鲍曼不动杆菌氨基糖苷类药物修饰酶基因类型的研究

The study of aac (3)-Ⅰ和 aac(6')-Ⅰ genes in acinetobacter baumannii

目的 研究常州地区鲍曼不动杆菌氨基糖苷类药物修饰酶基因类型及其耐药特点。 方法 用琼脂稀释法检测庆大霉素、阿米卡星、妥布霉素、奈替米星等 4种药物对 2 0株多重耐药性鲍曼不动杆菌的最低抑菌浓度。用PCR法检测氨基糖苷类药物修饰酶基因。 结果 庆大霉素、阿米卡星对 2 0株鲍曼不动杆菌MIC50 、MIC90 均 >10 2 4mg/L ,耐药率分别为 10 0 %、90 %。奈替米星、妥布霉素的耐药率分别为85 %、80 %。鲍曼不动杆菌对庆大霉素等 4种抗生素为高浓度耐药。从 2 0株菌中检出两种修饰酶基因 ,其中 16株带有aac(3) Ⅰ基因 ,3株带有aac(6 ') Ⅰ基因 ;3株菌同时具有上述两种基因 ,未检出aph(3) Ⅵ基因。 结论 常州地区鲍曼不动杆菌对氨基糖苷类药物耐药与aac(3) Ⅰ、aac(6 ')

Objective To study genotypes of aminoglycoside modifying enzymes in acinetobacter baumannii and its resistant characteristics. Methods The minimal inhibitory concentrations (MICs) of gentamicin , amikacin ,tobramycin and netilmicin were detected against 20 strains of multipleresistant acinetobacter baumannii by agar two-fold dilution.The PCR method were performed to determine the genotypes of aminoglycoside modifying enzymes. Results MIC 50 and MIC 90 of gentamicin and amikacin in 20 strains were >1024, ,and resistant rates was 100% and 90%, respectively.The resistant rate of tobramycin and netilmicin was 85% or 80%,respectively. Acinetobacter baumannii is of high-level resistance against these four aminoglycosides. Two modifying enzyme genotypes were found from 20 strains.There was aac(3)-Ⅰgene in 16 strains ,and aac(6')-Ⅰ in 3 strains. aac (3)-Ⅰand aac(6')-Ⅰgenes simultaneously occurred in 3 strains,but aph(3')-Ⅵ gene was not found. Conclusion Acinetobacter baumannii in Changzhou area were highly resistant to aminoglycosides in associate with aac(3)-Ⅰand aac(6')-Ⅰgenes.