Dubey J P, Graham D H, da Silva Daniele Seipel, Lehmann T, Bahia-Oliveira Lilian M G
Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, United States Department of Agriculture, Agricultural Research Service, Building 1001, Beltsville, Maryland 20705, USA.
J Parasitol. 2003 Aug;89(4):851-3. doi: 10.1645/GE-60R.
Most isolates of Toxoplasma gondii can be grouped into 3 genetic lineages. In the present study, 67 isolates of T. gondii were obtained by bioassay in mice inoculated with brains and hearts of 96 asymptomatic chickens from an area highly endemic to human infection in Rio de Janeiro, Brazil. Of the 48 isolates genotyped using the SAG2 locus, 34 (70%) were of type I and 13 (27%) were of type III. No isolate of type II was recovered. Isolates from 1 chicken contained a type I and type III mixed infection, indicating natural multiparasite infection in the same animal. Cats fed mice infected with 11 type I strains shed 19-535 million oocysts in their feces, indicating that type I isolates can circulate in the environment.
大多数刚地弓形虫分离株可分为3个基因谱系。在本研究中，通过对来自巴西里约热内卢人类感染高度流行地区的96只无症状鸡的脑和心脏接种小鼠进行生物测定，获得了67株刚地弓形虫分离株。在使用SAG2基因座进行基因分型的48株分离株中，34株（70%）为I型，13株（27%）为III型。未回收II型分离株。来自1只鸡的分离株含有I型和III型混合感染，表明同一动物存在自然多重寄生虫感染。用感染了11株I型菌株的小鼠喂养的猫在粪便中排出了1.9亿至5.35亿个卵囊，表明I型分离株可在环境中传播。
