MLVA distribution characteristics of Yersinia pestis in China and the correlation analysis.
BACKGROUND
Yersinia pestis, the aetiological agent of plague, has been well defined genotypically on local and worldwide scales. In November 2005, five cases of severe pneumonia of unknown causes, resulting in two deaths, were reported in Yulong, Yunnan province. In this study, we compared Y. pestis isolated from the Yulong focus to strains from other areas.


RESULTS
Two hundred and thirteen Y. pestis strains collected from different plague foci in China and a live attenuated vaccine strain of Y. pestis (EV76) were genotyped using multiple-locus variable-number tandem repeat analysis (MLVA) on 14 loci. A total of 214 Y. pestis strains were divided into 85 MLVA types, and Nei's genetic diversity indices of the various loci ranged between 0.02 - 0.76. Minimum spanning tree analysis showed that Y. pestis in China could be divided into six complexes. It was observed that Microtus strains were different from the other three biovar strains. Each plague focus had its own unique MLVA types.


CONCLUSIONS
The strains isolated from Yulong, Yunnan province had a unique MLVA type, indicating a new clone group. Our results suggest that Yulong strains may have a close relationship with strains from the Qinghai-Tibet Plateau plague focus.
National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Changping, Beijing 102206, PR China. zhangxiaoai_0922@163.com
Xiaoai
X
Zhang
Rong
R
Hai
Jianchun
J
Wei
Zhigang
Z
Cui
Enmin
E
Zhang
Zhizhong
Z
Song
Dongzheng
D
Yu
D015373:Bacterial Typing Techniques; D002681:China; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D005838:Genotype; D005843:Geography; D018598:Minisatellite Repeats; D010802:Phylogeny; D010930:Plague / Q000382:microbiology*; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D015010:Yersinia pestis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
D004269:DNA, Bacterial