PDF(Pubmed)
Abstract：
Primary amebic meningoencephalitis (PAM) is a rare and fatal central nervous system infection caused by Naegleria fowleri, a free-living amoeba found in the environment. To date, eight pathogenic N. fowleri genotypes have been reported worldwide. We aimed to explore the genotypes of N. fowleri that cause primary amebic meningoencephalitis in Thailand. In 2021, the 17th PAM case was reported, and a retrospective literature search of PAM cases in Thailand from 1982 through April 2021 was performed. Phylogenetic and genotyping analyses of the two mitochondrial (12S rRNA and 16S rRNA) and nuclear (ITS1 and 5.8s rRNA) genes of N. fowleri were performed on four available clinical isolates. Based on the mitochondrial and nuclear genes, N. fowleri genotype T3 was found to cause PAM in three out of four cases. However, disagreement between the genotype based on the mitochondrial and nuclear genes was found in one of the PAM cases, in which the 12S rRNA locus suggested the causative genotype as T1, while the ITS1 implied genotype T4. The discrepancy between the mitochondrial and nuclear genome was previously observed, which suggests the possible horizontal gene transfer among N. fowleri species. Based on the ITS1 gene, two N. fowleri genotypes, T3 and T4, were found to be the genotypes causing PAM in this study. In addition, N. fowleri genotype T2 was previously reported in a traveler who was infected in Thailand. Thus, at least three genotypes (T2, T3, and T4) of N. fowleri are found to be associated with PAM in Thailand.
摘要：
原发性阿米巴脑膜脑炎（PAM）是一种罕见的致命的中枢神经系统感染，在环境中发现的一种自由生活的变形虫。迄今为止,世界范围内已报道了8种致病性猪瘟病毒基因型。我们的目的是探讨在泰国引起原发性阿米巴脑膜脑炎的鸡传染性猪瘟的基因型。2021年，报告了第17例PAM病例，并对1982年至2021年4月泰国的PAM病例进行了回顾性文献检索。对四个可用的临床分离株进行了两个线粒体（12SrRNA和16SrRNA）和核（ITS1和5.8srRNA）基因的系统发育和基因分型分析。基于线粒体和核基因，在4例中的3例中发现N.fowleri基因型T3引起PAM。然而,在其中一个PAM病例中发现了基于线粒体和核基因的基因型之间的分歧，其中12SrRNA基因座提示致病基因型为T1，而ITS1暗示基因型为T4。以前观察到线粒体基因组和核基因组之间的差异，这表明N.fowleri物种之间可能的水平基因转移。基于ITS1基因,两种N.Fowleri基因型，在这项研究中发现T3和T4是导致PAM的基因型。此外,N.fowleri基因型T2以前曾在一名在泰国感染的旅行者中报道过。因此，在泰国，至少有三种基因型（T2，T3和T4）与PAM相关。
