108株耐碳青霉烯肺炎克雷伯菌的临床分布与耐药基因研究

Study on clinical distribution and antibiotic resistance genes of 108 isolates of carbapenem-resistant Klebsiella pneumoniae

目的了解仁济医院耐碳青霉烯肺炎克雷伯菌株(carbapenem-resistant Klebsiella pneumoniae,CRKP)的临床分布与耐药基因型。方法收集2013年1月—2015年7月仁济医院临床分离108株CRKP,进行K-B纸片法检测18种抗菌药物敏感性、超广谱β-内酰胺酶(ESBLs)初筛及表型确证试验、聚合酶链反应检测ESBLs、碳青霉烯酶、质粒介导的AmpC酶与喹诺酮耐药基因。结果 108株CRKP对复方磺胺耐药率最低(32.4%),其次为磷霉素、庆大霉素和阿米卡星(82.4%、95.4%和97.2%)。科室分布前3位为神经外科、外科ICU和普外科。ESBLs基因中CTX-M-9,SHV和TEM酶基因阳性率为96.3%、85.2%和75.9%。108株CRKP均检测出KPC-2基因。而金属酶基因仅1株检测出IMP-1。喹诺酮耐药基因中qnrB基因检出率达91.7%(99/108)。AmpC酶中只检测出DHA基因,阳性率13.9%(15/108)。结论我院临床分离CRKP携带多种耐药基因,对数10种临床常用抗菌药物同时耐药,应加强对该类菌株的监控,控制其在院内的传播流行。

Objective To understand the clinical distribution and investigate the resistant genes carried in the clinical isolates of carbapenem-resistant Klebsiellapneumoniae （CRPK） in Renji Hospital. Methods A total of 108 carbapenem-resistant Klebsiella pneumoniae isolates were collected from January 2013 to July 2015 in Renji Hospital. Antibiotic susceptibility to 18 drugs of the isolates were determined by Kirby Bauer disk diffusion method. ESBLs- producing initial screen test and phenotypic confirmatory test were performed to detect the resistance phenotype of theisolates. Antibiotic resistance genes were investigated by PCR amplification, including ESBLs genes, carbapenemase genes, plasmid-mediated AmpC 13-1actamasegenes and quinolone resistance genes. Results 108 isolates had the lowest resistancerates to compound sulfamethoxazole （32.4%）. The resistant rates to fosfomycin, gentamycin and amikacin were 82.4%, 95.4% and 97.2%, respectively. The isolates were mainly distributed in Neurosurgery, Surgical ICU and General Surgery, accounting for 18.5%, 18.5% and 15.7%, respectively. Among the ESBLs genes detected, the positive rates of CTX-M-9, SHV and TEM encoding genes were 96.3%, 85.2%, and 75.9%, respectively. KPC- 2 encoding gene was detected in all 108 isolates, while among all detected metallo-β-1actamases only IMP-1 was detected in one isolate, qnrB gene was the most frequently detected quinolone gene and its positive rate reach 91.7%（99/108）. Among all investigated AmpC β-lactamasegenes only DHA was detected, of which the positive rate is 13.9 %（15/108）. Conclusion The isolates of carbapenem-resistant Klebsiellapneumoniae in our hospital are resistant to various antibiotics commonly used in the clinic and carry multiple resistant genes, which has been a growing concern in the clinical treatment. It is necessary to strengthen the surveillance to prevent the further spread of the carbapenemresistant strains in the hospital.