title: Acute otitis media caused by Streptococcus pneumoniae serotype 19A ST320 clone: epidemiological and clinical characteristics.
abstract: BACKGROUND
  Streptococcus pneumoniae serotype 19A ST320, a highly multiresistant and virulent clone, has emerged as a common pathogen causing acute otitis media (AOM) in children.
  
  
  METHODS
  Patients aged 0-18 years with AOM who presented at Mackay Memorial Hospital, Taipei, Taiwan were prospectively enrolled between December 1, 2009, and November 30, 2012. For each patient, a specimen of middle-ear fluid was obtained and cultured. S. pneumoniae isolates were tested by serotyping, antibiotic-resistance profiling, and multilocus sequence typing. Demographic characteristics and clinical history of patients with pneumococcal AOM were recorded.
  
  
  RESULTS
  Pneumococcal AOM was observed in 108 (24.8%) of 436 episodes. One hundred and four isolates of S. pneumoniae were available for study. The most common serotypes were 19A (67 isolates, 64.4%), followed by 19F (16 isolates, 15.4%), and 3 (7 isolates, 6.7%). Among the 85 sequence-typed isolates, Serotype 19A ST320 (50, 58.8%) was the most frequent. Children with AOM caused by Serotype 19A ST320 were younger (33.9 ± 21.4 months vs. 46.7 ± 35.9 months, p = 0.04) and had a higher rate of spontaneous rupture of the tympanic membrane (64.0% vs. 40%, p = 0.05) than those caused by isolates of other sequence types. Serotype 19A ST320 caused 90% of AOM episodes in children aged ≤ 12 months and had had higher resistance rates to penicillin according to meningeal breakpoints (p = 0.011), amoxicillin (p < 0.001) and trimethoprim/sulfamethoxazol (p < 0.001).
  
  
  CONCLUSIONS
  It is better to use pneumococcal conjugate vaccine effective against Serotype 19A in early infancy to prevent the first and subsequent episodes of AOM in children in Taiwan.
authors.affiliation: Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan; Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Nursing, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan; Department of Medicine, Mackay Medical College, New Taipei City, Taiwan.
authors.forename: Hsin
authors.initials: H
authors.lastname: Chi
authors.affiliation: Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan; Department of Nursing, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan.
authors.forename: Nan-Chang
authors.initials: NC
authors.lastname: Chiu
authors.affiliation: Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Fu-Yuan
authors.initials: FY
authors.lastname: Huang
authors.affiliation: Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Chyong-Hsin
authors.initials: CH
authors.lastname: Hsu
authors.affiliation: Department of Otorhinolaryngology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Kuo-Sheng
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Huang
authors.affiliation: Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan. Electronic address: ychsieh@cgmh.org.tw.
authors.forename: Yu-Chia
authors.initials: YC
authors.lastname: Hsieh
mesh_terms: D000293:Adolescent; D000328:Adult; D000658:Amoxicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D010033:Otitis Media / Q000453:epidemiology* / Q000382:microbiology* / Q000517:prevention & control*; D010406:Penicillins / Q000494:pharmacology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines; D015995:Prevalence; D065288:Serogroup; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D013420:Sulfamethoxazole / Q000494:pharmacology; D013624:Taiwan / Q000453:epidemiology; D014295:Trimethoprim / Q000494:pharmacology; D018074:Vaccines, Conjugate / Q000276:immunology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D010406:Penicillins; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate; D000658:Amoxicillin; D014295:Trimethoprim; D013420:Sulfamethoxazole
keywords: Serotype 19A; Streptococcus pneumoniae; acute otitis media