title: Longitudinal European surveillance study of antibiotic resistance of Haemophilus influenzae.
abstract: OBJECTIVE
  We assessed the current resistance rates of Haemophilus influenzae against beta-lactams and other agents in Europe and compared the results with those of our previously performed surveillance study.
  
  
  METHODS
  MICs of the antibiotics were determined using broth microdilution. The penicillin-binding domain of PBP3 of beta-lactamase (BL)-negative, amoxicillin-resistant (BLNAR) isolates was sequenced.
  
  
  RESULTS
  The percentage of BL-positive and BLNAR strains ranged from 0% to 17.6% and 0% to 33.9%, respectively. Compared with 1997/98 and 2002/03, the overall percentage of strains non-susceptible to amoxicillin decreased from 19.8% and 23.3%, respectively, to 16.4% in 2004/05. The percentage of BL-producing strains decreased from 11.0% and 13.7%, respectively, to 7.6%, whereas the number of BLNAR strains remained stable (8.8% and 9.6%, respectively, versus 8.8% in 2004/05). Comparison of penicillin binding protein (PBP) 3B gene sequences between BLNAR and susceptible strains revealed novel amino acid mutations.
  
  
  CONCLUSIONS
  In spite of large inter-regional differences, the overall resistance of H. influenzae to amoxicillin in Europe seems to decline due to a decreasing number of BL-producing strains, whereas the overall percentage of BLNAR strains seems relatively constant.
authors.affiliation: Eijkman-Winkler Center for Medical Microbiology and Infectious Diseases, University Medical Center Utrecht G 04.614, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands. W.T.M.Jansen@umcutrecht.nl
authors.forename: W T M
authors.initials: WT
authors.lastname: Jansen
authors.forename: A
authors.initials: A
authors.lastname: Verel
authors.forename: M
authors.initials: M
authors.lastname: Beitsma
authors.forename: J
authors.initials: J
authors.lastname: Verhoef
authors.forename: D
authors.initials: D
authors.lastname: Milatovic
mesh_terms: D000658:Amoxicillin / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005060:Europe; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests; D046915:Penicillin-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011159:Population Surveillance; D017422:Sequence Analysis, DNA; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000378:metabolism; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D046915:Penicillin-Binding Proteins; D047090:beta-Lactams; D000658:Amoxicillin; D001618:beta-Lactamases