title: Molecular detection of enterotoxins E, G, H and I in Staphylococcus aureus and coagulase-negative staphylococci isolated from clinical samples of newborns in Brazil.
abstract: OBJECTIVE
  The objective of this study was to investigate the detection of SEE, SEG, SEH and SEI in strains of Staphylococcus aureus and coagulase-negative staphylococci (CNS) using RT-PCR.
  
  
  RESULTS
  In this study, 90 Staph. aureus strains and 90 CNS strains were analysed by PCR for the detection of genes encoding staphylococcal enterotoxins (SE) E, G, H and I. One or more genes were detected in 54 (60%) Staph. aureus isolates and in 29 (32.2%) CNS isolates. Staphylococcus epidermidis was the most frequently isolated CNS species (n = 64, 71.1%), followed by Staphylococcus warneri (n = 8, 8.9%) and other species (Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus lugdunensis, Staphylococcus simulans, Staphylococcus saprophyticus and Staphylococcus xylosus: n = 18, 20%). The genes studied were detected in Staph. epidermidis, Staph. warneri, Staph. haemolyticus, Staph. hominis, Staph. simulans and Staph. lugdunensis. The highest frequency of genes was observed in Staph. epidermidis and Staph. warneri, a finding indicating differences in the pathogenic potential between CNS species and highlighting the importance of the correct identification of these micro-organisms. RT-PCR used for the detection of mRNA revealed the expression of SEG, SEH and/or SEI in 32 (59.3%) of the 90 Staph. aureus isolates, whereas expression of some of these genes was observed in 10 (34.5%) of the 90 CNS isolates.
  
  
  CONCLUSIONS
  Staphylococcus epidermidis was the most toxigenic CNS species. Among the other species, only Staph. warneri and Staph. lugdunensis presented a positive RT-PCR result. PCR was efficient in confirming the toxigenic capacity of Staph. aureus and CNS.
  
  
  CONCLUSIONS
  This study permitted to confirm the toxigenic capacity of CNS to better characterize the pathogenic potential of this group of micro-organisms. In addition, it permitted the detection of SEG, SEH and SEI, enterotoxins that cannot be detected by commercially available immunological methods.
authors.affiliation: Department of Microbiology and Immunology, Institute of Biosciences, UNESP-Universidade Estadual Paulista, Botucatu, São Paulo, Brazil.
authors.forename: N G
authors.initials: NG
authors.lastname: Vasconcelos
authors.forename: V C
authors.initials: VC
authors.lastname: Pereira
authors.forename: J P
authors.initials: JP
authors.lastname: Araújo Júnior
authors.forename: M de L R S
authors.initials: Mde L
authors.lastname: da Cunha
mesh_terms: D001938:Brazil; D003030:Coagulase / Q000032:analysis*; D004269:DNA, Bacterial / Q000235:genetics; D004768:Enterotoxins / Q000235:genetics* / Q000302:isolation & purification; D005798:Genes, Bacterial; D006801:Humans; D007231:Infant, Newborn; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000382:microbiology; D013210:Staphylococcus / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D013211:Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity
chemical_list: D003030:Coagulase; D004269:DNA, Bacterial; D004768:Enterotoxins