Molecular characteristics of extended-spectrum β-lactamases in clinical isolates of Enterobacteriaceae from the Philippines.

β-Lactamases, including extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases, are major resistance mechanisms of Enterobacteriaceae. Emergence of plasmid-mediated quinolone resistance (PMQR) determinants in ESBL-producing isolates poses a global threat. The molecular characterisitcs of ESBL and PMQR determinants in the Philippines are not well characterized.