title: Dam methylation is required for efficient biofilm production in Salmonella enterica serovar Enteritidis.
abstract: The ecological success of Salmonella enterica to survive in different environments is due, in part, to the ability to form biofilms, something which is especially important for food industry. The aim of the current study was to evaluate the involvement of Dam methylation in biofilm production in S. Enteritidis strains. The ability to generate biofilms was analyzed in wild type and dam mutant strains. In S. Enteritidis, the absence of Dam affected the capacity to develop pellicles at the air-liquid interface and reduced the ability to form biofilm on polystyrene surfaces. Curli and cellulose production, determined by Congo red and calcofluor assays, were affected in dam mutant strains. Relative quantitative real-time PCR experiments showed that the expression of csgD and csgA genes is reduced in mutants lacking dam gene with respect to the wild type strains, whereas transcript levels of bcsA are not affected in the absence of Dam. To our knowledge, this is the first report on the participation of Dam methylation on biofilm production in Enteritidis or any other serovar of S. enterica. Results presented here suggest that changes in gene expression required for biofilm production are finely regulated by Dam methylation. Thus, Dam methylation could modulate csgD expression and upregulate the expression of factors related with biofilm production, including curli and cellulose. This study contributes to the understanding of biofilm regulation in Salmonella spp. and to the design of new strategies to prevent food contamination and humans and animals infections.
authors.affiliation: Instituto de Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina. Electronic address: rosaritoaya@gmail.com.
authors.forename: María del Rosario
authors.initials: Mdel R
authors.lastname: Aya Castañeda
authors.affiliation: Instituto de Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: Sebastián Hernán
authors.initials: SH
authors.lastname: Sarnacki
authors.affiliation: Instituto de Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: Mariángeles
authors.initials: M
authors.lastname: Noto Llana
authors.affiliation: Instituto de Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: Adriana Gabriela
authors.initials: AG
authors.lastname: López Guerra
authors.affiliation: Instituto de Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: Mónica Nancy
authors.initials: MN
authors.lastname: Giacomodonato
authors.affiliation: Instituto de Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina. Electronic address: ccerquetti@fmed.uba.ar.
authors.forename: María Cristina
authors.initials: MC
authors.lastname: Cerquetti
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms; D015964:Gene Expression Regulation, Bacterial; D008745:Methylation; D009154:Mutation; D060888:Real-Time Polymerase Chain Reaction; D012477:Salmonella enteritidis / Q000235:genetics / Q000502:physiology*; D065288:Serogroup; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)
keywords: Biofilm; Cellulose; Curli fimbriae; DNA adenine methyltransferase; Gene regulation; Salmonella Enteritidis