The sensitivity of an enrichment culture procedure for detecting Clostridium botulinum type E in whitefish chubs (Leucichthys sp.) was assayed. Data demonstrated that fish inoculated with 10 or more viable C. botulinum spores regularly develop specifically neutralizable enrichment cultures. Mild heat treatment (60 C, 15 min) substantially reduced the sensitivity of enrichment culturing. This ef...

In USA, the potency of commercial vaccines containing Clostridium botulinum type C toxoid is determined by a mink vaccination-challenge assay outlined in the Code of Federal Regulations, Title 9, Part 113.110. A more humane potency test is desired, and this study provides preliminary data in support of a serological assay that correlates post-vaccination antitoxin titers of guinea pigs to vacci...

On farms involved in botulism outbreaks, cycles of Clostridium botulinum have occurred. The cycles were initiated by feeding brewers' grains contaminated with proteolytic C. botulinum type B to the cows. Spreading of manure containing feces of these cows increased the contamination of the pastures. In grass silages prepared with wilted grass from these pastures the number of C. botulinum type B...

One strain of Clostridium botulinum belonging to type F has been isolated from a soil sample taken in Buenos Aires Province, Argentina. Comparative studies carried out with strain Langeland of C. botulinum type F have shown a few differences between the two strains.

Cold-tolerant, neurotoxigenic, endospore forming Clostridium (C.) botulinum type E belongs to the non-proteolytic physiological C. botulinum group II, is primarily associated with aquatic environments, and presents a safety risk for seafood. High pressure thermal (HPT) processing exploiting the synergistic effect of pressure and temperature can be used to inactivate bacterial endospores. We inv...

Sanger and shotgun sequencing of Clostridium botulinum strain Af84 type Af and its botulinum neurotoxin gene (bont) clusters identified the presence of three bont gene clusters rather than the expected two. The three toxin gene clusters consisted of bont subtypes A2, F4 and F5. The bont/A2 and bont/F4 gene clusters were located within the chromosome (the latter in a novel location), while the b...

UNLABELLED Heat treatment is an important controlling factor that, in combination with other hurdles (e.g., pH, aw), is used to reduce numbers and prevent the growth of and associated neurotoxin formation by nonproteolytic C. botulinum in chilled foods. It is generally agreed that a heating process that reduces the spore concentration by a factor of 10(6) is an acceptable barrier in relation to...

Gerwing et al. described the isolation and purification from culture filtrates of the toxin of Clostridium botulinum type B and characterized it as a homogeneous protein of less than 10,000 molecular weight. Analysis by various methods of samples of this toxin obtained from Gerwing et al., and preparations produced by their methods in our laboratories, furnished convincing evidence that neither...

A modified protocol for the preparation of botulinum type A toxic crystals is decribed. The essential change was the substitution of chromatography on diethylaminoethyl-Sephadex for the step in which toxin was precipitated with ethanol. Colored materials and nucleic acids were removed by the chromatography so that crystal lots of greater uniformity could be produced. Significantly more of toxin...