Studies on origin of retroviruses from wild carnivore

在越南社会主义共和国（越南），有很多在日本不存在的争执（不和）。已知三种逆转录病毒（猫白血病病毒（FIV）、猫免疫缺陷病毒（FIV）和猫合胞病毒（FSV））会感染家猫。本研究的目的是分离和鉴定来自越南几个地区的逆转录病毒，并将其与已知的逆转录病毒进行比较。我们调查了河内和胡志明市附近的家猫和豹猫。在河内附近，我们未发现家猫和豹猫感染FIV或FeLV的发生率。然而，我们发现29%的家猫和71%的豹猫感染了FSV。我们分离了9株FSV并进行了系统发育分析。除1株分离物外，其余分离物在系统发育树上形成一个簇。从结果来看，我们认为越南最早出现了FSV，或者家猫的FIV最近感染了豹猫，反之亦然。在胡志明市附近，我们未发现家猫和豹猫感染FeLV的病例。与在河内市附近获得的结果相反，我们发现22%的家猫感染了FIV，而没有豹猫感染病毒。此外，我们发现78%的家猫和25%的豹猫感染了FSV。我们成功分离了5株FIV，并测定了env基因V3-V5群的核苷酸序列。系统发育分析显示5株为C亚型，1株为d亚型。据报道，C亚型在加拿大和台湾流行。

In Socialist Republic of Vietnam (Vietnam), there are lots of camivors (feuds) which are not present in Japan. Three retroviruses (feline leukemia virus (FIV), feline immunodeficiency virus (FIV), and feline syncytial virus (FSV)) are known to infect domestic cats. The purpose of this study is to isolate and identify retroviruses from several feuds in Vietnam and to compare them with known retroviruses. We surveyed domestic and leopard cats in the vicinity of Hanoi and HoChiMinh city.In the vicinity of Hanoi, we could not find any incidence of infection of FIV or FeLV in both domestic and leopard cats. However, we found that 29% of domestic cats and 71% of leopard cats were infected with FSV.We isolated 9 strains of FSV and conducted phylogenetic analysis. All the isolates except one isolate formed a cluster in the phylogenetic tree. Form the result, we considered that FSV has been present in Vietnam from the earliest time or FIV of domestic cats infect leopard cats recently, or vice versa.In the vicinity of HoChiMinh city, we could not find any incidence of infection of FeLV in both domestic and leopard cats. Contrary to the result obtained in the vicinity of Hanoi city, we found that 22% of domestic cats were ***ected with FIV whereas no leopard cats were infected with the virus. In addition, we found that 78% of domestic cats and 25% of leopard cats were infected with FSV.We succeeded in isolation of five strains of FIV and determined the nucleotide sequence of the V3-V5 legion of env gene. The phylogenetic analysis revealed that five strains belonged to subtype C and one strain belonged to subtype D.FIV Subtype C is reported to be prevalent in Canada and Taiwan. From the results obtained here, we considered that FIV invaded southern Vietnam recently from other countries including Canada and Taiwan, or domestic cats in southern Vietnam retained FIV subtype C from the earliest time.