携带blaKPC-2基因耐药菌在我院流行传播现状及耐药分析

Epidemic Status and Resistance Analysis of Drug-Resistant Bacteria Carrying blaKPC-2 Gene in Our Hospital

目的研究携带blaKPC-2基因的耐碳青霉烯类抗生素耐药菌在南昌大学第一附属医院流行传播现状,对其作流行病学分析,为遏制该类耐药菌株在南昌大学第一附属医院流行传播提供相关研究依据。方法收集南昌大学第一附属医院2016年1—12月对碳青霉烯类抗生素不敏感菌株,采用Vitek2compact全自动微生物鉴定仪对菌株进行菌株鉴定,提取菌株的DNA,采用PCR特异性扩增blaKPC-2基因,对阳性扩增产物作基因测序,将鉴定为blaKPC-2阳性的菌株作体外药物敏感性试验;采用改良碳青霉烯酶灭活实验(modified carbapenem inactivation method,mCIM)对blaKPC-2阳性的菌株作碳青霉烯酶表型筛查;收集blaKPC-2阳性菌株相关临床资料,分析其在南昌大学第一附属医院的流行传播现状。结果收集的568株对碳青霉烯类抗生素不敏感菌株中筛选出blaKPC-2阳性耐药菌株63株,总阳性率为11.09%;其中98株肺炎克雷伯杆菌检测出blaKPC-2阳性菌株59株,阳性率为60.20%;186株鲍曼不动杆菌中blaKPC-2阳性菌株2株,阳性率为1.08%;72株大肠埃希菌中blaKPC-2阳性菌株2株,阳性率为2.78%;125株阴沟肠杆菌和87株铜绿假单胞菌未筛到blaKPC-2阳性菌株;所有blaKPC-2阳性的菌株mCIM实验均阳性;通过查询blaKPC-2阳性菌株标本的临床资料发现,南昌大学第一附属医院18个临床科室均有blaKPC-2阳性耐药菌株流行分布,其中ICU科室是该类耐药菌株重点流行科室;药物敏感性试验显示该类耐药菌株对碳青霉烯类中亚胺培南、美罗培南,喹诺酮类抗生素中的左氧氟沙星、环丙沙星,氨基糖苷类抗生素中的阿米卡星、庆大霉素及妥布霉素表现高水平耐药,其他临床常用抗生素多为中等水平耐药。结论南昌大学第一附属医院携带blaKPC-2基因的耐药菌株在肺炎克雷伯菌、大肠埃希菌、鲍曼不动杆菌均有分布,其中主要分布在肺炎克雷伯菌中;药物敏感性试验显示其对碳青霉烯类、喹诺酮类、氨基糖苷类等抗生素高度耐药,该类耐药菌株在南昌大学第一附属医院广泛分布,ICU科室是其流行传播的重点区域,应当引起重视,做好防控措施。

Objective To study the epidemic bapenems resistant bacteria carrying blaKPC-2 University, and to provide research evidence for status and epidemiological characteristics of car gene in the First Affiliated Hospital of Nanchang restraining the epidemic transmission of this kindof drug resistant strains in our hospital. Methods The carbapenems insensitive strains collected in the First Affiliated Hospital of Nanchang University from January 2016 to December 2016 were identified by Vitek2 compact automatic microorganism identification instrument. The DNA was extracted and blaKPC-2 gene was specifically amplified by PCR. Gene sequencing was performed in positive amplification products,and all blaKPC-2 positive strains were used for in vitro drug sensitivity test. The modified carbapenem inactivation method（mCIM） was used to screen the phenotype of carbapenemase. Furthermore, clinical data of all b/akpc 2 positive strains were col lected to analyze the epidemic status in our hospital. Results A total of 63 blakpc 2 positive strains（ll.09%） were detected in the 586 collected carbapenems insensitive. Among them, 59 （60%） were screened from 98 Klebsiella pneumoniae strains,2（1.08%） from 186 Acinetobact er baumannii, and 2 （2.78%） from 72 Escherichia coli strains. No bla kpc 2 positive strains were found in 125 Enterobacter cloacae strains and 87 Pseudomonas aeruginosa strains.The mCIM test showed positive results in all the blakpc 2 positive strains. Clinical data demonstrated that there was epidemic distribution of blaKPC-2 positive drug resistant strains in all 18 clinical depart ments of our hospital, especially in ICU department. Susceptibility test indicated that blakpc 2 positive strains were highly resistant to imipenem, meropenem, levofloxacin, ciprofloxacin, amika cin, gentamycin and tobramycin, but moderately resistant to other commonly used antibiotics. Conclusion Drug resistant strains carrying blakpc 2 gene in our hospital are distributed in Kleb siella pneumoniae, Escherichia coli and Acinetobacter baumannii（especially in Klebsiella pneu moniae） ,and are highly resistant to carbapenem, quinolone and aminoglycoside antibiotics. This kind of drug resistant strains are widely distributed in our hospital and ICU department is the key epidemic area.Therefore,more attention should be paid to the prevention and control of carbapen eros resistant bacteria carrying blaKPC-2 gene.