铜绿假单胞菌临床分离株β内酰胺类和氨基糖苷类耐药基因分析

Study on the drug-resistant genes associated with β-lactams and aminoglycosides in clinically isolated Pseudomonas aeruginosa

目的 了解临床分离的铜绿假单胞菌中β内酰胺类和氨基糖苷类抗生素相关耐药基因的存在状况。方法 从烧伤患者创面分泌物中分离出20株铜绿假单胞菌，经药物敏感试验后将多重耐药菌株挑出，采用PCR检测其16种β内酰胺类抗生素耐药基因TEM、SHV、OXA-10群、PER、VEB、GES、CARB、CTX-M-Ⅰ、IMP、VIM、SPM、GIM、DHA、MOX、FOX和oprD2和aac（3）-Ⅰ、aac（3）-Ⅱ、aac（6′）-Ⅰ、aac（6′）-Ⅱ、ant（3″）-Ⅰ、ant（2″）-Ⅰ等6种氨基糖苷类修饰酶基因的存在情况。结果 20株B内酰胺类耐药基因中TEM阳性20株（100％）、GES阳性20株（100％），5株oprD2基因缺失（25％），其余基因均为阴性。氨基糖苷类耐药基因中aac（6′）-Ⅰ阳性20株（100％）、ant（2″）-Ⅰ阳性7株（35％），其余基因均为阴性。结论 临床分离的铜绿假单胞菌TEM、GES和aae（6′）-Ⅰ基因携带率高，且检出新型基因GES-5，表明烧伤患者铜绿假单胞菌感染耐药性严重。

Objective To investigate drug-resistant genes associated with β-1actams and aminoglycosides in clinically isolated Pseudomonas aeruginosa. Methods Twenty strains of Pseudomonas aeruginosa were isolated from wound excretion of hospitalized burn patients. The strains resistant to 14 antibiotics were selected for detection of 16 kind of drug-resistant genes （ TEM, SHV, OXA-10cluster, PER, VEB, GES, CARB, CTX-M- I , IM P, VIM, SPM, GIM, DHA, MOX, FOX, oprD2 ） and 6 kind of aminoglycoside modification genes （aac（3）-Ⅰ ,aac（3）-Ⅱ ,aac（6′）-Ⅰ ,aac（6′）-Ⅱ ,ant（3″）-Ⅰ ,ant（2″）-Ⅰ ）in them by PCR. Results Among the 20 strains resistant to β-lactam , all of them were TEM and GES positive（ 100% ） , oprD2 gene depletion in 5 strains （25%） . All other genes were negative . Among aminoglyeoside resistant genes ,20 strains were aac （6′） - Ⅰ positive （ 100% ） , 7 were ant （ 2″） -Ⅰ positive （ 35 % ） , and negative for other stains. Conclusion There were very high existence rates of TEM, GES and aac（6′）- Ⅰ genes in Pseudomonas aeruginosa isolated from clinical burn patients. The fact that GES-5 gene has also been detected in Pseudomonas aeruginosa ,suggesting this organism is highly drug resistant in our burn unit.