耐亚胺培南铜绿假单胞菌和嗜麦芽寡养单胞菌抗菌药物耐药基因研究

Study on the antimicrobial-resistant genes in imipenem-resistant Pseudomonas aeruginosa and Stenotrophomonas maltophilia

目的分析浙江省湖州解放军第98医院自临床分离的耐亚胺培南铜绿假单胞菌(IRPa)和嗜麦芽寡养单胞菌(Sm)中抗菌药物相关耐药基因存在状况。方法2003年9月至2004年10月间从临床分离28株IRPa和19株Sm,采用聚合酶链反应及序列分析的方法分析8种β-内酰胺酶基因(blaIM P、blaV IM、blaTEM、blaSHV、blaOXA、blaPER、blaVEB和blaGES)、9种氨基糖苷类修饰酶基因(AM E s基因)[aac(3)-Ⅰ、aac(3)-Ⅱ、aac(3)-Ⅲ、aac(3)-Ⅳ、aac(6′)-Ⅰ、aac(6′)-Ⅱ、ant(3")-Ⅰ、ant(2")-Ⅰ和aph(3′)-Ⅵ]、外膜孔蛋白D 2基因(op rD)、消毒剂-磺胺耐药相关基因(qacE△1-su l1)、氯霉素乙酰转移酶基因(ca tB)、氯霉素外排蛋白基因(cm l1)。结果28株IRPa中blaTEM、blaOXA、aac(3)-Ⅱ、aac(6′)-Ⅱ、ant(3")-Ⅰ、ant(2")-Ⅰ和qacE△1-su l1基因的阳性株数(%)分别为20株(71.4%)、1株(3.6%)、23株(82.1%)、10株(35.7%)、15株(53.6%)、8株(28.6%)和24株(85.7%),AM E s基因总阳性率为89.3%,blaOXA基因经序列分析确认为blaOXA-10型超广谱β-内酰胺酶,25株(89.3%)发生op rD基因缺失突变。19株Sm中aac(6′)-Ⅱ、ant(2")-Ⅰ及qacE△1-su l1基因的阳性株数(%)均为2株(10.5%);其余基因均阴性。结论临床分离的IRPa中存在blaTEM、blaOXA-10、aac(3)-Ⅱ、aac(6′)-Ⅱ、ant(3")-Ⅰ、ant(2")-Ⅰ和qacE△1-su l1基因,op rD基因缺失突变率很高。Sm中存在aac(6′)-Ⅱ、ant(2")-Ⅰ及qacE△1-su l1基因。

Objective To analyze the antimicrobial-resistant genes in imipenem-resistant Pseudomonas aeruginosa （IRPa） and Stenotrophomonas maltophilia （Sin） isolated from the People＇s Liberation Army 98th Hospital, Huzhou District, Zhejiang Province, China. Methods Twenty eight strains of IRPa and nineteen strains of Sm were isolated from hospitalized patients between Sep,2003 and Oct, 2004. Genotyping of eight kinds of β-lactemase genes （including blaIMP, blaVIM, blaTEM, blaSHV, blaOXA, blaPER, blaVER and blaGES）, nine kinds of aminoglycoside modifying enzyme genes [including aac（3）- Ⅰ , aac（3）- Ⅰ , aac（3）-Ⅱ , aac（3）-Ⅳ , aac（6＇）- Ⅰ , aac（6＇）- Ⅱ , ant（3＂）- Ⅰ , ant（2＂）- Ⅰ , and aph（3＇）-Ⅵ ], oprD, qacE△1-sul1, catB, and cml1 were analyzed by PCR and verificated by DNA sequencing. Results In 28 strains of IRPa the positive rates of blaTEM, blaoxA, aac（3）- Ⅰ , aac（6＇）- Ⅱ , ant（3＂）- Ⅰ , ant（2＂）- Ⅰ , and qacE△1-sul1 were 71.4%, 3. 6%, 82.1%, 35.7%, 53. 6%,28.6%, and 85.7% respectively, the total positive rate of AMEs genes was 89.3%, and the deficiency rate of oprD gene was 89.3%. The gene of OXA enzyme was sequenced and determined to be subtype extended-spectrum β-lactamases gene. In 19 strains of Sm, the positive rates of aac（6＇）-Ⅱ , ant（2＂）- Ⅰ , and qacE△1-sul1 were all 10. 5%. But the rest of genes were all negative. Conclusion There are genes of blaTEM, blaOXA-10, aac（3）- Ⅱ , aac（6＇）- Ⅱ , ant（3＂）- I , ant（2″）- Ⅰ , and qacE△1-sul1 in IRPa isolates, and the deficiency rate of oprD gene was very high. There are genes of aac（6′）- Ⅱ , ant（2＂）- Ⅰ , and qacE△1-sul1 in Sm isolated.