Habitat.—Soil, water, intestinal canal of man and other animals.

Natural vectors.Blaberus craniifer, U.S.A. (Wedberg et al., 1949): From feces.

Blattella germanica, U.S.A. (Janssen and Wedberg, 1952): From intestinal canal and feces.

Periplaneta americana, U.S.A. (Bitter and Williams, 1949): From intestinal tract.

Escherichia intermedium (Werkman and Gillen) Vaughn and Levine

Habitat.—Soil, water, intestinal canal of man and other animals.

Natural vectors.Periplaneta americana, U.S.A. (Bitter and Williams, 1949): From intestinal canal.

* Klebsiella pneumoniae (Schroeter) Trevisan

Experimental vectors.Blatta orientalis, Italy (Cao, 1898).

* Paracolobactrum aerogenoides Borman, Stuart and Wheeler