铜绿假单胞菌氨基糖苷类修饰酶基因与耐药表型的研究

Study on the Relationship between Genotype of Aminoglycoside Modification Enzymes and Phenotype of Drug Resistance in Pseudomona Aeruginosa

目的探讨临床分离的22株铜绿假单胞菌(Pa)氨基糖苷类修饰酶(AMES)基因与耐药表型的关系。方法对22株铜绿假单胞菌采用稀释法检测庆大霉素、阿米卡星、奈替米星、妥布霉素4种抗菌药物的最低抑菌浓度(MIC),并用聚合酶链反应(PCR)法检测6种氨基糖苷类修饰酶基因。结果本组22株Pa菌庆大霉素耐药15株(68.2%)、阿米卡星耐药3株(13.6%)、奈替米星14株(63.6%)、妥布霉素15株(68.2%),检出aac(3)-阳性14株(63.6%)、aac(6′)-阳性5株(22.7%)、aac(6′)-阳性3株(13.6%)、ant(3″)-阳性1株(4.5%)和ant(2″)-阳性7株(31.8%),aac(3)-为阴性。共有18株检出氨基糖苷类修饰酶基因(81.8%)。结论分离自临床的铜绿假单胞菌氨基糖苷类修饰酶基因检出率高,且与耐药表型一致。

Objective To study the relationship between the genotype of aminoglycoside modification enzymes （AMEs） and the phenotype of drug resistance in 22 strains clinically isolated Pseudomona aeruginosa（Pa）. Method For 22 strains Pa,MICs （minimal inhibitory concentration） of gentamicin, amikacin, netilmicin and tobramycin were detected by agar dilution method ,and PCR（polymerase chain reaction） assays were carried out to detect 6 genes for AMEs. Results 15（68.2%）, 3（13.6%）,14（63.6%） and 15（68.2%） from the 22 strains of Pa were resistant to gentamicin,amikacin, netilmicin and tobramycin ,respectively. The genes for aac（3）- Ⅱ , aac（6＇）- Ⅰ , aac（6＇）- Ⅰ , ant（3″）- Ⅰ and ant（2″）- Ⅰ were positive in 14（63. 6%）,5（22. 7%）,3（13. 6%）,1（4. 5%） and 7（31.8%） strains, respectively. However,aac（3）-Ⅰ gene could not be detected in all samples. The genes of AMEs existed in 18 strains（81.8%）. Conclusion The high positive rate of AMEs genes is in accord with the phenotype of drug resistance in Pa isolated from clinical patients.