自然感染和接种的牛奶中单核细胞增生李斯特菌的耐热性

Heat resistance of Listeria monocytogenes in naturally infected and inoculated cow's milk.

作者信息

Kovincić I, Mrdjen M, Komnenov-Pupovac V, Vujicić I F, Vulić M, Svabić-Vlahović M, Tierney J T

机构信息

Veterinary Science Institute, Novi Sad, Yugoslavia.

出版信息

Acta Microbiol Hung. 1991;38(1):3-6.

PMID:1810108

Abstract

A two phase slug flow tubular heat exchanger was used for the thermal inactivation of Listeria monocytogenes in natural infected milk from seven cows. L. monocytogenes serotype 4b inoculated UHT sterilized milk was monitored in a parallel study. The two milks were heated at 71.1 degrees C for holding times of 2, 4, 10, 15, 20 and 30 s. Milk was assayed for survivors immediately after heat treatment and weekly thereafter for 4 weeks during storage at 4 degrees C. No survivors were detected in the naturally infected milk at any of the holding times. Survivors were found at 2 and 4 s in the inoculated UHT milk with initial titres of 8 x 10(2) to 7.1 x 10(3) c.f.u./ml, only after storage at 4 degrees C for 28 days. No survivors were detected for 10 through 30 s holding times.

摘要

使用两相段塞流管式热交换器对来自七头奶牛的天然感染牛奶中的单核细胞增生李斯特菌进行热灭活。在一项平行研究中，对接种了单核细胞增生李斯特菌4b血清型的超高温灭菌牛奶进行了监测。将两种牛奶在71.1摄氏度下加热，保持时间分别为2、4、10、15、20和30秒。热处理后立即检测牛奶中的存活菌数，此后在4摄氏度储存4周期间每周检测一次。在任何保持时间下，天然感染牛奶中均未检测到存活菌。接种的超高温灭菌牛奶在初始滴度为8×10²至7.1×¹⁰³ c.f.u./ml时，仅在4摄氏度储存28天后，在2秒和4秒的保持时间下发现了存活菌。在10至30秒的保持时间内未检测到存活菌。