PDF(Pubmed)
Abstract：
UNASSIGNED: Malaysia has more than 630 culturists who are involved in the ornamental fish industry and culture 250 species, including local and exotic species. Among these viruses, megalocytiviruses have been associated with severe systemic diseases and economic losses in ornamental fish. The intensity of Megalocytivirus infection in Pterophyllum scalare in Malaysia remains unknown. Thus, this study aimed to investigate the occurrence of Megalocytivirus while discovering its associated risk factors and the genotypes of its causative agents in an ornamental fish farm in Malaysia.
UNASSIGNED: Seven broodstock pairs of P. scalare were used in this study to follow the life stages of fish, from egg to market size. Water samples and other samples, such as mucus swabs, gill swabs, P. scalare eggs, fries, juveniles, snails, snail eggs, live feed (Tubifex worms and Moina spp.), sediment samples, and wild fish, were collected periodically for initial environmental sampling from day 0 to day 60. Nested polymerase chain reaction amplifications were performed for megalocytivirus-related sequences. The phylogenetic tree, including the sampled causative agents of megalocytiviruses, was inferred from the major capsid protein genes of all known Iridoviridae species. Pearson\'s correlation coefficients were calculated to determine the strength of the correlation between the presence of megalocytiviruses in P. scalare samples and the associated risk factors.
UNASSIGNED: A total of 312 out of 935 pooled and individual samples tested positive for the presence of Megalocytivirus-related sequences, except snail eggs and wild fish (Poecilia reticulata). No clinical symptoms were observed in any fish samples. Megalocytivirus-associated viruses detected in water samples indicate horizontal transmission of the virus. All the nucleotide sequences found in this study had high nucleotide identities of 95%-99 % and were closely related to Megalocytivirus genotype I infectious spleen and kidney necrosis virus. Risk factors associated with Megalocytivirus include water temperature, dissolved oxygen (DO), pH, ammonia, nitrate, nitrite, and the life stages of P. scalare. High Megalocytivirus infection was detected when the water temperature, DO, and pH were high in P. scalare, high water temperature and nitrate in the water samples, and the same rate of Megalocytivirus infection in P. scalare fry and juveniles.
UNASSIGNED: This is the first study to confirm the existence of different possible routes of megalocytivirus distribution in ornamental fish farms in Malaysia. Nevertheless, the connection between the mode of transmission and the risk factors for this virus needs to be explored further to recognize the evolution and potential new host species.
UNASSIGNED: Seven broodstock pairs of P. scalare were used in this study to follow the life stages of fish, from egg to market size. Water samples and other samples, such as mucus swabs, gill swabs, P. scalare eggs, fries, juveniles, snails, snail eggs, live feed (Tubifex worms and Moina spp.), sediment samples, and wild fish, were collected periodically for initial environmental sampling from day 0 to day 60. Nested polymerase chain reaction amplifications were performed for megalocytivirus-related sequences. The phylogenetic tree, including the sampled causative agents of megalocytiviruses, was inferred from the major capsid protein genes of all known Iridoviridae species. Pearson\'s correlation coefficients were calculated to determine the strength of the correlation between the presence of megalocytiviruses in P. scalare samples and the associated risk factors.
UNASSIGNED: A total of 312 out of 935 pooled and individual samples tested positive for the presence of Megalocytivirus-related sequences, except snail eggs and wild fish (Poecilia reticulata). No clinical symptoms were observed in any fish samples. Megalocytivirus-associated viruses detected in water samples indicate horizontal transmission of the virus. All the nucleotide sequences found in this study had high nucleotide identities of 95%-99 % and were closely related to Megalocytivirus genotype I infectious spleen and kidney necrosis virus. Risk factors associated with Megalocytivirus include water temperature, dissolved oxygen (DO), pH, ammonia, nitrate, nitrite, and the life stages of P. scalare. High Megalocytivirus infection was detected when the water temperature, DO, and pH were high in P. scalare, high water temperature and nitrate in the water samples, and the same rate of Megalocytivirus infection in P. scalare fry and juveniles.
UNASSIGNED: This is the first study to confirm the existence of different possible routes of megalocytivirus distribution in ornamental fish farms in Malaysia. Nevertheless, the connection between the mode of transmission and the risk factors for this virus needs to be explored further to recognize the evolution and potential new host species.
摘要：
■马来西亚有超过630名从事观赏鱼业和文化的文化学家250种，包括本地和外来物种。在这些病毒中,巨细胞病毒与观赏鱼的严重全身性疾病和经济损失有关。在马来西亚，蝶藻中巨细胞病毒感染的强度仍然未知。因此，本研究旨在调查马来西亚观赏鱼场中巨细胞病毒的发生，同时发现其相关危险因素及其致病因子的基因型。
■在这项研究中使用了七种亲鱼对鱼类的生命阶段，从鸡蛋到市场规模。水样和其他样品，如粘液拭子，ill拭子,P.scalare卵，薯条,少年,蜗牛,蜗牛蛋,活饲料（Tubifex蠕虫和Moinaspp。),沉积物样本,和野生鱼，定期收集，用于从第0天到第60天的初始环境采样。对巨细胞病毒相关序列进行巢式聚合酶链反应扩增。系统发育树，包括采样的巨细胞病毒病原体，是从所有已知的病毒科物种的主要衣壳蛋白基因中推断出来的。计算Pearson相关系数以确定P.scalare样本中巨细胞病毒的存在与相关风险因素之间的相关性强度。
■在935个合并和单独的样本中，总共312个被测试为存在巨细胞病毒相关序列呈阳性，除了蜗牛卵和野生鱼（Poeciliareticulata）。在任何鱼样品中均未观察到临床症状。在水样中检测到的巨细胞病毒相关病毒表明病毒的水平传播。在这项研究中发现的所有核苷酸序列具有95％-99％的高核苷酸同一性，并且与巨细胞病毒I型传染性脾和肾坏死病毒密切相关。与巨细胞病毒相关的危险因素包括水温，溶解氧（DO），pH值,氨,硝酸盐,亚硝酸盐,以及P.scalare的生命阶段。当水温升高时，检测到巨细胞病毒感染，DO,P.scalare的pH值很高，高水温和水样中的硝酸盐，和巨细胞病毒感染率相同。
■这是第一个确认马来西亚观赏鱼场存在不同可能的巨细胞病毒分布途径的研究。然而，这种病毒的传播方式和危险因素之间的联系需要进一步探索，以认识到进化和潜在的新宿主物种。
■在这项研究中使用了七种亲鱼对鱼类的生命阶段，从鸡蛋到市场规模。水样和其他样品，如粘液拭子，ill拭子,P.scalare卵，薯条,少年,蜗牛,蜗牛蛋,活饲料（Tubifex蠕虫和Moinaspp。),沉积物样本,和野生鱼，定期收集，用于从第0天到第60天的初始环境采样。对巨细胞病毒相关序列进行巢式聚合酶链反应扩增。系统发育树，包括采样的巨细胞病毒病原体，是从所有已知的病毒科物种的主要衣壳蛋白基因中推断出来的。计算Pearson相关系数以确定P.scalare样本中巨细胞病毒的存在与相关风险因素之间的相关性强度。
■在935个合并和单独的样本中，总共312个被测试为存在巨细胞病毒相关序列呈阳性，除了蜗牛卵和野生鱼（Poeciliareticulata）。在任何鱼样品中均未观察到临床症状。在水样中检测到的巨细胞病毒相关病毒表明病毒的水平传播。在这项研究中发现的所有核苷酸序列具有95％-99％的高核苷酸同一性，并且与巨细胞病毒I型传染性脾和肾坏死病毒密切相关。与巨细胞病毒相关的危险因素包括水温，溶解氧（DO），pH值,氨,硝酸盐,亚硝酸盐,以及P.scalare的生命阶段。当水温升高时，检测到巨细胞病毒感染，DO,P.scalare的pH值很高，高水温和水样中的硝酸盐，和巨细胞病毒感染率相同。
■这是第一个确认马来西亚观赏鱼场存在不同可能的巨细胞病毒分布途径的研究。然而，这种病毒的传播方式和危险因素之间的联系需要进一步探索，以认识到进化和潜在的新宿主物种。
