2014年北京市西城区40例麻疹患者分离的麻疹病毒基因型及同源性

Genotypes and homology of measles virus isolated from 40 patients with measles in Beijing Xicheng District in 2014

摘要:

目的了解北京市某城区2014年分离的麻疹病毒基因型，及时发现输入性麻疹病例。方法采用荧光聚合酶链反应（PCR）方法，对北京市西城区2014年采集的标本进行病毒核酸鉴定、RTPCR扩增，扩增产物进行测序及序列比对分析。结果2014年北京市西城区共采集81例麻疹疑似患者的82份标本，其中咽拭子63份，尿19份。麻疹病毒核酸检测阳性70例，RTPCR扩增、测序获得基因序列40份，麻疹病毒培养阳性毒株37例。种系进化树分析显示，获得的40份麻疹病毒基因序列与H基因簇代表株Chin9322/H1a，以及世界卫生组织推荐的代表株MVi/Hunan.CHN/0.93/7/H1在同一分支上，核苷酸水平上同源性分别为98％～98.9％、96.9％～97.8％；氨基酸水平上同源性分别为97.3％～99.3％、95.3％～98％。结论2014年北京市西城区麻疹病例以本土基因型(H1)病例为主，进一步加强麻疹病例病原学监测对麻疹输入性病例的控制和预防具有重要意义。

Abstract:

ObjectiveTo understand the genotypes of measles virus isolated from patients with measles in Beijing Xicheng District in 2014, and timely find out imported measles cases. MethodsMeasles virus nucleic acid was identified with fluorescent polymerase chain reaction (PCR), then amplified by realtime PCR (RTPCR), amplified products were sequenced and analyzed. Results82 specimens from 81 suspected measles patients in Beijing Xicheng District in 2014 were taken, 63 were throat swab specimens and 19 were urine specimens. 70 cases were positive for measles virus nucleic acid, 40 of which were obtained gene sequence through sequencing, 37 were positive culture for measles virus. The phylogenetic tree analysis showed that gene sequences of 40 measles virus isolates were belonged to the same branch as H genotype representative strain Chin9322/H1a and MVi/Hunan.CHN/0.93/7/H1 recommended by World Health Organization.  The homology of nucleotide were 98%-98.9% and 96.9%-97.8% respectively, homology of amino acid were 97.3%-99.3% and 95.3%-98% respectively. ConclusionThe main genotype of measles cases in Beijing Xicheng District in 2014 was the local genotype (H1), surveillance of measles cases should be strengthened further to control and prevent the imported measles cases.