耐亚胺培南铜绿假单胞菌的耐药性及金属β-内酰胺酶基因的检测

Study of Carbapenemase Genotype Among Pseudomonas Aeruginosa in Daqing District

目的初步分析铜绿假单胞菌的耐药机制。方法采用纸片扩散法(K-B法)进行药物敏感试验;用2-巯基丙酸(2-MPA)协同试验筛查金属酶;通过改良三维水解试验、聚合酶链反应(PCR)、基因测序等方法,分析本地区铜绿假单胞菌所产的碳青霉烯酶表型及基因类型。结果在20株铜绿假单胞菌中,其中9株(45%)为耐亚胺培南的铜绿假单胞菌;2-巯基丙酸协同试验9株结果为阳性;PCR产物电泳,IMP-1引物有5株菌阳性,IMP-2引物有3株菌阳性,VIM通用引物有4株菌阳性,VIM-2引物有2株菌阳性,OXA-23引物有2株菌阳性,OXA-24引物均为阴性;选取3株产IMP-2条带的菌株基因进行测序,结果为IMP-16金属β内酰胺酶基因。结论铜绿假单胞菌耐药机制复杂,存在多种类型的碳青霉烯酶的流行,在医院病区存在产碳青霉烯酶铜绿假单胞菌克隆株的流行。

Objective This study was designed to investigate the drug- resistance carbapenemase genotype and the epidemicity of Pseudomonas aeruginosa （PA） isolated from Daqing district, analyze the drug - resistance mechanism of these strains and direct the proper use of antimicrobial in local district. Methods Twenty strains of Pseudomonas aeruginosa were selected randomly from clinical isolated strains. Drug- resistance was analyzed by K- B paper scraps spread method. The drug - resistance phenotype of these strains was detected by using 2 - mercaptopropanoic acid- disc （2 - MPA） synergy test and three - dimensional test. The carbapenemase genotype of these strains was analyzed by PCR and sequence analysis. Results Nine strains of PA were suggested to produce metaUo - beta - lactamase by 2 - MPA synergy test. By using PCR, 5 kinds of carbapenemase genes were detected in 20 strains of PA including 5 strains of using IPM - 1 primer, 3 strains of using IPM - 2 primer, 4 strains of using VIM primer, 2 strains of using VIM - 2 primer,2 strains of using OXA - 23 primer. The OXA - 24 type gene wasn＇ t detected in this test. Three IPM - 2 positive products were identified by sequence analysis and they were IMP - 16 metallo- beta- lactamase genes. Conclusion There were several kinds of carbapenemase genotype among Pseudomonas aeruginosa in Daqing district. It is recommended that proper measures shall be taken to control the prevalence of harboring carbapenemase strains in the hospital.