OBJECTIVE To study resistant mechanisms in a pan-resistant Pseudomonas putida strain.METHODS To detect the susceptibility of antimicrobial agents by MIC,6 aminoglycoside-modifying enzymes(AMEs) genes of 1 strain of P.putida were measured by PCR,and verified by DNA sequencing and similarity searches of DNA sequencing data banks using BLAST.RESULTS In the strain,there were 4 positive kinds of AMEs resistant genes(aac(6′)-Ⅰb,aac(3)-Ⅱ,ant(3″)-Ⅰand ant(2″)-Ⅰ).Sequence analysis revealed that the 4 PCR products were AMEs,the aac(6′)-Ⅰb was a new type(GenBank EU 137667).CONCLUSIONS The mechanisms of resistance to aminoglycosides of the pan-resistant P.putida are mainly related to 4 kinds of AMEs,the aac(6′)-Ⅰb is a new type.

OBJECTIVE To study 6 kinds of aminoglycoside-modifying enzymes (AMEs) genes in Chryseobacterium spp isolates. METHODS The isolates were identified by API20NE Gram-negative identification cards,and the susceptibility of antimicrobial agents was detected by MIC kits ( bioM?rieux ) 6 AMEs genes of 2 strains of Chryseobacterium spp were measured by PCR,and verified by DNA sequencing and sequence analysis. RESULTS In the 2 strains,2 kinds of resistant genes [aac(6′)-Ⅱ and ant(2″)-Ⅰ] were positive,and 4 kinds genes of AMEs [aac (6′)-Ⅰb,aac(3)-Ⅱ,ant(3″)-Ⅰ and aac(3)-Ⅰ] were negative.The amplicons were purified,sequenced and analyzed with BLAST 2.0 and found to be identical to aac(6′)-Ⅱ and ant(2″)-Ⅰ. CONCLUSIONS There are AMEs in Chryseobacterium spp isolates. This is the first report on AMEs genes [coexistance of aac(6′)-Ⅱ and ant(2″)-Ⅰ] in Chryseobacterium spp.

OBJECTIVE To study 40 kinds of resistant-related genes in a pan-resistant Pseudomonas aeruginosa.METHODS To detect the susceptibility of antimicrobial agents by MIC,40 resistant-related genes including 29 ?-lactamases genes,porin oprD2 genes,6 aminoglycoside-modifying enzymes(AMEs)genes,chlorhexidine/sulfadiazine resistant gene(qacE△1-sul1)and intergron(intⅠ1,2,3),etc,form 1 strain of P.aeruginosa were measured by PCR,and verified by DNA sequencing.RESULTS In the strain,there were positive of 6 kinds of resistant-related genes(blaTEM,blaOXA10,aac(6′)-Ⅱ,aac(3)-Ⅱ,qacE△1-sul1 and intⅠ1),but without oprD2 genes.Twenty-seven kinds of ?-lactamases genes,4 kinds of AMEs(aac(6′)-Ⅰb,aac(3)-Ⅰ,ant(3″)-Ⅰ and ant(2″)-Ⅰ),and 2 kinds of intⅠ(intⅠ2 and intⅠ3) were negative.CONCLUSIONS The multi-resistant mechanisms of pan-resistant P.aeruginosa are mainly related to 7 kinds of resistant-related genes(blaTEM,blaOXA10,oprD2,aac(6′)-Ⅱ,aac(3)-Ⅱ,qacE△1-sul1 and intⅠ1).