论文部分内容阅读
目的研究左氧氟沙星对金黄葡萄球菌小RNA表达的影响及对细菌生长的作用。方法分别在不同抑菌浓度左氧氟沙星干扰情况下,培养金黄葡萄球菌实验株RN6390和RN1HG001,提取RNA,用实时定量逆转录聚合酶链反应(qRT-PCR)检测不同菌株中RNAⅢ、RsaA、RsaE、RsaG、RsaH的含量,比较不同抑菌浓度左氧氟沙星作用下小RNA的表达差异。结果在MH培养液和BH培养液中左氧氟沙星对RN6390和RN1HG001的MIC均为0.25μg/ml。5种小RNA中,RNAⅢ的表达量最多,RsaG最少;当左氧氟沙星浓度≥1/4MIC时,开始对金黄葡萄球菌的生长产生明显抑制作用,5种小RNA的表达均开始下降;在RN6390菌株,1/16 MIC和1/8 MIC的左氧氟沙星能促进RsaH表达。结论不同浓度左氧氟沙星对金黄葡萄球菌小RNA表达具有抑制或者促进作用,提示除了其本身具有的阻碍细菌DNA合成的功能外还可能影响细菌基因的转录。
Objective To study the effect of levofloxacin on small RNA expression of Staphylococcus aureus and its effect on bacterial growth. Methods Staphylococcus aureus experimental strains RN6390 and RN1HG001 were cultured in the presence of different concentrations of levofloxacin, RNA was extracted and RNAi, RsaA, RsaE and RsaG were detected by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) , RsaH content of different concentrations of bacteriostatic levofloxacin small RNA expression differences. Results The MIC of levofloxacin to both RN6390 and RN1HG001 in both MH and BH media was 0.25 μg / ml. Among the five kinds of small RNAs, the expression of RNAⅢ was the most, and RsaG was the least. When the concentration of levofloxacin ≥1 / 4MIC, the growth of Staphylococcus aureus began to be inhibited and the expression of five kinds of small RNAs began to decline. In RN6390 strain, Levofloxacin at 1/16 MIC and 1/8 MIC promoted RsaH expression. Conclusion Different concentrations of levofloxacin inhibit or promote the expression of small RNA of Staphylococcus aureus, suggesting that in addition to its own function of hindering bacterial DNA synthesis may also affect the bacterial gene transcription.