ICU铜绿假单胞菌感染暴发的随机扩增多态性DNA分子分型

Molecular typing of Pseudomonas aeruginosa from ICU by random amplification polymorphism DNA

目的对铜绿假单胞菌(PA)进行随机扩增多态性DNA(RAPD)分子分型,探讨重症监护室(ICU)中PA医院感染的流行规律。方法采用RAPD技术对13株分离自某院ICU临床诊断为医院感染肺炎患者下呼吸道标本的PA进行分型,并与抗菌药物耐药谱分型比较。结果 13株PA产生A型(12株,92.31%)和B型(1株,7.69%)2种耐药表型,优势耐药表型为A型;RAPD分型可分2型,分别为Ⅰ型(6株,46.15%)和Ⅱ型(7株,53.85%)。7株分子Ⅱ型和5株分子Ⅰ型的耐药A型PA是优势菌株,可判断为引起ICU中PA医院感染暴发的病原菌。结论 ICU存在PA暴发流行,流行株为耐药A型/分子Ⅱ型、耐药A型/分子Ⅰ型。PA产生多重耐药性,RAPD分型是目前比较理想的分子流行病学溯源手段。

Objective To evaluate the epidemic characteristics of Pseudomonas aeruginosa （PA）infection in patients in ICU through typing of PA by random amplification polymorphism DNA （RAPD）. Methods Thirteen strains of PA from lower respiratory tract in patients with nosoeomial-acquired pneumonia were typied by RAPD method, and were compared with antimicrobial drug-resistance spectrum typing. Results Thirteen strains of PA were divided into two drug-resistance phenotypes, type A （12 strains, 92. 31% ） and type B （1 strain, 7. 69 %）, the dominant strain was type A; these strains were divided into two genotypes with RAPD typing, type Ⅰ （6 strains, 46. 15%） and type Ⅱ （7 strains, 53. 85%）. The dominant strains were 7 strains with both drug-resistance type A and molecular type Ⅱas well as 5 strains with both drug-resistance type A and molecular type Ⅰ , these dominant strains were the pathogens causing PA nosocomial infection in ICU. Conclusion PA can cause outbreak and epidemic of infection in ICU, the epidemic strains were drug-resistance type A/molecular type Ⅱ as well as drug-：esist ance type A/molecular type Ⅰ. PA can cause multi-drug resistance, RAPD typing is the ideal molecular epidemiological method for tracing source of infection.