title: Staphylococcus epidermidis and Staphylococcus haemolyticus: detection of biofilm genes and biofilm formation in blood culture isolates from patients in a Brazilian teaching hospital.
abstract: Infections with coagulase-negative staphylococci are often related to biofilm formation. This study aimed to detect biofilm formation and biofilm-associated genes in blood culture isolates of Staphylococcus epidermidis and S. haemolyticus. Half (50.6%) of the 85 S. epidermidis isolates carried the icaAD genes and 15.3% the bhp gene, while these numbers were 42.9% and 0 for S. haemolyticus, respectively. According to the plate test, 30 S. epidermidis isolates were biofilm producers and 40% of them were strongly adherent, while only one (6%) of the 17 S. haemolyticus biofilm-producing isolates exhibited a strongly adherent biofilm. The concomitant presence of icaA and icaD was significantly associated with the plate and tube test results (P ≤ 0.0004). The higher frequency of icaA in S. epidermidis and of icaD in S. haemolyticus is correlated with the higher biofilm-producing capacity of the former since, in contrast to IcaD, IcaA activity is sufficient to produce small amounts of polysaccharide. Although this study emphasizes the importance of icaAD and bhp for biofilm formation in S. epidermidis, other mechanisms seem to be involved in S. haemolyticus.
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu, SP, Brazil; Laboratório de Patologia,Instituto Lauro de Souza Lima, Bauru, SP, Brazil. Electronic address: luizapinheiro@ibb.unesp.br.
authors.forename: Luiza
authors.initials: L
authors.lastname: Pinheiro
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu, SP, Brazil.
authors.forename: Carla Ivo
authors.initials: CI
authors.lastname: Brito
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu, SP, Brazil. Electronic address: adilson270193@gmail.com.
authors.forename: Adilson de
authors.initials: Ad
authors.lastname: Oliveira
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu, SP, Brazil. Electronic address: cataneli@ibb.unesp.br.
authors.forename: Valéria Cataneli
authors.initials: VC
authors.lastname: Pereira
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu, SP, Brazil. Electronic address: cunhamlr@ibb.unesp.br.
authors.forename: Maria de Lourdes Ribeiro de Souza da
authors.initials: Mde L
authors.lastname: Cunha
mesh_terms: D016470:Bacteremia / Q000382:microbiology*; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D001938:Brazil; D005798:Genes, Bacterial; D006784:Hospitals, Teaching; D006801:Humans; D013203:Staphylococcal Infections / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D041162:Staphylococcus haemolyticus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*
keywords: Biofilm; Staphylococcus epidermidis; Staphylococcus haemolyticus; bhp; ica genes