Applegate Savannah F, Englishbey April K, Stephens Tyler P, Sanchez-Plata Marcos X
International Center for Food Industry Excellence, Department of Animal and Food Sciences, Texas Tech University, Lubbock, TX 79409, USA.
Qualicon Diagnostics Division, Hygiena, LLC, 2 Boulden Circle, New Castle, DE 19720, USA.
Foods. 2023 Jan 16;12(2):419. doi: 10.3390/foods12020419.
The United States Department of Agriculture Food Safety and Inspection Service (USDA FSIS) does not maintain a zero-tolerance policy for Salmonella in poultry and poultry products, despite being a known food safety hazard throughout the poultry industry. In 2016, USDA FSIS established performance standards for a 52-week moving window with the maximum acceptable percent positive for comminuted turkey (325 g sample) at 13.5% (7 of 52 samples). Based upon FSIS verification sampling results from one 52-week moving window, the Salmonella prevalence for each poultry establishment in category 1 (below limit), 2 (meeting limit), or 3 (exceeding limit) are published for public viewing. Moreover, many poultry producers continue to have post-intervention samples test positive. Therefore, the use of quantification would be more valuable to determine the efficacy of process control interventions, corrective actions, and final product Log CFU/g of Salmonella to make rapid, within shift, food safety decisions. Therefore, the objectives of these studies are to develop, verify, and validate a rapid and reliable quantification method utilizing RT-PCR to enumerate Salmonella in the poultry industry from flock to final product and to utilize the method in an application study. BAX® System SalQuant® is an application of the BAX® System Real-Time PCR Assay for Salmonella to enumerate low levels of Salmonella with shortened enrichment times. Curve development encompassed inoculating poultry matrix samples at four levels with an ATCC strain of Salmonella, with three biological replicates per inoculation level, and five technical replicates being run on the BAX® System for various timepoints, gathering the data, and creating a linear-fit equation. A linear-fit equation was provided for each timepoint. The ideal timepoint, based on the statistical parameters surrounding the equation (R2 > 0.80, Log RMSE < 0.60, and enumerable range 0.00 to 4.00 Log CFU/mL (g)) that most accurately estimate Salmonella compared to most probable number (MPN), was chosen to be utilized for further studies.
美国农业部食品安全检验局(USDA FSIS)对家禽及家禽产品中的沙门氏菌并未实行零容忍政策,尽管沙门氏菌在整个家禽行业中是已知的食品安全危害。2016年,USDA FSIS针对52周的移动窗口制定了性能标准,碎火鸡(325克样本)的最大可接受阳性百分比为13.5%(52个样本中的7个)。根据FSIS一个52周移动窗口的验证抽样结果,公布了第1类(低于限值)、第2类(符合限值)或第3类(超过限值)中每个家禽企业的沙门氏菌流行率,供公众查看。此外,许多家禽生产商干预后的样本检测仍呈阳性。因此,使用定量方法对于确定过程控制干预措施、纠正措施的效果以及最终产品中沙门氏菌的每克对数CFU,以便在班次内迅速做出食品安全决策会更有价值。因此,这些研究的目的是开发、验证和确认一种快速可靠的定量方法,该方法利用逆转录聚合酶链反应(RT-PCR)对家禽行业从鸡群到最终产品中的沙门氏菌进行计数,并在应用研究中使用该方法。BAX® System SalQuant®是BAX® System实时PCR检测沙门氏菌的一种应用,用于在缩短增菌时间的情况下对低水平的沙门氏菌进行计数。曲线绘制包括用一株美国典型培养物保藏中心(ATCC)的沙门氏菌菌株在四个水平接种家禽基质样本,每个接种水平有三个生物学重复,并在BAX® System上针对不同时间点进行五次技术重复,收集数据并创建线性拟合方程。为每个时间点提供了一个线性拟合方程。根据围绕该方程的统计参数(R2>0.80、对数均方根误差(Log RMSE)<0.60以及可计数范围为0.00至4.00对数CFU/毫升(克)),选择最能准确估计沙门氏菌的理想时间点,与最大可能数(MPN)相比,该时间点将用于进一步研究。