State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China.
PLoS Negl Trop Dis. 2020 Dec 29;14(12):e0008888. doi: 10.1371/journal.pntd.0008888. eCollection 2020 Dec.
Brucella spp. are facultative intracellular pathogens that can persistently colonize host cells and cause the zoonosis- brucellosis. The WHO recommended a treatment for brucellosis that involves a combination of doxycycline, rifampicin, or streptomycin. The aim of this study was to screen rifampicin-resistance related genes by transcriptomic analysis and gene recombination method at low rifampicin concentrations and to predict the major rifampicin- resistance pathways in Brucella spp. The results showed that the MIC value of rifampicin for B. melitensis bv.3 Ether was 0.5 μg / mL. Meanwhile, B. melitensis had an adaptive response to the resistance of low rifampicin in the early stages of growth, while the SNPs changed in the rpoB gene in the late stages of growth when incubated at 37°C with shaking. The transcriptome results of rifampicin induction showed that the functions of significant differentially expressed genes were focused on metabolic process, catalytic activity and membrane and membrane part. The VirB operon, β-resistance genes, ABC transporters, quorum-sensing genes, DNA repair- and replication -related genes were associated with rifampicin resistance when no variations of the in rpoB were detected. Among the VirB operons, VirB7-11 may play a central role in rifampicin resistance. This study provided new insights for screening rifampicin resistance-related genes and also provided basic data for the prevention and control of rifampicin-resistant Brucella isolates.
布鲁氏菌属是兼性细胞内病原体，能够在宿主细胞中长期定植并引起人畜共患病-布鲁氏菌病。世界卫生组织（WHO）推荐了一种治疗布鲁氏菌病的方案，其中包括多西环素、利福平或链霉素的联合治疗。本研究旨在通过转录组分析和基因重组方法，在低利福平浓度下筛选与利福平耐药相关的基因，并预测布鲁氏菌属中主要的利福平耐药途径。结果表明，B. melitensis bv.3 Ether 对利福平的 MIC 值为 0.5 μg/ml。同时，B. melitensis 在生长早期对低浓度利福平的耐药性具有适应性反应，而在 37°C 摇床孵育后期，rpoB 基因中的 SNPs 发生变化。利福平诱导的转录组结果表明，显著差异表达基因的功能集中在代谢过程、催化活性和膜及膜部分。当 rpoB 中未检测到变异时，VirB 操纵子、β-耐药基因、ABC 转运蛋白、群体感应基因、DNA 修复和复制相关基因与利福平耐药相关。在 VirB 操纵子中，VirB7-11 可能在利福平耐药中发挥核心作用。本研究为筛选利福平耐药相关基因提供了新的见解，也为预防和控制利福平耐药布鲁氏菌分离株提供了基础数据。
