Jainonthee Chalita, Chaisowwong Warangkhana, Ngamsanga Phakamas, Wiratsudakul Anuwat, Meeyam Tongkorn, Pichpol Duangporn
Veterinary Public Health and Food Safety Centre for Asia Pacific (VPHCAP), Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand.
Center of Excellence in Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand.
Vet Sci. 2022 Mar 8;9(3):122. doi: 10.3390/vetsci9030122.
is one of the leading causes of foodborne illness worldwide. is commonly found in poultry. It is the most frequent cause of contamination and thus resulting in not only public health concerns but also economic impacts. To test for this bacterial contamination in food processing plants, this study attempted to employ a simple and rapid detection assay called loop-mediated isothermal amplification (LAMP). The best cutoff value for the positive determination of calculated using real-time LAMP quantification cycle (C) was derived from the receiver operating characteristic (ROC) curve modeling. The model showed an area under curve (AUC) of 0.936 (95% Wald CI: 0.903-0.970). Based on Youden's J statistic, the optimal cutoff value which had the highest sensitivity and specificity from the model was calculated as 18.07. The LAMP assay had 96.9% sensitivity, 95.8% specificity, and 93.9 and 97.9% positive and negative predictive values, respectively, compared to a standard culture approach for identification. Among all non- strains, the LAMP assay gave each of 12.5% false-positive results to and (1 out of 8 samples). The assay can detect at the lowest concentration of 10 CFU/mL. Our results suggest a preliminary indicator for the application of end-point LAMP assays, such as turbidity and UV fluorescence tests, to detect in field operations. The LAMP assay is an alternative screening test for contamination in food samples. The method provides a rapid detection, which requires only 9 min with a cutoff value of C. We performed the extraction of DNA from pure cultures and the detection of using the LAMP assay within 3 h. However, we were not able to reduce the time for the process of enrichment involved in our study. Therefore, we suggest that alternative enrichment media and rapid DNA extraction methods should be considered for further study. Compared to other traditional methods, our proposed assay requires less equipment and time, which is applicable at any processing steps in the food production chain.
是全球食源性疾病的主要原因之一。常见于家禽中。它是污染的最常见原因，不仅导致公共卫生问题，还造成经济影响。为了检测食品加工厂中的这种细菌污染，本研究尝试采用一种名为环介导等温扩增（LAMP）的简单快速检测方法。使用实时LAMP定量循环（C）计算的用于阳性判定的最佳临界值来自受试者工作特征（ROC）曲线建模。该模型显示曲线下面积（AUC）为0.936（95% Wald CI：0.903 - 0.970）。基于约登指数（Youden's J statistic），计算出模型中具有最高灵敏度和特异性的最佳临界值为18.07。与用于鉴定的标准培养方法相比，LAMP检测的灵敏度为96.9%，特异性为95.8%，阳性预测值和阴性预测值分别为93.9%和97.9%。在所有非菌株中，LAMP检测对和的假阳性结果均为12.5%（8个样本中的1个）。该检测方法能够检测到低至10 CFU/mL浓度的。我们的结果为在现场操作中应用终点LAMP检测（如浊度和紫外荧光测试）来检测提供了一个初步指标。LAMP检测是食品样本中污染的一种替代筛选检测方法。该方法提供快速检测，仅需9分钟，临界值为C。我们在3小时内从纯培养物中提取DNA并使用LAMP检测进行检测。然而，我们未能缩短本研究中涉及的富集过程的时间。因此，我们建议应考虑使用替代富集培养基和快速DNA提取方法进行进一步研究。与其他传统方法相比，我们提出的检测方法所需设备和时间更少，适用于食品生产链中的任何加工步骤。
