Immunochemical characterization of cell wall protein antigen purified from the cell wall autolysate of Clostridium botulinum type A.

The cell wall protein antigen was solubilized from the isolated cell walls of Clostridium botulinum type A by autolysis and purified by diethylaminoethyl-cellulose column chromatography followed by gel filtration on Sephadex G-150. The two fractions showed a high degree of the serological activity and produced a main fused precipitin line in immunodiffusion tests against the homologous antiserum. The fact that antigenic fractions contained various kinds of amino acids but no detectable amounts of amino sugars or carbohydrates suggests that the antigens were principally composed of proteins. The protein antigen possessed multiple antigenic components in immunoelectrophoresis. As serological activity, the antigen was heat-stable and resistant to tryptic digestion but sensitive to the actions of pronase, nagarse or pepsin. The protein antigen appeared to be responsible for the common antigenicity among the proteolytic strains of C. botulinum.     

Characterization of Clostridium perfringens (welchii) Isolated from Market Poultry

Strains of Clostridium perfringens capable of producing heat-resistant spores, characteristic of the food-poisoning types, were not recovered in a random survey of feces and livers of market poultry. Favorable growth response with a known food-poisoning strain indicated that the media and methods employed were adequate. Spores produced in vitro from this strain survived at 100 C for several hours. Animal feeding experiments with this strain showed that heat-resistant spores (surviving for 1 hr at 100 C) could be readily demonstrated 24 hr after oral instillation of vegetative cells in mouse feces, but not in chicken feces. One experiment suggests that this strain might adapt to the environment of the intestinal tract of chickens, but not all of the spores recovered were as heat resistant as those of the parent culture.     

Sporulation of Clostridium perfringens (welchii) in Four Laboratory Media

S ummary . Sporulation of 7 strains of Clostridium perfringens ( welchii ) was investigated in 4 laboratory media. A method to induce rapid and simultaneous sporulation was attempted which involved obtaining a purely vegetative culture to inoculate the test media. Heat resistance of spores produced in the individual media by each of 4 selected strains was investigated. The clean spores for the heating tests were obtained by a special procedure which included chilling to 6° for a minimum of 1 week immediately following the usual incubation period, then centrifuging, resuspending to volume in 0.85% NaCl solution and pasteurizing at 75° for 20 min before subjecting to the heating tests. Morphology of each strain was studied using stained microscopic preparations from the 24 h sporulating cultures.
In the Ellner medium spore counts approaching 10⁷/ml were recorded and this medium appeared to be the most efficient when judged in terms of numbers of spores produced. In other media the counts were in the range 10⁴-10⁵ spores/ml. Cooked meat medium yielded slightly higher spore counts than did either SEC broth or modified Wagenaar & Dack medium, the latter contained in a dialysis sac apparatus. A period of chilling to 6° for a minimum of 1 week following incubation enhanced maturation in all cultures except those grown in SEC broth for 24 h or 15 days and those grown 15 days in the modified Wagenaar & Dack medium.
Considerable heat resistance, expressed as percentage spore survival, was recorded for spores of 4 strains when heated at 80°, and heat resistance generally increased with lengthening of incubation time for the culture. Survival of spores heated at 100° for 10 min was usually less than 0.01% but spores in SEC broth after 15 days showed a somewhat greater heat resistance than the others. In no instance did total destruction of spores occur at 100°.     

The cell wall proteins of Clostridium difficile

Abstract The proteins which can be released by 6 M urea treatment from the cell walls of Clostridium difficile represent the major cell surface proteins. In the 5 strains examined there are one to three of these major proteins. They appear to be strain-specific antigens being detected in immunoblots only with homologous antiserum. A common cell-surface protein of M _r 73 kDa has been identified as a minor component of the urea extract.