Genetic support of extended-spectrum β-lactamases

Abstract

Genes encoding extended-spectrum β-lactamases (ESBLs) have been reported in a variety of Gram-negative species, mostly in Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii. They are mostly either TEM or SHV derivatives, CTX-M-like enzymes - now emerging worldwide - or, less frequently, VEB, GES, and PER ESBLs. The mechanisms responsible for their acquisition are very diverse, and mostly are related to insertion sequences (ISs), transposons, class1 integrons, and also sul1-type integrons containing the IS CR1 element. This diversity of genetic vehicles at the origin of these mobilisation/ acquisition processes enhances the spread of ESBLs. © 2008 The Authors Journal Compilation © 2008 European Society of Clinical Microbiology and Infectious Diseases.