Molecular characterization of Streptococcus pyogenes isolates collected during periods of increased acute rheumatic fever activity in Utah.
BACKGROUND
Salt Lake City, Utah has seen a continuing resurgence of rheumatic fever (RF) since 1985.


METHODS
emm genotyping and multilocus sequence typing of streptococcal isolates from periods of increased RF activity were performed.


RESULTS
Multiple genotypes were present during 1985 and 1998, two peak years of RF activity, and in 1992, a year with reduced RF activity. emm3 and emm18.1 were present in 1985 and 1998, but not in 1992. Two other emm types, 12 and L28, were significantly elevated in 1998 (a peak RF year) over 1992 (a non-peak RF year). Allelic profiles for the emm3 and emm18.1 isolates exhibited clonality.


CONCLUSIONS
During years of increased RF activity multiple emm types, including emm18.1 and emm3, were circulating in the community. During a year of decreased RF activity, emm3 and emm18.1 genotypes were absent. The clonality of the emm3 and emm18.1 types suggests that specific clones of both types are important in the resurgence of RF during these peak years. Two other genotypes, emm12 and emmL28, may also be associated with the persistence of RF in the Salt Lake City, UT area.
Miner
Lonnie J
LJ
Department of Pediatrics, University of Utah Health Sciences Center, Salt Lake City, UT, USA.
Petheram
Susan J
SJ
Daly
Judy A
JA
Korgenski
E Kent
EK
Selin
Kristie S
KS
Firth
Sean D
SD
Veasy
L George
LG
Hill
Harry R
HR
Bale
James F
JF
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D015331:Cohort Studies; D016001:Confidence Intervals; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D008297:Male; D008969:Molecular Sequence Data; D016017:Odds Ratio; D016133:Polymerase Chain Reaction / Q000379:methods; D012213:Rheumatic Fever / Q000453:epidemiology* / Q000382:microbiology*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000175:diagnosis / Q000453:epidemiology*; D013297:Streptococcus pyogenes / Q000235:genetics* / Q000302:isolation & purification; D014589:Utah / Q000453:epidemiology
D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial