Multilocus sequence typing and genetic structure of Cryptosporidium hominis from children in Kolkata, India
Multilocus sequence typing and genetic structure of Cryptosporidium hominis from children in Kolkata, India
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DOI：
10.1016/j.meegid.2006.08.006
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发表时间：
2007-03-01
影响因子：
3.2
通讯作者：
Xiao, Lihua
中科院分区：
文献类型：
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作者：
Gatei, Wangeci;Das, Pradeep;Xiao, Lihua
使用多位点序列分型（MLST）对2001年至2004年从印度加尔各答儿科患者收集的标本进行了寄生虫遗传结构分析。基因型分析显示，在49例、2例和1例患者中分别存在人隐孢子虫（Cryptosporidium hominis）、火鸡隐孢子虫（Cryptosporidium meleagridis）和猫隐孢子虫（Cryptosporidium felis）（2例患者有人隐孢子虫和火鸡隐孢子虫混合感染）。为了评估人隐孢子虫的遗传异质性程度，对三个不同染色体中的小卫星、微卫星和多态性标记进行了测序，包括编码60 kDa糖蛋白（GP60）、47 kDa蛋白（CP47）、一种类粘蛋白（Mucin1）、一种丝氨酸重复抗原（MSC6 - 7）以及6号染色体中56 kDa跨膜蛋白（CP56）的基因，2号染色体中的70 kDa热休克蛋白（HSP70）以及3号染色体中的一个富含T的基因片段（Chrom3T）。基于多位点基因序列的人隐孢子虫种群亚结构显示，通过组合序列长度和核苷酸多态性确定了25种多位点亚型，在该种群中形成了四个不同的组。观察到显著的基因内和基因间连锁不平衡，只有少数亚型发生重组或扩增，所有这些都表明其种群结构主要是克隆性的。这些结果强调了高分辨率MLST在研究隐孢子虫种群亚结构中的重要性，特别是当长度多态性可能不足以识别独特亚型时。人隐孢子虫内多样的MLST与地理和时间因素以及疾病临床表现的相关性值得进一步研究。（c）2006爱思唯尔公司。版权所有。
specimens collected between 2001 and 2004 from pediatric patients in Kolkata, India were analyzed for parasite genetic structure using multilocus sequence typing (MLST). Genotype analyses showed the presence of Cryptosporidium hominis, Cryptosporidium meleagridis and Cryptosporidium felis in 49, 2 and I patients, respectively (two patients had mixed infections of C. hominis and C. meleagridis). To assess the extent of genetic heterogeneity of C. hominis, minisatellites, microsatellites and polymorphic markers in three different chromosomes were sequenced, including genes encoding the 60 kDa glycoprotein (GP60), a 47 kDa protein (CP47), a mucin-like protein (Mucinl), a serine repeat antigen (MSC6-7), and a 56 kDa trans-membrane protein (CP56) in chromosome 6, the 70 kDa heat shock protein (HSP70) in chromosome 2, and a T-rich gene fragment (Chrom3T) in chromosome 3. Population sub-structure of C. hominis based on multilocus gene sequences showed that there were 25 multilocus subtypes defined by combined sequence length and nucleotide polymorphism, which formed four distinct groups in this population. Significant intra- and inter-genic linkage disequilibria were observed with minimum recombination or expansion of limited subtypes, all indicative of a mostly clonal population structure. The results highlight the importance of high resolution MLST in studying Cyptosporidium population sub-structure especially when length polymorphism may be inadequate in identifying unique subtypes. The significance of the diverse MLST within C. hominis in relation to geographical and temporal factors and clinical manifestations of disease warrants further investigations. (c) 2006 Elsevier B.V. All rights reserved.