Psychrotrophic clostridia mediated gas and botulinal toxin production in vacuum-packed chilled meat

A cocktail Of washed spores from six psychrotrophic Clostridium strains iso lated from blown vacuum-packed meats was inoculated onto lamb chumps, rh se cond washed spore cocktail of four toxigenic reference Cl. botulinum strain s, types A, B (two strains) and E, and a Cl. butyricum type E strain, was s imilarly inoculated onto lamb chumps. All inoculated lamb chumps were indiv idually vacuum-packed and placed into storage at various temperatures typic al of good to grossly abusive chilled storage (-1 degrees C to 15 degrees C ). All packs were observed for gas production (pack-'blowing') over a 12 we ek storage period. On gas production, or after 12 weeks oi storage, packs w ere examined by mouse bioassay for botulinum toxin production. The packs in oculated with the meat isolate cocktail showed evidence of gas production e arlier than packs inoculated with reference strains. No botulinum toxin was recovered from the meat isolate inoculated packs, while botulinal toxin wa s detected in reference strain inoculated packs down to a nominal storage t emperature of 2 degrees C.