Gram negative organisms with enzymes that confer resistance to 3rd generation cephalosporins in addition to lower order beta-lactams.
Generally, normal GI flora that have a plasmid encoding ESBL.
Community-acquired and nosocomial infections occur, especially if patient has received antimicrobials or has travelled to areas of high prevalence (i.e. Asia/India).
Human-to-human transmission occurs and outbreaks have been described.
Can also pick up from environment/water, surfaces, animals, and meat.
Any syndrome caused by the organism carrying it (see specific organism for more information)
ESBLs vs. AmpC: Most ESBLs are plasmid-encoded, whereas AmpCs are usually inducible and chromosomal.
In the lab, ESBLs test susceptible to cefoxitin and cefotetan, and are inhibited by beta-lactamse inhibitors such as tazobactam. They test resistant to aztreonam.