众所周知,长期和过度使用抗生素会导致抗生素耐药性。然而,临床推荐和预防剂量药物诱导耐药菌的特点和机制尚不清楚.本研究旨在观察细菌肽敏感金黄色葡萄球菌FS127菌株在细菌肽(BAC)暴露下的耐药趋势。在体外和鸡肠中诱导。采用药敏试验检测金黄色葡萄球菌在体外和鸡肠道中对庆大霉素的敏感性,氯霉素,四环素,多西环素,青霉素和氯霉素.研究结果表明,杆菌肽在体外和体内均可诱导金黄色葡萄球菌耐药。从鸡肠中分离的金黄色葡萄球菌对杆菌肽的耐药率与杆菌肽给药的剂量和时间呈正相关。结果表明,体内诱导的耐杆菌肽金黄色葡萄球菌对氯霉素的敏感性增强,但在体外没有这种变化。同时,RT-qPCR检测vraD的表达水平,布拉德,具有不同杆菌肽耐药水平的典型菌株中的braR和bacA。发现BacA可能在金黄色葡萄球菌的杆菌肽抗性中起关键作用。总之,这项工作揭示了杆菌肽在体内和体外诱导的耐杆菌肽金黄色葡萄球菌的特性和机制。
It is common knowledge that prolonged and excessive use of antibiotics can lead to antimicrobial resistance. However, the characteristics and mechanism of resistant-bacteria induced by clinically recommended and prophylactic dose drugs remain largely unclear. This study aimed to observe the trends of drug resistance of the
bacitracin-susceptible Staphylococcus aureus strain FS127 under exposure to
bacitracin (BAC), which were induced in vitro and in chicken gut. Antimicrobial susceptibility testing was used to detect the susceptibility of S. aureus induced in vitro and in the chicken gut to gentamicin, chloramphenicol, tetracycline, doxycycline, penicillin and chloramphenicol. The research results showed that bacitracin could induce drug resistance in S. aureus both in vitro and in vivo. The bacitracin-resistance rate of S. aureus isolated from chicken gut was positively correlated with the dose and time of
bacitracin administration. The findings revealed that bacitracin-resistant S. aureus induced in vivo had enhanced susceptibility to chloramphenicol but no such change in vitro. Meanwhile, RT-qPCR assay was used to detect the expression levels of vraD, braD, braR and bacA in typical strains with different bacitracin-resistance levels. It was found that BacA may play a key role in the
bacitracin resistance of S. aureus. In conclusion, this work reveals the characteristics and mechanism of bacitracin-resistant S. aureus induced by
bacitracin in vivo and in vitro respectively.