Numerical Taxonomy of Clostridium botulinum and Clostridium sporogenes Strains, and Their Susceptibilities to Induced Lysins and to Mitomycin C

Abstract

An attempt to classify fourteen strains of Clostridium sporogenes and thirty strains of Clostridium botulinum types A, B, C, D, E, and F by numerical taxonomy was made. All proteolytic strains of C. botulinum types A, B, and F and C. sporogenes were classified in the phenon I at a level of 86% S‐value. In the phenon I, these strains coexisted in a mixed‐up fashion, irrespective of conventional species or type of bacteria. A concentrated lysin solution, which was prepared from an induced lysate of a C. botulinum A190 culture, lysed vegetative cells of all proteolytic C. botulinum and C. sporogenes strains classified in the phenon I, but did not lyse the cells of the other Clostridia. However, cells of nonproteolytic C. botulinum F‐OSU and four out of five strains of Clostridium tetani were lysed by the concentrated lysin to a limited extent. The phenon II contained all nonproteolytic strains of C. botulinum B, C, D, E, and F, which were mutually linked with S values of more than 85%. Strains of Clostridium histolyticum used as a reference group formed the phenon III. Any strain grouped in one phenon was differentiated from strains grouped in the other phenons by low S‐values, that were less than 77%. A striking difference in the number of strains susceptible to mitomycin C was demonstrated between C. botulinum and C. sporogenes. In all thirty‐five cultures, except four substrains of C. botulinum B‐NIH, of proteolytic and nonproteolytic C. botulinum, bacterial lysis was consistently induced by the treatment of 1 μg per ml of mitomycin C, while only four out of thirty‐seven C. sporogenes strains were as sensitive to mitomycin C as C. botulinum. Toxigenic substrains of C. botulinum B‐NIH, NIH15 and NIH19, were sensitive to mitomycin C, but nontoxigenic strains, NIH5, and NIH‐NP, were not.

Clostridium sporogenes Isolates and their Relationship to C. botulinum based on Deoxyribonucleic Acid Reassociation

“…Several investigators have demonstrated that some strains of C. sporogenes cannot be differentiated from proteolytic C. botulinum using phenetic and genetic data (Kiritani et al, 1973;Lee & Riemann, 1970;Wu et al, 1972). In the present study colony-type 11 strains of C. sporogenes were homologous to C. botulinum strain type A I~O in DNA-DNA reassociation assays, and colony-type I strains of C. sporogenes differed from C. botulinum only by 30 to 40 % homology.…”

“…A laboratory strain of C. botulinum type A I~O was used as a reference strain for the DNA reassociation assays; this is the representative strain of C. botulinum type A most frequently used in Japan (Iida, 1964;Kiritani et al, 1973;Takumi & Kawata, 1970).…”

Mitomycin-Induced Lysis of Clostridium Sordellii

“…Kiritani et al (1973) also stated that a non-toxigenic substrain, NIH-5, obtained from C. botulinum type B, strain NIH, was not susceptible to MC, whereas the toxigenic substrain NIH-19 obtained from the same parent strain was susceptible to the drug. These findings imply that lysogeny is closely related with toxigenicity of clostridia.…”

“…Mitsui, Kiritani and Nishida (1973) demonstrated the presence of a lytic agent as well as of phage-like particles in MC lysate of a C. botulinum strain, used the C. botulinum-C. sporogenes group-specifx lysin for taxonomic purposes. The lytic agent of C. sordellii described in the present paper also seems to have taxonomic usefulness.…”

Isolation of Nontoxigenic Variants Associated with Enhanced Sporulation and Alteration in the Cell Wall from Clostridium botulinum Type A 190L by Treatment with Detergents

“…Many phages with empty heads were observed in the lysate if fixation with formalin was omitted and washing was performed in water, suggesting that the phage is fragile or sensitive to osmotic shock. DISCUSSION Kiritani et al (13) reported that bacterial lysis was induced in all toxigenic strains of C. botulinum by treatment with MC and an induced lytic agent(s) was produced in the lysate. Although the presence of bacteriophages or phage-related particles was shown in MC-or UV-induced lysates of C. botulinum types A, B, E, and F (3,4,9), there was no available information concerning relationships between toxicity and lysogeny except for type B (13).…”