title: Biofilm formation of Brazilian meticillin-resistantStaphylococcus aureusstrains: prevalence of biofilm determinants and clonal profiles.
abstract: Biofilms plays an important role in medical-device-related infections. This study aimed to determine the factors that influence adherence and biofilm production, as well as the relationship between strong biofilm production and genetic determinants in clinical isolates of meticillin-resistantStaphylococcus aureus(MRSA). Fifteen strains carrying different chromosomal cassettes recovered from hospitalized patients were selected; five SCCmecII, five SCCmecIII and five SCCmecIV. The SCCmectype,agrgroup and the presence of the virulence genes (bbp, clfA, icaA, icaD, fnbB, bap, sasCand IS256) were assessed by PCR. PFGE and multilocus sequence typing (MLST) techniques were also performed. The initial adhesion and biofilm formation were examined by quantitative assays. The surface tension and hydrophobicity of the strains were measured by the contact angle technique to evaluate the association between these parameters and adhesion ability. SCCmecIII and IV strains were less hydrophilic, with a high value for the electron acceptor parameter and higher adhesion in comparison with SCCmecII strains. Only SCCmecIII strains could be characterized as strong biofilm producers. The PFGE showed five major pulsotypes (A-E); however, biofilm production was related to the dissemination of one specific PFGE clone (C) belonging to MLST ST239 (Brazilian epidemic clonal complex). The genesagrI,fnbBand IS256in SCCmecIII strains were considered as genetic determinants associated with strong biofilm-formation by anica-independent biofilm pathway. This study contributes to the understanding of biofilm production as an aggravating factor potentially involved in the persistence and severity of infections caused by multidrug-resistant MRSA belonging to this genotype.
authors: Medical School (FAMED), Federal University of Uberlândia, Campus Umuarama, Uberlândia, Brazil.
authors: Deivid
authors: D
authors: William da Fonseca Batistão
authors: Laboratory of Molecular Microbiology, Biomedical Science Institute, Federal University of Uberlândia, Campus Umuarama, Uberlândia, Brazil.
authors: Paola
authors: P
authors: Amaral de Campos
authors: Laboratory of Molecular Microbiology, Biomedical Science Institute, Federal University of Uberlândia, Campus Umuarama, Uberlândia, Brazil.
authors: Nayara
authors: N
authors: Caroline Camilo
authors: Laboratory of Molecular Microbiology, Biomedical Science Institute, Federal University of Uberlândia, Campus Umuarama, Uberlândia, Brazil.
authors: Sabrina
authors: S
authors: Royer
authors: Laboratory of Molecular Microbiology, Biomedical Science Institute, Federal University of Uberlândia, Campus Umuarama, Uberlândia, Brazil.
authors: Bruna
authors: B
authors: Fuga Araújo
authors: Laboratory of Molecular Microbiology, Biomedical Science Institute, Federal University of Uberlândia, Campus Umuarama, Uberlândia, Brazil.
authors: Karinne
authors: K
authors: Spirandelli Carvalho Naves
authors: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors: Margarida
authors: M
authors: Martins
authors: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors: Maria
authors: M
authors: Olívia Pereira
authors: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors: Mariana
authors: M
authors: Henriques
authors: Laboratory of Molecular Microbiology, Biomedical Science Institute, Federal University of Uberlândia, Campus Umuarama, Uberlândia, Brazil.
authors: Paulo
authors: P
authors: Pinto Gontijo-Filho
authors: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors: Cláudia
authors: C
authors: Botelho
authors: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors: Rosário
authors: R
authors: Oliveira
authors: Laboratory of Molecular Microbiology, Biomedical Science Institute, Federal University of Uberlândia, Campus Umuarama, Uberlândia, Brazil.
authors: Rosineide
authors: R
authors: Marques Ribas