title: The heterogeneity of endemic community pediatric group a streptococcal pharyngeal isolates and their relationship to invasive isolates.
abstract: By use of molecular techniques, the genetic heterogeneity of 63 community pediatric pharyngeal group A streptococcal (GAS) isolates circulating within a 3-week period were compared with 17 contemporaneous invasive pediatric isolates. Pharyngitis isolates represented 16 pulsed-field gel electrophoresis (PFGE) patterns with 12 emm serotypes, and invasive isolates represented 10 PFGE patterns with 9 emm serotypes. One-fourth of the pharyngeal isolates (16/63) were identical to at least 1 invasive isolate; conversely, 10 (59%) of 17 invasive isolates were identical to at least 1 pharyngeal strain. sic allele analysis of emm1 strains demonstrated additional heterogeneity and overlap. More pharyngeal (71%) than invasive isolates (35%) were positive for both speA and speC (P<.02). Many pharyngitis GAS strains circulate simultaneously. Most invasive pediatric GAS strains are identical to acute pharyngitis strains; thus, childhood pharyngitis is a major reservoir for strains with invasive potential. Pharyngeal isolates were more likely to be speA and speC positive than were the invasive isolates.
authors.affiliation: Division of General Medicine, Children's Memorial Hospital, Northwestern University Medical School, Chicago, Illinois 60614, USA.
authors.forename: Heather A
authors.initials: HA
authors.lastname: Haukness
authors.forename: Robert R
authors.initials: RR
authors.lastname: Tanz
authors.forename: Richard B
authors.initials: RB
authors.lastname: Thomson
authors.forename: Deirdre K
authors.initials: DK
authors.lastname: Pierry
authors.forename: Edward L
authors.initials: EL
authors.lastname: Kaplan
authors.forename: Bernard
authors.initials: B
authors.lastname: Beall
authors.forename: Dwight
authors.initials: D
authors.lastname: Johnson
authors.forename: Nancy P
authors.initials: NP
authors.lastname: Hoe
authors.forename: James M
authors.initials: JM
authors.lastname: Musser
authors.forename: Stanford T
authors.initials: ST
authors.lastname: Shulman
mesh_terms: D000293:Adolescent; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D016521:Electrophoresis, Gel, Pulsed-Field; D019353:Endemic Diseases; D005098:Exotoxins / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008565:Membrane Proteins / Q000235:genetics; D010614:Pharynx / Q000382:microbiology*; D012703:Serotyping; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D005098:Exotoxins; D008565:Membrane Proteins; C117980:SpeA protein, Streptococcus pyogenes; C027951:erythrogenic toxin