Genetic characterization of Toxoplasma gondii isolates in dogs from Vietnam suggests their South American origin
Genetic characterization of Toxoplasma gondii isolates in dogs from Vietnam suggests their South American origin
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DOI：
10.1016/j.vetpar.2007.03.008
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发表时间：
2007-05-31
影响因子：
2.6
通讯作者：
Su, C.
中科院分区：
文献类型：
--
作者：
Dubey, J. P.;Huong, Lam Thi Thu;Su, C.
狗被认为是弓形虫传播给人类的潜在风险，因为它们可以机械地将卵囊传播给人类，并且在世界某些地区，狗肉被人类食用。测定了来自越南农村的42只狗的弓形虫患病率。用改良凝集试验检测了42只犬的弓形虫抗体，其中21只（50%）的抗体滴度为1：20的6只，1：40的7只，1：80的2只，1：160的2只，1：320的2只，1：640的1只，1：1280或更高的1只。在猫、小鼠或两者中对21只血清阳性犬的心脏、舌头和脑进行生物测定。将8只血清反应阳性犬的组织喂给8只无刚地弓形虫的猫。检查猫粪便中的卵囊。用猫的生物测定法从8只狗身上分离出弓形虫。利用SAG 1、SAG 2、SAG 3、BTUB、GRA 6、c22-8、c29-2、L358、PK 1和新的SAG 2等10个核标记的多态性以及顶体标记Apico对这8个弓形虫分离株进行基因分型，发现了两种基因型。这两种基因型先前都是从哥伦比亚的犬分离株中鉴定出来的，表明它们起源于南美洲。然而，它们与广泛分布于北美和欧洲的主要I型、II型和III型谱系不同。这是越南首次从任何宿主中分离出活的弓形虫。(C)2007年由Elsevier B. V.出版。
Dogs are considered a potential risk for transmission of Toxoplasma gondii to humans because they can mechanically transmit oocysts to people and in certain parts of the world dog meat is consumed by humans. The prevalence of T gondii in 42 dogs from rural Vietnam was determined. Antibodies to T gondii were assayed by the modified agglutination test, and found in 21 (50%) of 42 dogs with titers of 1:20 in six, 1:40 in seven, 1:80 in two, 1: 160 in two, 1:320 in two, 1:640 in one, and 1: 1280 or higher in one. Hearts, tongues and brains of 21 seropositive dogs were bioassayed in cats, mice or both. Tissues from eight seropositive dogs were fed to eight T gondii-free cats. Feces of cats were examined for oocysts. T gondii was isolated from eight dogs by bioassay in cats. Genotyping of these eight T gondii isolates using polymorphisms at 10 nuclear markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and a new SAG2, and an apicoplast marker Apico revealed two genotypes. Both genotypes were previously identified from the dog isolates in Colombia, suggesting their South America origin. However, they are different from the predominant Type I, II and III lineages that are widely spread in North America and Europe. This is the first report of isolation of viable T gondii from any host in Vietnam. (C) 2007 Published by Elsevier B.V.