Survival and growth of enterotoxin-positive and enterotoxin-negative Clostridium perfringens in laboratory media.
The survival and growth characteristics of enterotoxin-positive and enterotoxin-negative Clostridium perfringens were compared. Spores of C. perfringens were heated and incubated in laboratory media to simulate the cooking and inadequate storage of cooked food. In our experiment, enterotoxin-positive and enterotoxin-negative spores were heated and incubated individually and it was found that spores of enterotoxin-positive strains were more heat-resistant than spores of the enterotoxin-negative strains. In another experiment, cocktails of enterotoxin-positive and enterotoxin-negative spores were heated and incubated. At the time of inoculation, the ratio of enterotoxin-positive spores to enterotoxin-negative spores was about 1:100. In the case of high-temperature heat treatment, the number of enterotoxin-negative spores decreased to below that of enterotoxin-positive spores after heating, and enterotoxin-positive strains grew to high levels during incubation. In the case of low-temperature heat treatment, the number of enterotoxin-negative spores remained almost unchanged after heating and enterotoxin-positive strains did not grow to high CFU levels during incubation.
Miwa
Norinaga
N
Shizuoka Institute of Environment and Hygiene, Kitaando, Japan. miwanm@lilac.ocn.ne.jp
Masuda
Takashi
T
Kwamura
Asako
A
Terai
Katsuya
K
Akiyama
Masato
M
D003016:Clostridium perfringens / Q000187:drug effects / Q000254:growth & development*; D015169:Colony Count, Microbial; D003470:Culture Media; D004768:Enterotoxins / Q000096:biosynthesis*; D005516:Food Microbiology; D006358:Hot Temperature / Q000009:adverse effects*; D013171:Spores, Bacterial / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors
D003470:Culture Media; D004768:Enterotoxins