A SIMPLIFIED MEDIUM FOR COUNTING CLOSTRIDIUM SPORES^ab

Abstract

J. Buc~., 62, 425-432 (1951). 21-25 (1950).

Relation of Dipicolinic Acid to Heat Resistance of Bacterial Spores

“…; samples were withdrawn at intervals, rapidly cooled in ice and stored in the refrigerator. Spore viability was determined by colony counts in oval culture tubes using the medium of Wynne, Schmieding & Daye (1955) solidified with 1-5 % agar.…”

THE ENUMERATION OF ANAEROBIC BACTERIA, AND OF CLOSTRIDIUM SPECIES IN PARTICULAR, IN FOODS

“…Culture Colony count/ml in medium containing: With the object of suppressing a t least some lactobacilli, a trial was then made of the anaerobic medium developed by Wynne, Schmieding t Daye (1955), which contains only yeast extract as a source of organic nutrients and is therefore even poorer than another, older American medium, that of Reynolds et al (1952) which had no liver extract but did contain tryptone and yeast extract. Nevertheless it was confirmed that Wynne's medium is as suitable for clostridia as standard, rich anaerobic media (Frank & Campbell, 1955).…”

New Media for Enumeration and Detection of Clostricfium sporogenes (PA3679) Spores

“…Sodium bicarbonate, known to improve recovery of Clostridium species (Wynne et al, 1955), markedly improved the recovery rate of heat activated and heat stressed PA3679 spores when it was included in MPA3679A. Like lysozyme, sodium bicarbonate was found to depress the recovery of heat-stressed spores when used in quantities greater than 0.1%.…”

“…The medium recommended to confirm NFPA's spore counts was Andersen's Pork Pea Infusion (APPI) using the Most Probable Number (MPN) technique (Andersen, 195 1;Bernard, 1983). As alternatives to APPI and the MPN method, several anaerobic plating media have been developed for enumeration of PA3679 spores (Wynne et al, 1955;Polvino and Bernard, 1982;Frank and Campbell, 1955;Hauschild and Hilsheimer, 1977;Pflug et al, 1979;Wheaton and Pratt, ,196l;Andersen, 1951;Odlaug and Pflug, 1977). Improvement in subculture methods and especially improvement in the subculture medium for recovering injured spores from inoculated pack tests would increase the accuracy of establishing a safe process.…”