The control of ESBL-producing bacteria

Abstract

Infections caused by Extended Spectrum Beta Lactamase (ESBL) producing Gram-negative bacteria have emerged over the last twenty years as a major worldwide problem for treatment. Initially the ESBL enzymes of the TEM and SHV type were identified, these did not reach high rates and were most common in Klebsiella spp rather than E.coli. ESBLs of the CTX-M type have become the most common and widespread type particularly in community strains of E.coli. Faecal colonisation in both infected patients and asymptomatic carriers is the most important source so successful infection control measures are directed at reducing spread from that source. Antibiotic restriction has been demonstrated to control the rate of ESBLs, reduction in third generation cephalosporins and quinolones having the greatest impact when combined with source control/hand washing as infection control interventions. Substitution of these selective agents by piperacillin/tazobactam and carbapenems results in ESBL reduction particularly if combined with use of a diversity of other narrow spectrum agents. There are widely differing rates of ESBLs around the world which broadly correlates with the overall hospital/community prescription, agricultural and over the counter usage of quinolones and cephalosporins. Application of antibiotic stewardship is an important control measure when supported by control of the sources and routes of spread of ESBL-producing Enterobacteriaceae.