辽宁省2008～2011年流行性腮腺炎野病毒SH蛋白基因特征分析

本研究用Vero/Slam细胞从辽宁省2008～2011年流行性腮腺炎暴发和散发患者的临床标本中分离到13株流行性腮腺炎野病毒(Mumps virus,MuV),应用逆转录-聚合酶链反应(RT-PCR)针对MuV分离株的SH基因的316个核苷酸片段进行扩增,并对该产物进行序列测定。将这13株MuV与从GenBank下载的世界卫生组织(WHO)MuV基因型参考株一起进行分子流行病学研究。结果提示:除2011-015株外,辽宁省2008～2011年12株MuV分离株均属于F基因型,核苷酸和氨基酸同源性为94.9%～100%和83.3%～100%。与F基因型参考株序列相比,核苷酸和氨基酸同源性分别为92.4%～97.2%和96.5%～84.2%。表明2008～2011年辽宁省流行的F基因型MuV发生较大的型内变异。另外还发现F基因型MuV在SH基因上存在着特异性突变(CNt65,CNt105,G Nt137,C Nt192,C Nt239,GNT262),而其它基因型MuV在这些位点上均未发生改变。F基因型MuV在SH基因编码的氨基酸保守位点也发生变化。如:第2位上由S→P,第6位上由P→L,第23位上由T→N,第48位上由L→P/R。与基因分型有关的氨基酸三联体,2008-01-007毒株也发生了改变,由IML变为TMP。2011-015株病毒与F基因型参考株平均核苷酸和氨基酸同源性分别为87.5%和79.8%,与G型参考株平均核苷酸和氨基酸同源性分别为96.8%和97.4%,属于G基因型。该基因型为中国内地首次发现。

SH Protein Genetic Characterization Analysis of Wild-Type Mumps Virus Isolated in Liaoning Province from 2008 to 2011

A total of 13 mumps virus strains were isolated using Vero/Slam cell line from the patients’ throat swabs and urines during mumps outbreaks and sporadics in liaoning Province from 2008 to 2011.Fragments of 316 nucleotides containing SH genes from 13 mumps virus isolates were amplified by RT-PCR,the PCR products were sequenced and analyzed.Based on the 316 nucleotides of SH gene,the phylogenetic trees were constructed with WHO mumps reference strains downloaded from GenBank and 13 mumps virus strains.It showed that the 12 mumps virus strains in 2008~2011 belonged to F genotype,nucleotide acids and amino acids similarities were 94.9%~100.0%and 83.3%~100.0%.Compared to the F reference strains,nucleotide acids and amino acids similarities were 92.4%~97.2%and 96.5%~84.2%,indicating that liaoning mumps strains had large genotype variation.Furthermore,compared to other genotype mumps strains,6 nucleotides mutations(CNt65,CNt105,GNt137,CNt192,CNt239,GNT262) in SH gene were shared in all of liaoning F genotype mumps viruses.However these mutations were not found in other genotypes of mumps viruses.Conserved amino acids in SH protein of some liaoning mumps strains had changed(S to P at position 2 P to L at position 6 T to N at positon 23 L to P/R at position 48).The genotype specific triplet IML(at position 28~30) was changed to TMP in strain 2008-001-007 2011-015 s,nucleotide acids and amino acids similarities of strain 2008-001-07 were 87.5% and 79.8%,compared to F reference strains respectively,and 96.8% and 97.4% respectively compared to the G reference strains,indicating strain 2008-001-07 belonged to G genotype,which was first found in mainland china.