title: Evaluation of mutations in penicillin binding protein-3 gene of non-typeable Haemophilus influenzae isolated from the nasopharynx of children with acute otitis media.
abstract: CONCLUSIONS
  Younger children tend to harbor more resistant strains because they are exposed to these pathogens more often through contacts with siblings or attendance at day-care centers and are frequently treated with antibiotics. The high prevalence of BLNAR strains should be taken into account in the treatment of AOM in young children.
  
  
  OBJECTIVE
  Non-beta-lactamase-producing ampicillin-resistant (BLNAR) strains with mutations in penicillin-binding protein (PBP) genes of Haemophilus influenzae have been prevalent recently among younger children.
  
  
  METHODS
  We investigated mutations in the ftsI gene encoding PBP-3 of H. influenzae isolated from the nasopharynx of children with acute otitis media (AOM) using polymerase chain reaction (PCR).
  
  
  RESULTS
  Strains containing the bla gene (beta-lactamase-producing ampicillin-resistant) were identified in 4.7% of cases. Strains with mutations in the ftsI gene (BLNAR) were identified in 23.3% of cases. Strains without mutations in the ftsI gene and that did not contain the bla gene (non-beta-lactamase-producing ampicillin-susceptible) were identified in 70.7% of cases. Strains with both expression of the bla gene and mutations in the ftsI gene (beta-lactamase-producing amoxicillin clavulanate-resistant) were identified in 1.3% of cases. The MICs of ampicillin against the strains evaluated in this study were 0.5-2.0 microg/ml. Cefditoren-pivoxil had the lowest MIC90 against the strains (0.06 microg/ml). Strains with mutations in the ftsI gene (BLNAR) were broadly identified among young children.
authors.affiliation: Department of Otolaryngology--Head and Neck Surgery, Wakayama Medical University, Wakayama, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Sakai
authors.forename: Muneki
authors.initials: M
authors.lastname: Hotomi
authors.forename: Dewan S
authors.initials: DS
authors.lastname: Billal
authors.forename: Kazuma
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Jun
authors.initials: J
authors.lastname: Shimada
authors.forename: Shinji
authors.initials: S
authors.lastname: Tamura
authors.forename: Keiji
authors.initials: K
authors.lastname: Fujihara
authors.forename: Noboru
authors.initials: N
authors.lastname: Yamanaka
mesh_terms: D000208:Acute Disease; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D017931:DNA Primers / Q000235:genetics; D005260:Female; D015870:Gene Expression / Q000235:genetics*; D006192:Haemophilus Infections / Q000150:complications*; D006193:Haemophilus influenzae / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D008297:Male; D009305:Nasopharynx / Q000382:microbiology*; D010033:Otitis Media / Q000235:genetics* / Q000382:microbiology*; D046915:Penicillin-Binding Proteins / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D046915:Penicillin-Binding Proteins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases