Nucleoprotein gene detection and sequence analysis of wild-type measles strains from patients in Bengbu,Anhui

Objective: To provide basis for the monitoring and prevention of measles by detecting the genotype of wild-type measles strains and analyze the gene characteristics of epidemic measles virus from in Bengbu,Anhui.Methods: Fifteen sporadic cases clinically diagnosed as measles from 2010 to 2011 in Bengbu Anhui were selected in the study.The patients' urine samples were collected in the acute infectious period,the virus RNA was extracted,the nucleotide protein gene of carboxyl-terminal 515 bp nucleotide fragment of measles virus was amplified by RT-PCR,and gene phylogenetic tree was constructed by nucleotide sequencing and analysis of PCR.Results: Forteen wild-type measles strains were isolated from the urine samples of the 15 cases of measles;the gene homology of the 515 bp fragment of nucleoprotein(N) carboxy-terminal was compared between 3 wild-type measles strains and 8 reference strains in Genebank.The corresponding genetic distance of the nucleotide sequence to the published H1,H2 genotype reference strains in Hunan,CHN93-7,Beijing and CHN94 in Gene bank was 0.020 to 0.026 and 0.064 to 0.075 respectively;the distance to H1a reference strain China 93-2 was the shortest,which was 0.009 to 0.015;the 515 nucleotide homology of the N gene carboxy-terminal of the 3 measles strain were 97.8% to 98.9%;the corresponding nucleotide homology to the reference strains H1 CHN93-7,H1a China 93-2 and H1b China 94-7 were from 97.4% to 98.0%,98.5% to 99.1% and 96.5% to 97.1%,respectively.Conclusions: The dominant genotype of wild-type measles strains is H1a.