Introduction: Pseudomonas aerouginosa is an important opportunistic
pathogen which causes clinical infections among ill patients. Metallo- Beta- lactamases
(MBLs) are important mechanisms of carbapenem (drug of choice) resistance
among Pseudomonas aerouginosa isolates. The aim of this study was to determine
B- lactamases genes (bla-genes) in P. aerouginosa isolates and to detect percentage
of MBLs among P. aerouginosa isolates in different wards.
Material and Methods: Clinical isolates of P. aerouginosa in patients hospitalized at
Children's Medical Center were collected in two years using a sterile swab. For differentiation
and identification of strains the BHI media, Sytrymaid agar and Oxidase
test were used and Kirby Baure method antibiotic susceptibility and PCR assay were
performed for detection of bla-genes.
Results: Based on the study results from a total of 269 isolates of P. aerouginosa, 39
isolates were found to be imipenem resistant. From these isolates, 19 strains of P.
aerouginosa isolates were determined to be MBL producers by phenotypic method.
All of the Imipenem resistant P. aerouginosa isolates were examined by PCR for the
presence of the bla-genes. All MBL- producing isolates carried bla-IMP Genes. And
the results of the antibiogram showed the greatest resistance to the Nitrofurantoin,
Nalidixic acid and Cotrimoxazole and Cefixime (100%) and resistance to other antibiotics
was also significant.
Conclusion: Considering the prevalence and clinical importance of MBL producing
isolates, rapid identification of them and use of the appropriate infection control
measures are necessary to prevent further spread of them by these organisms and to
help treatment of Infections.