Oscar T P
Microbial Food Safety Research Unit, Agricultural Research Service, USDA, Room 2111, Center for Food Science and Technology, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA.
Food Microbiol. 2007 Sep;24(6):640-51. doi: 10.1016/j.fm.2006.11.003. Epub 2006 Dec 26.
A single strain (ATCC 700408) of Salmonella typhimurium DT104 was used to investigate and model growth from a low (1.12 log10 mpn g(-1)) and high (3.7 log10 cfu g(-1)) initial density on ground chicken with a natural microflora. Kinetic data for growth of the pathogen on ground chicken were fit to a primary model to determine lag time (lambda), maximum specific growth rate (mu) and maximum population density (Nmax). Secondary models for lambda, mu and Nmax, as a function of temperature (10-40 degrees C), were developed and compared among initial densities. Variation of pathogen growth among replicates (n=4 or 5) was higher at 10-18 degrees C than at 22-40 degrees C and was higher for Nmax than lambda and mu. Prediction problems were observed when secondary models developed with one initial density were used to predict lambda, mu and Nmax from the other initial density, especially at 10-18 degrees C and for Nmax. These results indicated that variation of growth among replicate challenge studies and initial density are important factors to consider when developing predictive models for growth of S. typhimurium DT104 on ground chicken with a natural microflora.
使用鼠伤寒沙门氏菌DT104的单一菌株（ATCC 700408）来研究并模拟其在带有天然微生物群落的地面鸡肉上从低初始密度（1.12 log10 mpn g(-1)）和高初始密度（3.7 log10 cfu g(-1)）开始的生长情况。将该病原体在地面鸡肉上生长的动力学数据拟合到一个初级模型中，以确定延迟期（λ）、最大比生长速率（μ）和最大种群密度（Nmax）。开发了λ、μ和Nmax作为温度（10 - 40摄氏度）函数的二级模型，并在不同初始密度之间进行比较。在10 - 18摄氏度时，重复实验（n = 4或5）中病原体生长的变化高于22 - 40摄氏度时，且Nmax的变化高于λ和μ。当使用基于一种初始密度开发的二级模型来预测另一种初始密度下的λ、μ和Nmax时，尤其是在10 - 18摄氏度时以及对于Nmax，会出现预测问题。这些结果表明，在为带有天然微生物群落的地面鸡肉上鼠伤寒沙门氏菌DT104的生长开发预测模型时，重复挑战研究之间生长的变化和初始密度是需要考虑的重要因素。
