Genetic characterisation of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type
Genetic characterisation of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type
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DOI：
10.1016/j.ijpara.2011.06.005
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发表时间：
2011-09-01
影响因子：
4
通讯作者：
Su, C.
中科院分区：
文献类型：
--
作者：
Dubey, J. P.;Velmurugan, G. V.;Su, C.
对野生动物中弓形虫的遗传多样性知之甚少。在本研究中，对来自美国的野生动物进行了T。弓形虫感染在小鼠中对自然暴露动物的组织进行生物测定，以分离活寄生虫。维伯河从31种动物中分离出弓形虫，据我们所知，包括首次从白头鹰（Haliaeetus leucocephalus）、5只灰狼（Canis lupus）、1只林鼠（Neotoma micropus）中分离出弓形虫。和五只北极狐。另外，66 T。在小鼠中复活先前获得但未进行遗传表征的弓形虫分离物。采用11种PCR-限制性片段长度多态性（RFLP）标记（SAG、5 '-和3'-SAG 2、alt.SAG2、SAG 3、BTUB、GRA 6、c22-8、c29-2、L358、PK 1和Apico）对从这97份样本（31 + 66）中分离的弓形虫DNA进行表征。共有95个分离株成功进行了基因分型。除克隆Ⅱ型和Ⅲ型外，还发现了12种不同的基因型。先前从北美野生动物中分离的弓形虫分离株的特征和169个分离株的复合数据集包括22种基因型，包括克隆II型、III型和20种非典型基因型。系统发生网络分析表明，有限的多样性与优势最近指定的第四克隆类型（12型）在北美，其次是II型和III型谱系。这三个主要谱系共占北美菌株的85%。12型谱系包括先前鉴定的来自海獭的A型和X型菌株。本研究表明，12型谱系占分离株的46.7%（79/169），在北美野生动物中占主导地位。在这些野生动物分离株中未鉴定出克隆I型菌株。这些结果表明T.北美洲野生动物中的弓形虫株的多样性有限，只有少数几个主要的克隆类型。(C)2011年澳大利亚寄生虫学会由爱思唯尔有限公司出版。保留所有权利。
Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study wild animals, from the USA were examined for T. gondii infection. Tissues of naturally exposed animals were bioassayed in mice for isolation of viable parasites. Viable T. gondii was isolated from 31 animals including, to our knowledge for the first time, from a bald eagle (Haliaeetus leucocephalus), five gray wolves (Canis lupus), a woodrat (Neotoma micro pus). and five Arctic foxes (Alopex lagopus). Additionally, 66 T. gondii isolates obtained previously, but not genetically characterised, were revived in mice. Toxoplasma gondii DNA isolated from these 97 samples (31 + 66) was characterised using 11 PCR-restriction fragment length polymorphism (RFLP) markers (SAG, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). A total of 95 isolates were successfully genotyped. In addition to clonal Types II, and III, 12 different genotypes were found. These genotype data were combined with 74 T. gondii isolates previously characterised from wildlife from North America and a composite data set of 169 isolates comprised 22 genotypes, including clonal Types II, Ill and 20 atypical genotypes. Phylogenetic network analysis showed limited diversity with dominance of a recently designated fourth clonal type (Type 12) in North America, followed by the Type II and III lineages. These three major lineages together accounted for 85% of strains in North America. The Type 12 lineage includes previously identified Type A and X strains from sea otters. This study revealed that the Type 12 lineage accounts for 46.7% (79/169) of isolates and is dominant in wildlife of North America. No clonal Type I strain was identified among these wildlife isolates. These results suggest that T. gondii strains in wildlife from North America have limited diversity, with the occurrence of only a few major clonal types. (C) 2011 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.