单增李斯特菌在乳粉中的生存特性  

Study on the Existence Characteristics of Listeria monocytogenes in Milk Powder

作　　者：王海艳 石新华 蒙嵘 李昕 李凤利 张小玲 盛万里 Wang Haiyan;Shi Xinhua;Meng Rong;Li Xin;Li Fengli;Zhang Xiaoling;Sheng Wanli(Huhhot Customs,Huhhot,Inner Mongolia 010020,China;Inner Mongolia Autonomous Region Agriculture and Livestock Technology Extension Center,Huhhot,Inner Mongolia 010010,China)

机构地区：[1]呼和浩特海关,内蒙古呼和浩特010020 [2]内蒙古自治区农牧业技术推广中心,内蒙古呼和浩特010010

出　　处：《中国动物检疫》2021年第11期54-59,共6页China Animal Health Inspection

基　　金：科技部科研院所社会公益研究专项(2004DIA2J004-3)。

摘　　要：单增李斯特菌是乳粉中常见的致病菌之一。为了解不同水活性(Aw)干乳粉、复水乳粉和热冲调乳粉中单增李斯特菌的生存特性,通过人工方法将单增李斯特菌添加于不同Aw的干奶粉、复水奶粉中,并在不同温度或pH条件下培养,通过菌落计数来分析单增李斯特菌的生存特性。结果显示:在4℃条件下,单增李斯特菌可在较低Aw (0.81、0.92)的干奶粉中长期保持生长活力,并且当Aw较高(0.96)时,会有增长趋势;在25℃条件下,干奶粉中的单增李斯特菌的生长活力很快减退,细菌处于亚损伤状态。复水奶粉中的单增李斯特菌能够生长的温度为-1.5~37℃,在pH4.4~8.0的复水奶粉中,高温条件下(30℃)比在低温条件下(4℃)生长快,但在低温条件下,对酸碱的耐受程度比在高温条件下大。单增李斯特菌在复水的高糖高脂奶粉中比原料奶粉中对热的耐受力强。结果表明,高温条件更易使干奶粉中单增李斯特菌生长活力减退,复水奶粉如果污染单增李斯特菌,在低温条件下贮存则能够控制单增李斯特菌的生长,高糖高脂成分可提高单增李斯特菌的热抵制能力。本研究为乳粉中单增李斯特菌的风险评估和关键控制措施的制定提供了依据。Listeria monocytogenes is one of pathogenic bacteria commonly found in milk powder.In order to learn its existence characteristics in dry milk powder,rehydrated milk powder and hot diluted milk powder with different water activities,Listeria monocytogenes was artificially added into dry milk powder and rehydrated milk powder with different water activities to be cultured at different temperatures or pH conditions and analyzed through colony counting.It was found that,the growth activity of Listeria monocytogenes maintained in dry milk powder at lower water activity(0.81 and 0.92) for a long time at 4 ℃,trended to grow at higher water activity(0.96),and rapidly decreased at 25 ℃,and the bacteria remained in a sub-damaged status.Listeria monocytogenes grew in rehydrated milk powder at -1.5 to 37 ℃,and was faster in that with pH4.4 to 8.0 at higher temperature(30℃) compared to lower one(4℃),but its tolerance against acid and alkali was higher at lower temperature(4℃) than at higher temperature(30℃),and its heat tolerance was stronger in rehydrated high-sugar and high-fat milk powder than in raw milk powder.In conclusion,the growth activity of Listeria monocytogenes could decrease in dry milk powder at higher temperature,and be controlled through storage at lower temperature in case of re hydrated milk powder infected with Listeria monocytogenes.In addition,the hot tolerance of Listeria monocytogenes could be improved by the components with high sugar and fat.A basis was thereby provided for risk assessment of Listeria monocytogenes in milk powder and development of key control measures.

关 键 词：单增李斯特菌 乳粉 生存特性 

分 类 号：S851.3[农业科学—预防兽医学]