Department of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei City, 106, Taiwan; Zoonoses Research Center and School of Veterinary Medicine, National Taiwan University, Taipei City, 106, Taiwan.
Elanco (Taiwan) Animal Health Co., Ltd. 9F, Taipei City, 105, Taiwan.
Poult Sci. 2022 Jul;101(7):101943. doi: 10.1016/j.psj.2022.101943. Epub 2022 Apr 30.
Nontyphoidal Salmonella infection was one of the predominant foodborne illnesses in humans. The medical burden and antimicrobial resistance of salmonellosis gained importance in public health and requested the poultry industry to seek effective measures to control the disease. The objective of this study was to evaluate the safety and effectiveness of a commercial bivalent live attenuated vaccine (AviPro Salmonella DUO) in specific-pathogen-free (SPF) chickens and field layers. It explored its safety and efficacy against medically important strains, Salmonella Enteritidis (SE) and S. Typhimurium (ST). The results demonstrated that ten vaccine doses in SPF chickens and regular doses in commercial layers showed desirable safety without affecting chicken health. Vaccinated layers demonstrated lower flock mortality and higher egg production performance than the unvaccinated layers during the raising and egg production periods. Additionally, no visceral colonization and egg contaminations were detected. Cloacal shedding of vaccine strains was noted, but the colonization of Salmonella disappeared within four weeks of the last vaccination. Regarding vaccine efficacy, one dose significantly reduced Salmonella cloacal shedding (P = 0.037 for SE and P = 0.027 for ST) and viable cell counts (P = 0.003 for SE and ST) on day 7 post the challenges. Significantly low Salmonella loads of cloacal samples on day 14 after the challenges were also determined in the vaccinated group (P = 0.006 for SE; P = 0.041 for ST). Triple immunizations effectively prevented layers from the cloacal shedding on either day 7 or day 14 post Salmonella challenges. Total viable counts of SE and ST in tissues of vaccinated layers were also reduced on day 14 after the challenges (P = 0.026 for SE; P = 0.002 for ST). To conclude, one dose of vaccine exhibited inhibitory effects on Salmonella shedding and tissue invasions in young layers. Following the regimen of triple vaccinations, Salmonella shedding was completely inhibited, and tissue invasions were significantly reduced. Incorporating this vaccine into a comprehensive Salmonella control program is promising to protect layers from the risks of contaminating the flocks and egg products.
非伤寒沙门氏菌感染是人类主要的食源性疾病之一。沙门氏菌病的医疗负担和抗生素耐药性在公共卫生方面变得尤为重要，这要求家禽业寻求有效措施来控制这种疾病。本研究的目的是评估一种商业二价活减毒疫苗（AviPro Salmonella DUO）在 SPF 鸡和商品蛋鸡中的安全性和有效性。它探索了针对重要的医学菌株——肠炎沙门氏菌（SE）和鼠伤寒沙门氏菌（ST）的安全性和效果。结果表明，在 SPF 鸡中接种十剂疫苗和在商品蛋鸡中定期接种疫苗对鸡的健康没有影响，并且具有良好的安全性。与未接种疫苗的蛋鸡相比，接种疫苗的蛋鸡在饲养和产蛋期间的死亡率较低，产蛋性能更高。此外，未检测到内脏定植和鸡蛋污染。检测到疫苗株的泄殖腔脱落，但在最后一次接种后四周内，沙门氏菌定植消失。关于疫苗效力，一剂疫苗可显著减少 SE（P=0.037）和 ST（P=0.027）攻毒后第 7 天的沙门氏菌泄殖腔脱落和活菌数（P=0.003）。在接种组中，攻毒后第 14 天，粪便样本中的沙门氏菌载量也明显较低（SE：P=0.006；ST：P=0.041）。三次免疫可有效防止蛋鸡在 SE 或 ST 攻毒后第 7 天或第 14 天的泄殖腔脱落。攻毒后第 14 天，接种鸡的 SE 和 ST 组织中的总活菌数也减少（SE：P=0.026；ST：P=0.002）。总之，一剂疫苗对雏鸡的沙门氏菌脱落和组织侵袭具有抑制作用。按照三次免疫的方案，完全抑制了沙门氏菌的脱落，显著降低了组织侵袭。将该疫苗纳入综合沙门氏菌控制计划有望保护蛋鸡免受污染鸡群和蛋品的风险。
