南京地区鲍曼不动杆菌氨基糖苷类药物修饰酶基因类型的调查

Investigation for main types of aminoglycoside-modifying gene of Acinetobacter baumannii in Nanjing region

目的调查和研究南京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性。方法用K-B法测定97株鲍曼不动杆菌对庆大霉素、阿米卡星2种抗菌药物的耐药性,用PCR法检测氨基糖苷类药物修饰酶基因。结果同时耐庆大霉素、阿米卡星的鲍曼不动杆菌44株,庆大霉素耐药阿米卡星敏感的有4株,庆大霉素敏感阿米卡星耐药的有3株,从51株表型耐药菌中检出4种修饰酶基因,其中带有aac(3)Ⅰ-基因19株(37.3%);带有aac(3)-Ⅱ基因15株(29.4%);有aac(6′)-Ⅰ基因8株(15.7%);ant(3″)Ⅰ-基因为3株(5.8%);同时具有aac(3)Ⅰ-和aac(6′)Ⅰ-基因的5株(9.8%);有aac(3)-Ⅱ和aac(6′)Ⅰ-基因的1株(1.9%)。结论南京地区鲍曼不动杆菌所带基因以aac(3)-Ⅰ和aac(3)-Ⅱ为主,其与氨基糖苷类药物耐药有一定的关系。

Objective To investigate the main types of aminoglycoside-modifying gene of Acinetobacter baumannii in Nanjing region, and analyze its relationship to aminoglycoside resistance. Methods Totally 97 isolates of Acinetobacter baumannii were collected from five hospitals in Nanjing region randomly, and their resistances to gentamicin and amikacin were detected by Kirby-Bauer method. The main types of the aminoglycoside modifying gene were assayed by PCR. Results Among the 97 isolates 44 were resistant to amikacin and gentamicin,4 were amikacin susceptible and gentamicin resistant, and 3 were gentamicin susceptible and amikacin resistant. In 51 aminoglycoside resistant isolates,four kinds of gene coding for aminoglycoside-inactivating enzymes were detectable, aac （3）- Ⅰ gene were found in 19 isolates （37.3%） ,aac（3）- Ⅱ were in 15 isolates （29.4%） ,aac（6′）- Ⅰ were in 8 isolates （15.7%） ,and ant（3＂）- Ⅰ were in 3 isolates （5.8%） respectively. In addition, aac （ 3 ） - Ⅰ together with aac （6′） - Ⅰ gene was detectable in 5 isolates （ 9. 8% ） and aac（3 ）-Ⅱ together with aac（6′ ）- Ⅰ gene was detectable in 1 isolates（ 1.9% ）. Conclusion In Nanjing region,aac（ 3 ）- Ⅰ and aac （3） - Ⅱ are the main types of aminoglycoside-modifying gene of Acinetobacter baumannii. All the detectable resistant genes are related to resistance of Acinetobacter baumannii isolates to aminoglycoside antibiotics.