The Biological Characters of B. actinoides Variety Muris

Abstract

The biological characters of rat-type Bacillus actinoides are presented in detail and compared with those of the original sp. derived from calves. A broadly similar nature of growth characteristics exists outside the host,[long dash]in particular a common production of a peculiar form of capsule. In growth requirements, the rat type is somewhat less specialized than the calf type. Direct introduction of the rat type into the middle ear cavity of rats frequently induces a purulent otitis, with subsequent recovery of the organisms. Similar introduction of the calf type produces only microscopic lesions, from which the organism is not recovered. Continued cultivation shows no convergent characteristics of the 2 types. Immunological methods of differentiation are not readily applicable. Attempts to produce anti-serum have failed. The author concludes that the biology of the organism is imperfectly understood and the isolation and study of B. actinoides from other animal sources would materially assist in establishing relationships within the sp.