The Minimal Nutritional Requirements of Organisms of the Genus Bordetella López

SUMMARY: Eight strains of bronchiseptica, six strains of parapertussis and fifteen strains of pertussis were examined for their minimal nutritional requirements in defined media. All strains showed an absolute requirement for nicotinic acid and no other vitamin was required for growth. Amino acids were essential for parapertussis and pertussis, but bronchiseptica would grow in either a mixture of amino acids, or lactate or citrate. Two old laboratory strains were exceptional in that they could utilize either glutamic acid, α-ketoglutaric acid, citrate, lactate, succinate or pyruvate. The amino acid requirements of the three species were relatively simple and showed some similarities. Bronchiseptica would grow in a mixture of glutamic acid, proline and leucine, while parapertussis required added cystine and methionine, and pertussis required in addition alanine, asparagine and serine. In simple amino acid mixtures glutamic acid was essential, but was replaceable by α-ketoglutaric acid. Nutritionally the species are very similar, but are quite different from the Haemophilus influenzae-parainfluenzae-canis, or the Brucella abortus-suis-melitensis groups of organisms. The nutritional evidence supports the already impressive evidence on other grounds that these three groups should be classified separately. If generic status is given to one group it should be given to all three. López (1952) has proposed a new genus Bordetella, consisting of the species B. pertussis, B. parapertussis and B. bronchiseptica, and this seems a reasonable solution to the present anomalous position. The three species can be differentiated by tests for inhibition. Thus B. bronchiseptica is the only species not inhibited by 20% citrate and B. pertussis the only species inhibited by colloidal copper sulphide.