title: Methicillin resistance and virulence genes in invasive and nasal Staphylococcus epidermidis isolates from neonates.
abstract: Staphylococcus epidermidis is an opportunistic pathogen involved in hospital-acquired infections, particularly in those related to medical devices. This study characterized 50 genetically unrelated S. epidermidis isolates from bloodstream infections (BSIs, n = 31) and nares (n = 19) of neonates in relation to staphylococcal chromosomal cassette mec (SCCmec) type, biofilm production and associated genes, and the arginine catabolic mobile elements (ACME), in order to detect virulence factors that could discriminate a potential invasiveness isolate or predict an increasing pathogenicity.
  
  
  
  Isolates from both groups showed no difference for biofilm production and ACME genes detection. However, BSI isolates harbored more frequently the sdrF and sesI genes (p < 0.05), whereas biofilm producer isolates were associated with presence of the aap gene. The sdrF gene was also significantly more in the biofilm producer isolates from BSI. The SCCmec type IV and the ccr2 complex were related to BSI isolates (p < 0.05), while 83% of the nasal isolates were non-typeable for the SCCmec elements, with the mec complex and ccr undetectable as the most frequent profile.
  
  
  
  Despite the great clonal diversity displayed by S. epidermidis isolates from neonates, BSI isolates harbored more frequently the sdrF and sesI adhesin genes, while nasal isolates were very variable in SCCmec composition. These aspects could be advantageous to improve colonization in the host increasing its pathogenicity.
authors.affiliation: Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Av Carlos Chagas Filho, no 373, CCS, Bloco I, Sala 010, Cidade Universitária, Rio de Janeiro, Brazil.
authors.forename: Vivian Carolina
authors.initials: VC
authors.lastname: Salgueiro
authors.affiliation: Departamento de Ciências Básicas, Universidade Federal Fluminense, R. Dr. Silvio Henrique Braune, no 22, Nova Friburgo, Rio de Janeiro, Brazil.
authors.forename: Natalia Lopes Pontes
authors.initials: NL
authors.lastname: Iorio
authors.affiliation: Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Av Carlos Chagas Filho, no 373, CCS, Bloco I, Sala 010, Cidade Universitária, Rio de Janeiro, Brazil.
authors.forename: Marcelle Cristina
authors.initials: MC
authors.lastname: Ferreira
authors.affiliation: Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Av Carlos Chagas Filho, no 373, CCS, Bloco I, Sala 010, Cidade Universitária, Rio de Janeiro, Brazil.
authors.forename: Raiane Cardoso
authors.initials: RC
authors.lastname: Chamon
authors.affiliation: Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Av Carlos Chagas Filho, no 373, CCS, Bloco I, Sala 010, Cidade Universitária, Rio de Janeiro, Brazil. santoskrn@micro.ufrj.br.
authors.forename: Kátia Regina Netto
authors.initials: KR
authors.lastname: Dos Santos
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics; D001120:Arginine / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification; D018441:Biofilms / Q000254:growth & development; D001938:Brazil / Q000453:epidemiology; D004269:DNA, Bacterial / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D007231:Infant, Newborn; D016106:Methicillin Resistance / Q000235:genetics*; D058885:Multilocus Sequence Typing; D009296:Nasal Cavity / Q000382:microbiology*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000097:blood / Q000453:epidemiology / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C487495:MecA protein, Staphylococcus epidermidis; D037521:Virulence Factors; D001120:Arginine
keywords: Bloodstream infection; Nasal; Neonates; S. epidermidis; SCCmec; Virulence