Sequence analysis of UL142 gene of human cytomegalovirus virus strain in Guangzhou

Abstract

Objective To detect UL142 gene sequence characteristics of the clinical low passage human cytomegalovirus (HCMV) isolates in Guangzhou. Methods From March 2014 to December 2015 at the Guangzhou Medical University Affiliated pediatric clinic of Guangdong women and children's Hospital of 10 cases of symptomatic HCMV infection in children with urine samples as the research object. Identify virus strains isolated from urine samples of children with symptomatic HCMV infection using multiple polymerase chain reaction (PCR), and the whole sequence of UL142 gene was cloned into pMD18-T vector and amplified, the sequencing results were submitted to GenBank, and UL142 gene of the other 10 HCMV isolates in the GenBank were compared and analyzed together. Results Two HCMV clinical isolates were successfully isolated from the urine sample of children with symptomatic HCMV infection in Guangzhou, named for HCMV D3 and D2. The GenBank included them after cloning and sequencing, and the included sequences were DQ180370 and DQ180384. Homology comparison analysis showed UL142 gene sequences were more conservative, there were 69 base mutations, and all these 69 base mutations were base substitutions, and no insertion and deletion mutations. There were 306 amino acid residues in the protein coding, sequence and more conservative, of which 28 nucleotide point mutation resulted in the change of amino acids and bases for the rest of the mutation did not cause amino acid changes, different isolates variation rate for 0.9%-6.5%. The number of amino acids in the two stage structure of each isolate was different but the isoelectric points of all the isolated strains were in 6.48-8.27. Conclusions UL142 gene sequence and amino acid sequence of the HCMV clinical isolates in Guangzhou are more conservative, but there are still some polymorphism, it suggests that the UL142 gene may play an important role in the progress of HCMV infection and pathogenesis. Key words: Cytomegalovirus; Clinical low passage virus strain; UL142; Sequence analysis