Food and Feed Safety Research Unit, Southern Plains Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, 2881 F&B Road, College Station, Texas 77845, USA.
J Food Prot. 2013 Jul;76(7):1255-8. doi: 10.4315/0362-028X.JFP-12-317.
Recent investigations have found that Salmonella can be routinely recovered from peripheral lymph nodes (PLNs) of cattle presented for harvest. When contained within the PLNs, this foodborne pathogen is protected from currently used postharvest, inplant intervention strategies and, therefore, PLNs harboring Salmonella may be a potential contaminant of ground beef. The objective of this work was to develop a challenge model that effectively and repeatedly results in Salmonella -positive PLNs. A 10-lancet skin-allergy instrument was inoculated with Salmonella, and calves were inoculated intra- and/or transdermally by applying the device over various ventral regions of the skin. Salmonella was successfully and predictably recovered from regionspecific PLNs up to 8 days postchallenge. Furthermore, serotypes inoculated within specific regions were only recovered from the PLNs draining those regions. This model provides a method to predictably infect PLNs with Salmonella. Further, this model makes it possible to determine the duration of infection and to evaluate candidate interventions that may shorten the duration of infection.
最近的调查发现，在被送到屠宰场的牛的外周淋巴结（PLN）中可以常规回收沙门氏菌。当这种食源性病原体存在于 PLN 内时，它可以免受目前使用的收获后、厂内干预策略的影响，因此，携带沙门氏菌的 PLN 可能是碎牛肉的潜在污染物。这项工作的目的是开发一种能够有效且反复地导致 PLN 呈阳性的沙门氏菌挑战模型。使用 10 个刺血针皮肤过敏仪器接种沙门氏菌，然后通过将该设备应用于皮肤的各个腹侧区域，对小牛进行皮内和/或经皮接种。在挑战后 8 天内，成功且可预测地从特定区域的 PLN 中回收了沙门氏菌。此外，接种于特定区域的血清型仅从引流这些区域的 PLN 中回收。该模型提供了一种可预测地用沙门氏菌感染 PLN 的方法。此外，该模型还可以确定感染的持续时间，并评估可能缩短感染持续时间的候选干预措施。
