title: Twelve-year survey (2001-2012) of the antimicrobial susceptibility of Streptococcus pneumoniae isolates from otorhinolaryngology clinics in Miyagi Prefecture, Japan.
abstract: BACKGROUND
  Streptococcus pneumoniae is one of the most common bacteria causing otorhinolaryngological infections, such as acute otitis media and upper respiratory tract infection. Our group surveyed the drug susceptibility profile of S. pneumoniae isolates from otorhinolaryngology patients.
  
  
  METHODS
  A total of 41,069 S. pneumoniae isolates were detected at Miyagi Medical Association Health Center between May 2001 and December 2012. Specimens were obtained from patients at 40 otorhinolaryngology outpatient clinics in Miyagi Prefecture, Japan. The minimum inhibitory concentrations (MICs) of 8 antimicrobial agents were measured using the broth microdilution method according to Clinical and Laboratory Standards Institute guidelines.
  
  
  RESULTS
  In children aged 0-2 years old, the MIC50 values of penicillins decreased after 2010 (PCG: 1 μg/ml (2010) to 0.06 μg/ml (2012); ABPC: 1 μg/ml (2010) to 0.25 μg/ml (2012)). The prevalence of penicillin-resistant S. pneumoniae (PRSP) decreased from 35.2% (2010) to 14.6% (2012) in rhinorrhea specimens and from 43.4% (2010) to 14.3% (2012) in otorrhea specimens. Susceptibility to cephems (ceftriaxone and cefditoren) and carbapenems (panipenem) also showed improvement after 2010. For macrolides (clarithromycin) and lincosamides (clindamycin), MIC50 values increased in all age groups during the study period, and a high level of resistance was seen until 2012. There were no marked changes of susceptibility to fluoroquinolones (LVFX) during the study period.
  
  
  CONCLUSIONS
  Improvement of susceptibility of S. pneumoniae to β-lactams occurred after 2010 in Miyagi Prefecture, Japan.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan; Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan. Electronic address: daiki-oz@med.tohoku.ac.jp.
authors.forename: Daiki
authors.initials: D
authors.lastname: Ozawa
authors.affiliation: Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Yano
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hidaka
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan; Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Risako
authors.initials: R
authors.lastname: Kakuta
authors.affiliation: Department of Clinical Laboratory, Miyagi Medical Association Health Center, Sendai, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Komatsu
authors.affiliation: Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Endo
authors.affiliation: Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Kanamori
authors.affiliation: Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kaku
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Katori
mesh_terms: D000293:Adolescent; D000328:Adult; D015780:Carbapenems / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D004423:Ear / Q000382:microbiology; D024841:Fluoroquinolones / Q000494:pharmacology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D055231:Lincosamides / Q000494:pharmacology; D018942:Macrolides / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology; D009666:Nose / Q000382:microbiology; D010036:Otolaryngology; D010406:Penicillins / Q000494:pharmacology; D010614:Pharynx / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects*; D055815:Young Adult
chemical_list: D015780:Carbapenems; D002511:Cephalosporins; D024841:Fluoroquinolones; D055231:Lincosamides; D018942:Macrolides; D010406:Penicillins
keywords: Acute otitis media; Antimicrobial susceptibility; Minimum inhibitory concentration; Streptococcus pneumoniae; Upper respiratory tract infection