STUDIES ON PASTEURELLA PESTIS I. BIOCHEMISTRY OF PASTEURELLA PESTIS, WITH SPECIAL REFERENCE TO FERMENTATION REACTIONS

Abstract

Biochemical reactions of Pasteurella pestis have been investigated by many workers. There are, however, some points of disagreement among them. I had a chance to study a collection of strains of Past. pestis preserved for many years at this institute. The results of biochemical studies with special reference to fermentation reactions of these strains will be described and discussed together with a review of the literature.Strains used: 69 strains preserved for many years at this institute. Regarding their history refer to my report follwing this paper.These strains were first plated on horse serum agar, typical coloniq were fished, transplanted on agar slant, and then used in the present experiments.Morphology: Slide preparations were fixed in a mixture of equal volumes of ether and ethyl alcohol for one minute, wormed by gas flame in order to evaporate the fixative, then stained with Loeffler's methylene blue or Pfeiffer's stain. The organisms were short thor rods with rounded ends, many of them oval, but their shape and size varied considerably, some being elongated as filaments. A few showed bipolar staining. Gram-negative. Degenerated forms in ager slants containing 2.5 per cent NaCl.Motility: Negative in broth culture at 37°C and 20°C. Tests of motility in the culture at 20°C are said to be important in respect of differentiation from Past pseudo-luberculosis (Arkwright) .Culture: Growth on ordinary media. Colonies on agar media peculier to Past. pestis with raised center, flatt margin and granular structure. In broth very, slightly turbid, later clear, with floccular deposit and pellicle.