Further Studies onProteus hydrophilus, the Etiological Agent in “Red Leg” Disease of Frogs

Abstract

A detailed study of many strains of the bacterium which causes "red-leg disease in aquarium frogs indicates that this organism is P. hydrophilus. Unlike other spp. of Proteus, this one does not produce the "swarming" type of growth on solid mediums, is not able to utilize urea as the sole source of N, produces acetyl-methyl-carbinol, and develops but 1 flagellum. There are several serologically different types of this organism with a probability that 2 predominate. This sp., when injd., is highly fatal for both cold- and warm-blooded animals, including mice, rabbits and guinea pigs. Serologically different types cross protect when used as vaccines. Passively, the antiserum of one type has no protection against another type. P. hydrophilus is strongly hemolytic for many kinds of erythrocytes. Bacteria-free broth culture fitrates of this organism are highly toxic to white mice, but no antitoxin has been developed.