Comparison of in vitro-cultured and wild-type Perkinsus marinus.: II.: Dosing methods and host response
Comparison of in vitro-cultured and wild-type Perkinsus marinus.: II.: Dosing methods and host response
复制标题
DOI：
10.3354/dao051203
复制
发表时间：
2002-10-04
影响因子：
1.4
通讯作者：
Ford, SE
中科院分区：
文献类型：
--
作者：
Chintala, MM;Bushek, D;Ford, SE
内寄生虫必须冲破宿主的屏障来建立感染，然后必须通过宿主的内部防御来引起疾病。这些障碍可能会阻碍通过“自然”方法实验性传播寄生虫的尝试。此外，宿主的状况可能会影响研究的结果。本实验研究了给药方法和寄主代谢条件对牡蛎寄生物滨海波金索毒力测定的影响。采用饲养、壳腔注射、肠内插管和内收肌注射等方法，对野生型和人工培养的海洋假单胞菌（P. marinus）进行攻毒试验。对于这两种寄生虫类型，内收肌注射引起的感染最重，其次是壳腔注射、肠插管和喂养。用急性和慢性剂量喂养培养细胞的牡蛎之间的寄生虫负荷没有差异，寄生虫负荷随着时间的推移趋于稳定，表明在入侵和消除之间存在动态平衡。P. marinus在攻毒牡蛎组织中的分布表明，寄生虫侵入地幔和鳃，以及肠道，这被认为是主要的入口。3个不同培养阶段攻毒牡蛎中marinus的频率分布显示出寄主间的聚集分布，表明静止期寄主最容易控制或消灭，而长周期寄主最难控制或消灭。宿主代谢状况也会影响实验结果，如正在产卵和/或暴露于低氧应激的牡蛎的感染水平增加所表明的那样。
Endoparasites must breach host barriers to establish infection and then must survive host internal defenses to cause disease. Such barriers may frustrate attempts to experimentally transmit parasites by 'natural' methods. In addition, the host's condition may affect a study's outcome. The experiments reported here examined the effect of dosing method and host metabolic condition on measures of virulence for the oyster parasite Perkinsus marinus. Oysters, Crassostrea virginica, were challenged with wild-type and cultured forms of P. marinus via feeding, shell-cavity injection, gut intubation and adductor-muscle injection. For both parasite types, adductor-muscle injections produced the heaviest infections followed by shell-cavity injection, gut intubation, and feeding. There was no difference in parasite burdens between oysters fed cultured cells by acute vs chronic dosing, and parasite loads stabilized over time, suggesting a dynamic equilibrium between invasion and elimination. P. marinus distribution among tissues of challenged oysters indicated that parasites invaded the mantle and gill, as well as the gut, which has been considered the primary portal of entry. Frequency distributions of P. marinus in oysters challenged with 3 different culture phases indicated an aggregated distribution among hosts and suggested that stationary-phase parasites were easiest for the oyster to control or eliminate and log-phase parasites were the most difficult. Host metabolic condition also affected experimental outcomes, as indicated by increased infection levels in oysters undergoing spawning and/or exposed to low oxygen stress.