title: Polymicrobial biofilms by diabetic foot clinical isolates.
abstract: Diabetes mellitus is a major chronic disease that continues to increase significantly. One of the most important and costly complications of diabetes is foot ulceration that may be colonized by pathogenic and antimicrobial resistant bacteria, which may express several virulence factors that could impair treatment success. These bacterial communities can be organized in polymicrobial biofilms, which may be responsible for diabetic foot ulcer (DFU) chronicity. We evaluated the influence of polymicrobial communities in the ability of DFU isolates to produce biofilm, using a microtiter plate assay and a multiplex fluorescent in situ hybridization, at three time points (24, 48, 72 h), after evaluating biofilm formation by 95 DFU isolates belonging to several bacterial genera (Staphylococcus, Corynebacterium, Enterococcus, Pseudomonas and Acinetobacter). All isolates were biofilm-positive at 24 h, and the amount of biofilm produced increased with incubation time. Pseudomonas presented the higher biofilm production, followed by Corynebacterium, Acinetobacter, Staphylococcus and Enterococcus. Significant differences were found in biofilm formation between the three time points. Polymicrobial communities produced higher biofilm values than individual species. Pseudomonas + Enterococcus, Acinetobacter + Staphylococcus and Corynebacterium + Staphylococcus produced higher biofilm than the ones formed by E. faecalis + Staphylococcus and E. faecalis + Corynebacterium. Synergy between bacteria present in dual or multispecies biofilms has been described, and this work represents the first report on time course of biofilm formation by polymicrobial communities from DFUs including several species. The biological behavior of different bacterial species in polymicrobial biofilms has important clinical implications for the successful treatment of these infections.
authors.affiliation: Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Mottola
authors.affiliation: Departamento de Medicina Interna, Hospital de Santa Marta/Centro Hospitalar de Lisboa Central, EPE, Lisboa, Portugal.
authors.forename: João J
authors.initials: JJ
authors.lastname: Mendes
authors.affiliation: Faculdade de Medicina, Universidade de Lisboa, Instituto de Microbiologia, Lisboa, Portugal.
authors.forename: José Melo
authors.initials: JM
authors.lastname: Cristino
authors.affiliation: TechnoPhage, S.A, Lisboa, Portugal.|Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Superior de Ciências da Saúde Egas Moniz, Monte de Caparica, Portugal.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Cavaco-Silva
authors.affiliation: Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Tavares
authors.affiliation: Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal. moliveira@fmv.ulisboa.pt.
authors.forename: Manuela
authors.initials: M
authors.lastname: Oliveira
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000302:isolation & purification*; D018441:Biofilms / Q000254:growth & development*; D060085:Coinfection / Q000382:microbiology*; D017719:Diabetic Foot / Q000382:microbiology*; D006801:Humans; D013997:Time Factors