Detection and analysis of genotypes of pseudanosa aerguinosa producing metallo-β-lactamase in clinical isolates

Objective: To study genetypes of metallo-β-lactamase in pseudomonas aeruginosa and analyze the transfer mechanism of resistance genes. Methods: Metallo-β-lactamase positive strains were screened from imipenem-resistant or ceftazidime-resistant pseudomonas aeruginosa isolates by E test strips of imipenem with and without EDTA. PCR was used to amplify the resistant genes of imp、 vim、 spm and gim. Resistance genes transmitted by plasmids was determined by conjugation. Results: 21 strains of Pseudomonas aeruginosa were shown to produce metallo-β-lactamase by E test, and they were used as templates to amplify imp, vim, spm and gim genes. Among them,specific bands of imp,vim and spm were from 11, 3 and 4 strains. However, 3 strains with positive E test results showed negative ampification by all primer pairs. Conclusion: The major MBL genetype of Pseudomonas aeruginosa in 301 hospital and Xinjiang areas are IMP.