GENETIC POLYMORPHISM OF rRNA GENE PATTERN OF BRUCELLA IN CHINA

Objective To investigate the genetic polymorphism of 99 Brucella strains isolated in China,so as to provide the basis for ribotyping and diagnosis of Brucella infection.Methods Chromosomal DNA of Brucella was digested with Eco RI,and separated by agarose gel electrophoresis and Southern blotting.Then it was transferred into a nylon filter and hybridized with 16 s rDNA which was labeled with digoxigenin-dUTP.Hybrid was detected by enzyme immunoassay.Compare the fingerprint of 16 s rRNA in different Brucella strains.Results 16 s rRNA fingerprint of different Brucella strains showed high polymorphism.99 Brucella strains detected belonged to 17 ribotypes(RT) according to the numbers and locations of strips on 16 s rRNA fingerprint.RT 15,as the most predominant ribotype,comprised 26.3% Brucella strains.The location of other ribotypes was scattered,some ribotype was only found in certain strain.Conclusions Brucella strains in China showed genetic polymprphism and clonal diversity,suggesting that the epidemic of Brucella is complicated.