Li Wenbo, Zeng Linzi, Yuan Rongmei, Qi Teng, Liao Hongyu, Cao Yuhangxi, Huang Shu, Liu Zhiguo, Li Zhenjun
Sichuan Provincial Center for Disease Control and Prevention, Chengdu, 610041, China.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
BMC Microbiol. 2025 Jan 14;25(1):21. doi: 10.1186/s12866-024-03739-x.
Human brucellosis is a re-emerging disease in Sichuan Province, China. In this study, bacteriology, conventional bio-typing, multi-locus sequence typing (MLST), and multiple locus variable-number tandem repeat analysis (MLVA) were applied to preliminarily characterize the strains in terms of genetic diversity and epidemiological links. A total of 101 Brucella strains were isolated from 16 cities (autonomous prefectures) from 2014 to 2021, and all of the strains were identified as Brucella melitensis bv. 3, suggesting that surveillance should focus on ruminants. MLST analysis identified four STs, namely, ST8 (n = 93), ST39 (n = 6), ST101 (n = 1), and ST118 (n = 1). The latter were new STs, indicating that strains displayed high population diversity. Six MLVA-8, namely, 42, 43, 45, 63, 83, and 114, and eight MLVA-11, namely, 111, 115, 116, 125, 180, 291, 298, and 342, genotypes were identified, demonstrating that all of the strains were from the Eastern Mediterranean lineage, and these strains exhibited a high genotype diversity. MLVA-16 analysis revealed that there was a co-existing transmission pattern, where sporadic cases and multiple outbreak events had a common origin. The dominant STs and MLVA genotypes of strains were epidemic in Northern, China, and 36 MLVA-16 genotypes were shared among strains (n = 51, 50.4%, 51/101) from Sichuan and strains from 22 other provinces. The findings imply that infected animals were introduced from outside the province. The surveillance and control of the disease have become public health challenges. Animal quarantines should be strengthened to prevent the spread of B. melitensis species among adjacent regions.
人类布鲁氏菌病在中国四川省是一种再度出现的疾病。在本研究中，运用了细菌学、传统生物分型、多位点序列分型（MLST）以及多位点可变数目串联重复序列分析（MLVA），以初步从遗传多样性和流行病学关联方面对菌株进行特征描述。2014年至2021年期间，共从16个市（自治州）分离出101株布鲁氏菌菌株，所有菌株均被鉴定为羊种布鲁氏菌生物变种3，这表明监测应聚焦于反刍动物。MLST分析确定了4个序列型，即ST8（n = 93）、ST39（n = 6）、ST101（n = 1）和ST118（n = 1）。后两者为新的序列型，表明菌株呈现出较高的群体多样性。鉴定出6种MLVA - 8基因型，即42、43、45、63、83和114，以及8种MLVA - 11基因型，即111、115、116、125、180、291、298和342，证明所有菌株均来自东地中海谱系，且这些菌株表现出较高的基因型多样性。MLVA - 16分析显示存在一种共存的传播模式，散发病例和多次暴发事件有共同起源。菌株的优势序列型和MLVA基因型在中国北方流行，来自四川的51株菌株（50.4%，51/101）与来自其他22个省份的菌株共有36种MLVA - 16基因型。这些发现意味着感染动物是从省外引入的。该疾病的监测和控制已成为公共卫生挑战。应加强动物检疫，以防止羊种布鲁氏菌在相邻地区传播。
