Biofilm formation of Brazilian meticillin-resistant Staphylococcus aureus strains: 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-resistant Staphylococcus aureus (MRSA). Fifteen strains carrying different chromosomal cassettes recovered from hospitalized patients were selected; five SCCmecII, five SCCmecIII and five SCCmecIV. The SCCmec type, agr group and the presence of the virulence genes (bbp, clfA, icaA, icaD, fnbB, bap, sasC and 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 genes agrI, fnbB and IS256 in SCCmecIII strains were considered as genetic determinants associated with strong biofilm-formation by an icaindependent 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.

Vascular access infection by Staphylococcus aureus from removed dialysis accesses

“…Furthermore, we found that the biofilm formation ability of MRSA isolates correlated with SCC mec types. Our results are consistent with a previous study showing that SCC mec type III‐harboring strains showed a significantly higher ability to form biofilms compared with the strains harboring SCC mec type IV; however, no difference in biofilm formation with type II‐positive isolates was observed after 4 and 24 hr of incubation, which differs from the literature (William da Fonseca Batistao et al, ). The multidrug‐resistant SCC mec type III isolates produced significantly stronger biofilms than types IV and V suggesting that biofilm formation in MRSA isolates plays a role in antibiotic resistance in the hospital setting.…”

Coagulase-negative staphylococci in Southern Brazil: looking toward its high diversity

“…Caio Fernando de Oliveira [1] , Jorunn Pauline Cavanagh [2], [3] , Elizabeth G. Aarag Fredheim [2], [3] , Keli Cristine Reiter [4] , Alexandre Rieger [5] , Claus Klingenberg [3] , Pedro Alves d'Azevedo [4] and Johanna Ericson Sollid [6] [1]. Programa de Pós Graduação em Promoção da Saúde, Universidade de Santa Cruz do Sul, Santa Cruz do Sul, Rio Grande do Sul, Brasil.…”

“…Laboratório de Biotecnologia e Genética, Universidade de Santa Cruz do Sul, Santa Cruz do Sul, Rio Grande do Sul, Brasil. [6]. Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Artic University of Norway, Tromsø, Norway.…”

“…formation (4) (5) (6) . This may result in infections with limited therapeutic options, increased risk of treatment failure, and high cost (6) .…”

“…This may result in infections with limited therapeutic options, increased risk of treatment failure, and high cost (6) . Moreover, their high genetic diversity and constant presence on the human body makes CoNS a permanent reservoir of genetic material for more virulent staphylococcal species including Staphylococcus aureus (7) .…”