title: Serotypes, biotypes and antibiotic susceptibility of 126 clinical isolates of Haemophilus influenzae.
abstract: Serotypes, biotypes, and antibiotic susceptibility of 126 Haemophilus influenzae isolates were determined. Five of the 126 isolates were from blood and were encapsulated type b strains; those taken from other sites were not typable. There were 13% biotype I, 36% biotype II, 38% biotype III, 5% biotype IV, 4% biotype V, and 4% biotype VI isolates. Antibiotic susceptibility tests using the standard disk diffusion method showed the following resistance: ampicillin 51%, cefamandole 10%, cefuroxime 3%, chloramphenicol 28%, tetracycline 37% and sulfamethoxazole-trimethoprim 49%. None of the five type b isolates were resistant to cefotaxime, a third generation cephalosporin. The second generation cephalosporins, cefamandole and cefuroxime, showed a superior activity against H. influenzae isolates, compared to other antibiotics. Multiple drug resistance was found in 64 (51%) isolates. Four of the five type b isolates were resistant to multiple drugs. The multiple-resistance pattern most frequently observed was to ampicillin, chloramphenicol, tetracycline and sulfamethoxazole-trimethoprim. Most clinical isolates did not contain plasmids; therefore, the antibiotic resistance of these H. influenzae strains was probably chromosome-mediated.
authors.affiliation: Department of Pediatrics, Chang Gung Children's Hospital, Taoyuan, Taiwan ROC.
authors.forename: C H
authors.initials: CH
authors.lastname: Chiu
authors.forename: J T
authors.initials: JT
authors.lastname: Ou
authors.forename: H C
authors.initials: HC
authors.lastname: Su
mesh_terms: D004352:Drug Resistance, Microbial; D006193:Haemophilus influenzae / Q000145:classification / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests; D012703:Serotyping