Abstract
We compared the growth of Bordetella pertussis strains (n = 32) on antibiotic-free and cephalexin (40 micrograms/ml)-containing charcoal agar supplemented with 10% defibrinated horse blood, defibrinated sheep blood, or anticoagulant-containing human blood. Plates were incubated either in air or in an atmosphere with 5 to 10% CO2. As assessed by mean colony numbers and rapidity of growth, normal air was preferable to CO2 enrichment for incubation. Growth on horse blood agar was more abundant and more rapid than on sheep blood agar, but the difference in general was not statistically significant. Human blood was clearly inferior to both horse and sheep blood.