评估利用自家疫苗减轻德克萨斯州育肥场牛淋巴结中沙门氏菌的效果。

Evaluation of Autogenous Vaccine Use in Mitigating Salmonella in Lymph Nodes from Feedlot Cattle in Texas.

机构信息

Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471 (ORCID: https://orcid.org/0000-0001-6346-9437 [A.N.A.]); and.

King Ranch Institute for Ranch Management, Texas A&M University, Kingsville, MSC 137, Kingsville, Texas 78363, USA.

出版信息

J Food Prot. 2021 Jan 1;84(1):80-86. doi: 10.4315/JFP-20-171.

DOI:10.4315/JFP-20-171

PMID:32853371

Abstract

ABSTRACT

Managing the presence of Salmonella in ground beef has been an ongoing challenge for the beef industry. Salmonella prevalence can vary regionally, seasonally, and within the animal, making the development of interventions difficult. The objective of this study was to assess the efficacy of an autogenous Salmonella vaccine in mitigating Salmonella in lymph nodes (LNs) of feedlot cattle. An autogenous vaccine was developed using the most common Salmonella enterica serovars (Salmonella Kentucky, Salmonella Anatum, Salmonella Muenchen, Salmonella Montevideo, and Salmonella Mbandaka) identified from cattle managed at a South Texas feedlot with historically high Salmonella prevalence. Fifty-five heifers were selected for even distribution across five groups: (i) BASE, which received no autogenous vaccinations and were harvested after the stocker stage, (ii) CNTRL, which received no autogenous vaccinations, (iii) FARM, which received autogenous vaccinations at the ranch only, (iv) SPLIT, which received autogenous vaccinations at both the ranch and feedlot, and (v) YARD, which received vaccinations at the feedlot only. One heifer each from the BASE and CNTRL groups did not complete the study. All treatment groups except BASE were harvested after reaching market weight. Left and right superficial cervical and subiliac LNs from each carcass were collected and analyzed for Salmonella presence, and positive samples were serotyped. No salmonellae were recovered from LNs derived from BASE, FARM, SPLIT, or YARD groups. Cattle in the BASE group were expected to have a low occurrence of Salmonella based on previous research. However, the percentage of Salmonella-positive animals in the CNTRL group was 20.0% (2 of 10), which is lower than expected based on historical data from the same feeding location. There could be several causes of decreased Salmonella presence in the LNs of control cattle, creating an opportunity for future investigation into the development of preharvest interventions to combat Salmonella in feedlots.

摘要

控制牛肉中的沙门氏菌一直是牛肉行业面临的一个持续挑战。沙门氏菌的流行情况因地区、季节和动物体内的情况而异，这使得干预措施的开发变得困难。本研究的目的是评估一种同源沙门氏菌疫苗在减轻牛场牛淋巴结（LN）中沙门氏菌的效果。该同源疫苗是使用从德克萨斯州南部一个牛场管理的牛中分离出的最常见的沙门氏菌血清型（沙门氏菌肯塔基、沙门氏菌阿纳特、沙门氏菌慕尼黑、沙门氏菌蒙得维的亚和沙门氏菌曼巴达卡）开发的。55 头小母牛被均匀分配到五个组中：（i）BASE，未接种同源疫苗，在育肥阶段后收获；（ii）CNTRL，未接种同源疫苗；（iii）FARM，仅在牧场接种同源疫苗；（iv）SPLIT，在牧场和牛场都接种同源疫苗；（v）YARD，仅在牛场接种疫苗。来自 BASE 和 CNTRL 组的每头小母牛都没有完成研究。除 BASE 组外，所有治疗组均在达到上市体重后收获。从每个胴体采集左、右颈浅淋巴结和髂下淋巴结进行沙门氏菌检测，阳性样本进行血清型鉴定。来自 BASE、FARM、SPLIT 或 YARD 组的 LN 中均未分离出沙门氏菌。基于先前的研究，BASE 组的牛预期会有较低的沙门氏菌发生率。然而，CNTRL 组的沙门氏菌阳性动物比例为 20.0%（10 头中有 2 头），低于同一饲养地点的历史数据预期。对照组牛 LN 中沙门氏菌减少的原因可能有几个，这为未来开发在牛场对抗沙门氏菌的收获前干预措施提供了机会。