title: Distribution of six effector protein virulence genes among Salmonella enterica enterica serovars isolated from children and their correlation with biofilm formation and antimicrobial resistance.
abstract: OBJECTIVE
  Salmonella enterica enterica encodes a variety of virulence factors. Among them, the type III secretion system (TTSS) encoded in the Salmonella pathogenicity islands (SPIs) is required for induction of proinflammatory responses, invasion of intestinal epithelial cells, induction of cell death in macrophages, and elicitation of diarrhea. The presence of the effector protein genes sopB, sopD, sopE, sopE2, avrA, and sptP of the SPIs was analyzed in 194 S. enterica enterica strains belonging to 19 serovars.
  
  
  METHODS
  S. enterica enterica strains were collected from children with gastroenteritis, either hospitalized or attending the outpatient clinic, aged 1-14 years. Nineteen different serotypes were included in the study. Serotyping, biofilm formation determination, and antimicrobial resistance of the planktonic as well as the biofilm forms of the strains have been reported previously.
  
  
  RESULTS
  At least one virulence gene was present in all Salmonella isolates. Biofilm formation was statistically independent of any of the six genes. Strains lacking sopE and sopE2 were more resistant to all the antimicrobials.
  
  
  CONCLUSIONS
  The association of the virulence genes with the antimicrobial resistance of Salmonella in general has been previously reported and is a matter of further investigation. For the clinical expression of pathogenicity in humans, the contribution of these genes is questionable, as some strains bearing only a single gene (either sptP or avrA) were still capable of causing gastroenteritis.
authors.affiliation: Department of Nursing, Faculty of Human Movement and Quality of Life Sciences, University of Peloponnese, Sparta General Hospital Building Complex, Sparta, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Ioannidis
authors.forename: K
authors.initials: K
authors.lastname: Papavasileiou
authors.forename: E
authors.initials: E
authors.lastname: Papavasileiou
authors.forename: S
authors.initials: S
authors.lastname: Bersimis
authors.forename: S
authors.initials: S
authors.lastname: Chatzipanagiotou
mesh_terms: D000293:Adolescent; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005759:Gastroenteritis / Q000382:microbiology; D005798:Genes, Bacterial; D006801:Humans; D007223:Infant; D012480:Salmonella Infections / Q000382:microbiology*; D019779:Salmonella enterica / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity* / Q000502:physiology; D012703:Serotyping; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism*
chemical_list: C495717:AvrA protein, Salmonella enterica; D001426:Bacterial Proteins; C116105:SopD protein, Salmonella; C103987:SopE protein, Salmonella; D037521:Virulence Factors; C489224:SopB protein, Salmonella