolution and speciation. RESULTS: Here we analyzed the twelve sequenced genomes of Streptococcus pyogenes by a naïve approach that examines the preferential nucleotide usage along the chromosome, namely the usage of G versus C (GC-skew) and T versus A (TA-skew). The cumulative GC-skew plot presented an inverted V-shape composed of two symmetrical linear segments, where the minimum and maximum corresponded to the origin and terminus of DNA replication. In contrast, the cumulative TA-skew presented a V-shape, which segments were interrupted by several steep slopes regions (SSRs), indicative of a different nucleotide composition bias. Each S. pyogenes genome contained up to nine individual SSRs, encompassing all described strain-specific prophages. In addition, each genome contained a similar unique non-phage SSR, the core of which consisted of 31 highly homologous genes. This core includes the M-protein, other mga-related factors and other virulence genes, totaling ten intrinsic virulence genes. In addition to a high content in virulence-related genes and to a peculiar nucleotide bias, this SSR, which is 47 kb-long in a M1GAS strain, harbors direct repeats and a tRNA gene, suggesting a mobile element. Moreover, its complete absence in a M-protein negative group A Streptococcus natural isolate demonstrates that it could be spontaneously lost, but in vitro deletion experiments indicates that its excision occurred at very low rate. The stability of this SSR, combined to its presence in all sequenced S. pyogenes sequenced genome, suggests that it results from an ancient acquisition. CONCLUSION: Thus, this non-phagic SSR is compatible with a pathogenicity island, acquired before S. pyogenes speciation. Its potential excision might bear relevance for vaccine development, because vaccines targeting M-protein might select for M-protein-negative variants that still carry other virulence determinants.
Sujets
PID Serval
serval:BIB_DE1F2114471F
PMID
Open Access
Oui
Date de création
2010-02-03T15:51:40.644Z
Date de création dans IRIS
2025-05-21T05:07:55Z
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Nom
BIB_DE1F2114471F.P001.pdf
Version du manuscrit
published
Taille
521.8 KB
Format
Adobe PDF
PID Serval
serval:BIB_DE1F2114471F.P001
URN
urn:nbn:ch:serval-BIB_DE1F2114471F0
Somme de contrôle
(MD5):43860e24f46d625c2b5b11ec3c2458a1