The carbon dioxide requirement of Klebsiellae

The growth of 95 strains of Klebsiella cultured in air with added CO2 is described. Twenty-two strains of K. ozaenae required CO2 for characteristic growth when cultured at 37 degrees C and growth was promoted by co-trimoxazole, tetracycline and sodium barbitone. Four strains of K. pneumoniae, two of K. edwardsii var. atlantae and one of K. edwardsii var. edwardsii gave increased viable counts after incubation in CO2. None of the 40 strains of K. aerogenes tested required CO2 for growth.