de Ruyter Tryssa, Littman Eric, Yazdi Zeinab, Adkison Mark, Camus Alvin, Yun Susan, Welch Timothy J, Keleher William R, Soto Esteban
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA.
School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Pathogens. 2023 Apr 22;12(5):632. doi: 10.3390/pathogens12050632.
is an important emergent bacterial pathogen of salmonids in the USA. The purpose of this study was to evaluate the protection conferred to rainbow trout () against by formalin-killed vaccines in immersion and injectable forms, as well as the enhanced protection afforded by booster vaccination. In the first challenge, fish were immunized via intracoelomic injection (IC) or immersion (Imm) routes alone. Approximately 418 degree days (Temperature in degree Celsius × days post-immunization) (dd) Imm, or 622 dd IC post-vaccination, fish were challenged via IC with wild-type In the second experiment, initial Imm vaccination was followed by booster vaccination via Imm or IC routes 273 dd post-immunization along with appropriate PBS controls. The various vaccination protocol efficacies were evaluated by challenging fish with by cohabitation with diseased fish 399 dd post-booster administration. A relative percent survival (RPS) of 89.5% and 28% was recorded in the IC and Imm single immunization treatments, respectively. In the second study, an RPS of 97.5%, 10.2%, 2.6% and -10.1% plus approximately 0%, 50%, 20%, and 30% bacterial persistence was recorded in the Imm immunized + IC boosted, Imm immunized + mock IC boosted, Imm immunized + Imm boosted, and Imm immunized + mock Imm boosted treatments, respectively. Only the Imm immunized + IC injection boosted treatments provided significant protection when compared to unvaccinated and challenged treatments ( < 0.05). In conclusion, although both Imm and IC vaccines appear safe for trout, the inactivated Imm vaccines seem to provide only mild and temporary protection against lactococcosis; whereas IC immunized trout develop a significantly stronger protective response in both challenges.
是美国鲑科鱼类中一种重要的新兴细菌病原体。本研究的目的是评估福尔马林灭活疫苗以浸泡和注射形式对虹鳟鱼（）抵抗的保护作用，以及加强免疫所提供的增强保护作用。在首次攻毒试验中，鱼只分别通过腹腔注射（IC）或浸泡（Imm）途径进行免疫。免疫后约418度日（摄氏度温度×免疫后天数）（dd）的浸泡免疫组，或622 dd的腹腔注射免疫组，在接种疫苗后通过腹腔注射野生型进行攻毒。在第二个实验中，最初的浸泡免疫接种后，在免疫后273 dd通过浸泡或腹腔注射途径进行加强免疫，并设置适当的PBS对照。通过在加强免疫后399 dd与患病鱼同居攻毒来评估各种疫苗接种方案的效果。在腹腔注射和浸泡单一免疫处理中，相对存活率（RPS）分别记录为89.5%和28%。在第二项研究中，浸泡免疫+腹腔注射加强免疫、浸泡免疫+模拟腹腔注射加强免疫、浸泡免疫+浸泡加强免疫和浸泡免疫+模拟浸泡加强免疫处理的RPS分别记录为97.5%、10.2%、2.6%和-10.1%，细菌持续存在率分别约为0%、50%、20%和30%。与未接种疫苗并攻毒的处理相比，只有浸泡免疫+腹腔注射加强免疫处理提供了显著的保护作用（<0.05）。总之，虽然浸泡和腹腔注射疫苗对鳟鱼似乎都是安全的，但灭活的浸泡疫苗似乎只能提供对乳球菌病的轻度和暂时保护；而腹腔注射免疫的鳟鱼在两次攻毒中都产生了明显更强的保护反应。
