Detecting the dual presence of AmpC and ESBL enzymes

Abstract

Inducible-chromosomal AmpC cephalosporinase enzymes have been recognised for several years in the ESCAPPM (Enterobacter spp., Serratia spp., Citrobacter freundii, Acinetobacter spp., Proteus vulgaris, Providencia spp. and Morganella morganii) group of gram-negative organisms, which result in the potential resistance to third-generation cephalosporin drugs. More recently several non-ESCAPPM Enterobacteriaceae (particularly E coli, Klebsiella and Proteus mirabilis) have been found to harbour a non-inducible-plasmid form of AmpC. This is particularly important when found in bacteremic patients where third-generation cephalosporins are often the first line drugs of choice.