New Trypanosoma evansi Type B Isolates from Ethiopian Dromedary Camels.
New Trypanosoma evansi Type B Isolates from Ethiopian Dromedary Camels.
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来自埃塞俄比亚式骆驼的新型锥虫埃文尼B型分离株。
DOI：
10.1371/journal.pntd.0004556
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发表时间：
2016-04
影响因子：
3.8
通讯作者：
Van Reet N
中科院分区：
文献类型：
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作者：
Birhanu H;Gebrehiwot T;Goddeeris BM;Büscher P;Van Reet N
锥虫属（T.）evansi是T.布氏杆菌已经获得了通过各种叮咬苍蝇传播的能力。T.伊氏骆驼可分为A型和B型，A型最多，见于非洲、亚洲和拉丁美洲，B型迄今仅从肯尼亚单峰骆驼中分离出来。本研究的目的是分离和遗传和表型特征的A型和B T。埃塞俄比亚北方的伊文思骆驼。T.通过用经寄生虫学证实的动物的冷冻保存的血沉棕黄层接种，在小鼠中分离伊氏病毒。因此，分离出14个原种，并使用靶向类型特异性变体表面糖蛋白基因、线粒体小环和大环、小卫星标记和F1-ATP合酶γ亚基基因的PCR进行基因分型。9个原种对应于A型，2个原种对应于B型，3个原种代表A和B之间的混合感染，但不是杂种。一个T evansi A型家系完全为运动不能型。五个股票适应于体外培养，并进行药物敏感性测定与盐酸蜜拉索明，二乙酰氨酰亚胺，异美他啶氯化物和苏拉明。在体外适应诱导一些损失的动质体在60天内。未观察到药物敏感性与不存在动基体之间的相关性。对F1-ATP合酶γ亚基的全编码序列进行测序，发现了新的类型特异性单核苷酸多态性和缺失。本研究讨论了目前T. evansi基因分型F1-ATP合成酶γ亚基基因多态性可能为T. evansi型不依赖于变异的表面糖蛋白基因或动基体DNA。锥虫属（T.）伊文思病毒在非洲、拉丁美洲和亚洲的各种动物中引起苏拉病。尽管引起重要的动物痛苦，经济损失和作为世界动物卫生组织（OIE）的应报告疾病，但在认识，控制干预和研究改进控制工具方面，苏拉被严重忽视。大多数血清学试验只能检测T。evansi A型，而分子测试依赖于检测高度可变的基因或脆弱的动质体DNA。更重要的是，默默无闻的T。伊文思B型病毒几十年前首次在肯尼亚被分离出来，由于缺乏可靠的诊断工具，它完全逃脱了监测。在本研究中，我们从埃塞俄比亚分离到新的B型种群，从而表明这种类型的T。伊凡西的分布可能比以前认为的更广泛。我们进一步报告了两种类型T的替代分子标记。evansi和埃塞俄比亚分离株的药物敏感性的数据。
Trypanosoma (T.) evansi is a dyskinetoplastic variant of T. brucei that has gained the ability to be transmitted by all sorts of biting flies. T. evansi can be divided into type A, which is the most abundant and found in Africa, Asia and Latin America and type B, which has so far been isolated only from Kenyan dromedary camels. This study aimed at the isolation and the genetic and phenotypic characterisation of type A and B T. evansi stocks from camels in Northern Ethiopia. T. evansi was isolated in mice by inoculation with the cryopreserved buffy coat of parasitologically confirmed animals. Fourteen stocks were thus isolated and subject to genotyping with PCRs targeting type-specific variant surface glycoprotein genes, mitochondrial minicircles and maxicircles, minisatellite markers and the F1-ATP synthase γ subunit gene. Nine stocks corresponded to type A, two stocks were type B and three stocks represented mixed infections between A and B, but not hybrids. One T. evansi type A stock was completely akinetoplastic. Five stocks were adapted to in vitro culture and subjected to a drug sensitivity assay with melarsomine dihydrochloride, diminazene diaceturate, isometamidium chloride and suramin. In vitro adaptation induced some loss of kinetoplasts within 60 days. No correlation between drug sensitivity and absence of the kinetoplast was observed. Sequencing the full coding sequence of the F1-ATP synthase γ subunit revealed new type-specific single nucleotide polymorphisms and deletions. This study addresses some limitations of current molecular markers for T. evansi genotyping. Polymorphism within the F1-ATP synthase γ subunit gene may provide new markers to identify the T. evansi type that do not rely on variant surface glycoprotein genes or kinetoplast DNA. Trypanosoma (T.) evansi causes surra in various animal species in Africa, Latin America and Asia. Despite inducing important animal suffering, economic losses and being a World Animal Health Organisation (OIE) notifiable disease, surra is severely neglected in terms of awareness, control interventions and research into improved control tools. Most serological tests can only detect T. evansi type A, while molecular tests rely on detection of highly variable genes or on fragile kinetoplast DNA. Even more, the obscure T. evansi type B, first isolated decades ago in Kenya, totally escapes surveillance due to absence of reliable diagnostic tools. In the present study we isolated new type B stocks from Ethiopia, thus suggesting that this type of T. evansi is probably more widely distributed than previously thought. We further report on an alternative molecular marker for both types of T. evansi and present data on the drug sensitivity of the Ethiopian isolates.