Key Findings

The study identified three clonally related CTX-M-15-producing Escherichia coli isolates with varying resistance to aminoglycosides and tetracycline. The isolates exhibited resistance to fluoroquinolones due to mutations in gyrA and parC genes, and resistance to aminoglycosides due to the aac(6')-1b gene. The CTX-M-15 β-lactamase conferred resistance to various β-lactam antibiotics.