title: Staphylococcus epidermidis and Staphylococcus haemolyticus: Molecular Detection of Cytotoxin and Enterotoxin Genes.
abstract: Although opportunistic pathogens, coagulase-negative staphylococci (CoNS), including Staphylococcus epidermidis and Staphylococcus haemolyticus, have long been regarded as avirulent organisms. The role of toxins in the development of infections caused by CoNS is still controversial. The objective of this study was to characterize the presence of enterotoxin and cytotoxin genes in S. epidermidis and S. haemolyticus isolates obtained from blood cultures. Cytotoxin genes were detected by PCR using novel species-specific primers. Among the 85 S. epidermidis and 84 S. haemolyticus isolates, 95.3% and 79.8%, respectively, carried at least one enterotoxin gene. The most frequent enterotoxin genes were sea (53.3%), seg (64.5%) and sei (67.5%). The seg gene was positively associated with S. epidermidis (p = 0.02), and this species was more toxigenic than S. haemolyticus. The hla/yidD gene was detected in 92.9% of S. epidermidis and the hla gene in 91.7% of S. haemolyticus isolates; hlb was detected in 92.9% of the S. epidermidis isolates and hld in 95.3%. Nosocomial Staphylococcus epidermidis and S. haemolyticus isolates exhibited a high toxigenic potential, mainly producing the non-classical enterotoxins seg and sei. The previously unreported detection of hla/yidD and hlb in S. epidermidis and S. haemolyticus using species-specific primers showed that these hemolysin genes differ between CoNS species and that they are highly frequent in blood culture isolates.
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, UNESP-Univ Estadual Paulista, Botucatu, SP 18618-970, Brasil. luizapinheiro@ibb.unesp.br.
authors.forename: Luiza
authors.initials: L
authors.lastname: Pinheiro
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, UNESP-Univ Estadual Paulista, Botucatu, SP 18618-970, Brasil.
authors.forename: Carla Ivo
authors.initials: CI
authors.lastname: Brito
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, UNESP-Univ Estadual Paulista, Botucatu, SP 18618-970, Brasil. adilsonoliveiralp@ig.com.br.
authors.forename: Adilson
authors.initials: A
authors.lastname: de Oliveira
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, UNESP-Univ Estadual Paulista, Botucatu, SP 18618-970, Brasil. ciayf@yahoo.com.br.
authors.forename: Patrícia Yoshida Faccioli
authors.initials: PY
authors.lastname: Martins
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, UNESP-Univ Estadual Paulista, Botucatu, SP 18618-970, Brasil. valeriacataneli@gmail.com.
authors.forename: Valéria Cataneli
authors.initials: VC
authors.lastname: Pereira
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, UNESP-Univ Estadual Paulista, Botucatu, SP 18618-970, Brasil. cunhamlr@ibb.unesp.br.
authors.forename: Maria de Lourdes Ribeiro de Souza
authors.initials: Mde L
authors.lastname: da Cunha
mesh_terms: D003603:Cytotoxins / Q000235:genetics* / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D004768:Enterotoxins / Q000235:genetics* / Q000302:isolation & purification; D005798:Genes, Bacterial; D006801:Humans; D013212:Staphylococcus epidermidis / Q000378:metabolism*; D041162:Staphylococcus haemolyticus / Q000378:metabolism*
chemical_list: D003603:Cytotoxins; D004269:DNA, Bacterial; D004768:Enterotoxins
keywords: Staphylococcus epidermidis; Staphylococcus haemolyticus; cytotoxins; enterotoxins