title: Streptococcus pyogenes emm-types in northern Spain; population dynamics over a 7-year period.
abstract: OBJECTIVE
  To know the clinical entities caused by Streptococcus pyogenes as well as the characteristics of the isolates involved in them throughout a 7-year-study.
  
  
  METHODS
  All S. pyogenes infectious episodes from the community recorded in the reference hospital of Gipuzkoa between 2005 and 2011 were included (n = 11,342). A random selection of 10% of total isolates was characterized by emm-type, T-type and multilocus-sequence-type.
  
  
  RESULTS
  Main clinical presentations were: pharyngitis (n = 9467), otitis (n = 797), dermal infections (n = 506), and genital infections (n = 374). Highest frequency of pharyngitis and otitis was detected in children aged 2-8 years old and 1-year old, respectively. Among 29 emm-types, 8 (emm4, emm89, emm3, emm87, emm1, emm12, emm6 and emm75) grouped >70% of isolates. emm4 was significantly associated with 0-4 year-old patients, and emm89 and emm77 with patients >64 years; by infection type, emm4, emm87 and emm12 were associated with pharyngitis, emm1 and emm6 with otitis, emm89 with dermal infections, and emm77 with genital infections.
  
  
  CONCLUSIONS
  Predominant emm-type changed every year, although the diversity was similar throughout the study period. S. pyogenes pharyngitis maximum incidence presented at earlier age than expected. emm-type associations with age and specific clinical presentations were influenced by population immunity and strain tropism.
authors.affiliation: Microbiology Department, Hospital Universitario Donostia-Instituto Biodonostia, San Sebastián, Spain; Biomedical Research Centre Network for Respiratory Diseases (CIBERES), San Sebastián, Spain. Electronic address: esther.tamayooya@osakidetza.net.
authors.forename: Esther
authors.initials: E
authors.lastname: Tamayo
authors.forename: Milagrosa
authors.initials: M
authors.lastname: Montes
authors.forename: José María
authors.initials: JM
authors.lastname: García-Arenzana
authors.forename: Emilio
authors.initials: E
authors.lastname: Pérez-Trallero
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D004427:Ear Diseases / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010612:Pharyngitis / Q000453:epidemiology / Q000382:microbiology; D015995:Prevalence; D011446:Prospective Studies; D013030:Spain / Q000453:epidemiology; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D022541:Streptococcal Vaccines; D013297:Streptococcus pyogenes / Q000145:classification / Q000235:genetics*; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D022541:Streptococcal Vaccines; C014689:streptococcal M protein
keywords: Group A streptococcus infection; MLST; Otitis; Pharyngitis; T-type; Vaccine; emm-Subtype; emm-Type