Disk diffusion susceptibility testing of Haemophilus influenzae using haemophilus test medium.
A three-center collaborative study was performed with the aim of determining the reproducibility of disk diffusion and broth microdilution susceptibility tests of Haemophilus influenzae with 19 different antimicrobial agents using a newly described medium, Haemophilus Test Medium. The results of both methods were found to be highly reproducible. Using Haemophilus Test Medium, inhibitory zone diameters and MICs were then determined for 150 test strains of Haemophilus influenzae, selected with an emphasis on known mechanisms of resistance. Regression analysis of zone diameter-MIC comparisons was used to define zone diameter interpretive criteria and MIC correlates for Haemophilus Test Medium disk diffusion tests performed with Haemophilus spp. for the following antimicrobial agents: ampicillin, amoxicillin/clavulanate, ampicillin/sulbactam, cefaclor, cefuroxime, cefamandole, ceftriaxone, cefotaxime, ceftizoxime, ceftazidime, cefixime, trimethoprim/sulfamethoxazole, rifampin, chloramphenicol, tetracycline, imipenem, aztreonam and ciprofloxacin.
Doern
G V
GV
Department of Clinical Microbiology, University of Massachusetts Medical Center, Worcester 01655.
Jorgensen
J H
JH
Thornsberry
C
C
Snapper
H
H
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015169:Colony Count, Microbial; D003470:Culture Media; D006193:Haemophilus influenzae / Q000187:drug effects*; D008826:Microbial Sensitivity Tests / Q000379:methods*; D012044:Regression Analysis; D015203:Reproducibility of Results
D000900:Anti-Bacterial Agents; D003470:Culture Media