الفهرس 
general aspect of P.aergunosaOnly 14 pages are availabe for public view
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Abstract
Metallo-β-lactamases (MBLs) have been increasingly recognized
from Pseudomonas aeruginosa isolates worldwide, but the laboratory detection of
these strains is not well defined.
Methods: We used an EDTA disk screen test and a molecular diagnostic assay for
the detection of MBL-producing Pseudomonas aeruginosa from Kasr Al ainy
hospital isolated from April 2012 to March2013. Using CLSI disk methodology,
inhibition zone diameters were determined in tests with imipenem (IPM) and
meropenam (MEM) disks alone and in combination with 750 μg of EDTA. This
test was compared with the MBL Etest. Detection for MBL production genes
(blaIMP & blaVIM ) was done using PCR .
Results: Of the fifty clinical strains of IPM-nonsusceptible P. aeruginosa, 32/50
(64.0%) were MBL positive using disc diffusion methods , 26/50 (52.0%) were
positive for MBL by E-test while 17/50(34.0%) were positive for MBL genes:
17/50 (34.0%) for blaVIM and 0/50(0%) for blaIMP. The EDTA disk screen test
using IPM showed 100% sensitivity and 54.5% specificity for detecting MBLs in
clinical strains. While E-test showed 100% sensitivity and 69.7% specifity.
Conclusion: The EDTA disk screen test was simple to perform and to interpret and
can easily be introduced into the workflow of a clinical laboratory. We recommend
that all IPM-nonsusceptible P. aeruginosa isolates be routinely screened for MBL
production using the EDTA disk screen test and that PCR confirmation be
performed.