School of Aquatic and Fishery Sciences, University of Washington Seattle, WA, USA.
School of Aquatic and Fishery Sciences, University of Washington Seattle, WA, USA ; Washington Cooperative Fish and Wildlife Research Unit, U.S. Geological Survey, University of Washington Seattle, WA, USA.
Front Microbiol. 2014 Mar 18;5:78. doi: 10.3389/fmicb.2014.00078. eCollection 2014.
Black abalone, Haliotis cracherodii, populations along the NE Pacific ocean have declined due to the rickettsial disease withering syndrome (WS). Natural recovery on San Nicolas Island (SNI) of Southern California suggested the development of resistance in island populations. Experimental challenges in one treatment demonstrated that progeny of disease-selected black abalone from SNI survived better than did those from naïve black abalone from Carmel Point in mainland coastal central California. Unexpectedly, the presence of a newly observed bacteriophage infecting the WS rickettsia (WS-RLO) had strong effects on the survival of infected abalone. Specifically, presence of phage-infected RLO (RLOv) reduced the host response to infection, RLO infection loads, and associated mortality. These data suggest that the black abalone: WS-RLO relationship is evolving through dual host mechanisms of resistance to RLO infection in the digestive gland via tolerance to infection in the primary target tissue (the post-esophagus) coupled with reduced pathogenicity of the WS-RLO by phage infection, which effectively reduces the infection load in the primary target tissue by half. Sea surface temperature patterns off southern California, associated with a recent hiatus in global-scale ocean warming, do not appear to be a sufficient explanation for survival patterns in SNI black abalone. These data highlight the potential for natural recovery of abalone populations over time and that further understanding of mechanisms governing host-parasite relationships will better enable us to manage declining populations.
黑鲍，Haliotis cracherodii，由于立克次体病枯萎综合征（WS），沿东北太平洋的种群数量已经减少。南加州圣尼古拉岛（SNI）的自然恢复表明岛屿种群已经发展出了抗性。在一项处理中进行的实验性挑战表明，来自 SNI 的患病黑鲍的后代比来自加利福尼亚州中部沿海卡梅尔角的天真黑鲍的后代更能存活。出乎意料的是，一种新观察到的噬菌体感染 WS 立克次体（WS-RLO）的存在对受感染的鲍鱼的存活有强烈影响。具体来说，噬菌体感染的 RLO（RLOv）的存在降低了宿主对感染的反应、RLO 感染负荷和相关死亡率。这些数据表明，黑鲍：WS-RLO 关系正在通过两种宿主机制进化，即在消化腺中通过对感染的耐受性来抵抗 RLO 感染，同时通过噬菌体感染降低 WS-RLO 的致病性，从而有效地将原发性靶组织（食管后）中的感染负荷降低一半。与最近全球范围海洋变暖暂停相关的南加州外海的海面温度模式似乎并不能充分解释 SNI 黑鲍的存活模式。这些数据强调了鲍鱼种群随着时间的自然恢复的潜力，并且进一步了解控制宿主-寄生虫关系的机制将使我们能够更好地管理数量下降的种群。
