What is a common characteristic of AmpC beta-lactamases?

AmpC beta-lactamases are enzymes produced by certain bacteria that confer resistance to a range of antibiotics, specifically cephalosporins. This resistance occurs because AmpC beta-lactamases can hydrolyze the beta-lactam ring present in cephalosporins, rendering these antibiotics ineffective. A key feature of AmpC producers is their ability to resist standard treatment with these classes of antibiotics, complicating infection management.

In contrast, other options are not characteristic of AmpC beta-lactamases. For instance, they are not limited to Gram-positive bacteria; in fact, they are primarily found in Gram-negative bacteria, such as Enterobacter, Citrobacter, and some strains of E. coli. Additionally, AmpC beta-lactamases do not increase susceptibility to penicillins; rather, they often allow for resistance and can particularly impact the effectiveness of cephalosporins. Lastly, these enzymes are not easily inhibited by beta-lactam antibiotics, making treatment choices challenging when dealing with infections caused by AmpC-producing organisms.