title: Community outbreak of macrolide-resistant Mycoplasma pneumoniae in Yamagata, Japan in 2009.
abstract: BACKGROUND
  We detected a community outbreak of macrolide-resistant Mycoplasma pneumoniae infection that occurred predominantly among students at 2 schools in Yamagata, Japan.
  
  
  METHODS
  Throat swab specimens were collected from patients who were clinically suspected to have M. pneumoniae infection after testing negative for influenza virus by a nasopharyngeal swab rapid antigen test. We performed cultures for M. pneumoniae, and all isolates were sequenced for the presence of a mutation of the 23S rRNA gene.
  
  
  RESULTS
  Of 96 specimens collected between July 2009 and January 2010, 83 were from students attending junior high school A and primary schools B, C and D. A total of 47 M. pneumoniae isolates were obtained; among them, 25, 15 and 4 were isolated from students attending schools A, B and D, respectively, and M. pneumoniae could not be isolated from students who attended school C. An A2063T mutation in domain V of the 23S rRNA gene, which is associated with macrolide resistance, was identified in 39 (83.0%) isolates. The rates of macrolide resistance at schools A, B and D were 96.0%, 86.7% and 0%, respectively. The minimum inhibitory concentrations for isolates with an A2063T transversion showed high resistance to clarithromycin (minimum inhibitory concentration, 16-64 mg/L), and clarithromycin prescribed initially was clinically ineffective.
  
  
  CONCLUSIONS
  This school-based cluster of macrolide-resistant M. pneumoniae infections, which was identified in 2 geographically close schools, indicates that the transmission principally occurred by close contact between students at school. Monitoring the spread of macrolide-resistant M. pneumoniae and clinical guidelines for the appropriate medication against such infections would be needed to control outbreaks of M. pneumoniae.
authors.affiliation: Department of Microbiology, Yamagata Prefectural Institute of Public Health, Yamagata, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Itagaki
authors.forename: Junji
authors.initials: J
authors.lastname: Seto
authors.forename: Akiko
authors.initials: A
authors.lastname: Kaneko
authors.forename: Chieko
authors.initials: C
authors.lastname: Abiko
authors.forename: Katsumi
authors.initials: K
authors.lastname: Mizuta
authors.forename: Yoko
authors.initials: Y
authors.lastname: Matsuzaki
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D018942:Macrolides / Q000494:pharmacology*; D008297:Male; D008826:Microbial Sensitivity Tests; D009177:Mycoplasma pneumoniae / Q000187:drug effects* / Q000302:isolation & purification; D010614:Pharynx / Q000382:microbiology; D011019:Pneumonia, Mycoplasma / Q000453:epidemiology* / Q000382:microbiology; D017354:Point Mutation; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D018942:Macrolides; D012338:RNA, Ribosomal, 23S