Megalocytivirus of family Iridoviridae has been identified as a pathogen that caused the fatal systemic infection to lead to massive death of numerous fish species in both ornamental and food fish industries. It caused significant economic losses due to severe mortality of infected fish. Since 2011 in Indonesia, megalocytivirus in giant gourami (Osphronemus goramy) had been found as the main pathogen in some cases of giant gourami outbreak, especially in West Java, Central Java, and Bali. The aim of this study is to identify and characterize the pathogen known as a megalocytivirus infection in freshwater-cultured giant gourami. We identified the virus using universal and specific primers for megalocytivirus and infectious spleen and kidney necrosis virus (ISKNV). Sequencing and BLAST analysis were used to develop a phylogenetic tree. The result showed that phylogenetic analysis of major capsid protein (MCP) gene unveiled a new member of megalocytivirus, designated as giant gourami iridovirus (GGIV). GGIV-formed cluster belonged to ISKNV and has 100% homology to ISKNV complete genome. Artificial infection by intraperitoneal injection with supernatant homogenate from spleen and kidney of naturally infected fish showed 93% cumulative mortality in 12 days. Fish showed a clinical sign of infection as lethargic, loss of appetite, pale or darken body color, and hemorrhages. Internal organ on dead fish showed swollen spleen and kidney and also a pale liver. Quantitative PCR analysis on internal organs showed spleen had the highest viral DNA copy number followed by kidney, gill, and liver. Histopathological analysis showed many abnormally hypertrophied cells in spleen which is typical histopathological characteristic of megalocytivirus infection. In conclusion, GGIV belonged to ISKNV from genus megalocytivirus.

Iridoviridae家族的巨轮病毒已被确认为是一种致病性致病菌，可导致致命的全身感染，从而导致观赏鱼和食用鱼行业中许多鱼类的大规模死亡。由于受感染的鱼类严重死亡，造成了重大的经济损失。自2011年以来在印度尼西亚，巨型瓜拉米（Osphronemus goramy）中存在巨轮病毒在某些巨大的古拉米暴发病例中，尤其是在西爪哇，中爪哇和巴厘岛，这种细菌已被发现为主要病原体。这项研究的目的是鉴定和表征在淡水养殖的巨大古拉米鱼中被称为巨轮病毒的病原体。我们使用针对巨细胞病毒和感染性脾肾坏死病毒（ISKNV）的通用引物和特异性引物鉴定了该病毒。测序和BLAST分析用于建立系统发育树。结果表明，主要衣壳蛋白（MCP）基因的系统发育分析揭示了巨轮虫病毒的新成员，被称为巨型古拉米虹膜病毒（GGIV）。GGIV形成的簇属于ISKNV，与ISKNV完整基因组具有100％的同源性。通过腹腔注射天然感染鱼的脾脏和肾脏上清液匀浆进行的人工感染在12天内显示93％的累积死亡率。鱼表现出感染的临床症状，如嗜睡，食欲不振，肤色苍白或变暗以及出血。死鱼的内脏显示脾脏和肾脏肿胀，肝色苍白。对内部器官的定量PCR分析显示，脾脏的病毒DNA拷贝数最高，其次是肾脏，腮和肝脏。组织病理学分析显示脾脏中有许多异常肥大的细胞，这是巨细胞病毒感染的典型组织病理学特征。总之，GGIV属于巨细胞病毒属ISKNV。体色苍白或变暗，并有出血。死鱼的内脏显示脾脏和肾脏肿胀，肝色苍白。对内部器官的定量PCR分析显示，脾脏的病毒DNA拷贝数最高，其次是肾脏，腮和肝脏。组织病理学分析显示脾脏中有许多异常肥大的细胞，这是巨细胞病毒感染的典型组织病理学特征。总之，GGIV属于巨细胞病毒属ISKNV。体色苍白或变暗，并有出血。死鱼的内脏显示脾脏和肾脏肿胀，肝色苍白。对内部器官的定量PCR分析显示，脾脏的病毒DNA拷贝数最高，其次是肾脏，腮和肝脏。组织病理学分析显示脾脏中有许多异常肥大的细胞，这是巨细胞病毒感染的典型组织病理学特征。总之，GGIV属于巨细胞病毒属ISKNV。组织病理学分析显示脾脏中有许多异常肥大的细胞，这是巨细胞病毒感染的典型组织病理学特征。总之，GGIV属于巨细胞病毒属ISKNV。组织病理学分析显示脾脏中有许多异常肥大的细胞，这是巨细胞病毒感染的典型组织病理学特征。总之，GGIV属于巨细胞病毒属ISKNV。