Biochemical Properties of Clostridium botulinum Type G and Clostridium hasti forme

Biochemical properties, toxin production and bacteriophages of four type G strains of Clostridium botulinum were studied. All four strains were motile, hemolytic, weakly proteolytic and positive in H2S production as well as gelatin liquefaction. All strains, however, were nonsaccharolytic and negative in catalase, lecithinase, lipase and indole production as well as nitrate reduction. Many spores were formed only when the organisms were incubated in Tarozzi medium （Cooked Meat Medium containing 2% Bact peptone and 0.4% NaCl）. Purified spores （2×1μ in size） were obtained by incubating the Tarozzi medium culture fluid in TBYS medium （Trypticase peptone; 5%, Bact peptone; 0.5%, Yeast extract; 0.1%, NaCl; 0.4%, TGC; 0.1%）. Low levels of toxin were produced in regular broth cultures but a high titer of toxin （22,400 mouse 50% lethal doses per ml） was produced by the dialysis tubing method. The toxicity was increased to about 20 times by the treatment with trypsin. These charac-teristics were different from those of other types of C. botulinum. Lysis of cells was induced by mitomycin C （MC） treatment or ultraviolet （UV） irradiation. In the lysate, no complete phage was observed but many sheath-like rods, the size of which was 200nm long and 25nm wide, were found by electron microscopy. One strain （G-2740） was treated with acridine orange, nitrosoguanidine and MC or UV irradiation in order to get nontoxigenic （and nonlysogenic） variants. Although a total of 600 colonies were checked, no nontoxigenic strain was found. Characteristics of the four strains of Clostridium hastiforme were also studied. They demonstrated the same biochemical properties as those of C. botulinum type G except for the toxin production. C. hastiforme seems to be a nontoxigenic variant of type G strain. In the MC induced lysates of C. hastiforme, complete phages were observed. These data suggest that no relationship exists between the toxigenicity of type G strain and bacteriophages.departmental bulletin pape