Relationship between Heat Resistance and Germination of Spores of Clostridium perfringens

Abstract

A total of 16 strains of Clostridium perfringens type A (13 strains from the United States, England, and Japan, implicated in food-poisoning outbreaks, and 3 strains from natural sources) have been studied to determine the relationship between heat-resistance and germination properties of spores. The results obtained are summarized as follows:1) On the basis of spore resistance at 95°C for 30min, these strains were divided into two groups: i) the strains producing heat-sensitive spores (5 food-poisoning strains and 3 strains from natural sources), ii) the strains producing heat-resistant spores (8 food-poisoning strains).2) Both heated and unheated spores of the strains of the heat-sensitive group were able to germinate completely in medium “A” containing a combination of L-alanine, inosine, and calcium chloride in the presence of carbon dioxide, although they hardly germinated in medium “K” containing potassium chloride and potassium phosphate buffer (pH7.0, 50mM).3) Heated spores of the strains of the heat-resistant group were able to germinate in both media “A” and “K”, the extent of germination being slightly greater in the latter than in the former. However, little or no germination occurred with unheated spores of the same strains in these media.Accordingly, there appears to exist a relationship in these 16 strains of C. perfringens between spore heat-resistance and spore germination properties.