Abstract：
The objective of this study was to compare preharvest monitoring strategies by evaluating three different sampling methods in the lairage area to determine pathogen recovery for each sampling method and incoming pathogen prevalence from the cattle to inform in-plant decision making. Samples were gathered over a 5-month period, from February to June 2022, at a harvesting and processing facility located in Eastern Nebraska. Sampling methods included (i) fecal pats, (ii) boot swabs, and (iii) MicroTally swab. A total of 329 samples were collected over the study period (fecal pats: n = 105, boot swabs: n = 104, and MicroTally swabs: n = 120). Specific media combinations, an incubation temperature of 42°C, and incubation timepoints (18-24 h) were utilized for each matrix and the prevalence of Salmonella, Escherichia coli O157:H7, and six non-O157 Shiga-toxin producing E. coli (STEC) was evaluated using the BAX system Real-Time PCR assay. Overall, results from the study concluded that boot swabs were an effective sampling method for pathogen detection in the cattle lairage area. Boot swabs (97.1%) were statistically more likely to detect for Salmonella (p < 0.05) when compared to fecal pats (67.6%) and MicroTally swab (77.5%) methods. For E. coli O157:H7 and STEC - O26, O121, O45, and O103 prevalence, boot swabs were significantly better at detecting for these pathogens (p < 0.05) than MicroTally swabs (OR = 3.16 - 11.95) and a comparable sampling method to fecal pats (OR = 0.93 - 2.01, p > 0.05). Lastly, all three sampling methods detected a very low prevalence for E. coli O111 and O145; therefore, no further analysis was conducted. The boot swab sampling method was strongly favored because they require little training to implement, are inexpensive, and they do not require much sampling labor; therefore, would be a simple and effective sampling method to implement within the industry to evaluate pathogen prevalence preharvest.
摘要：
这项研究的目的是比较收获前的监测策略，方法是评估林区的三种不同采样方法，以确定每种采样方法的病原体回收率和来自牛的传入病原体流行率，以告知植物内决策。收集了5个月的样本,2022年2月至6月，位于内布拉斯加州东部的收获和加工设施。取样方法包括(I)粪便拍打，(ii)靴子拭子，和(iii)MicroTally拭子。在研究期间共收集329个样品(粪便拍子:n=105,靴拭子:n=104,和MicroTally拭子:n=120)。特定的媒体组合，培养温度为42°C，和孵育时间点（18-24小时）用于每个基质和沙门氏菌的流行，使用BAX系统实时PCR测定法评估大肠杆菌O157:H7和6种非O157产志贺毒素的大肠杆菌(STEC)。总的来说,研究结果得出结论，靴拭子是牛栏区病原体检测的有效采样方法。与粪便拍打（67.6％）和MicroTally拭子（77.5％）方法相比，在统计学上更有可能检测到沙门氏菌（p<0.05）。对于大肠杆菌O157：H7和STEC-O26、O121、O45和O103患病率，靴拭子在检测这些病原体方面（p<0.05）明显优于MicroTally拭子（OR=3.16-11.95），并且采样方法与粪便样本具有可比性（OR=0.93-2.01，p>0.05）。最后,所有三种采样方法检测到大肠杆菌O111和O145的患病率非常低；因此，未进行进一步分析.靴子拭子采样方法受到了强烈的青睐，因为它们需要很少的培训来实施，便宜,他们不需要太多的抽样劳动力；因此，将是一种简单有效的采样方法，可以在行业内实施，以评估收获前的病原体患病率。
