Resumen

Introduction: The emergence and rapid spread of bla_IMP and bla_VIM metallo-beta-lactamase (MBL) producing Gram-negative bacteria causing nosocomial infections are of concern worldwide due to limited treatment options. Methodology: A total of 179 nonreplicate, consecutive, carbapenem resistant Pseudomonas aeruginosa (61), Acinetobacter baumannii (116), Acinetobacter lwoffii (1) and Pseudomonas stutzeri (1) isolated from patients hospitalized for 48 hours or more were included in the study. The minimum inhibitory concentrations (MIC) to imipenem and meropenem were determined and interpreted according to Clinical Laboratory Standards Institute guidelines. The Modified Hodge Test (MHT) and inhibitor potentiated disk diffusion tests with ethylenediaminetetraacetic acid (EDTA) were used for screening of carbapenamases and MBL production respectively. Polymerase chain reaction (PCR) was performed for the detection of MBL (bla_VIM and bla_IMP) genes. Gene sequencing was performed for representative isolates. Results: MHT was positive in 94.4% (n = 169). MBL screening with EDTA was positive in 80.4% (n = 144). MBL genes bla_VIM and bla_IMP were detected in 92 (51.4%) isolates. Bla_VIM alone was detected in 89 isolates while two isolates had bla_IMP alone. One isolate had both bla_VIM and bla_IMP. Among the P. aeruginosa, 36 carried the MBL gene. In A. baumannii, 54 carried the MBL gene. Bla_VIM was found in P. stutzeri and A. lwoffii isolates. Conclusion: Carbapenem resistance in P. aeruginosa and A. baumannii is chiefly mediated by MBL production. The common MBL gene is the bla_VIM.

Palabras clave: Carbapenems metallo-beta-lactamases polymerase chain reaction.

2013-01-18   |   363 visitas   |   Evalua este artículo 0 valoraciones

Vol. 6 Núm.11. Noviembre 2012 Pags. 575-762 J Infect Developing Countries 2012; 6(11)