Centre of Food Safety & Innovation, University of Tasmania, Private Bag 54, Sandy Bay, Tasmania, 7005, Australia.
Department of Food Science and Technology, University of Nebraska-Lincoln, 1901 N 21st St, Lincoln, NE, 68588, United States.
Food Microbiol. 2023 Jun;112:104231. doi: 10.1016/j.fm.2023.104231. Epub 2023 Feb 4.
Bacillus cereus phylogenetic group III and IV strains are commonly associated with food products and cause toxin mediated foodborne diseases. These pathogenic strains have been identified from milk and dairy products, such as reconstituted infant formula and several cheeses. Paneer is a fresh, soft cheese originating from India that is prone to foodborne pathogen contamination, such as by Bacillus cereus. However, there are no reported studies of B. cereus toxin formation in paneer or predictive models quantifying growth of the pathogen in paneer under different environmental conditions. This study assessed enterotoxin-producing potential of B. cereus group III and IV strains, isolated from dairy farm environments, in fresh paneer. Growth of a four-strain cocktail of toxin-producing B. cereus strains was measured in freshly prepared paneer incubated at 5-55 °C and modelled using a one-step parameter estimation combined with bootstrap re-sampling to generate confidence intervals for model parameters. The pathogen grew in paneer between 10 and 50 °C and the developed model fit the observed data well (R = 0.972, RMSE = 0.321 log CFU/g). The cardinal parameters for B. cereus growth in paneer along with the 95% confidence intervals were: μ 0.812 log CFU/g/h (0.742, 0.917); T is 44.177 °C (43.16, 45.49); T is 4.405 °C (3.973, 4.829); T is 50.676 °C (50.367, 51.144). The model developed can be used in food safety management plans and risk assessments to improve safety of paneer while also adding to limited information on B. cereus growth kinetics in dairy products.
蜡样芽胞杆菌 III 组和 IV 组菌株通常与食品有关，并导致毒素介导的食源性疾病。这些病原菌已从牛奶和乳制品中鉴定出来，如复原婴儿配方奶粉和几种奶酪。印度产的新鲜软奶酪-paneer 容易受到食源性病原菌的污染，如蜡样芽胞杆菌。然而，目前还没有关于-paneer 中产毒蜡样芽胞杆菌毒素形成的研究，也没有预测模型来量化不同环境条件下该病原菌在-paneer 中的生长情况。本研究评估了从奶牛场环境中分离出的 III 组和 IV 组蜡样芽胞杆菌菌株在新鲜-paneer 中产肠毒素的潜力。在 5-55°C 下培养新鲜制备的-paneer 中，四株产毒蜡样芽胞杆菌混合菌株的生长情况进行了测量，并使用一步参数估计与自举重采样相结合的方法进行了建模，以生成模型参数的置信区间。该病原菌在 10-50°C 之间的-paneer 中生长，所开发的模型很好地拟合了观测数据（R=0.972，RMSE=0.321 log CFU/g）。蜡样芽胞杆菌在-paneer 中的生长的关键参数及其 95%置信区间如下：μ=0.812 log CFU/g/h（0.742，0.917）；T is=44.177°C（43.16，45.49）；T is=4.405°C（3.973，4.829）；T is=50.676°C（50.367，51.144）。所开发的模型可用于食品安全管理计划和风险评估，以提高-paneer 的安全性，同时也为乳制品中蜡样芽胞杆菌生长动力学的有限信息提供补充。
