Find in Library

<div><table cellspacing="0" cellpadding="0" align="left"><tbody><tr><td align="left" valign="top"><p><strong><em>Background</em></strong><strong>:   </strong>Imipenem-resistant gram negative bacteria, resulting from metallo-beta-lactamase (MBLs)-producing strains have been reported to be among the important causes of nosocomial infections and of serious therapeutic problem worldwide. Because of their broad range, potent carbapenemase activity and resistance to inhibitors, these enzymes can confer resistance to almost all beta-lactams. The prevalence of metallo-beta-lactamase among imipenem-resistant <em>Acinetobacter </em>spp., <em>Pseudomonas </em>spp. and <em>Enerobacteriaceae</em> isolates is determined.</p><p><strong><em>Methods</em></strong><strong>:   </strong>In this descriptive study 864 clinical isolates of <em>Acinetobacter </em>spp., <em>Pseudomonas </em>spp. and <em>Enterobacteriaceae</em>, were initially tested for imipenem susceptibility. The metallo-beta-lactamase production was detected using combined disk diffusion, double disk synergy test, and Hodge test. Then all imipenem resistant isolates were tested by PCR for <em>imp</em>, <em>vim</em> and <em>ndm </em>genes. </p><p><strong><em>Results</em></strong><strong>:   </strong>Among 864 isolates, 62 (7.17 %) were imipenem-resistant. Positive phonetypic test for metallo-beta-lactamase was 40 (64.5%), of which 24 (17.1%) and 16 (9.2%) isolates were <em>Acinetobacter </em>spp. and <em>Pseudomonas </em>spp., respectively. By PCR method 30 (48.4%) of imipenem resistant <em>Acinetobacter, </em>and<em> Pseudomonas</em> isolates were positive for MBL-producing genes. None of the <em>Enterobacteriaceae</em> isolates were positive for metallo-beta-lactamase activity. </p><p><strong><em>Conclusion</em></strong><strong>:   </strong>The results of this study are indicative of the growing number of nosocomial infections associated with multidrug-resistant gram negative bacteria in this region leading to difficulties in antibiotic therapy. Thereby, using of phenotypic methods can be helpful for management of this problem.</p></td></tr></tbody></table></div>