Enterobacteriaceae with extended spectrum betalactamases: Their importance as nosocomial pathogen agents [Enterobacterias con betalactamasas de espectro extendido: Su importancia como patogenos nosocomiales]

This article reviews the emergence evolution, epidemiology, laboratory detection and options for therapy and control of bacteria capable of producing extended spectrum betalactamases (ESBL). ESBL producing bacteria is now commonly found in nosocomial isolates like Klebsiella pneumoniae. ESBL mediated resistance first appeared in Europe in 1983, soon after oxymino- cephalosporins were introduced, and then spread to the America in 1988. ESBL bacteria are acquired by hospitalized patients that have risk factors that include duration of stay, invasive procedures and previous antibiotic exposure. Nosocomial infections caused by ESBL producing bacteria increase the morbidity, mortality and costs of the hospitalized patients. The therapeutic options are limited and complicated by the production of other mechanisms of resistance to the antibiotics of choice for the treatment of nosocomialisolates resistant to third-generation cephalosporins