摘要
目的了解云南地区鼠类和人自然感染恙虫病东方体的情况。方法采用鼠夹和鼠笼捕鼠,从鼠类脾脏及人血中提取DNA,应用巢式聚合酶链反应扩增恙虫病东方体(Ot)sta56基因,并进行基因序列测定分析。结果捕获小型哺乳动物7属11种485只,收集到不明原因发热病例血液样本23份。从动物脾脏样本中检出Ot sta56基因片段2份(HHSP65和HHSP112),阳性率0.41%;序列分析显示两者同源性100%,而与中国台湾TT0711a株的同源性最高为89.6%,与日本Kawasaki株的同源性为79.7%;进化树分析显示HHS65与TT0711a株不在同一分支上。从不明原因发热患者血液样本中检出Ot sta56基因片段1份(DLRX9),阳性率4.35%;序列分析显示该序列与泰国PG9和Li3b株及中国浙江Jin/2012株的同源性最高,均为98.4%,与Karp株的同源性为81.9%,与HHSP65株的同源性64.8%;进化树显示DLRX9与泰国PG9和Li3b、中国浙江Jin/2012株在同一分支上。结论病原学初步证实引发云南地区恙虫病流行的Ot不仅有Karp基因型Ot,还有新型Ot,该新型Ot可能为日本Kawasaki类似株。
Objective To investigate the natural infection of Orientia tsutsugamushi（ Ot） in rodents and human＇in some areas of Yunnan province. Methods Rat clip and cage traps were used to capture rodents. The spleens of the captured mice and blood samples from patients with fever of unknown origin were collected. DNAs were extracted from mice spleens and blood samples of patients,Ot sta56 segment were amplified by using nested-polymerase chain reaction（ n PCR）,sequenced to analyze the homology with other known sequences. Results A total of 485 rodents from 7 genera in 11 species were captured,and 23 blood samples of patients were collected for Ot sta56 segment detection with n PCR,the positive rates were0. 41% and 4. 35% for rodent spleen samples（ HHSP65 and HHSP112） and blood samples of patients（ DLRX9）respectively. Compared with sta56 gene sequences of other known Ot strains from Gen Bank,HHSP65 strain shared 100%homology with HHSP112 strain,and they shared 89. 6% homology with TT0711 a strains and 79. 7% homology with Japan Kawasaki strain. DLRX9 strain shared 81. 9% homology with Karp strain,98. 4% homology with PG9 and Li3 b strains from Thailand and Jin /2012 strains from Zhejiang of China and 64. 8% homology with HHSP65. Phylogenetic analysis showed that HHSP65 strain and TT0711 a strains were in different branches,and DLRX9,PG9,Li3 b and Jin /2012 stains were in same branch. Conclusion It was confirmed that the Ots causing scrub typhus in some areas of Yunnan province were Karp type Ot and newgenotype Ot,which might be related to Japan Kawasaki type.
出处
《疾病监测》
CAS
2016年第2期145-148,共4页
Disease Surveillance
关键词
恙虫病东方体
自然感染
基因同源性
云南地区
Orientia tsutsugamushi
Natural infection
Gene homology
Yunnan province
