title: Minimum inhibitory concentrations of erythromycin and other antibiotics for Czech strains of Bordetella pertussis.
abstract: OBJECTIVE
  To test the susceptibility to first-line and alternative antibiotics of 70 Bordetella pertussis (B. pertussis) strains recovered from patients with whooping cough through national pertussis surveillance in the Czech Republic (CR) in 1967-2010.
  
  
  METHODS
  The minimum inhibitory concentrations (MICs) of erythromycin, clarithromycin, azithromycin, ciprofloxacin, and co-trimoxazole were tested by the reference agar dilution method on Bordet-Gengou agar with 15 % defibrinated sheep blood.
  
  
  RESULTS
  Each of the 70 study strains was inhibited by two concentrations of erythromycin and azithromycin (0.06 and 0.12 mg/l) and by three concentrations of clarithromycin (0.03, 0.06, and 0.12 mg/l), with the highest concentration of the MIC range being 0.12 mg/l for all these similar antibiotics. Tested in a 2-fold geometric dilution series, the concentration of erythromycin required to inhibit 90 % of the study strains (MIC90) was one dilution step lower (0.06 mg/l) than those of clarithromycin and azithromycin (0.12 mg/l). All study strains were inhibited by a single concentration of ciprofloxacin (0.06 mg/l) and two concentrations of co-trimoxazole (0.12 and 0.25 mg/l).
  
  
  CONCLUSIONS
  The panel of 70 Czech strains of B. pertussis appears to be homogeneous in terms of the MICs of the antibiotics tested, with two to three low concentrations being effective against all strains. To be inhibited, no strain required a higher concentration of erythromycin, clarithromycin, azithromycin, ciprofloxacin, or co-trimoxazole.
authors: V
authors: V
authors: Jakubů
authors: J
authors: J
authors: Zavadilová
authors: K
authors: K
authors: Fabiánová
authors: P
authors: P
authors: Urbášková
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001886:Bordetella pertussis / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D018153:Czech Republic; D004917:Erythromycin / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D014917:Whooping Cough / Q000453:epidemiology / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D004917:Erythromycin
keywords: Bordetella pertussis - minimum inhibitory concentration (MIC) - antibiotics.