Bactericidal Activity of a Silver Formulation against Hospital-Acquired Bacterial Strains

Esquén M.C.F.L.; Espinoza M.A.V.; Del Castillo A.S.V.; Vega J.L.R. · Revista Cubana de Medicina Tropical (2026)

Resumen

Introduction: Bacterial resistance to antibiotics is a global problem. In Latin America, extended-spectrum beta-lactamase-producing Enterobacteriaceae are frequently encountered. Silver possesses antimicrobial properties, yet studies regarding its use as an alternative treatment for infections caused by these bacteria are lacking. Objective: To determine the bactericidal activity of an aqueous silver formulation against hospital-acquired strains of Escherichia coli and Klebsiella pneumoniae isolated from a surgery department in Lambayeque during 2023. Methods: A descriptive, experimental, longitudinal study was conducted. Fifteen strains (14 Escherichia coli and 1 Klebsiella pneumoniae, all extended-spectrum beta-lactamase-producing) were obtained from wound secretions of hospitalized patients. A silver solution was synthesized via electrolysis at concentrations ranging from 10 ppm to 0.625 ppm. The Minimum Inhibitory Concentration, Minimum Bactericidal Concentration, and bacterial kill curves (0–24 hours) were determined. ANOVA and the Tukey test were applied (p < 0.05). Results: The Minimum Inhibitory Concentration and Minimum Bactericidal Concentration of the silver solution were 2.5 ppm for both bacteria. The kill curve showed the onset of activity at four hours with 10 ppm (100% bacterial kill). The aqueous silver solution demonstrated a concentration- and time-dependent bactericidal effect against extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae (p < 0.05). Conclusions: The silver nanoparticle solution obtained via electrolysis demonstrated potent bactericidal activity at low doses against extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae. Esta obra está bajo una licencia: https://creativecomons.org/licenses/by-nc/4.0/deed.es_ES

Instituciones: Universidad Nacional Pedro Ruiz Gallo