Comparison of media for agar dilution susceptibility testing ofBordetella pertussis andBordetella parapertussis

Antimicrobial susceptibility testing of the fastidious speciesBordetella pertussis andBordetella parapertussis is not standardized. In an attempt to find the optimal medium for agar dilution testing, the activity of erythromycin againstBordetella pertussis andBordetella parapertussis (34 isolates each) was assessed using homologous broth/agar combinations of Bordet-Gengou, charcoal, Iso-Sensitest (Oxoid) and Mueller-Hinton media. Each medium was supplemented with 5 % and 20 % whole defibrinated horse blood. Mueller-Hinton medium supplemented with 5 % horse blood performed best overall.