铜绿假单胞菌临床分离株基因型分析

摘要

Objective To analyze the genotypes of Pseudomonas aeruginosa ( PA) isolated from inpatients with long-term and continuous infection in various departments of hospital , the and to explore the genetic variation of PA .Methods The strains of PA were collected from specimens of various departments of inpatients , and then we amplified the strains in which the infection lasted for more than 30 days, obtained the RAPD fingerprinting by random amplified polymorphic DNA ( RAPD) genotyping technique , analyzed homology by homology clustering , and understood the genetic relationship be-tween PA through the similarity coefficient .At the same time, we compared the RAPD type to determine whether there was an epidemic outbreak and whether there was a variation between the strains from the same patients with continuous infec -tion.Results A total of 293 strains of PA were collected , including 117 strains in which the infection duration was longer than 30 days, and then 19 genotypes were amplified with A-S type, and the classification rate is 100%.The similarity co-efficient ranged from 0.64 to 0.93, the similarity coefficient of genotypes A and G , genotypes B and R , genotypes D and E, genotypes M and P was 0.93, indicating a high degree of homology between them .In the intensive care unit and burn plastic surgery , the same RAPD type was detected in different patients , the rest of the patients had different RAPD types . The PA fingerprints of 4 patients who suffered continuous infection changed .Conclusion There are many genotypes in PA isolates from patients in various departments of the hospital , which suggests that PA gene mutation occurs in the process of infection, and there is a genetic polymorphism .%目的：分析某院各科室长期持续感染的铜绿假单胞菌（ PA）分离株的基因型，探讨PA的基因变异情况。方法从某院各科室住院患者送检的标本中分离PA，对感染持续时间大于30天的菌株采用随机扩增多态性DNA （ RAPD）基因分型技术获得RAPD指纹图谱，并进行同源性聚类分析，通过相似性系数了解PA之间的亲缘关系；对比PA的RAPD型别，判断是否存在爆发流行及同一患者连续感染的PA基因是否发生变异。结果共收集PA 293株，其中感染持续时间大于30天的菌株117株，扩增出19种基因型条带，分别为A～S型，分型率100％；基因型相似系数范围为0．64～0．93，基因型A和G、基因型B和R、基因型D和E、基因型M和P的相似系数均为0．93，说明它们之间具有高度的同源性。重症医学科及烧伤整形外科各发生一起在不同患者之间检出相同RAPD型别PA菌株的情况，其余患者RAPD型别各不相同。4例患者连续感染的PA指纹图谱发生改变。结论某院各科室长期持续感染的PA分离株存在多种基因型，提示PA在感染过程中可发生基因变异，存在基因多态性。