UNASSIGNED: In this study, we evaluated the susceptibility of both the standard strain and clinical isolates of R. anatipestifer to doxycycline. And the expression levels of tet(X), tet(A), and tet(O) genes were detected. To assess drug susceptibility, shuttle plasmids were constructed to transfer the tet(X) gene into the standard strain of R. anatipestifer followed by treatment with chlorogenic acid.
UNASSIGNED: The results revealed that the minimum inhibitory concentration of doxycycline for the standard strain was 0.25μg/mL, whereas it exceeded 8μg/mL for the clinical isolates. Furthermore, there was a significant upregulation observed in expression levels of tet(X), tet(A), and tet(O) genes among induced strains. Interestingly, when transferring the tet(X) gene into the standard strain, its sensitivity to doxycycline decreased; however, MIC values for chlorogenic acid remained consistent between both standard and drug-resistant strains of R. anatipestifer. Moreover, we made a surprising discovery that screening passage with chlorogenic acid resulted in increased sensitivity of R. anatipestifer to doxycycline. Further analysis demonstrated a reversal in expression trends among three differentially expressed genes within induced drug resistance group after intervention with chlorogenic acid. The main objective behind this study is to investigate both killing effect exerted by chlorogenic acid on drug-resistant R. anatipestifer as well as its regulatory impact on drug resistance genes. This will provide novel insights and theoretical basis towards development of chlorogenic acid as a promising drug for treatment and control of drug resistance in R. anatipestifer.
■在这项研究中,我们评估了标准菌株和临床分离株对多西环素的敏感性。和tet(X)的表达水平,tet(A),并检测tet(O)基因。为了评估药物敏感性,构建穿梭质粒以将tet(X)基因转移到R.anatipestifer的标准菌株中,然后用绿原酸处理。
■结果表明,多西环素对标准菌株的最低抑菌浓度为0.25μg/mL,而临床分离株超过8μg/mL。此外,在tet(X)的表达水平中观察到显着的上调,tet(A),和诱导菌株之间的tet(O)基因。有趣的是,当将tet(X)基因转移到标准菌株中时,它对多西环素的敏感性下降;然而,绿原酸的MIC值在R.anatipestifer的标准菌株和耐药菌株之间保持一致。此外,我们有一个令人惊讶的发现,用绿原酸筛选传代可提高鼠疫菌对多西环素的敏感性。进一步分析表明,绿原酸干预后,诱导耐药组中三个差异表达基因的表达趋势逆转。这项研究的主要目的是研究绿原酸对耐药R.anatipestifer的杀伤作用及其对耐药基因的调节作用。这将为绿原酸作为一种有前途的药物开发提供新的见解和理论基础。