Molecular characteristics of Brucella melitensis isolates from humans in Qinghai Province, China

Infectious Diseases of Poverty

Ji-Quan Li¹  Zhi-Jun Zhao²  Li Ma²  Yu-Min Qin²  Jian-Ling Wang²  Hong-Mei Xue²  Yuan-Bo Zhao²  Qiang Li²  Li-Qing Xu²  Xu-Xin Yang²  Guang Tian²  Hai Jiang³  Hong-Yan Zhao⁴  Dong-Ri Piao⁴  Xiao-Wen Yang⁴  Guo-Zhong Tian⁴ 

[1]Key Laboratory of Plague Prevention and Research, Qinghai Institute for Endemic Disease Prevention and Control, National Health Commission (2019PT310004) and Key Laboratory for Plague Prevention and Control of Qinghai Province, 810021, Xining, Qinghai, China

[2]Qinghai Institute for Endemic Disease Prevention and Control, The department of brucellosis prevention and control, 810021, Xining, Qinghai, China

[3]Qinghai Institute for Endemic Disease Prevention and Control, The department of brucellosis prevention and control, 810021, Xining, Qinghai, China

[4]State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China

[5]State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China

关键词: Brucella melitensis;    Multiple-locus variable-number tandem repeats analysis;    Whole-genome sequencing;    Single-nucleotide polymorphism;   

DOI  :  10.1186/s40249-021-00829-0

来源: Springer

【 摘 要 】

BackgroundThe prevalence of human brucellosis in Qinghai Province of China has been increasing rapidly, with confirmed cases distributed across 31 counties. However, the epidemiology of brucellosis transmission has not been fully elucidated. To characterize the infecting strains isolated from humans, multiple-locus variable-number tandem repeats analysis (MLVA) and whole-genome single-nucleotide polymorphism (SNP)-based approaches were employed.MethodsStrains were isolated from two males blood cultures that were confirmed Brucella melitensis positive following biotyping and MLVA. Genomic DNA was extracted from these two strains, and whole-genome sequencing was performed. Next, SNP-based phylogenetic analysis was performed to compare the two strains to 94 B. melitensis strains (complete genome and draft genome) retrieved from online databases.ResultsThe two Brucella isolates were identified as B. melitensis biovar 3 (QH2019001 and QH2019005) following conventional biotyping and were found to have differences in their variable number tandem repeats (VNTRs) using MLVA-16. Phylogenetic examination assigned the 96 strains to five genotype groups, with QH2019001 and QH2019005 assigned to the same group, but different subgroups. Moreover, the QH2019005 strain was assigned to a new subgenotype, IIj, within genotype II. These findings were then combined to determine the geographic origin of the two Brucella strains.ConclusionsUtilizing a whole-genome SNP-based approach enabled differences between the two B. melitensis strains to be more clearly resolved, and facilitated the elucidation of their different evolutionary histories. This approach also revealed that QH2019005 is a member of a new subgenotype (IIj) with an ancient origin in the eastern Mediterranean Sea.

【 授权许可】

CC BY