In vitro susceptibility of Haemophilus influenzae to trimethoprim-sulfamethoxazole.
Thirty-four strains of Haemophilus influenzae (20 ampicillin sensitive and 14 ampicillin resistant), mostly type b isolates from cerebrospinal fluid or blood, were tested for susceptibility to a combination of trimethoprim-sulfamethoxazole (TMP-SMZ) in a ratio of 1 part TMP to 19 parts SMZ. All strains were very susceptible to the TMP-SMZ combination, with minimal inhibitory concentrations ranging from 0.007-0.14 to 0.06-1.18 mug of TMP-SMZ per ml. There was little difference in the susceptibility of the ampicillin-sensitive and ampicillin-resistant strains to TMP-SMZ.
D000667:Ampicillin / Q000494:pharmacology; D003470:Culture Media; D006193:Haemophilus influenzae / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance; D013420:Sulfamethoxazole / Q000494:pharmacology*; D014295:Trimethoprim / Q000494:pharmacology*
D003470:Culture Media; D000667:Ampicillin; D014295:Trimethoprim; D013420:Sulfamethoxazole