[Antibiotic sensitivity of Haemophilus influenzae clinically isolated in the Sendai area].
Antibiotic sensitivity of H. influenzae collected from 8 hospital laboratories in the Sendai area during Jan. and Apr., 1984 were determined. One hundred and eighty-seven strains of H. influenzae isolated from different infectious sites were tested for their susceptibility to several representative antibiotics. Twenty-six strains (13.9%) of the isolates were beta-lactamase positive and none of these strains could be serotyped because of a lack of capsules. It was remarkable that beta-lactamase positives strains were rather common in infants under 1 year of age (4 from 23 strains, 17.4%). Minimum inhibitory concentrations (MICs) of antibiotics against H. influenzae revealed that most beta-lactamase negative strains were highly sensitive to both ampicillin and amoxicillin (AMPC), while their MICs to beta-lactamase positive strains were widely distributed from 1.56 (3.13) to more than 100 micrograms/ml. BRL 25000, a formulation of AMPC and clavulanic acid, inhibited the growth of all beta-lactamase positive strains at concentrations of 1.56 micrograms/ml or less. Among cephalosporins, the sensitivity to drugs did not differ between beta-lactamase negative and positive strains. It was also noteworthy that 7 strains (3.8%) of the isolated H. influenzae were resistant to chloramphenicol, and 2 of them were beta-lactamase positive. The most active drug against H. influenzae, therefore, seemed to be the third generation of cephalosporins, especially cefmenoxime which was extremely active to all the strains tested.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D004352:Drug Resistance, Microbial; D004917:Erythromycin / Q000494:pharmacology; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D007223:Infant; D007564:Japan; D008875:Middle Aged; D013752:Tetracycline / Q000494:pharmacology; D001618:beta-Lactamases / Q000096:biosynthesis
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D004917:Erythromycin; D001618:beta-Lactamases; D013752:Tetracycline