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

Infectious Diseases of Poverty

Ji-Quan Li¹  Yuan-Bo Zhao²  Guang Tian²  Li Ma²  Qiang Li²  Jian-Ling Wang²  Li-Qing Xu²  Hai Jiang²  Hong-Mei Xue²  Yu-Min Qin²  Zhi-Jun Zhao²  Xu-Xin Yang²  Hong-Yan Zhao³  Xiao-Wen Yang³  Guo-Zhong Tian³  Dong-Ri Piao³ 

[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

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

[3]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

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: DOAJ

【 摘 要 】

Abstract Background The 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. Methods Strains 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. Results The 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. Conclusions Utilizing 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】

Unknown