Klebsiella pneumoniae Resistance to Ceftriaxone

Mechanisms of Resistance

K. pneumoniae can acquire resistance to cephalosporins and aztreonam through production of extended-spectrum β-lactamases (ESBLs) 1
Plasmids encoding ESBLs often carry resistance to multiple antibiotics, making K. pneumoniae frequently multidrug-resistant 1
Production of extended-spectrum β-lactamases (ESBLs) that hydrolyze the β-lactam ring is a mechanism of resistance to ceftriaxone and other cephalosporins 1
Plasmid-mediated AmpC-type enzymes that confer resistance to cephalosporins are another mechanism of resistance 1

While some ESBL-producing strains remain susceptible to carbapenems, resistance to carbapenems is increasing due to production of carbapenemases 1, 2
For suspected or confirmed ESBL-producing K. pneumoniae, carbapenems remain the treatment of choice for susceptible strains 3
For carbapenem-resistant strains, newer β-lactam/β-lactamase inhibitor combinations such as ceftazidime/avibactam or meropenem/vaborbactam are recommended as first-line options 3
Local antibiotic resistance patterns should guide empiric therapy choices 3
Resistance rates vary geographically, so local antibiogram data should be consulted 1
Even if in vitro testing shows susceptibility to ceftriaxone, clinical failure may occur due to inducible resistance mechanisms 1