title: Killing effect of nanoencapsulated colistin sulfate on Pseudomonas aeruginosa from cystic fibrosis patients.
abstract: Pseudomonas aeruginosa frequently infects the respiratory tract of cystic fibrosis (CF) patients. Multidrug-resistant phenotypes and high capacity to form stable biofilms are common. Recent studies have described the emergence of colistin-resistant isolates in CF patients treated with long-term inhaled colistin. The use of nanoparticles containing antimicrobials can contribute to overcome drug resistance mechanisms. The aim of this study was to explore antimicrobial activity of nanoencapsulated colistin (SLN-NLC) versus free colistin against P. aeruginosa clinical isolates from CF patients and to investigate their efficacy in biofilm eradication. Susceptibility of planktonic bacteria to antimicrobials was examined by using the broth microdilution method and growth curve assay. Minimal biofilm eradication concentration (MBEC) and biofilm prevention concentration (BPC) were determined to assess antimicrobial susceptibility of sessile bacteria. We used atomic force microscopy (AFM) to visualize treated and untreated biofilms and to determine surface roughness and other relevant parameters. Colistin nanoparticles had the same antimicrobial activity as free drug against planktonic bacteria. However, nanoencapsulated colistin was much more efficient in the eradication of biofilms than free colistin. Thus, these formulations have to be considered as a good alternative therapeutic option to treat P. aeruginosa infections.
authors.affiliation: Dept. Pathology and Experimental Therapeutics, Medical School, University of Barcelona, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Sans-Serramitjana
authors.affiliation: Dept. Pathology and Experimental Therapeutics, Medical School, University of Barcelona, Barcelona, Spain; Dept. Public Health, Mental Health and Perinatal Nursing, US of Nursing, University of Barcelona, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Fusté
authors.affiliation: Dept. Pathology and Experimental Therapeutics, Medical School, University of Barcelona, Barcelona, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Martínez-Garriga
authors.affiliation: Dept. Pathology and Experimental Therapeutics, Medical School, University of Barcelona, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Merlos
authors.affiliation: Laboratory of Pharmaceutics, University of the Basque Country (UPV/EHU) and CIBER-BBN, Vitoria-Gasteiz, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Pastor
authors.affiliation: Laboratory of Pharmaceutics, University of the Basque Country (UPV/EHU) and CIBER-BBN, Vitoria-Gasteiz, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Pedraz
authors.affiliation: Laboratory of Pharmaceutics, University of the Basque Country (UPV/EHU) and CIBER-BBN, Vitoria-Gasteiz, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Esquisabel
authors.affiliation: Fundación Investigaciones Sanitarias Islas Baleares (FISIB), Development and Regeneration Program (CSIC), Bunyola, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Bachiller
authors.affiliation: Dept. Pathology and Experimental Therapeutics, Medical School, University of Barcelona, Barcelona, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Vinuesa
authors.affiliation: Dept. Pathology and Experimental Therapeutics, Medical School, University of Barcelona, Barcelona, Spain; CESPU, INNFACTS, Gandra, Portugal. Electronic address: mvinyas@ub.edu.
authors.forename: M
authors.initials: M
authors.lastname: Viñas
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D018441:Biofilms / Q000187:drug effects*; D002648:Child; D003091:Colistin / Q000008:administration & dosage / Q000493:pharmacokinetics; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology / Q000628:therapy; D016503:Drug Delivery Systems / Q000379:methods; D016903:Drug Monitoring / Q000379:methods; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053758:Nanoparticles / Q000008:administration & dosage; D017063:Outcome Assessment, Health Care; D011552:Pseudomonas Infections / Q000175:diagnosis / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology; D012137:Respiratory System / Q000382:microbiology; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology; D013030:Spain / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D003091:Colistin
keywords: Antimicrobial effect; Colistin sulfate; Cystic fibrosis; Lipid nanoparticles; Pseudomonas aeruginosa