Phenotypic detection of metallo-β-lactamase in imipenem resistant Pseudomonas aeruginosa in al-Sadr Hospital. Iraq

Abstract EN

From October 2013 to the end of March 2014, 26 isolates of Pseudomonas aeruginosa were isolated from patients visited Al-Sadr Medical City Hospital suffering from various infections.

These isolates were tested using disk diffusion test for susceptibility of imipenem, where five isolates were resistant to this agent, 3 were moderate, while 18 isolates were susceptible.

The resistant isolates were submitted to Minimum Inhibitory Concentration (MIC) assay using E-test strips (Dilution and Diffusion method).

The MIC values varied from 1-12 µg/ml.

Phenotypic detection for Metallo–β–Lacamases enzymes in resistant isolates was done using two tests, the Double Disk Synergy Test (DDST), and Combined Disk Test (CDT).

The results showed that three isolates were positive to MBL production by (DDST)at (10) mm, and two at (15)mm , only one isolate was positive by the CDTs giving diameter difference (16) mm.