Study On The Common Drug Resistant Mechanism And The Strain Relationship Of Mutlti-resistant Pseudomonas Aeruginosa

OBJECTIVE To investigate the correlated resistant genes encodingβ-lactamases,aminoglycoside and genetic marker of integron and transposon in mutlti-resistant pseudomonas aeruginosa(MRPA) isolated from clinical specimens .and study the multi-resistant strain relationship by phylogenetic analysisMETHODS Twelve kinds of genes encodingβ-lactamases modifying enzymes ,one porin endcoding gene,six kinds aminoglycoside modifying enzymes encoding genes,and two 16SrRNA methylase genes,two integron-I genes and one transposon genetic gene were analyzed by PCR and verified by DNA sequencing. mutlti-resistant genes cluster analysis was performed by UPGMA.RESULTS The resistant rates ofβ-lactamases and aminoglycoside including FAM,ZOX,CTX,CRO,TCC,TZP,FEP,CAZ,IMI,MEM,GEN,AKN,TOB in 164 strains of P.aeruginosa were 96.9%,95.1%,93.9%,91.4%,40.2%,33.5%,29.2%,25%,7.92%,4.2%,60.9%,42%,40.8% respectively. the positive rates of CARB,oprD2,aac(3)-Ⅱ,aac(6′)-Ⅱ,ant(2″)-Ⅰ,intⅠ1,qacE△1-sul1,merA in 20 strains of MRPA were 15%,100%,70%,15%,15%,85%,85%,85%,and other genes were negative.it was calssfied to three subgroup by the mutlti-resistant genes cluster analysis:A clone carries the genes of aac(3)-Ⅱ,merA,intⅠ1,qacE△1-sul1 and shows the deficiency of oprD2.B clone shows the deficiency of oprD2,C clone carries the genes of CARB,aac(6')-Ⅱ,an(t2")-Ⅰ,merA,intⅠ1,qacE△1-sul1 and shows the deficiency of oprD2.CONCLUSIONS MRPA isolated from clinical specimens has carried many resistant genes. the deficiency rate of oprD gene is very high .the positive rate of genetic mark genes about integron and transposon is very high.it may be the main mutlti-resistant mechanism of MRPA,. mutlti-resistant genes cluster analysis shows that there is clone transmition in MRPA.and can induce nosocomial infection prevalence.