title: M-protein gene-type distribution and hyaluronic acid capsule in group A Streptococcus clinical isolates in Chile: association of emm gene markers with csrR alleles.
abstract: Streptococcus pyogenes causes a variety of infections because of virulence factors such as capsular hyaluronic acid and M protein. The aim of this study was to determine emm types and capsule phenotype in 110 isolates of S. pyogenes from patients with invasive (sterile sites) and non-invasive (mainly pharyngitis) infections in Chile, and the relationship between both virulence factors. The most abundant types found were emm12, emm1, emm4 and emm28 and their distribution was similar to that seen in Latin America and developed countries, but very different from that in Asia and Pacific Island countries. Ten of 16 emm types identified in pharyngeal isolates were found in sterile-site isolates, and three of nine emm types of sterile-site isolates occurred in pharyngeal isolates; three emm subtypes were novel. The amount of hyaluronic acid was significantly higher in sterile-site isolates but did not differ substantially among emm types. Only three isolates were markedly capsulate and two of them had mutations in the csrR gene that codes for a repressor of capsule synthesis genes. We found a non-random association between emm types and csrR gene alleles suggesting that horizontal gene transfer is not freely occurring in the population.
authors: Laboratorio de Microbiología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors: A
authors: A
authors: Wozniak
authors: P
authors: P
authors: Rojas
authors: C
authors: C
authors: Rodríguez
authors: A
authors: A
authors: Undabarrena
authors: C
authors: C
authors: Garate
authors: I
authors: I
authors: Riedel
authors: J C
authors: JC
authors: Román
authors: A M
authors: AM
authors: Kalergis
authors: P
authors: P
authors: García
mesh_terms: D000483:Alleles; D000942:Antigens, Bacterial / Q000235:genetics*; D016667:Bacterial Capsules / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D002677:Chile; D005838:Genotype; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism*; D010641:Phenotype; D012097:Repressor Proteins / Q000235:genetics*; D013223:Statistics as Topic; D013290:Streptococcal Infections / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C432143:CsrR protein, Streptococcus pyogenes; D012097:Repressor Proteins; D037521:Virulence Factors; C014689:streptococcal M protein; D006820:Hyaluronic Acid