Most M type 5 group A streptococcal strains were found to contain a single emm-like gene between virR and scpA (the Vir regulon), but two distinct emm-like genes were identified in the Vir regulon of the M5 strain NCTC8193. The complete sequences of both of these genes were determined. One, called emm5.8193, was shown to be a minor variant of the previously described emm5 gene from strain Manfredo. The second, designated enn5.8193, expresses an IgG-binding protein when cloned in Escherichia coli. A comparison of enn5.8193 with emm-like gene sequences from other strains indicated that it has a mosaic structure, consisting of distinct segments originating from emm-like genes in different OF+ and OF- strains. These data provide the first clear evidence that the horizontal transfer of emm-like sequences between distinct strains contributes to the evolution of group A streptococcal emm-like genes and Vir regulons.
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http://dx.doi.org/10.1111/j.1365-2958.1994.tb00316.x | DOI Listing |
mSphere
January 2020
Molecular Bacteriology Laboratory, Université Libre de Bruxelles, Brussels, Belgium
The core Mga (multiple gene activator) regulon of group A (GAS) contains genes encoding proteins involved in adhesion and immune evasion. While all GAS genomes contain genes for Mga and C5a peptidase, the intervening genes encoding M and M-like proteins vary between strains. The genetic make-up of the Mga regulon of GAS was characterized by utilizing a collection of 1,688 GAS genomes that are representative of the global GAS population.
View Article and Find Full Text PDFFront Microbiol
March 2019
Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
is an animal pathogen which occasionally causes infections in humans. The M-like protein (SCM) encoded by the gene, is its best characterized virulence factor but previous studies suggested it could be absent in a substantial fraction of isolates. We studied the distribution and variability of the gene in 188 isolates recovered from companion animals ( = 152), wild animal species ( = 20), and humans ( = 14).
View Article and Find Full Text PDFJpn J Infect Dis
January 2017
Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University.
We surveyed group C and group G β-hemolytic streptococci for emm and emmL (emm -like) genes which encode the M protein, as well as determined their antimicrobial susceptibilities. A total of 97 isolates 79 GCS/GGS isolates and 18 isolates from other groups were tested for the M protein gene by PCR. Focusing on invasive infections with group A (GAS), group C (GCS), and group G (GGS) β-hemolytic streptococci isolated from blood, the M protein gene was found in 90.
View Article and Find Full Text PDFJ Bacteriol
June 2016
W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
Unlabelled: The genome of an invasive skin-tropic strain (AP53) of serotype M53 group A Streptococcus pyogenes (GAS) is composed of a circular chromosome of 1,860,554 bp and carries genetic markers for infection at skin locales, viz, emm gene family pattern D and FCT type 3. Through genome-scale comparisons of AP53 with other GAS genomes, we identified 596 candidate single-nucleotide polymorphisms (SNPs) that reveal a potential genetic basis for skin tropism. The genome of AP53 differed by ∼30 point mutations from a noninvasive pattern D serotype M53 strain (Alab49), 4 of which are located in virulence genes.
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