Dennis Michelle M, Becker Anne A M J, Freeman Mark A
Center for Conservation Medicine and Ecosystem Health, Ross University School of Veterinary Medicine, St. Kitts, West Indies.
Dis Aquat Organ. 2020 Sep 17;141:79-89. doi: 10.3354/dao03523.
Disease is contributing to the decline of coral reefs globally, but the cause and pathogenesis of most coral diseases are poorly understood. Using Gorgonia ventalina and G. flabellum as a model for coral disease diagnosis, we histologically and microbiologically examined 45 biopsies of lesions resembling Gorgonia multifocal purple spots (MFPS) with the aim of forming a comprehensive case definition based on gross and microscopic morphologic descriptions and associated etiologies. Macroscopically, all lesions were small circular areas of purple pigmentation. Gross morphologies included pigmentation only (4/45, 9%), or pigmentation with branchlet expansion and fusion (19/45, 22%), sessile masses (17/45, 38%), or hard nodules (5/45, 9%). Histological morphologic diagnoses included amoebocyte encapsulation (9/45, 20%), coenenchymal amoebocytosis (6/45, 13%), melanin (17/45, 38%), and gorgonin deposition (13/45, 29%). Sixty-four percent of instances of fungi and 86% of labyrinthulomycetes were localized to grossly normal portions of the biopsy, whereas barnacles were only within lesions, and 87% of instances of algae and 82% of cyanobacteria were within lesioned area of the biopsy. Penicillium (n = 12) was the predominant genus of fungi isolated from biopsies. Barnacles were identified as Conopea sp. using molecular techniques. The pathology and etiology underlying MFPS lesions are diverse, consistent with a highly nonspecific lesion pattern rather than a specific disease. This study demonstrates the importance of microscopic examination of tissues for accurate classification of coral diseases and lesion patterns.
疾病正在导致全球珊瑚礁衰退，但大多数珊瑚疾病的病因和发病机制仍知之甚少。我们以扇枝柳珊瑚（Gorgonia ventalina）和扇形柳珊瑚（G. flabellum）作为珊瑚疾病诊断的模型，对45份类似扇枝柳珊瑚多灶性紫斑（MFPS）的病变活检样本进行了组织学和微生物学检查，目的是根据大体和微观形态学描述以及相关病因形成一个全面的病例定义。从宏观上看，所有病变均为紫色色素沉着的小圆形区域。大体形态包括仅色素沉着（4/45，9%），或伴有小枝扩张和融合的色素沉着（19/45，22%）、固着性肿块（17/45，38%）或硬结节（5/45，9%）。组织学形态学诊断包括变形细胞包囊（9/45，20%）、共肉变形细胞增多（6/45，13%）、黑色素（17/45，38%）和柳珊瑚素沉积（13/45，29%）。64%的真菌和86%的网黏菌定位于活检样本大体正常的部分，而藤壶仅存在于病变内，87%的藻类和82%的蓝细菌存在于活检样本的病变区域内。青霉属（n = 12）是从活检样本中分离出的主要真菌属。利用分子技术将藤壶鉴定为Conopea属。MFPS病变的病理学和病因是多样的，这与高度非特异性的病变模式而非特定疾病一致。本研究证明了对组织进行显微镜检查对于准确分类珊瑚疾病和病变模式的重要性。
