CHEMICALLY DEFINED MEDIUM FOR SOME MICROAEROPHILIC VIBRIOS

GASEOUS ENVIRONMENT AND GROWTH OF MICROAEROPHILIC VIBRIOS

Fletcher, R. D. (University of Connecticut, Storrs), and W. N. Plastridge. Gaseous environment and growth of microaerophilic vibrios. J. Bacteriol. 87:352-355. 1964.-Strains of microaerophilic vibrios from cattle, chickens, man, and sheep were placed in four groups on the basis of catalase and H(2)S production and glycine tolerance. By these tests group I was + - -, group II was + - +, group III was + + +, and group IV was - + +. On yeast extract-agar, the optimal oxygen level was 2.5% for group I, and 5.0% for the other three groups; the optimal carbon dioxide level was 10% for all four groups; the group I strains from man and sheep and the group II strains differed from the group I strains from cattle, by tolerating higher levels of both oxygen and carbon dioxide. On a chemically defined medium, the optimal oxygen level was 1.0%, and the optimal carbon dioxide level was 10% for groups I and II; the group II strains were more sensitive to high levels of carbon dioxide than were group I strains from cattle.

Chemically defined media for auxotyping of Campylobacter jejuni

A set of chemically defined media has been developed for the cultivation of Campylobacter jejuni strains of human origin. A minimal medium, a complete medium and 5 different nutrient-deficient media (NDM1-NDM5) are described. Some of the strains investigated required L-methionine(lacking in NDM1), L-cystine and L-cysteine (NDM2), K2HPO4 (NDM 3), KH2PO4 (NDM4) and NAD, thiamine and calcium pantothenate (NDM5). 57.7% of the strains investigated required L-methionine. The strains grew at pH 6.6-7.7. The media described are not suitable for C. intestinalis.

Ascorbic acid inhibition of Campylobacter jejuni growth

The inhibitory effect of ascorbic acid on Campylobacter jejuni is described. In vitro growth of clinical strains, as measured spectrophotometrically, was inhibited by 0.5 mg of freshly prepared L-ascorbic acid per ml. Alkaline-treated or aged L-ascorbic acid increased inhibition, as did copper; however, L-cysteine, L-cystine, and glutathione prevented inhibition. Biochemical analysis of the medium and cultures indicated that one or more of the oxidation products of L-ascorbic acid, e.g., L-dehydroascorbic acid or L-diketogulonic acid, were more effective inhibitors than was reduced L-ascorbic acid.