Molecular epidemiological study on the SERA antigen gene in Plasmodium falciparum

我们前期对恶性疟原虫血清抗原基因的分子分析研究表明：(1)在印度尼西亚，fcr3型最占优势，k1型较少占优势，没有洪都拉斯1型；(2)在泰国和越南，这三种类型都有分布；(3)在缅甸，k1型最占优势，因此每个国家都存在特定的等位基因类型。在本研究中，我们进一步研究了分布在印度尼西亚、缅甸和越南的血清抗原基因的基因多样性。在印度尼西亚，我们分析了从弗洛雷斯岛采集的32株分离株，发现10个新的fcr3型等位基因，其中13个分离株为已知的fcr3型，9个分离株为k1型2。在越南，我们分析了从Bao Loc采集的83株分离株，发现FCR3型分离株21株（FCR3-型分离株18株，其中3株为F34-35新等位基因），洪都拉斯1型分离株12株（H6和h11 -19新等位基因），k1型分离株50株（T9-102、T1-7、T22和T26-29新等位基因）。在缅甸，我们分析了从Thatone采集的56株分离株，再次检测到许多k1型（40株T9.102、T2-5和T22）。此外，在6株分离株中检测到相同的fcr3型等位基因，因此血清基因的分布与；这在越南是一样的，但在印度尼西亚却大不相同。此外，在缅甸首次分离到的10株菌株中均发现了宏都拉斯1型，均为新的等位基因形式，丝氨酸重复区末端为G-S-S-S。这些结果可能表明，东南亚大陆国家（如泰国、缅甸和越南）的血清抗原基因的遗传多样性彼此非常相似，但与岛国印度尼西亚的差异很大。

Our previous studies on molecular analysis of the SERA antigen gene in Plasmodium falciparum indicated that (1) In Indonesia, the FCR3-type is the most dominant, and the K1-type is less dominant with no Honduras1-type, (2) In Thailand and Vietnam, all three types are distributing, (3) In Myanmar, the K1-type is the most dominant, and therefore, specific allelic types are existing in each country. In this study, we further investigated gene diversity in the SERA antigen gene distributing in Indonesia, Myanmar and Vietnam.1. In Indonesia, we analyzed 32 isolates collected from the Flores Island, and found 10 new allelic types in the FCR3-type with 13 isolates in tie already-known FCR3-type and 9 isolates in the K1-type.2. In Vietnam, we analyzed 83 isolates collected from Bao Loc, and found 21 isolates of the FCR3-type (18 isolates of the FCR3- type with 3 isolates of new allelic types of F34-35), 12 isolates of the Honduras 1-type (H6 and new alleles of H 11-19), and 50 isolates of the K1-type (T9-102, T1-7, T22 and new alleles of T26-29).3. In Myanmar, we analyzed 56 isolates collected from Thatone, and detected many K1-types again (40 isolates of T9.102, T2-5, and T22). In addition, the same allele of the FCR3-type was detected in six isolates, and thus distribution of the SERA gene was similar to ;hat in Vietnam, but much differed from that in Indonesia. Furthermore, the Honduras1-type was found in 10 isolates first time from Myanmar, and all of them were new allelic forms, having G-S-S-S at the end of the serine repeat region.These results may indicate that genetic diversity in the SERA antigen gene in the continental Southeast Asian countries such as Thailand, Myanmar and Vietnam is quite similar each other, but much differed from that of an island country, Indonesia.