Genetic support and diversity of acquired extended-spectrum β-lactamases in Gram-negative rods

Infect Genet Evol. 2012 Jul;12(5):883-93. doi: 10.1016/j.meegid.2012.02.008. Epub 2012 Mar 3.


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 either TEM- or SHV-derivatives, CTX-M-like enzymes and less frequently of the GES, PER, or VEB types. The mechanisms at the origin of their acquisition are diverse, and mostly are related to insertion sequences, transposons and class 1 integrons. This diversity of genetic vehicles at the origin of these mobilization/acquisition processes may explain spread of ESBLs worldwide.

Publication types

  • Review

MeSH terms

  • DNA Transposable Elements
  • Gram-Negative Bacteria / enzymology*
  • Gram-Negative Bacteria / genetics*
  • Integrons
  • Phylogeny
  • beta-Lactam Resistance
  • beta-Lactamases / genetics*


  • DNA Transposable Elements
  • beta-Lactamases