Study reveals key role of AcrAB and OqxAB efflux pumps in ciprofloxacin resistance of Klebsiella pneumoniae

A groundbreaking study published in Current Molecular Pharmacology has uncovered the pivotal role of AcrAB and OqxAB efflux pumps in driving ciprofloxacin resistance in Klebsiella pneumoniae, a leading cause of hospital-acquired infections. Researchers from Çukurova University analyzed 50 clinical isolates, revealing alarming resistance rates—100% to cefotaxime and 92% to ciprofloxacin.

"These findings underscore the urgent need to target efflux pumps to combat antibiotic resistance," said lead author Dr. Manaf AlMatar. The team observed 4- to 64-fold reductions in ciprofloxacin MICs when efflux pump inhibitor CCCP was applied, confirming pump involvement. RT-PCR data showed acrA/B and oqxA/B were overexpressed up to 139-fold and 190-fold, respectively, in resistant strains.

Regulator genes marA, soxS, and rarA also showed elevated expression, suggesting complex control mechanisms. "This paints a worrying picture of how K. pneumoniae evades antibiotics," noted co-author Dr. Fatih Köksal. The study calls for efflux pump inhibitors as adjunct therapies and highlights Turkey's high MDR rates, urging global surveillance.