Comparison of modified Bordet-Gengou and modified Regan-Lowe media for the isolation of Bordetella pertussis and Bordetella parapertussis.

Culture and fluorescent-antibody methods for detection of Bordetella species were evaluated by two state public health laboratories. Field-inoculated plates of Regan-Lowe agar medium were most useful if incubation was initiated on the day of collection. Regan-Lowe and Bordet-Gengou media were comparable for subculturing nasopharyngeal specimens that were transported and enriched in half-strength Regan-Lowe agar. Maximum sensitivity was achieved when the media were used in parallel. Fluorescent-antibody-stained smears of nasopharyngeal specimens were more sensitive for detection of Bordetella pertussis than for detection of Bordetella parapertussis. The fluorescent-antibody method, however, was too insensitive for use without culture.

Antimicrobial susceptibilities of Bordetella species isolated in a Multicenter Pertussis Surveillance Project.

MICs for 90% (MIC90s) of 75 Bordetella pertussis strains for amoxicillin, erythromycin, rifampin, and sulfamethoxazole-trimethoprim were 1, less than or equal to 0.12, 1, and 4 micrograms/ml, respectively. Susceptibility rates were all greater than or equal to 93%. Only 17% of the strains were susceptible to tetracycline. The MIC90s of ciprofloxacin, enoxacin, norfloxacin, ofloxacin, and roxithromycin were less than or equal to 0.06, 0.5, 0.25, 0.12, and 0.5 micrograms/ml, respectively. For B. parapertussis, the MIC90s were 16-fold higher with amoxicillin and rifampin and 2- to 4-fold higher with the fluoroquinolones and roxithromycin.