OBJECTIVETo identify and characterize the Brucella strains from Guizhou province in 2010-2013.

METHODSA total of 12 strains of Brucella suspicious bacteria were isolated in Guizhou province from 2010 to 2013. Four strains (GZLL3, GZLL4, GZLL11 and SH2) were isolated from goat blood samples and eight strains (SH4, GZZY, GZSQ, GZZA, BR13001, BR13004, BR13005 and BR13006) were isolated from blood samples of patient 12 Brucella suspicious strains were identified and characterized using conventional methods. Brucella genus specific gene BCSP31-based PCR (BCSP31-PCR) was used to identify the genus of Brucella and IS711 insert sequence-based PCR (AMOS-PCR) was applied to identify the species of Brucella strains. Goats and patients originated Brucella strains were comparatively analysed using Pulse-field Gel Electrophoresis (PFGE).

RESULTSBoth of conventional methods and PCR identified the 12 Brucella suspicious strains as B. melitensis biotype 3. BCSP31-PCR identification results showed that a specific DNA bands (223 bp) were detected in all the 12 strains and positive control samples with no DNA band in negative samples. AMOS-PCR amplified a 731 bp-DNA bands in all the 12 strains, with 731 bp, 498 bp and 275 bp in M5, S2 and A19 strains, respectively, and no DNA band was detected in the negative control samples. PFGE analysis showed that 12 Brucella isolates from patients and goats showed consistent PFGE patterns with the digestion of restriction enzyme Xba I.

CONCLUSIONThe epidemic species/type of Brucella in both human and animal in Guizhou province was B. melitensis biotype 3 and goat was the main animal source of infection of brucellosis in Guizhou province.

Animals ; Bacterial Typing Techniques ; Brucella ; classification ; Brucellosis ; epidemiology ; China ; epidemiology ; DNA, Bacterial ; Goats ; Humans ; Molecular Typing ; Polymerase Chain Reaction

OBJECTIVETo understand the genetic and epidemiologic characteristic of Brucella (B.) melitensis strains isolated in Guizhou province in 2010-2012.

METHODSB. genus specific BCSP31-PCR and species-specific AMOS-PCR were used to identify the bacteria strain, while the identified strains were analyzed under MLVA-16 and cluster analysis of B. melitensis strains. The strains were isolated from Guizhou and other provinces.

RESULTSSix B. melitensis strains were identified as B. melitensis using the BCSP31-PCR and AMOS-PCR. Data from the MLVA-16 analysis revealed the differences of repeated numbers at parts of the VNTR locus in the six strains isolated in Guizhou province. The six strains from Guizhou province and 105 B. melitensis strains from other province could be divided into 72 MLVA types(MT). Strain ZY and ZA from Guizhou province were typed as MT63, and LL3, LL4 and LL11 were typed as MT67, while strain SQ was typed as MT72. Data from the clustering analysis showed that ZY,ZA, LL3, LL4 and LL9 were most closely clustered with B. melitensis isolates from Yunnan, Fujian and Guangdong provinces, but strain SQ was genetically remote from other strains.

CONCLUSIONPCR methods, combined with MLVA-16, identified the six B. melitensis strains isolated in Guizhou province in 2010-2012 as B. melitensis biovar 3, with the genetic diversity of the strains showed. Six strains were closely related to the B. melitensis strains from Yunnan, Fujian and Guangdong provinces. The results of this study provided scientific basis for the control and prevention of Brucellosis in Guizhou province.

Brucella melitensis ; genetics ; isolation & purification ; Brucellosis ; epidemiology ; China ; epidemiology ; Cluster Analysis ; Genetic Variation ; Humans ; Minisatellite Repeats ; Polymerase Chain Reaction