Metallo-beta-lactamases among imipenem-resistant Pseudomonas aeruginosa in a Brazilian university hospital
Clinics
;
65(9): 825-829, 2010. tab
Artículo
en Inglés
| LILACS
| ID: lil-562822
ABSTRACT
INTRODUCTION:
Imipenem-resistant Pseudomonas aeruginosa resulting from metallo-β-lactamases has been reported to be an important cause of nosocomial infection and is a critical therapeutic problem worldwide, especially in the case of bacteremia.OBJECTIVES:
To determine the frequency of metallo-β-lactamases among imipenem-resistant Pseudomonas aeruginosa isolates and to compare methods of phenotypic and molecular detection.METHODS:
During 2006, 69 imipenem-resistant Pseudomonas aeruginosa samples were isolated from blood and tested for metallo-β-lactamase production using both phenotypic methods. Minimal Inhibitory Concentratrions (MIC) (μg/mL) was determined with commercial microdilution panels. Pulsed Field Gel Electrophoresis (PFGE) was performed among metallo-β-lactamase producers.RESULTS:
Of all the blood isolates, 34.5 percent were found to be imipenem-resistant Pseudomonas aeruginosa. Positive phenotypic tests for metallo-β-lactamases ranged from 28 percent-77 percent, and Polymerase Chain Reaction (PCR) were positive in 30 percent (of note, 81 percent of those samples were blaSPM-1 and 19 percent were blaVIM-2). Ethylenediamine tetracetic acid (EDTA) combinations for the detected enzymes had low kappa values; thus, care should be taken when use it as a phenotypic indicator of MBL. Despite a very resistant antibiogram, four isolates demonstrated the worrisome finding of a colistin MIC in the resistant range. PFGE showed a clonal pattern.CONCLUSION:
Metallo-β-lactamases among imipenem-resistant Pseudomonas aeruginosa were detected in 30.4 percent of imipenem-resistant Pseudomonas aeruginosa isolates. This number might have been higher if other genes were included. SPM-1 was the predominant enzyme found. Phenotypic tests with low kappa values could be misleading when testing for metallo-β-lactamases. Polymerase Chain Reaction detection remains the gold standard.
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Pseudomonas aeruginosa
/
Beta-Lactamasas
/
Imipenem
/
Antibacterianos
Tipo de estudio:
Estudio diagnóstico
/
Estudio pronóstico
Límite:
Humanos
País/Región como asunto:
America del Sur
/
Brasil
Idioma:
Inglés
Revista:
Clinics
Asunto de la revista:
Medicina
Año:
2010
Tipo del documento:
Artículo
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