Studies of intestinal microflora. VII. Effect of diet and fecal microbial flora on survival of animals exposed to x irradiation.

Changes in the numbers and ratios of bacteria in the feces of rats were produced by administration of three different diets-grain, meat alone, and meat plus lactose. After significant alterations in the intestinal flora had developed, the animals were exposed to a midlethal dose of X irradiation (1,550 R). This treatment led to 100% deaths in rats in which the numbers of coliforms were increased by diet prior to irradiation.

Studies of intestinal microflora. VI. Effect of x irradiation on the fecal microflora of the rat.

The effect of sublethal, midlethal, and lethal doses of total-body X irradiation on the fecal microbial population of the rat was studied. No changes were observed in animals receiving sublethal doses of X ray. Midlethal and lethal doses produced an increase in the numbers of fecal coliforms, staphylococci, streptococci, and fungi; these changes were transient in rats that survived, but were more marked and persisted during life in those that died.

Purified staphylococcal alpha toxin: effect on epithelial ion transport.

Purified staphylococcal alpha toxin, when added to the serosal bathing medium of the isolated toad bladder, causes a rapid fall in short-circuit current and transepithelial potential difference. It has no effect when added to the mucosal bathing medium. Oxygen consumption by suspensions of minced bladder tissue is stimulated by the toxin.