Study on the Mechanism of Quinolone Resistance in Pseudomonas Aeruginosa / 现代检验医学杂志

ABSTRACT

Objective 30 Pseudomonasaeruginosa mechanism of resistance to quinolones.Methods For the determination of ciprofloxacin MIC by agar dilution method.Used PCR on DNA gyrase and topoisomerase Ⅳ,resistance genes gyrA,gyrB, parC and parE were amplified,and BLAST,to determine whether there was resistance to bits mutation point;using pulsed-field gel electrophoresis (PFGE)of these 30 strains homology analysis.Results The 28 bacterial strains gyrA gene ampli-fied fragment of 137 points were C→T mutation causes T83I;17 strains gyrB gene amplified fragment of 351 G→C lead to G466A;parC gene amplification 21 bacteria fragment 277 point increase with C→U mutation causes S87L change two differ-ent strains parE gene locus C→U mutation A425V and A473V cause change.PFGE results:30 Pseudomonas aeruginosa could be divided into six clones,Aclone 4,B clone 7,C clone 3,D clone 14,and two other single clones.Conclusion The tar-get mutant strains closely related to the epidemic clone type,the same changes in the same pop-type strains of drug targets, and proportional to the level of ciprofloxacin MICs value,the more the number of mutated genes,MICs value higher.GyrA gene most prone to mutation,the mutation was also the first to be discovered,more than any other target of the mutation mutations on binding of drugs and targets that would be the focus of concern.