title: Streptococcus pneumoniae serotype 19A in children, South Korea.
abstract: Despite the concern of replacement disease, notably by serotype 19A after 7-valent conjugate vaccine (PCV7) use, serotype 19A was increasingly recognized in Korean children before the introduction of PCV7. To understand the dynamics of serogroup 19 prevalence from 1991-2006, we serotyped 538 pediatric pneumococcal isolates. Serogroup 19 isolates (n = 126) were characterized by antimicrobial drug susceptibility, presence of mefA/ermB, and multilocus sequence typing. Overall, the proportion of serotype 19A isolates increased but serotype 19F decreased. Among children <5 years of age, the proportion of serotype 19A isolates in invasive pneumococcal disease increased from 0% in 1991-1994 to 8%-10% in 1995-2000, reached 26% in 2001-2003, and remained at 20% in 2004-2006 when vaccine coverage did not exceed 25% (p = 0.005 for trend). This study demonstrates that the expansion of multidrug-resistant ST320 was responsible for the increase in serotype 19A before PCV7 use.
authors.affiliation: Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Eun Hwa
authors.initials: EH
authors.lastname: Choi
authors.forename: So Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Byung Wook
authors.initials: BW
authors.lastname: Eun
authors.forename: Sun Jung
authors.initials: SJ
authors.lastname: Kim
authors.forename: Nam Hee
authors.initials: NH
authors.lastname: Kim
authors.forename: Jina
authors.initials: J
authors.lastname: Lee
authors.forename: Hoan Jong
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007723:Korea / Q000453:epidemiology; D008565:Membrane Proteins / Q000235:genetics; D008826:Microbial Sensitivity Tests; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D015995:Prevalence; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C117866:MefA protein, Streptococcus; D008565:Membrane Proteins