Sabike Islam I, Fujikawa Hiroshi, Edris Abobakr M
Laboratory of Veterinary public health, Faculty of Agriculture, Tokyo University of Agriculture and technology.
Biocontrol Sci. 2015;20(3):185-92. doi: 10.4265/bio.20.185.
The growth kinetics of Salmonella Enteritidis in raw beef has been little studied so far. Thus, this study aimed to clarify the growth kinetics of the pathogen in ground beef using a growth model. When Salmonella cells inoculated at various initial doses into ground beef were incubated at a given temperature (24℃), the maximum population (Nmax) of the microbe at the stationary phase varied with the doses. This relationship was expressed with a polynomialequation for Nmax using the initial dose. The combination of the growth model and the polynomial equation successfully predicted Salmonella growth at a given initial dose. When Salmonella cells inoculated in ground beef were incubated at various constant temperatures, the growth curves of the pathogen and natural microflora (NM) were well described with the growth model. The rate constant of growth and the Nmax values for Salmonella and NM were then analyzed kinetically. From these results, growth curves of Salmonella and NM in ground beef stored at dynamic temperatures were successfully predicted. Competition between Salmonella and NM in ground beef was also found during the storage. This study could give usable information on the growth of Salmonella and NM in ground beef at various temperatures.
迄今为止，肠炎沙门氏菌在生牛肉中的生长动力学鲜有研究。因此，本研究旨在通过生长模型阐明该病原菌在碎牛肉中的生长动力学。当将不同初始剂量接种的沙门氏菌细胞接种到碎牛肉中，并在给定温度（24℃）下培养时，微生物在稳定期的最大数量（Nmax）随剂量而变化。这种关系用一个使用初始剂量的Nmax多项式方程来表示。生长模型和多项式方程的组合成功预测了给定初始剂量下沙门氏菌的生长。当接种在碎牛肉中的沙门氏菌细胞在不同恒温下培养时，该病原菌和天然微生物群（NM）的生长曲线可用生长模型很好地描述。然后对沙门氏菌和NM的生长速率常数和Nmax值进行动力学分析。根据这些结果，成功预测了在动态温度下储存的碎牛肉中沙门氏菌和NM的生长曲线。在储存过程中还发现了碎牛肉中沙门氏菌和NM之间的竞争。本研究可为不同温度下碎牛肉中沙门氏菌和NM的生长提供有用信息。
