慢性乙型肝炎患者体内乙型肝炎病毒准种特点的初步研究

探讨乙型肝炎病毒（HBV）在慢性患者中存在状态，以HBV基因序列为依据。设计特异性多聚酶链反应（PCR）引物，自2例慢性患者体内扩增HBV全S基因片段，克隆入T载体。限制片段长度多态性（RFLP）法确定HBV的变异现象，DNA测序确定病毒的变异程度，质粒EcoRI酶切RFLP结果提示自2例患者血清中克隆出的29和28个阳性克隆中各有5种不同的长度带型，PCR产物XhoI酶切RFLP结果则表现为高度保守，测序结果发现HBV体内毒株碱基序高度一致，同一患者两株全S区序列测序结果表明DNA序列的同源性大于97%。本结果提示HBV慢性患者体内有HBV准种共存，且呈现出一定的优势克隆现象。

The preliminary study on hepatitis B virus (HBV) quasispecies in patients with chronic HBV infection

To investigate the HBV status in the patients with chronic HBV infection, A set of specific primers was synthesized according to HBV DNA sequence of adr subtype, the whole S gene was amplified from the serum of two patients with chronic HBV infection and subcloned into pGEM Teasy vectors. By restriction fragment length polymorphism (RFLP)method. use EcoR I to digest the recombinant plasmids and Xho I to digest the PCR products to display the mutated status of HBV. Sequence analysis of the HBV S region indicated the site of mutation. The RFLP results show there were at least 5 different kinds of fragment length in each recombinant plasmid group (29, patient 1; 28, patient 2 )from the two patients. The physical map of PCR products has shown high identity in both groups. Sequencing results proved the high consistency, with more than 97% homology between 2 strains from same patient. There are HBV quasispecies in the patients with chronic HBV infection, where preponderant strain can be found in serum.