title: Increased penicillin nonsusceptibility of nonvaccine-serotype invasive pneumococci other than serotypes 19A and 6A in post-7-valent conjugate vaccine era.
abstract: According to population-based invasive pneumococcal surveillance in the United States during 2007, 898 (26%) of 3,511 isolates were penicillin nonsusceptible. Non-7-valent pneumococcal conjugate vaccine (PCV7) serotypes other than 19A accounted for 40% of these penicillin-nonsusceptible isolates; of these, serotypes 15A (11%), 23A (8%), 35B (8%), and 6C (5%) were most common (cumulatively 32% of penicillin-nonsusceptible isolates). Each except 6C represented a single serotype and clonal complex combination that predated the introduction of PCV7. We evaluated the genetic characteristics and nonsusceptibility to penicillin of non- PCV7 serotypes, and we found increased proportions of specific penicillin-nonsusceptible clones in serotypes 15A, 23A, 35B, and 6C, which potentially indicates a basic change of population structure within these individual serotypes.
authors.affiliation: Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Gertz
authors.forename: Zhongya
authors.initials: Z
authors.lastname: Li
authors.forename: Fabiana C
authors.initials: FC
authors.lastname: Pimenta
authors.forename: Delois
authors.initials: D
authors.lastname: Jackson
authors.forename: Billie A
authors.initials: BA
authors.lastname: Juni
authors.forename: Ruth
authors.initials: R
authors.lastname: Lynfield
authors.forename: James H
authors.initials: JH
authors.lastname: Jorgensen
authors.forename: Maria da Gloria
authors.initials: Mda G
authors.lastname: Carvalho
authors.forename: Bernard W
authors.initials: BW
authors.lastname: Beall
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D005260:Female; D005838:Genotype; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology*; D011008:Pneumococcal Infections / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000276:immunology*; D015995:Prevalence; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects* / Q000302:isolation & purification; D014481:United States / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D010406:Penicillins; D022242:Pneumococcal Vaccines