Abstract：
BACKGROUND: Over the last several decades, the AcrAB and OqxAB efflux pumps have been found to cause multidrug resistance (MDR) in various bacteria, most notably Klebsiella pneumoniae. Antibiotic resistance surges with increased expression of the acrAB and oqxAB efflux pumps.
METHODS: In accordance with CLSI guidelines, a disk diffusion test was carried out using 50 K. pneumoniae isolates obtained from various clinical samples. CT was computed in treated samples and compared to a susceptible ciprofloxacin strain (A111). The final finding is presented as the fold change in the target gene\'s expression in treated samples relative to a control sample (A111), normalized to a reference gene. As ΔΔCT = 0 and 2 to the power of 0 = 1, relative gene expression for reference samples is often set to 1 Results: The highest rates of resistance were recognized with cefotaxime (100%), cefuroxime (100%), cefepime (100%), levofloxacin (98%), trimethoprimsulfamethoxazole (80%), and gentamicin (72%), whereas imipenem (34%) had the lowest rates. Overexpression of acrA and acrB, oqxA and oqxB, regulators marA, soxS, and rarA were greater in ciprofloxacin-resistant isolates compared to the reference strain (strain A111). There was also a moderate connection between ciprofloxacin MIC and acrAB gene expression and a moderate connection between ciprofloxacin MIC and oqxAB gene expression.
CONCLUSIONS: This work provides a deeper knowledge of the role of efflux pump genes, particularly acrAB and oqxAB, as well as transcriptional regulators marA, soxS, and rarA, in bacterial resistance to ciprofloxacin.
METHODS: In accordance with CLSI guidelines, a disk diffusion test was carried out using 50 K. pneumoniae isolates obtained from various clinical samples. CT was computed in treated samples and compared to a susceptible ciprofloxacin strain (A111). The final finding is presented as the fold change in the target gene\'s expression in treated samples relative to a control sample (A111), normalized to a reference gene. As ΔΔCT = 0 and 2 to the power of 0 = 1, relative gene expression for reference samples is often set to 1 Results: The highest rates of resistance were recognized with cefotaxime (100%), cefuroxime (100%), cefepime (100%), levofloxacin (98%), trimethoprimsulfamethoxazole (80%), and gentamicin (72%), whereas imipenem (34%) had the lowest rates. Overexpression of acrA and acrB, oqxA and oqxB, regulators marA, soxS, and rarA were greater in ciprofloxacin-resistant isolates compared to the reference strain (strain A111). There was also a moderate connection between ciprofloxacin MIC and acrAB gene expression and a moderate connection between ciprofloxacin MIC and oqxAB gene expression.
CONCLUSIONS: This work provides a deeper knowledge of the role of efflux pump genes, particularly acrAB and oqxAB, as well as transcriptional regulators marA, soxS, and rarA, in bacterial resistance to ciprofloxacin.
摘要：
背景：在过去的几十年里，已发现AcrAB和OqxAB外排泵在各种细菌中引起多药耐药性（MDR），最著名的是肺炎克雷伯菌。随着acrAB和oqxAB外排泵的表达增加，抗生素耐药性激增。
方法：根据CLSI指南，我们使用从各种临床样本中获得的50株肺炎克雷伯菌进行了纸片扩散试验.在处理过的样品中计算CT，并与易感的环丙沙星菌株（A111）进行比较。最终发现以处理样品中靶基因表达相对于对照样品(A111)的倍数变化表示,标准化为参考基因。CT=0，20等于1，参考样品的相对基因表达通常设置为1。
结果：头孢噻肟的耐药率最高（100％），头孢呋辛（100%），头孢吡肟(100%),左氧氟沙星（98%），甲氧苄啶-磺胺甲恶唑（80%），和庆大霉素（72%），而亚胺培南(34%)的发病率最低。acrA和acrB的过表达,OQXA和OQXB，监管机构MarA,SOXS,与参考菌株（菌株A111）相比，环丙沙星耐药菌株中的rarA更高。环丙沙星MIC和acrAB基因表达之间也存在中度联系，环丙沙星MIC和oqxAB基因表达之间也存在中度联系。
结论：这项工作为外排泵基因的作用提供了更深入的知识，特别是acrAB和oqxAB，以及转录调节因子MarA，SOXS,还有RarA,细菌对环丙沙星的耐药性。
方法：根据CLSI指南，我们使用从各种临床样本中获得的50株肺炎克雷伯菌进行了纸片扩散试验.在处理过的样品中计算CT，并与易感的环丙沙星菌株（A111）进行比较。最终发现以处理样品中靶基因表达相对于对照样品(A111)的倍数变化表示,标准化为参考基因。CT=0，20等于1，参考样品的相对基因表达通常设置为1。
结果：头孢噻肟的耐药率最高（100％），头孢呋辛（100%），头孢吡肟(100%),左氧氟沙星（98%），甲氧苄啶-磺胺甲恶唑（80%），和庆大霉素（72%），而亚胺培南(34%)的发病率最低。acrA和acrB的过表达,OQXA和OQXB，监管机构MarA,SOXS,与参考菌株（菌株A111）相比，环丙沙星耐药菌株中的rarA更高。环丙沙星MIC和acrAB基因表达之间也存在中度联系，环丙沙星MIC和oqxAB基因表达之间也存在中度联系。
结论：这项工作为外排泵基因的作用提供了更深入的知识，特别是acrAB和oqxAB，以及转录调节因子MarA，SOXS,还有RarA,细菌对环丙沙星的耐药性。
