Studies on the Variation of Clostridium chauvoei

Abstract

Cl. chauvoe appears in tissues and cultures as a straight, roundended rod measuring-about 0.6 X 3-8μ. It usually appears singly, and this fact is useful in distinguishing it from Cl. septicum and other anaerobic bacilli which frequently occur in materials suspected of blackleg which is similar to gasgangrene in human beings. Cl. septicum usually occur in long chains or in long filament. Spores are oval and appear excentrically, swelling the rods into lemon-shaped structures. Very young cultures are motile by means of pertrichic flagella. It is strictly anaerobic and will not grow on ordinary glucose agar. The addition of blood or tissue makes ordinary broth and agar favorable for it. It grows well on all media made with a liver extract but not luxuriantly.
Deep colonies in tube agar are delicate and compact, being lensshaped. In liver-liver broth the fluid becomes moderatly clouded. Gelatin containing a little serum is slowly liquefied, and a few gas bubbles are formed. Acid and gas are formed from glucose, levulose, galactose, maltose, lactose, and sucrose. Inulin, mannitol, glycerol, rhamnose, and dulcit are not fermented. All strains produce antign for agglutination, which. is kowever not shared with Cl. septicum.
This organism exists in the soil, and when pastures or grazing grounds once contaminated with it, it will infect ruminants, susceptible to the diseasease especially cattle year after year. The disease seems to be a wound infection and to be similar to gasgangrene in human beings.
In rare cases, some strains form R type colonies in tube agar, which are very simiar to those of Cl. septicum, and it is very difficult to distinguish them from Cl. septicum from the point of the shape of colonies, and the characters of R type is not. clarified yet. Therefore, the author made a variant of Cl. chauvoei, R type, by means of serial passage through liver-liver broth added with acriflavin and compared the characters and pathogenecity between S type and R type straits.
1) Artificial variation of chauvoei.
Virulent strain Hokkaido (II) or Okinawa (0) was cultivated in liver-liver broth added with acriflavin at 0.01% for 72 hours at 37°C, thereafter a drop of cultivated. broth was poured in tube agar. A deep colony in the tube agar was fished and inoculated. in acriflavin-added liver-liver. broth. Thus, the cultivation was carried out alternately and S type colonies variated to R type. In case of the strains O.R type, colonies of 30-80 generations of serial passage and in case of the strains H.R type, colonies of 50-110 generations were used for experiments. The former was named as O.R and the latter H.R.
2) Bio-chemical charactrs of R type organisms.
a) R type colnies of both strains are very similar to those of Cl. septicum, and the organisms occur in long filament like Cl. septicum.
Spores were not readily formed. The organism dcmonstrated a lesser degree of resistance to the heating and survived for a shorter in refrigerator than S type. Even young cultures became much less motile suggesting the loss of flagella
b) There is no difference in fermentation of sugars between S type and R type, but only strain H.R lost its coagulability of milk.
3) Sero-reaction in case of R type.
Original strains 0 and H, and variant strains O.R and H.R were used for making: antiserum by means of hyperimmunization against rabbits. In addition to these strains, . Cl. septicum was used to prepare hyperimmunized serum to compare the antigenicity of both bacilli.
a) Stype organisms (O and H) could not absorb the and-R serum completely leaving a part of antibody unabsorbed R. type organisms showed simiar results. Namely, it might be said that R type organisms lost a part of S type and was shared with other antigen.
b) R type organisms showed a decrease of the ability in producing antibody in rabbit and of agglutinability in contrast to the S type organisms.