scholarly journals Molecular Epidemiology Characteristics of Brucella Abortus Strains in China and Their Relationships With World Lineages

2020 ◽  
Author(s):  
Xu-Ming Wang ◽  
Zhongzhi Zhao ◽  
Miao Wang ◽  
Buyun Cui ◽  
Zhiguo Liu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Epidemiology ◽  
Brucella Abortus ◽  
Variable Number Tandem Repeat ◽  
Northern China ◽  
Variable Number ◽  
Snp Analysis ◽  
High Genetic Diversity ◽  
Geographic Origins ◽  
Epidemic Area

Abstract Background Brucella abortus is a facultative intracellular Gram-negative bacterium that causes chronic persistent infections in humans and livestock. In this study, conventional bio-typing, multiple-locus variable-number tandem repeat analysis (MLVA), and whole-genome sequencing-single-nucleotide polymorphism (WGS-SNP) were used to investigate the molecular epidemiology characteristics of Brucella abortus strains in China and their relationships to world lineages. Results A total of 100 strains were collected from 1953 to 2013, suggesting that B. abortus circulated in China in the past five decades. Moreover, most strains were mainly distributed in the Northwest areas, suggest that provinces in the Northwest were a dominant epidemic area of this disease. During this period, seven biovars were found, indicating that B. abortus had a high diversity of biovars and it is also a potential reason for the disease ongoing spread in the Northern provinces. Strains have high genetic diversity, and bruce07 is the most helpful locus for genotyping of this population. Moreover, 17 MLVA-11 genotypes were found; 13 of them are of known genotypes and four are unassigned genotypes, indicating that B. abortus in this study had several geographic origins. Still, strains from unassigned genotypes may originate from China. Many shared MLVA-16 genotypes were observed in strains from the same provinces in Northern China, which confirmed a B. abortus brucellosis outbreak within Northern regions. WGS-SNP analysis showed that eight Chinese strains formed a ladder-like phylogram (C. Ⅶ) with strains from nine countries, including Uganda, Iraq, Russia, Georgia, Spain, Italy, Egypt, Mongolia, and China; suggest that strains were introduced to these countries from a single source. Conclusions Chinese B. abortus strains had high biovars and genetic diversity as well as represent characteristics of multiple geographic origins, and B. abortus strains from several mainly epidemic areas were closely related to strains from Russia and Mongolia; frequent animal (cattle) trade and exchanges may promote this process. We will provide new and valuable information to strengthening surveillance and control of B. abortus brucellosis in China.

scholarly journals Molecular Epidemiology Characteristics of Brucella abortus Strains in China and Their Relationships with World Lineages

2020 ◽  
Author(s):  
Xu-ming Wang ◽  
Zhong-zhi Zhao ◽  
miao wang ◽  
buyun cui ◽  
Zhi-guo Liu ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Brucella Abortus ◽  
Variable Number Tandem Repeat ◽  
Northern China ◽  
Variable Number ◽  
Snp Analysis ◽  
High Genetic Diversity ◽  
Persistent Infections ◽  
Geographic Origins ◽  
Northern Regions

Brucella abortus is a facultative intracellular Gram-negative bacterium that causes chronic persistent infections in humans and livestock. In this study, conventional bio-typing, multiple-locus variable-number tandem repeat analysis (MLVA), and whole-genome sequencing-single-nucleotide polymorphism (WGS-SNP) were used to investigate the molecular epidemiology characteristics of Brucella abortus strains in China and their relationships to world lineages. A total of 100 strains were collected from 1953 to 2013, suggesting that B. abortus circulated in China in the past five decades. Moreover, most strains were mainly distributed in the northwest area. During this period, seven biovars were found, indicating that B. abortus displayed a high diversity of biovars and that the main epidemic areas are in the northern provinces. Strains have high genetic diversity, and bruce07 is the most helpful locus for genotyping of this population. Moreover, 17 MLVA-11 genotypes were found; 13 of them are of known genotypes and four are unassigned genotypes, indicating that B. abortus in this study had several geographic origins. Still, strains from unassigned genotypes may originate from China. Many shared MLVA-16 genotypes were observed in strains from the same provinces in Northern China, which confirmed a brucellosis outbreak within northern regions. WGS-SNP analysis showed that eight Chinese strains formed a ladder-like phylogram (C. Ⅶ) with strains from nine countries, including Uganda, Iraq, Russia, Georgia, Spain, Italy, Egypt, Mongolia, and China; strains were introduced to these countries from a single source. Notably, Chinese strains were closely related to strains from Russia and Mongolia; frequent animal (cattle) trade and exchanges may promote this process. We will provide new and insightful information for strength surveillance and control of B. abortus brucellosis in China.

HIV Type 1 Molecular Epidemiology in Cuba: High Genetic Diversity, Frequent Mosaicism, and Recent Expansion of BG Intersubtype Recombinant Forms

2006 ◽  
Vol 22 (8) ◽  
pp. 724-733 ◽  
Author(s):  
Lissette Pérez ◽  
Michael M. Thomson ◽  
María J. Bleda ◽  
Carlos Aragonés ◽  
Zoila González ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Epidemiology ◽  
High Genetic Diversity ◽  
Hiv Type 1

scholarly journals Examination of Taxonomic Uncertainties Surrounding Brucella abortus bv. 7 by Phenotypic and Molecular Approaches

2013 ◽  
Vol 80 (5) ◽  
pp. 1570-1579 ◽  
Author(s):  
Bruno Garin-Bastuji ◽  
Virginie Mick ◽  
Gilles Le Carrou ◽  
Sebastien Allix ◽  
Lorraine L. Perrett ◽  
...  
Keyword(s):  
Brucella Abortus ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Epidemiological Methods ◽  
Content Type ◽  
Phenotypic Profile ◽  
Molecular Approaches ◽  
Content Classification ◽  
Species Specific ◽  
Kenyan Strain

ABSTRACTBrucellataxonomy is perpetually being reshuffled, at both the species and intraspecies levels. Biovar 7 ofBrucella abortuswas suspended from theApproved Lists of Bacterial NamesBrucellaclassification in 1988, because of unpublished evidence that the reference strain 63/75 was a mixture ofB. abortusbiovars 3 and 5. To formally clarify the situation, all isolates previously identified asB. abortusbv. 7 in the AHVLA and ANSES strain collections were characterized by classical microbiological and multiple molecular approaches. Among the 14 investigated strains, including strain 63/75, only four strains, isolated in Kenya, Turkey, and Mongolia, were pure and showed a phenotypic profile in agreement with the former biovar 7, particularly agglutination with both anti-A/anti-M monospecific sera. These results were strengthened by molecular strategies. Indeed, genus- and species-specific methods allowed confirmation that the four pure strains belonged to theB. abortusspecies. The combination of most approaches excluded their affiliation with the recognized biovars (biovars 1 to 6 and 9), while some suggested that they were close to biovar 3.These assays were complemented by phylogenetic and/or epidemiological methods, such as multilocus sequence analysis (MLSA) and variable-number tandem repeat (VNTR) analysis. The results of this polyphasic investigation allow us to propose the reintroduction of biovar 7 into theBrucellaclassification, with at least three representative strains. Interestingly, the Kenyan strain, sharing the same biovar 7 phenotype, was genetically divergent from other three isolates. These discrepancies illustrate the complexity ofBrucellataxonomy. This study suggests that worldwide collections could include strains misidentified asB. abortusbv. 7, and it highlights the need to verify their real taxonomic position.

Sign in / Sign up

Export Citation Format

Share Document