The Resistance To Carbapenpems And Parts Of Mechanisms Of Pseudomonas Aeruginosa

Objective: Pseudomonas aeruginosa (Pa) is a clinical usually conditional pathogen in hospital, having located the first of clinical Gram-negative pathogen. As antibiotic widespread application, the resistance of imipenem in Pseudomonas aeruginosa has become an important problem for the clinician.To analyze the resistance profile of Pseudomonas aeruginosa isolated from our hospital to 12 antimicrobial agents, and to compare the resistance among different division; To investigate metallo-β-lactamases(MBL) inhibitor (EDTA.Na2) to carbapenems in Pseudomonas aeruginosa clinical isolates. To confirm the role of metallo-β- lactamases and OprD2 in the resistance to imipenem and meropenem in clinical strains of Pseudomonas aeruginosa.Methods: The 368 strains were isolated from inpatients of the Fourth Clinical Medical College of Hebei Medical University from 2006.1 to 2007.1. The minimal inhibitory concentrations (MICs) of 12 antimicrobial agents were detected by MicroScan WalkAway 40 according to NCCLS. 94 imipenem resistant strains were determined by the double 2 disk synergy test and MBL E-test against , and observe the number of detected metall -β- lactamase positive strains. The resistance gene was analyzed by PCR. The relative amounts of OprD2 from 94 strains with imipenem resistant were assayed by SDS-PAGE and PCR.Results:1 A total of 368 Pa clinical isolates mainly isolated from ICU (62.50%) and the department of respiration (12.77%); Sputum were the dominant specimens (86.14%). The resistant rate of IMP,P/T,CAZ,were 41.58%,41.03%,46.20% ;2 In 94 strains Pa with imipenem resistant, 15 strains were choused by the double 2 disk synergy test with IMP,MER,CAZ combined with EDTA; 3 strains were choused by MBL E-test; but none were determined by PCR.3 4 strains were determined holo-loss of OprD2 by PCR and SDS-PAGE electrophoresis in 94 strains.Conclusion:1 The resistant rate of IMP was 41.58% in the Fourth Clinical Medical College of Hebei Medical University; 368 Pa clinical isolates mainly isolated from ICU(62.50%) and the department of respiration (12.77%);Sputum were the dominant specimens(86.14%).2 In the Fourth Clinical Medical College of Hebei Medical University the imipenem resistance is mainlv mediated by OprD2 deficiency or loss gene,but no relation to Metallo-β-lactamases.