与一次李斯特菌病暴发相关的、由天然污染的冰淇淋制备的温度滥用奶昔中,单核细胞增生李斯特菌的恢复及生长潜力
Recovery and Growth Potential of Listeria monocytogenes in Temperature Abused Milkshakes Prepared from Naturally Contaminated Ice Cream Linked to a Listeriosis Outbreak.
作者信息
Chen Yi, Allard Emma, Wooten Anna, Hur Minji, Sheth Ishani, Laasri Anna, Hammack Thomas S, Macarisin Dumitru
机构信息
Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park MD, USA.
College of Life Sciences and Agriculture, University of New Hampshire, Durham NH, USA.
出版信息
Front Microbiol. 2016 May 18;7:764. doi: 10.3389/fmicb.2016.00764. eCollection 2016.
The recovery and growth potential of Listeria monocytogenes was evaluated in three flavors of milkshakes (vanilla, strawberry, and chocolate) that were prepared from naturally contaminated ice cream linked to a listeriosis outbreak in the U.S. in 2015, and were subsequently held at room temperature for 14 h. The average lag phase duration of L. monocytogenes was 9.05 h; the average generation time was 1.67 h; and the average population level increase per sample at 14 h was 1.14 log CFU/g. Milkshake flavors did not significantly affect these parameters. The average lag phase duration of L. monocytogenes in milkshakes with initial contamination levels ≤ 3 CFU/g (9.50 h) was significantly longer (P < 0.01) than that with initial contamination levels > 3 CFU/g (8.60 h). The results highlight the value of using samples that are contaminated with very low levels of L. monocytogenes for recovery and growth evaluations. The behavior of L. monocytogenes populations in milkshakes prepared from naturally contaminated ice cream linked to the listeriosis outbreak should be taken into account when performing risk based analysis using this outbreak as a case study.
对由与2015年美国一次李斯特菌病暴发相关的天然污染冰淇淋制备的三种口味奶昔(香草味、草莓味和巧克力味)中单核细胞增生李斯特菌的复苏和生长潜力进行了评估,随后将其在室温下保存14小时。单核细胞增生李斯特菌的平均延滞期为9.05小时;平均世代时间为1.67小时;14小时时每个样品的平均菌数增加量为1.14 log CFU/g。奶昔口味对这些参数没有显著影响。初始污染水平≤3 CFU/g的奶昔中单核细胞增生李斯特菌的平均延滞期(9.50小时)显著长于(P < 0.01)初始污染水平>3 CFU/g的奶昔(8.60小时)。结果突出了使用极低水平单核细胞增生李斯特菌污染的样品进行复苏和生长评估的价值。以此次暴发为案例进行基于风险的分析时,应考虑由与李斯特菌病暴发相关的天然污染冰淇淋制备的奶昔中单核细胞增生李斯特菌菌数的变化情况。