title: MLVA genotyping of Chinese human Brucella melitensis biovar 1, 2 and 3 isolates.
abstract: BACKGROUND
  Since 1950, Brucella melitensis has been the predominant strain associated with human brucellosis in China. In this study we investigated the genotypic characteristics of B. melitensis isolates from China using a multiple-locus variable-number tandem-repeat analysis (MLVA) and evaluated the utility of MLVA with regards to epidemiological trace-back investigation.
  
  
  RESULTS
  A total of 105 B. melitensis strains isolated from throughout China were divided into 69 MLVA types using MLVA-16. Nei's genetic diversity indices for the various loci ranged between 0.00 - 0.84. 12 out 16 loci were the low diversity with values < 0.2 and the most discriminatory markers were bruce16 and bruce30 with a diversity index of > 0.75 and containing 8 and 7 alleles, respectively. Many isolates were single-locus or double-locus variants of closely related B. melitensis isolates from different regions, including the north and south of China. Using panel 1, the majority of strains (84/105) were genotype 42 clustering to the 'East Mediterranean' B. melitensis group. Chinese B. melitensis are classified in limited number of closely related genotypes showing variation mainly at the panel 2B loci.
  
  
  CONCLUSIONS
  The MLVA-16 assay can be useful to reveal the predominant genotypes and strain relatedness in endemic or non-endemic regions of brucellosis. However it is not suitable for biovar differentiation of B. melitensis. Genotype 42 is widely distributed throughout China during a long time. Bruce 16 and bruce 30 in panel 2B markers are most useful for typing Chinese isolates.
authors: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping, Beijing 102206, PR China.
authors: Hai
authors: H
authors: Jiang
authors: Mengguang
authors: M
authors: Fan
authors: Jingdiao
authors: J
authors: Chen
authors: Jingchuan
authors: J
authors: Mi
authors: Ruiping
authors: R
authors: Yu
authors: Hongyan
authors: H
authors: Zhao
authors: Dongri
authors: D
authors: Piao
authors: Changwen
authors: C
authors: Ke
authors: Xiaoling
authors: X
authors: Deng
authors: Guozhong
authors: G
authors: Tian
authors: Buyun
authors: B
authors: Cui
mesh_terms: D015373:Bacterial Typing Techniques; D017347:Brucella melitensis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D002006:Brucellosis / Q000453:epidemiology / Q000382:microbiology; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000235:genetics; D005838:Genotype; D006801:Humans; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing
chemical_list: D004269:DNA, Bacterial