肝炎病人中不同基因型TTV的检出及序列分析

目的：了解TTV在肝炎病人中的感染率及基因型别。方法：采用半式套式PCR方法，对72例不同型别的肝炎病人血清进行TTV DNA的PCR检测并对部分阳性株进行序列测定及计算机分析。结果：在72例不同肝炎病人中，共检出39例TTV DNA阳性血清， 总检出率为54．16％。其中在非甲庚型肝炎病人中TTV DNA阳性率为87．5％，而在明确诊断为甲－庚型肝炎病人中TTV DNA阳性率为50％，两组相比差异显（x^2＝4．0278，P＜0．05）。测序的6分离株相互间的核酸同源性为60．4％－93．2％，氨基酸的同源性为54．1％－97．3％。这6个分离株与9个G1、G2代表株核酸的同源性为60．4％－99．1％，氨基酸的同源性为55．4％－98．6％。经系统发育分析表明这6株TTV可分属于G1、G2两个基因型的4个亚型。结论：非甲－庚型肝炎病人的TTV感染率明显高于明确病原的甲－庚型肝炎的病原之一。检出的TTV至少可分属于G1、G2两个基因型中的4个亚型。

Dectection of TT DNA Virus(TTV) and Partial Sequence Analyses in Hepatitis Patients

Objective To study the prevalence and gene types of TTV in hepatitis patients.Methods Sera from hepatitis patients were tested by a hemi nested polymerase chain reaction(PCR) assay for the presence of TTV DNA and six amplified products were sequenced and the data were analyzed with the computer programs.Results The total detection rate of TTV DNA in those 72 objects was 54 16%.The TTV positive rate was 87 5% in non A-G hepatitis(7 of 8),but 50% in hepatitis patients whose diagnosis were clear.Six sequences of 222bp of ORF1 selected for the positive samples were analyzed and compared with sequenced representation of publics isolates which reveal that they can be classfied into subgroup of group G1 and G2.Conclusion TTV infection maybe one of the cause of non A-G hepatitis.TTV isolates from patients can be classified into group G1 and G2 respectively.