title: Searching for new strategies against biofilm infections: Colistin-AMP combinations against Pseudomonas aeruginosa and Staphylococcus aureus single- and double-species biofilms.
abstract: Antimicrobial research is being pressured to look for more effective therapeutics for the ever-growing antibiotic-resistant infections, and antimicrobial peptides (AMP) and antimicrobial combinations are promising solutions. This work evaluates colistin-AMP combinations against two major pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, encompassing non- and resistant strains. Colistin (CST) combined with the AMP temporin A (TEMP-A), citropin 1.1 (CIT-1.1) and tachyplesin I linear analogue (TP-I-L) was tested against planktonic, single- and double-species biofilm cultures. Overall synergy for planktonic P. aeruginosa and synergy/additiveness for planktonic S. aureus were observed. Biofilm growth prevention was achieved with synergy and additiveness. Pre-established 24 h-old biofilms were harder to eradicate, especially for S. aureus and double-species biofilms; still, some synergy and addictiveness was observed for higher concentrations, including for the biofilms of resistant strains. Different treatment times and growth media did not greatly influence AMP activity. CST revealed low toxicity compared with the other AMP but its combinations were toxic for high concentrations. Overall, combinations reduced effective AMP concentrations, mainly in prevention scenarios. Improvement of effectiveness and toxicity of therapeutic strategies will be further investigated.
authors.affiliation: CEB - Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal.
authors.forename: Paula
authors.identifier: http://orcid.org/0000-0002-0094-7830
authors.initials: P
authors.lastname: Jorge
authors.affiliation: Lipopharm.pl, Zblewo, Poland.
authors.forename: Daria
authors.initials: D
authors.lastname: Grzywacz
authors.affiliation: Lipopharm.pl, Zblewo, Poland.|Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Kamysz
authors.affiliation: ESEI - Escuela Superior de Ingeniería Informática, Universidad de Vigo, Ourense, Spain.|CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal.
authors.forename: Anália
authors.initials: A
authors.lastname: Lourenço
authors.affiliation: CEB - Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal.
authors.forename: Maria Olívia
authors.initials: MO
authors.lastname: Pereira
mesh_terms: D016475:3T3 Cells; D000465:Algorithms; D029845:Amphibian Proteins / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002470:Cell Survival / Q000187:drug effects; D003091:Colistin / Q000494:pharmacology*; D004268:DNA-Binding Proteins / Q000494:pharmacology; D004357:Drug Synergism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D008856:Microscopy, Fluorescence; D010456:Peptides, Cyclic / Q000494:pharmacology; D010933:Plankton / Q000382:microbiology; D011506:Proteins / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology
chemical_list: D029845:Amphibian Proteins; D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D004268:DNA-Binding Proteins; D010456:Peptides, Cyclic; D011506:Proteins; C121829:citropin 1.1 protein, Litoria; C104501:temporin; C057636:tachyplesin peptide, Tachypleus tridentatus; D003091:Colistin