Activity of human β-defensins 2 and 3 against ESBL-producing Klebsiella strains

Open Access
Publisher Website
Google Scholar
Abstract
Objectives: To test the bactericidal activity of human β-defensins (hBDs) 2 and 3 against extended-spectrum β-lactamase (ESBL)-producing Klebsiella strains. Methods: Thirty-six Klebsiella pneumoniae and seventeen Klebsiella oxytoca ESBL-producing isolates from nosocomial infections were tested. The bactericidal activity of recombinantly synthesized hBD-2 and -3 was tested and the results were given either as lethal doses killing ≥90% of bacteria (LD90s) or as MBCs (≥99.9% killing). Results: Except for one intermediately susceptible strain (MBC = 25 mg/L), all other ESBL-producing strains were highly susceptible to both defensins (LD90s and MBCs ≤ 12.5mg/L). Conclusions: The results underline the high efficacy of hBD-2 and -3 against ESBL-producing Klebsiella, making both defensins attractive candidates as antimicrobial agents to combat these increasingly troublesome bacteria.