耐亚胺培南铜绿假单胞菌耐药特征及β-内酰胺类耐药基因研究

Investigation on the antimicrobial resistance characteristics and resistant genes of β-lactam antibiotics in imipenem-reslstant Pseudomonas aeruginosa

目的 分析我院2005年1．12月临床分高34株耐亚胺培南铜绿假单胞菌对常用抗生素的耐药特征以及β-内酰胺类耐药相关基因存在状况。方法 应用BD Phoenix100全自动微生物分析仪进行细菌鉴定和药物敏感试验，头孢哌酮，舒巴坦采用K-B法。应用PCR方法检测12种β-内酰胺类耐药相关基因，分别为TEM、SHV、CARB、OXA．10、PER、VEB、GES、DHA、IMP、VIM、GIM、SPM。结果 亚胺培南耐药铜绿假单胞菌除对阿米卡星100％敏感外，对哌拉西林、哌拉西林，他唑巴坦敏感率为48％-54％，对三代、四代头孢菌素，氨曲南，喹诺酮类等抗生素抗菌活性差，敏感率为3％-29％。对美洛培能有29％敏感，对氨苄西林，舒巴坦、氯霉素、四环素、复方新诺明全部耐药。β-内酰胺类耐药相关基因TEM、CARB、DHA、IMP阳性率分别为5．9％、32．4％、14．7％、17．6％，而SHV、OXA-10、PER、VEB、GES、VIM、GIM．SPM均为阴性。结论 耐亚胺培南的铜绿假单胞菌除对阿米卡星敏感外，对其它常用抗生素耐药严重。携带TEM、CARB、DHA、IMP基因是本组试验菌株对β-内酰胺类抗生素和亚胺培南耐药的重要机制。

Objective To investigate the antimicrobial resistance characteristics and the β--lactamase coding genes existence in 34 strains of pseudomonas aeruginosa clinically isolated in our hospital from January to December in 2005. Method Bacterium identification and drug sensitivity test were performed by BD Phoenixl00 automatic microbial analysis system, cefoperazone/sulbactam was performed by K-B method. β--lactamase coding genes were detected by PCR method, including TEM, SHV, CARB, OXA-10, PER, VEB, GES, DHA, IMP, VIM, GIM, SPM. Results Imipcnem-resistant pseudomonas aeruginosa were all sensitive to amikacin; the sensitivities to piperacillin and pipercillin/tazobactam was between 48% and 54%; the sensitivities to other cephlosporins, aztreonam and quinolone were between 3% and 29%. There were 29% of pseudomonas aeruginosa sensitive to meropcnem and all resistant to amoxicillin/clavulanate, chloramphenicol, tetracycline and trimethoprim/sulfamethoxazole. The positive rate of β--1actam antibiotics resistant genes TEM, CARB, DHA and IMP were 5.9%, 32.4%, 14.7% and 17.6%, respectively. While SHV, OXA-10, PER, VEB, GES, VIM, GIM, SPM genes were all negative. Conclusion Except sensitive to amoxicillin, the pseudomonas aeruginosa resistant to imipenem is severely resistant to other commonly used antibiotics. These strains carry genes of TEM, CARB, DHA, and IMP, which are the essential resistant mechanism of β--lactam antibiotics and imipenem in pseudomonas aeruginosa.