12例烧烫伤患者耐碳青霉烯类黏质沙雷菌耐药机制及同源性分析

Resistance mechanism and homology analysis of carbapenem-resistant Serratia marcescens isolated from burnt patients

目的分析耐碳青霉烯类黏质沙雷菌(CRSM)的耐药机制及同源性,为临床合理用药提供依据。方法收集2014年-2015年烧伤病区CRSM菌株12株,分析其耐药机制及同源性。结果菌株对青霉素类、头孢菌素类和氨基糖苷类耐药率为100%,氟喹诺酮类和复方磺胺甲恶唑敏感率为100%,哌拉西林/他唑巴坦敏感率为91.7%;碳青霉烯类耐药率为91.7%;10株改良三维试验和改良Hodge试验阳性;11株Carba NP试验阳性;8株3-氨基苯硼酸试验阳性;2株EDTA抑制试验阳性;PCR显示9株携带bla_(KPC-2);2株携带bla_(IMP-1);未发现有合产碳青霉烯酶;PFGE显示有4株菌株为同一克隆株。结论本院烧伤病区患者分离的CRSM耐药机制以携带bla_(KPC-2)为主,并同时产ESBLs和AmpC酶;其次是携带bla_(IMP-1);有4株为同源株;应引起临床和实验室的重视。

Objective To analyze the resistance mechanism and homology of carbapenem - resistant Serratia marcescens （CRSM） , so as to provided basis for the rational use of antimierobial agents in clinical. Methods 12 strains of non - repetitive CRSM were collected from 2014 to 2015 in burn unit, and their resistance mechanisms and homology were analyzed. Results The resistance rate of CRSM to penicillin, cephalosporin and aminoglycoside was 100%. But the sensitivity to fluoroquinolone and compound sulfamethoxazole was 100% , and it was 91.7% to piperacillin/tazobactam; the resistance to earbapeneros was 91.7%. 10 strains were positive for the modified three - dimensional and Hodge test; 11 strains were positive for Carba NP test ; 8 strains were positive for 3 - Aminobenzene sulfonic acid inhibition test. 2 strains were positive for EDTA. The results of PCR showed that 9 strains carry blaKPC-2 ; 2 strains carry blaIMP-1. The combined produce of earbapenemase was not found. PFGE show that 4 strains belong to the same colon one. Conclusion The resistance mechanism is given priority to carrying blaKPC-2 from burn unit, the strains produce ESBLs and AmpC enzyme at the same time. As for blaIMP-1 canting strains, 4 strains are in homology, which should be paid more attention in clinical and laboratory.