[Detection among "E. aerogenes" strains of capsular antigens related to those of "klebsiella". Interest of growth in metahydroxybenzoate to differenciate "E. aerogenes" and "K. pneumoniae" (author's transl)].

Forty-three strains of E. aerogenes isolated chiefly in Morocco and France have been studied. Thirty-five strains (81%) are surrounded with a thin capsule, antigenically related to Klebsiella capsular antigens: K4 (2 strains), K4, 59 (1 strain), K11 (2 strains), K26 (7 strains), K42 (5 strains), K59 (3 strains), K68 (14 strains). One strain is capsulated but not typable with Klebsiella capsular antisera. E. aerogenes and Klebsiella capsular antigens are not identical but share common fractions yielding cross reactions. To differenciate E. aerogenes from K. pneumoniae in addition with the three major characters, i.e. motility, ornithine-decarboxylase and urease, the author points out the value of growth in metahydroxybenzoate as sole source of carbon and energy (positive test with E. aerogenes and negative with K. pneumoniae).