New highly divergent rRNA sequence among biodiverse genotypes of Enterocytozoon bieneusi strains isolated from humans in Gabon and Cameroon
New highly divergent rRNA sequence among biodiverse genotypes of Enterocytozoon bieneusi strains isolated from humans in Gabon and Cameroon
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DOI：
10.1128/jcm.02554-06
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发表时间：
2007-08-01
影响因子：
9.4
通讯作者：
Thellier, Marc
中科院分区：
文献类型：
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作者：
Breton, Jacques;Bart-Delabesse, Emmanuelle;Thellier, Marc
由双胞虫引起的肠道微孢子虫病是严重免疫缺陷人类免疫缺陷病毒（HIV）阳性患者慢性腹泻的主要原因。由于艾滋病毒流行病的严重程度和恶劣的卫生条件，这可能是非洲的一个公共卫生问题。我们在中非设计了两项关于比氏埃希氏体的流行病学研究，第一个研究对象是来自加蓬城市环境的艾滋病毒阳性患者，第二个研究对象是喀麦隆未选择的农村人口。采用免疫荧光抗体试验和PCR对粪便样本进行分析。在加蓬的822名艾滋病毒阳性患者中有25人，在喀麦隆的758名村民中有22人被发现对比埃内乌斯杆菌呈阳性反应。这两项研究的患病率惊人地相似（3.0%和2.9%）。rRNA基因内部转录间隔区基因型分析显示，两国样本存在高度多样性。在加蓬，15株分离株显示7种不同的基因型：先前报道的基因型A、D和K，以及4种新的基因型，称为CAF1、CAF2、CAF3和CAF4。在喀麦隆，在20株分离株中发现了5种基因型：已知的基因型A、B、D和K以及新的基因型CAF4。基因型A和CAF4在喀麦隆占主导地位，而K、CAF4和CAF1在加蓬更为常见，这表明不同基因型的感染风险与免疫状态和生活条件有关。在hiv阴性和hiv阳性受试者中发现的新基因型CAF4的系统发育分析表明，它代表了一种高度分化的菌株。
Intestinal microsporidiosis due to Enterocytozoon bieneusi is a leading cause of chronic diarrhea in severely immunocompromised human immunodeficiency virus (HIV)-positive patients. It may be a public health problem in Africa due to the magnitude of the HIV pandemic and to poor sanitary conditions. We designed two prevalence studies of E. bieneusi in Central Africa, the first with HIV-positive patients from an urban setting in Gabon and the second with a nonselected rural population in Cameroon. Stool samples were analyzed by an immunofluorescence antibody test and PCR. Twenty-five out of 822 HIV-positive patients from Gabon and 22 out of 758 villagers from Cameroon were found to be positive for E. bieneusi. The prevalence rates of the two studies were surprisingly similar (3.0% and 2.9%). Genotypic analysis of the internal transcribed spacer region of the rRNA gene showed a high degree of diversity in samples from both countries. In Gabon, 15 isolates showed seven different genotypes: the previously reported genotypes A, D, and K along with four new genotypes, referred to as CAF1, CAF2, CAF3, and CAF4. In Cameroon, five genotypes were found in 20 isolates: the known genotypes A, B, D, and K and the new genotype CAF4. Genotypes A and CAF4 predominated in Cameroon, whereas K, CAF4, and CAF1 were more frequent in Gabon, suggesting that different genotypes present differing risks of infection associated with immune status and living conditions. Phylogenetic analysis of the new genotype CAF4, identified in both HIV-negative and HIV-positive subjects, indicates that it represents a highly divergent strain.