Genetic analyses of Chinese isolates of Toxoplasma gondii reveal a new genotype with high virulence to murine hosts
作者单位：Center for Parasitic OrganismsSchool of Life Sciencesand Key Laboratory of Tropical Disease Control of the Ministry of EducationZhongshan School of MedicineSun Yat-Sen University
会议名称：《第十一届全国寄生虫学青年工作者学术研讨会》
会议日期：2018年
学科分类：1001[医学-基础医学(可授医学、理学学位)] 100103[医学-病原生物学] 10[医学]
基 金：supported by the grants from the National Natural Science Foundation of China(#31472058,#31402029,#31672276) Guangdong Natural Science Funds for Distinguished Young Scholar(2016A030306048) Guangzhou Science Technology and Innovation Commission(201506010011) the Natural Science Foundation of Guangdong Province(2014A030313164,2015A030311042)
关 键 词：Chinese Toxoplasma gondii Genotype MLST RFLP Virulence
摘 要：Toxoplasma gondii is an obligate but opportunistic intracellular pathogen which infects almost all warm-blooded vertebrates including *** was estimated that up to one-third of the human population around the world are chronically infected with this parasite.A great deal of evidence demonstrates that a strongly clonal population structure of *** strains exists in humans and animals in North America and Europe,while the strains from South America are genetically separate and more *** differences in virulence between different strains mean that an understanding of strain diversity is important to human and animal ***,to date,only one predominant genotype,Toxo DB#9(Chinese I),and a few other genotypes,including Toxo DB#205,have been identified in *** using DNA sequence-based phylogenetic analyses,we have re-evaluated the population structure of *** strains collected from China and compared them with other global *** on phylogenetic analysis of restriction fragment length polymorphisms,multilocus sequence typing and intron sequences from ***,we propose that the Chinese isolates described as Chinese I are divided into two groups called Chinese I and Chinese *** addition,genetic differentiation among the genotypes was assessed using population genetic FST pairwise comparisons,and there is statistical significance between Chinese strains and other reference *** results demonstrate that significant differences were found in mouse mortality caused by some Chinese strains,and also the archetypal I,II,III strains in ***,a comparison of cyst loading in the brains of infected rats showed some Chinese strains to be capable of a high degree of cyst *** we show that genotyping using neutral genetic markers may not be a useful predictor of pathogenic phenotypes.