Genetic correlations among Brucella melitensis isolates from sheep in four provinces of northwest China
10.3969/j.issn.1002-2694.2024.00.150
- VernacularTitle:西北地区羊种布鲁氏菌遗传相关性分析
- Author:
Xiao-An CAO
1
;
Zhi-Jie LIU
;
Ping LIU
;
Jin-Yan WU
;
You-Jun SHANG
;
Ji-Jun HE
;
Zhi-Guo LIU
;
Zhen-Jun LI
Author Information
1. 中国农业科学院兰州兽医研究所,动物疫病防控全国重点实验室,兰州 730046
- Keywords:
Brucella melitensis;
MLST;
MLVA;
genetic correlation;
Northwest China
- From:
Chinese Journal of Zoonoses
2024;40(10):922-927
- CountryChina
- Language:Chinese
-
Abstract:
Investigating the species/biovars,distribution patterns,and genetic correlations of Brucella from sheep in north-west China is critical to reveal the population and epidemiological characteristics of the Brucella melitensis.In this study,con-ventional identification and AMOS-PCR were used to determine the species/biovars of Brucella isolated from 13 regions in northwest China.MLST and MLVA-16 genotyping methods were used to analyze the genetic characteristics of the strains.Con-ventional identification and AMOS-PCR detection revealed that 59 Brucella melitensis were isolated in this study,in-cluding 22 strains from Inner Mongolia,17 strains from Xin-jiang,13 strains from Gansu,and 7 strains from Qinghai,of which 58 strains were B.melitensis biovar 3,and one strain was B.melitensis biovar 1.MLST analysis indicated that 90％(53/59)of B.melitensis were of ST8 sequence type,the dominant epidemic population.The MLVA-11 survey demonstrated that 59 B.melitensis strains clustered into six MLVA-11 genotypes,and 87％of the strains were of MLVA-11 genotype 116.Therefore,the predominant strains in the northwest region were from the Eastern Mediterranean lineage.MLVA-16 divided 59 strains of B.melitensis into 40 gen-otypes,eight of which were shared genotypes.Each genotype was composed of two to seven strains from the same region,thereby indicating that the cases of each shared genotype were outbreaks from a common source of infection.All shared MLVA-16 genotypes comprised strains from the same province,thus indicating apparent regional clustering characteristics of strains in each province.In a genetic comparison between populations and isolated strains from the spleens of sheep,multiple identical MLVA-16 genotypes were found to be composed of strains from different hosts.These findings indicated a transmission path-way from sheep/goats to humans.B.melitensis biovar 3 was the main pathogen causing animal brucellosis in the northwest re-gion,and infected sheep were the main brucellosis infection source in the regional population.The ST8 strains were the domi-nant epidemic population,and the MLVA genotype of strains in each region showed clear regional clustering characteristics.
