Data from: White Syndrome in Acropora muricata: Non-specific bacterial infection and ciliate histophagy

Selective antibiotic treatment of White Syndrome (WS)-affected corals (Acropora muricata) from Fiji was used to identify 3 potential bacterial pathogens of the disease. Interestingly, the suite of bacterial associates of the disease was different to that recently identified using identical primer sets for WS on the GBR and in the Solomon Islands. In addition to the three bacterial pathogenic candidates and as previously shown for WS and more recently for White Band Disease (WBD) in the Caribbean, all samples of the disease were specifically associated with the histophagous ciliate Philaster lucinda. From the pattern of disease progression and histopathology in relation to the selective elimination of microbial groups, we conclude that these ‘white’ diseases are a result of a non-specific bacterial infection and a ‘secondary’ infection by the P. lucinda ciliate. Although we have not observed the initiation of infection, a non-specific, multi-species bacterial infection appears to be a co-requirement for WS lesion progression and we hypothesize that the bacterial infection occurs initially, weakening the defences of the host to predation by the ciliates. Such ciliate histophagy, gives rise to the characteristic white band of denuded coral skeleton that gives these diseases their names. The characteristics of the microbial communities of WBD and WS appear identical, and since the bacterial associates of WS vary geographically (and/or temporally), there appears to be no logical distinction between WS in the Indo-Pacific and WBD in the Caribbean.对来自斐济的受白色综合征（White Syndrome, WS）感染的细枝鹿角珊瑚（Acropora muricata）开展选择性抗生素处理，以此鉴定出该疾病的3种潜在细菌性致病菌。值得注意的是，该疾病的细菌共生菌群与近期在大堡礁（Great Barrier Reef, GBR）和所罗门群岛利用相同引物组针对WS开展的研究所鉴定出的菌群存在差异。除上述3株候选致病菌外，正如此前针对WS以及近期针对加勒比海地区的白色带状病（White Band Disease, WBD）的研究结果所示，所有患病样本均特异性地与噬组织纤毛虫（Philaster lucinda）存在关联。基于针对微生物类群选择性清除的疾病进展模式与组织病理学特征，我们推断此类“白色”疾病是由非特异性细菌感染以及由P. lucinda纤毛虫引发的“继发性”感染共同导致的。尽管我们尚未观察到感染的起始过程，但多物种非特异性细菌感染似乎是WS病损进展的共同必要条件；我们据此提出假说：细菌感染最初发生，会削弱宿主抵御纤毛虫捕食的能力。这种纤毛虫的噬组织行为会形成裸露珊瑚骨骼所特有的白色条带，这也正是此类疾病得名的缘由。WBD与WS的微生物群落特征看似一致；鉴于WS的细菌共生菌群存在地理（及/或时间）异质性，因此印度洋-太平洋海域的WS与加勒比海地区的WBD之间似乎并无合理的分类学区分。