Vibrio Metschnikovi is a spirillum closely resembling that of cholera and is found in the feces of chicken cholera. Is somewhat thicker and shorter than the S. cholerae. Growth is very similar to that of the cholera spirillum, but is slower. Not pathogenic for man, but kills chickens, pigeons, and guinea-pigs.

Spirillum of relapsing fever is a long, undulating, actively motile, flagellated spirillum, about 0.1 µ in diameter and 20 to 40 µ long. Non-sporogenous. Are found in the blood of patients during the height of the attack, but disappear after the temperature has fallen.

Stains by ordinary methods, but not by Gram's.

Culture

Has never been grown outside of the body.

Fig. 98. - Spirilla of Relapsing Fever in Human Blood. X 1000 (Boston).

Can be transmitted to monkeys by inoculating with infected blood.