title: Recent epidemiology of Streptococcus pneumoniae in nasopharynxes of Korean children with acute otitis media.
abstract: BACKGROUND
  This prospective study was performed to evaluate serotype distribution, multilocus sequence typing, and antibiotic susceptibility of Streptococcus pneumoniae identified in Korean children with acute otitis media (AOM) after the introduction of a 7-valent pneumococcal conjugate vaccine (PCV7).
  
  
  METHODS
  Nasopharyngeal aspirates were collected from children diagnosed with AOM in seven hospitals in Korea. The bacteria identified in these samples and the serotypes, sequence types (STs), and antibiotic susceptibilities of S. pneumoniae isolates were evaluated.
  
  
  RESULTS
  A total of 390 children were enrolled, and bacteria were identified in 376 (96.4%) children. S. pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were identified in 155 (39.7%), 127 (32.6%) and 86 (22.1%) children, respectively. Serotype 19A (22.4%) was the most common S. pneumoniae serotype, with serogroups 11 (14.7%) and 15 (13.5%) following. ST320 (23.5%) was the most common ST; ST166 (17.0%) and ST83 (8.5%) followed. The overall susceptibility rates of S. pneumoniae to oral penicillin V and amoxicillin/clavulanate were 2.6% and 53.2%, respectively. The susceptibility rate to cefditoren was 91.0%; however, the rates for other cephalosporins were less than 10.0%. Compared with other serogroups, S. pneumoniae serogroups 19, 11, and 15 showed significantly lower susceptibility rates to all the antibiotics tested.
  
  
  CONCLUSIONS
  S. pneumoniae serotype 19A, serogroups 11 and 15 were the major nasopharyngeal-colonizing bacteria in Korean children with AOM after the introduction of PCV7. These relatively prevalent serotype/serogroups showed lower antibiotic susceptibility rates.
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; The Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Seung Beom
authors.initials: SB
authors.lastname: Han
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; The Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; The Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: kjhan@catholic.ac.kr.
authors.forename: Jin Han
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Department of Pediatrics, Fatima Hospital, Changwon, Republic of Korea.
authors.forename: Sang Hyuk
authors.initials: SH
authors.lastname: Ma
authors.affiliation: Department of Pediatrics, Keimyung University School of Medicine, Daegu, Republic of Korea.
authors.forename: Chun Soo
authors.initials: CS
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Republic of Korea; Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kyung-Hyo
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
authors.forename: Hwang Min
authors.initials: HM
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Young Youn
authors.initials: YY
authors.lastname: Choi
mesh_terms: D000208:Acute Disease / Q000453:epidemiology*; D000900:Anti-Bacterial Agents / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D006193:Haemophilus influenzae / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008826:Microbial Sensitivity Tests / Q000379:methods; D001936:Moraxella catarrhalis / Q000302:isolation & purification; D009305:Nasopharynx / Q000276:immunology / Q000382:microbiology*; D010033:Otitis Media / Q000276:immunology / Q000382:microbiology*; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000276:immunology; D015995:Prevalence; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D065288:Serogroup; D012703:Serotyping / Q000379:methods; D013296:Streptococcus pneumoniae / Q000276:immunology / Q000302:isolation & purification*; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D000900:Anti-Bacterial Agents; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Acute otitis media; Child; Korea; Streptococcus pneumoniae