Cook David W, Ruple Angela D
Gulf Coast Research Laboratory, P.O. Box 7000, Ocean Springs, Mississippi 39564-7000.
J Food Prot. 1992 Dec;55(12):985-989. doi: 10.4315/0362-028X-55.12.985.
Pure cultures of Vibrio vulnificus held at temperatures of 4 and 0°C underwent a time-dependent decrease in number of recoverable cells. A similar pattern of decreasing numbers was observed with naturally occurring V. vulnificus in cold stored shellstock oysters and shucked oyster meats. The time required for the bacterium to reach undetectable levels (MPN <3/g) may exceed the usual storage life of 14 d for shucked oyster meats and 21 d for shellstock oysters. Freezing and storage of pure cultures of V. vulnificus at -20°C reduced the number of culturable cells more quickly than did holding the cultures at 0°C. However, the organism was cultured from oysters frozen at -20°C for 12 weeks. While cold storage reduced the numbers of V. vulnificus in oysters, such treatment cannot be relied upon to eliminate the organism. Exposure to temperatures above 45°C causes death of V. vulnificus . Decimal reduction times at 47°C for 52 strains averaged 78 s (SD ± 30 s), and D values for 18 of the hardiest strains averaged 39.8 s (SD ± 12.2 s). Heating oysters for 10 min in water at 50°C proved adequate to reduce V. vulnificus to a nondetectable level. This treatment does not impart a noticeable cooked appearance or taste to the oysters and may be employed as a strategy to improve the safety of raw oysters.
创伤弧菌纯培养物在4°C和0°C温度下保存时，可培养细胞数量随时间减少。在冷藏的带壳牡蛎和去壳牡蛎肉中的天然创伤弧菌也观察到类似的数量减少模式。该细菌达到不可检测水平（MPN<3/g）所需的时间可能超过去壳牡蛎肉通常14天的储存期和带壳牡蛎21天的储存期。将创伤弧菌纯培养物在-20°C下冷冻和储存比在0°C下保存更快地减少了可培养细胞的数量。然而，在-20°C下冷冻12周的牡蛎中仍能培养出该菌。虽然冷藏减少了牡蛎中创伤弧菌的数量，但不能依靠这种处理来消除该菌。暴露于45°C以上的温度会导致创伤弧菌死亡。52株菌株在47°C下的D值平均为78秒（标准差±30秒），18株最耐温菌株的D值平均为39.8秒（标准差±12.2秒）。在50°C的水中将牡蛎加热10分钟足以将创伤弧菌减少到不可检测的水平。这种处理不会使牡蛎呈现出明显的煮熟外观或味道，可作为提高生牡蛎安全性的一种策略。
