Leptospira parva sp.npv.: some morphological and biological characters.

Two lines of a spirochete were isolated as contaminants in a culture of a leptospire and from a bottle of uninoculated medium. Studies on morphological and biological characters led to the conclusion that these lines represent a new species of the genes Leptospira, Leptospira parva sp. nov. The morphology of the cells was rather similar to that of previously examined leptospires, but the cells were shorter and had a shorter wavelength (more tightly wound). Furthermore, the surface layer of cells of L. parva formed numerous small blebs with no apparent substructure when detached during preparation for negative staining, while the surface layer of previously studied leptospires formed cross-striated tubules under similar conditions. L. parva shows biological characteristics of both parasitic and saprophytic leptospires. The deoxyribonucleic acid base composition of cells of this organism differed from that found in leptospires, as well as from that found in cells of Leptonema illini.