TABLE 2.

Susceptibility of worldwide isolates of H. influenzae (n = 8,523) to 23 antimicrobials and MIC50s and MIC90sa

AntimicrobialMIC50 (μg/ml)MIC90 (μg/ml)% S by PK/PDCLSI
% S% R
Ampicillin0.25>16NA81.917.0
Amoxicillin0.5>1681.683.216.8
Amoxicillin-clavulanate, lower dose0.5198.199.60.4
Amoxicillin-clavulanate, higher dose0.5199.6NANA
Cefaclor4161.489.73.6
Cefuroxime axetil1283.698.10.7
Cefixime0.030.0699.899.8NA
Ceftriaxone≤0.0040.008100100NA
Cefprozil2822.392.52.6
Cefdinir0.250.592.097.6NA
Erythromycin48<0.5NANA
Clarithromycin816<0.379.60.9
Azithromycin12<1.299.5NA
Chloramphenicol0.5198.197.91.9
Doxycycline0.5128.9NANA
Trimethoprim-sulfamethoxazole0.12>478.378.317.0
Ciprofloxacin0.0150.0399.999.9NA
Ofloxacin0.030.0699.999.9NA
Gemifloxacin0.0040.01599.9NANA
Levofloxacin0.0150.01599.999.9NA
Gatifloxacin0.0080.01599.999.9NA
Moxifloxacin0.0150.0399.899.8NA
  • a Data are from the Alexander Project 1998 to 2000 (64). S, susceptible; R, resistant; NA, not available.