The laboratory diagnosis of Pseudomonas aeruginosa that produce metallo-β-lactamases in a Dutch tertiary care centre
The laboratory diagnosis of Pseudomonas aeruginosa that produce metallo-β-lactamases in a Dutch tertiary care centre
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DOI：
10.3109/00365548.2011.574148
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发表时间：
2011-08-01
影响因子：
--
通讯作者：
Pitout, Johann D. D.
中科院分区：
文献类型：
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作者：
van Der Bij, Akke K.;Mol, Marco;Pitout, Johann D. D.
Background: The laboratory detection of Pseudomonas aeruginosa that produce metallo-beta-lactamases (MBLs) is not well defined in regions with a low prevalence of these enzymes. We report a study that developed ethylenediaminetetraacetic acid (EDTA) disk screen tests using doripenem, imipenem and meropenem and investigated the prevalence of these enzymes among clinical isolates of imipenem-resistant P. aeruginosa in Rotterdam during 2008-2009. Methods: Using strains with well-characterized beta-lactamases and the Clinical and Laboratory Standards Institute (CLSI) disk methodology similar to extended-spectrum beta-lactamase (ESBL) detection, inhibition zone diameters were determined in tests with doripenem, imipenem, and meropenem, alone and in combination with 370 mu g of EDTA. These tests were compared with the MBL E-test. A positive test was a >= 5 mm increase in zone diameter in the presence of EDTA. Results: The imipenem EDTA disk screen test showed a sensitivity of 100% and a specificity of 90% in 96 recent clinical isolates. Imipenem in combination with doripenem performed better than imipenem alone, meropenem, and the MBL E-test (sensitivity of 100%; specificity of 95%). The majority of clinical isolates were isolated from patient respiratory specimens. Of the 96 imipenem-resistant P. aeruginosa isolated, 35 (36%) were positive for bla(VIM) genes. Conclusions: The EDTA imipenem/doripenem disk test showed accurate and reproducible results with excellent sensitivity and specificity. It is simple to perform and interpret and can be easily introduced into the workflow of a clinical laboratory to screen for MBLs in imipenem-resistant P. aeruginosa. Due to its high specificity the test is also suitable for regions with a low prevalence of these enzymes.
