Increase in pilus islet 2-encoded pili among Streptococcus pneumoniae isolates, Atlanta, Georgia, USA.
To define the prevalence of pilus islet 2 (PI-2)-encoded pili in Streptococcus pneumoniae in a geographically defined area, we examined 590 S. pneumoniae isolates from population-based surveillance of invasive pneumococcal disease in Atlanta, Georgia, USA, 1994-2006. In 2006, PI-2 was present in 21% of all invasive isolates, including serotypes 1 (100%), 7F (89%), 11A (21%), 19A (40%), and 19F (75%). Only serotype 19F is included in the 7-valent pneumococcal conjugate vaccine that is in use worldwide. In 1999, PI-2-containing isolates were of the same serotypes but accounted for only 3.6% of all invasive isolates. The increase of PI-2 in 2006 resulted predominantly from the emergence of serotype 19A isolates of sequence type 320 and the expansion of serotype 7F isolates. The increase in PI-2-containing isolates and the finding that isolates of all identified serotypes expressed highly conserved PI-2 pili supports their potential as a vaccine candidate.
Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, Georgia 30322, USA. dzahner@emory.edu
Dorothea
D
Zähner
Aditya
A
Gudlavalleti
David S
DS
Stephens
D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D010861:Fimbriae, Bacterial / Q000235:genetics* / Q000378:metabolism; D005798:Genes, Bacterial; D014644:Genetic Variation; D005845:Georgia / Q000453:epidemiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000378:metabolism / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
D004269:DNA, Bacterial