Incidência de Klebsiella pneumoniae e Escherichia coli produtoras de betalactamase de espectro estendido (ESBL) em um hospital universitário

Abstract

Estended-spectrum beta-lactamases (ESBL) are bacterial enzymes that hydrolyses beta-lactam antibiotics with broad spectrum of action. Currently, ESBL-producing strains are important agents of nosocomial infection which may limit the available options available, necessitating the deployment of appropriate techniques for its detection. The ESBL is codified in plasmids that can be transferred to other microorganisms by conjugation. The indiscriminate use of broad-spectrum cephalosporins contributes to the selection of ESBL-producing strains and makes the problem of universal interest. This work carried out two techniques for detection of ESBL, the technique of Double Disks Diffusion and the technique of Clavulanate Disk Addition. Strains of Klebsiella sp (n=38) and Escherichia coli (n=114) routinely isolated from patients admitted in the university hospital from January 2004 to December 2005 were included in the study. Of those, 19 (50%) of samples of Klebsiella sp and 55 (48.3%) samples of E. coli were ESBL-producing. The technique the clavulanate disk addition showed greater sensitivity (100%) showing higher skill in the detection of ESBL, whereas the technique of Double Disk Diffusion had a sensitivity of 24.3%. Cefotaxima was the substrate that showed greater sensitivity in detecting ESBL. Both techniques showed high specificity (100%).

Keywords

• ESBL
• Klebsiella
• Escherichia coli
• beta-lactamases