黄柏提取物抗耐大环内酯类药物肺炎支原体的实验研究

目的 探讨黄柏提取物体外对大环内酯类药物耐药肺炎支原体(MP)的抗菌活性,并分析黄柏提取物对其耐药相关基因MPN421 mRNA表达的影响,通过检测黄柏提取物作用前后MPN421 mRNA表达改变情况,初步阐述黄柏提取物抗MP的相关分子机制。 方法 用实时荧光定量PCR鉴定45例MP临床分离株对大环内酯类药物耐药突变(23S rRNA区域),鉴定肺炎支原体的突变株(23S rRNA 2063点突变)和野生株;体外药物敏感试验检测45株肺炎支原体对黄柏提取物的最小抑菌浓度(MIC);实时荧光PCR检测黄柏提取物作用前后对MP MPN421 mRNA表达改变。 结果 45例MP临床分离株中发现30株23S rRNA 发生突变(突变株),15株MP 未发生突变(野生型);15株MP野生株的MIC值为0.036~0.576 mg/ml,30株肺炎支原体突变株的MIC值为0.036~1.152 mg/ml。15株野生株及30株突变株在无黄柏提取物作用下MPN421 mRNA相对表达量分别为0.079(0.071,0.089),0.083(0.062,0.084),P>0.05;黄柏提取物作用6 h和9 h后,无论是野生株还是突变株的MPN421 mRNA相对表达量均显著下降(均P<0.01)。 结论 MP野生株及突变株对黄柏提取物均敏感,其机制可能是降低MP MPN421 mRNA表达,对大环内酯类药物耐药MP感染有潜在治疗价值。 

The effect of Cortex Phellodendri extract on the macrolides-resistant Mycoplasma pneumoniae

Objective To explore Cortex Phellodendri extract antibacterial activity against macrolides resistant mycoplasma pneumoniae (MP) in vitro, and to analyze its effect on the expression change of resistance gene MPN421 of MP. Methods The 23S rRNA mutations of 45 clinical isolated MP strains were determined by real-time PCR which were related to macrolides resistant. In further, MICs of 45 MP strains for Cortex Phellodendri extract were tested by serial dilution method. The MPNA421 mRNA expression change was measured with real-time PCR before and after being effected by Cortex Phellodendri extract. Results From 45 clinical isolated strains, there were 30 strains detected 23 s rRNA mutations, no mutations were detected in the other 15 strains. The MICs of 15 wild-type MP strains were 0.036-0.576 mg/ml for Cortex Phellodendri extract; the MICs of 30 resistant strains were 0.036-1.152 mg/ml. Combined with the MICs of berberine hydrochloride for most of the common bacteria and fungi were in range of 0.5-1.0 mg/ml. The results showed that 45 strains of MP for Cortex Phellodendri extract all were sensitive. On the condition without Cortex Phellodendri extract effect, the relative expressions of MPN421 mRNA of 15 wild-type MP strains and 30 MP resistant strains were 0.079 (0.071, 0.089), 0.083 (0.062, 0.084), P>0.05, respectively. After administration of Cortex Phellodendri extract for 6 hours or 9 hours, the relative expression of MPN421 mRNA of both wild-type strains and resistant strains were decreasing significantly (all P<0.01). Conclusion Both wild-type MP strains and macrolides-resistant strains were sensitive to Cortex Phellodendri extract. Cortex Phellodendri extract could decrease the relative expression of MPN421 mRNA, which mean that it could be used in treatment of the macrolides-resistant MP strain infection.