[Clinical isolates of Pseudomonas aeruginosa producers of extended spectrum beta-lactamases at a private institution in Cordoba]. / Aislados clínicos de Pseudomonas aeruginosa productores de beta-lactamasa de espectro extendido en un centro privado de Córdoba.

Extended spectrum beta-lactamases (ESBL) are capable of inhibiting the action of extended spectrum cephalosporins and monobactams. The objective of this work is to describe six isolates of ESBL producing Pseudomonas aeruginosa, retrieved from intensive care patients. The susceptibility test was performed by diffusion. For the phenotypic detection of ESBL, the following was assessed: the difference between ceftazidime ceftazidime/clavulanic acid (CAZ-CAC) and the synergy between imipenem-ceftazidime (IMI-CAZ) and cefepime-ceftazidime/clavulanic acid -ceftazidime (FEP-CAC-CAZ). The presence of metallo-beta-lactamases (MBL) was discarded through the double disc imipenem-EDTA/mercaptoacetic-meropenem (IMI-EDTA/SMA-MER) method. Molecular characterization of ESBL was performed by polymerase chain reaction (PCR) with blaGES primers. Synergy IMI-CAZ was observed in the studied strains; ESBL type GES was confirmed in five of them. The strategic location of the discs and the evaluation of alert signals for the detection of ESBL is essential, thus contributing to the correct recommendation of treatment in the clinical report.

Aislados clínicos de Pseudomonas aeruginosa productores de ß-lactamasa de espectro extendido en un centro privado de Córdoba / Clinical isolates of Pseudomonas aeruginosa producers of extended spectrum ß-lactamases at a prívate institution in Córdoba

Extended spectrum p-lactamases (ESBL) are capable of inhibiting the action of extended spectrum cephalosporins and monobactams. The objective of this work is to describe six isolates of ESBL producing Pseudomonas aeruginosa, retrieved from intensive care patients. The susceptibility test was performed by diffusion. For the phenotypic detection of ESBL, the following was assessed: the difference between ceftazidime ceftazidime/clavulanic acid (CAZ-CAC) and the synergy between imipenem-ceftazidime (IMI-CAZ) and cefepime-ceftazidime/clavulanic acid -ceftazidime (FEP-CAC-CAZ). The presence of metallo-ß-lactamases (MBL) was discarded through the double disc imipenem-EDTA/mercaptoacetic-meropenem (IMI-EDTA/SMA-MER) method. Molecular characterization of ESBL was performed by polimerase chain reaction (PCR) with blaGES primers. Synergy IMI-CAZ was observed in the studied strains; ESBL type GES was confirmed in five of them. The strategic location of the discs and the evaluation of alert signáis for the detection of ESBL is essential, thus contributing to the correct recommendation of treatment in the clinical report.

Las (β-lactamasas de espectro extendido (BLEE) son capaces de inactivar cefalosporinas de espectro extendido y monobactámicos. El objetivo de este trabajo es describir seis aislados de Pseudomonas aeruginosa productores de BLEE recuperados de pacientes de cuidados intensivos. Las pruebas de sensibilidad se realizaron por difusión. Para la detección fenotípica de BLEE se evaluó: diferencia de diámetro entre los halos de ceftazidima-ceftazidima/ clavulánico (CAZ-CAC) y sinergia entre imipenem-cef-tazidima (IMI-CAZ)y cefepima-ceftazidima/clavulánico-ceftazidima (FEP-CAC-CAZ). Se descartó la presencia de metalo-β-lactamasas (MBL) por el método de doble disco imipenem-EDTA/mercaptoacético-meropenem (IMI-EDTA/SMA-MER). La caracterización molecular de BLEE se realizó por reacción de polimerasa en cadena con cebadores 6/aGES. En las cepas estudiadas se observó sinergia IMI-CAZ; en cinco de ellas se confirmó BLEE tipo GES. Es imprescindible la ubicación estratégica de los discos y la evaluación de señales de alarma para la detección de BLEE, contribuyendo así a la correcta recomendación del tratamiento en el informe clínico.