Objective: To analyze the resistance and beta-lactamases of 93 strains of Pseudomonas aeruginosa.
Methods: Antimicrobial activity to 93 strains of Pseudomonas aeruginosa were determined by K-B test, and the beta-lactamases produced by these strains were characterized by isoelectric focusing, three-dimensional test, 2-mercaptopropanoic acid inhibited assays, and polymerase chain reaction (PCR).
Results: The resistance of amikacin, cefepime, cefoperazone/sulbactam, ceftazidime, meropenem were 82.8%, 81.7%, 81.7%, 80.6%, 77.4%, respectively. The susceptibility of rate imipenem was 71.0%. Three-dimensional test showed that 14 strains produced carbapenemases, only and 2 strain produced metallo-beta-lactamase, which was in agreement with the result of 2-mercaptopropanoic acid inhibited assays, 13 strains produced AmpC enzymes, and 2 strains produced AmpC enzymes and ESBLs. The 15 strains and other two (Number 19, 54) had 1 band on IEF electrophoresis, and the isoelectric points were 9.0 and 6.3 respectively. The 2 metallo-beta-lactamases were revealed by amplified PCR products with VIM-2 specific PCR, the production was sequenced and revealed that the found to match with the known sequences of VIM-2.
Conclusion: The production of carbapenemases and AmpC enzymes was the main cause for multi-drug resistance in Pseudomonas aeruginosa in our hospital.