The heterogeneity of endemic community pediatric group a streptococcal pharyngeal isolates and their relationship to invasive isolates.
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.
Haukness
Heather A
HA
Division of General Medicine, Children's Memorial Hospital, Northwestern University Medical School, Chicago, Illinois 60614, USA.
Tanz
Robert R
RR
Thomson
Richard B
RB
Pierry
Deirdre K
DK
Kaplan
Edward L
EL
Beall
Bernard
B
Johnson
Dwight
D
Hoe
Nancy P
NP
Musser
James M
JM
Shulman
Stanford T
ST
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
D001426:Bacterial Proteins; D005098:Exotoxins; D008565:Membrane Proteins; C117980:SpeA protein, Streptococcus pyogenes; C027951:erythrogenic toxin