title: Genetic diversity of Group A Streptococcus M protein: implications for typing and vaccine development.
abstract: Group A Streptococci (GAS) are classified into 180 emm-types based on the sequence of the amino-terminal hyper-variable region of the M surface protein. The genetic relatedness of the whole surface-exposed part of M was investigated in well-characterized Belgian and Brazilian GAS isolates which belong to different epidemiological and clinical landscapes. Despite a small number of different emm-types and an apparent low diversity in the Belgian isolates (as revealed by the emm-typing method), our data showed that the overall genetic diversity of the M proteins was higher than expected. On the contrary, the M proteins from the Brazilian isolates were genetically highly related. Since M is a multi-functional protein, an analysis of the whole surface-exposed sequence that takes into account the different functional domains may provide tools for typing as well as for analyzing the molecular mechanisms of M virulence or defining vaccine strategies.
authors.affiliation: Laboratoire de Génétique et Physiologie Bactérienne, Institut de Biologie et de Médecine Moléculaires, Faculté des Sciences, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, 6041 Gosselies, Belgium. psmeeste@ulb.ac.be
authors.forename: Pierre R
authors.initials: PR
authors.lastname: Smeesters
authors.forename: Patrick
authors.initials: P
authors.lastname: Mardulyn
authors.forename: Anne
authors.initials: A
authors.lastname: Vergison
authors.forename: Raphaël
authors.initials: R
authors.lastname: Leplae
authors.forename: Laurence
authors.initials: L
authors.lastname: Van Melderen
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics* / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000276:immunology*; D001530:Belgium / Q000453:epidemiology; D001938:Brazil / Q000453:epidemiology; D002352:Carrier Proteins / Q000235:genetics* / Q000276:immunology*; D005798:Genes, Bacterial / Q000235:genetics / Q000276:immunology; D014644:Genetic Variation; D006801:Humans; D017720:Molecular Epidemiology; D010802:Phylogeny; D010958:Plasminogen / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013290:Streptococcal Infections / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology; D022541:Streptococcal Vaccines / Q000235:genetics* / Q000276:immunology*; D013297:Streptococcus pyogenes / Q000235:genetics* / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D022541:Streptococcal Vaccines; C014689:streptococcal M protein; D010958:Plasminogen