Diverse and atypical genotypes identified in Toxoplasma gondii from dogs in Sao Paulo, Brazil
Diverse and atypical genotypes identified in Toxoplasma gondii from dogs in Sao Paulo, Brazil
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DOI：
10.1645/ge-972r.1
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发表时间：
2007-02-01
影响因子：
1.3
通讯作者：
Su, C.
中科院分区：
文献类型：
--
作者：
Dubey, J. P.;Gennari, S. M.;Su, C.
对来自巴西圣保罗州圣保罗市的118只流浪犬进行了弓形虫感染率测定。抗T.用改良的弓形虫凝集试验检测了42只（35.8%）犬的弓形虫抗体，其中10只滴度为1：20，6只滴度为1：40，5只滴度为1：80，5只滴度为1：160，6只滴度为1：320，7只滴度为1：640，3只滴度为1：1,280或更高。在小鼠或猫或两者中对36只血清阳性犬的心脏和脑进行生物测定。将20只血清学阳性犬的组织喂给20只T。没有刚迪伊的猫检查猫粪便中的卵囊。通过小鼠生物测定，从15只狗中分离出弓形虫，1只从大脑中分离出弓形虫，4只从心脏中分离出弓形虫，10只从大脑和心脏中分离出弓形虫。15个分离株中有5个在初次感染时全部死于弓形虫病。在猫中通过生物测定获得了另外4株分离株。对这19株T.用SAG 1、SAG 2、SAG 3、BTUB、GRA 6、c22-8、c29-2、L358、PK 1和一个新的顶质体标记（Apico）SAG 2等10个核标记对弓形虫分离株进行多态性分析，共发现12种基因型。一个菌株在所有11个位点上都有III型等位基因，其余18个菌株含有不同等位基因的组合，分为11种基因型。在巴西没有II型被证实。该结果支持了之前的研究结果，即T.巴西的弓形虫种群遗传学高度多样。
The prevalence of Toxoplasma gondii in 118 unwanted dogs from Sao Paulo City, Sao Paulo State, Brazil, was determined. Antibodies to T. gondii were assayed by the modified agglutination test and found in 42 (35.8%) dogs, with titers of 1:20 in 10, 1:40 in 6, 1:80 in 5, 1:160 in 5, 1:320 in 6, 1:640 in 7, and 1:1,280 or higher in 3. Hearts and brains of 36 seropositive dogs were bioassayed in mice, or cats, or both. Tissues from 20 seropositive dogs were fed to 20 T. gondii-free cats. Feces of cats were examined for oocysts. Toxoplasma gondii was isolated from 15 dogs by a bioassay in mice, from the brain alone of 1, from the heart alone of 4, and from both brains and hearts of 10. All infected mice from 5 of 15 isolates died of toxoplasmosis during primary infection. Four additional isolates were obtained by bioassay in cats. Genotyping of these 19 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 (an apicoplast marker Apico) revealed 12 genotypes. One isolate had Type III alleles at all 11 loci, and the remaining 18 isolates contained a combination of different alleles and were divided into 11 genotypes. The absence of Type II in Brazil was confirmed. The result supports previous findings that T. gondii population genetics is highly diverse in Brazil.