脱氧核酶抑制耐药基因mecR1的表达逆转MRSA耐药性

Restoration of antibiotic susceptibilitly of MRSA by blocking mecR1 through deoxyribozyme

目的探讨脱氧核酶抑制耐甲氧西林金黄色葡萄球菌(M RSA)耐药基因m ecR1的表达对M RSA耐药性的影响。方法设计、合成特异性针对耐药基因m ecR1m RNA的硫代脱氧核酶,将其导入细菌,通过半定量RTP-CR观察脱氧核酶对耐药基因m ecR1及其下游基因m ecA表达的抑制作用,并通过平板克隆形成实验观察脱氧核酶对M RSA耐药性的影响。结果加入脱氧核酶后培养的M RSA,m ecR1与m ecA的m RNA表达水平较对照组显著降低(P<0.01),在含苯唑西林(6m g L/)的M H-琼脂培养基表面生长的菌落单元数也低于对照组(P<0.01)。结论特异性抗m ecR1脱氧核酶阻断耐药基因m ecR1m-ecA的表达,可以部分恢复M RSA对抗生素的敏感性。

Objective To investigate the effects of DNAzyme on drug-resistant gene mecR1 expression in methicillin-resistant Staphylococcus aureus（MRSA）. Methods Specific DNAzyme to mecR1 mRNA was designed and synthesized. After DNAzyme was introduced into MRSA, drug-resistant characters of MRSA were evaluated by plate cloning formation experiment. The inhibition effects of DNAzyme on the expressions of drug-resistant gene mecR1 and its downstream gene mecA were observed by RT-PCR. Results Colony forming units（CFU）of MRSA incubated with DNAzyme on the MH agar added oxacillin （6mg/L） were less than those of control group（P〈0.01）. Levels of mecR1 and mecA mRNA of the DNAzyme groups were lower than those of the control group （P〈0.01）. Conclusion Antibiotic sensitivity on MRSA may be partially restored by DNAzyme which blocks the expressions of drug-resistant genes mecR1-mecA.