PDF(Pubmed)
Abstract：
Pasteurella multocida (Pm) is one of the major pathogens of bovine respiratory disease (BRD), which can develop drug resistance to many of the commonly used antibiotics. Our earlier research group found that with clinical use of enrofloxacin, Pm was more likely to develop drug resistance to enrofloxacin. In order to better understand the resistance mechanism of Pm to enrofloxacin, we isolated PmS and PmR strains with the same PFGE typing in vitro, and artificially induced PmR to obtain the highly resistant phenotype, PmHR. Then transcriptome sequencing of clinically isolated sensitive strains, resistant and highly drug-resistant strains, treated with enrofloxacin at sub-inhibitory concentrations, were performed. The satP gene, of which the expression changed significantly with the increase in drug resistance, was screened. In order to further confirm the function of this gene, we constructed a satP deletion (ΔPm) strain using suicide vector plasmid pRE112, and constructed the C-Pm strain using pBBR1-MCS, and further analyzed the function of the satP gene. Through a continuously induced resistance test, it was found that the resistance rate of ΔPm was obviously lower than that of Pm in vitro. MDK99, agar diffusion and mutation frequency experiments showed significantly lower tolerance of ΔPm than the wild-type strains. The pathogenicity of ΔPm and Pm was measured by an acute pathogenicity test in mice, and it was found that the pathogenicity of ΔPm was reduced by about 400 times. Therefore, this study found that the satP gene was related to the tolerance and pathogenicity of Pm, and may be used as a target of enrofloxacin synergistic effect.
摘要：
多杀性巴氏杆菌(Pm)是牛呼吸道疾病(BRD)的主要病原之一,这可能会对许多常用的抗生素产生耐药性。我们早期的研究小组发现，随着恩诺沙星的临床使用，Pm更可能对恩诺沙星产生耐药性。为了更好地了解Pm对恩诺沙星的耐药机制,我们在体外分离了具有相同PFGE分型的PmS和PmR菌株，人工诱导PmR以获得高抗性表型，PmHR。然后对临床分离的敏感菌株进行转录组测序，耐药和高度耐药菌株，用亚抑制浓度的恩诺沙星治疗，被执行了。satP基因,其中表达随着耐药性的增加而显著变化，被筛选。为了进一步证实该基因的功能,我们使用自杀载体质粒pRE112构建了satP缺失（ΔPm）菌株，并使用pBBR1-MCS构建了C-Pm菌株，并进一步分析了satP基因的功能。通过连续诱导电阻测试，发现ΔPm在体外的耐药率明显低于Pm。MDK99，琼脂扩散和突变频率实验显示，对ΔPm的耐受性明显低于野生型菌株。通过小鼠急性致病性试验测定ΔPm和Pm的致病性,发现ΔPm的致病性降低了约400倍。因此,本研究发现satP基因与Pm的耐受性和致病性有关,并可作为恩诺沙星协同作用的靶点。
