College of Science and Engineering, Flinders University, Adelaide, SA, Australia.
South Australian Research and Development Institute (SARDI) Aquatic Sciences and Marine Innovation Southern Australia, West Beach, SA, Australia.
J Fish Dis. 2020 Feb;43(2):227-237. doi: 10.1111/jfd.13116. Epub 2019 Nov 21.
The haplosporidian Bonamia was first detected in Australian shellfish in 1991. Australian isolates in Ostrea angasi Sowerby, 1871 were identified as Bonamia exitiosa Hine, Cochennac and Berthe, 2001, which threatens development of an O. angasi aquaculture industry. European field data suggest that Bonamia ostreae Pichot, Comps, Tigé, Grizel and Rabouin, 1980 infections in Ostrea edulis Linnaeus, 1758 build slowly, but infection dynamics of B. exitiosa in O. angasi are unknown. We investigated B. exitiosa infection in O. angasi by cohabiting uninfected juvenile O. angasi with adults infected with B. exitiosa. Oysters were sampled at 10, 21 and 40 days after cohabitation, and B. exitiosa prevalence and intensity were assessed. Bonamia exitiosa rapidly infected and caused disease in O. angasi. Mortalities began at 12 days, with ˜50% mortality by day 21 and >85% mortality by day 40. Mortalities displayed pathology consistent with clinical B. exitiosa infection. Time to first infection is likely influenced by a combination of parasite infectivity, host exposure and host immune capacity. Host death is not required for transmission, but probably facilitates release of parasites from decaying tissue. Understanding B. exitiosa transmission informs design and interpretation of field studies and aids development of management strategies for oyster aquaculture.
1991 年，在澳大利亚贝类中首次发现了单孢子虫 Bonamia。在 1871 年的 Ostrea angasi Sowerby 中鉴定出的澳大利亚分离株为 Bonamia exitiosa Hine、Cochennac 和 Berthe，2001 年，这威胁到 O. angasi 水产养殖业的发展。欧洲实地数据表明，Bonamia ostreae Pichot、Comps、Tigé、Grizel 和 Rabouin，1980 年在 Ostrea edulis Linnaeus，1758 年的感染缓慢发展，但 B. exitiosa 在 O. angasi 中的感染动态尚不清楚。我们通过将未感染的幼年 Ostrea angasi 与感染了 B. exitiosa 的成年 Ostrea angasi 共栖来研究 B. exitiosa 在 Ostrea angasi 中的感染情况。在共栖后 10、21 和 40 天采样 Ostrea angasi，并评估 B. exitiosa 的流行率和强度。Bonamia exitiosa 迅速感染并导致 Ostrea angasi 发病。死亡率从第 12 天开始，第 21 天死亡率约为 50%，第 40 天死亡率超过 85%。死亡率显示出与临床 B. exitiosa 感染一致的病理。首次感染的时间可能受到寄生虫感染力、宿主暴露和宿主免疫能力的综合影响。宿主死亡不是传播所必需的，但可能有助于从腐烂组织中释放寄生虫。了解 B. exitiosa 的传播情况有助于设计和解释实地研究，并为牡蛎水产养殖的管理策略提供帮助。
