Aspectos fenotípicos e genotípicos da formação de biofilme e interação com superfícies abióticas e bióticas no potencial de virulência de Staphylococcus haemolyticus relacionados com quadros de bacteremias

• Autor(a) principal: Ribeiro, Paula Marcele Afonso Pereira
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/14375
• topic: Staphylococcus haemolyticus; Neonates; Fomites; PFGE; Multi-drug resistance; Biofilm; Antimicrobials; Estafilococos haemolyticus; Neonatos; Fômites; PFGE; Multiresistência; Biofilme; Antimicrobianos; Biofilme; Infecções neonatais; Infecções estafilocócicas; Eletroforese em gel; Drogas - Resistência em microorganismos; Antibióticos; Farmacorresistência Bacteriana Múltipla; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA::MICROBIOLOGIA APLICADA

Oxacillin-resistant Staphylococcus haemolyticus (ORSH) is the most common microrganism among clinical isolates of methicillin-resistant staphylococci. <i>S. haemolyticus</i> plays an important role in hospital-acquired opportunistic infections worldwide, including peritonitis, otitis, urinary tract infections, septicemia and prosthetic-device-associated infections. The range of fomites contributing to this pathogen dissemination through patients and hospital wards remains unknown. Among staphylococcal species, <i>S. haemolyticus</i> present a unique and large capacity to biofilm formation, often associated to multi-drug resistant (MDR), and may develop resistance to glycopeptides. The aim of this study was to evaluate the interactions of abiotic and biotic surfaces by phenotypic and genotypic aspects with <i>S. haemolyticus</i> different clonal types isolated from blood culture from neonates and adults and strains fomites isolates, as well as the ability to produce biofilm in the presence of antibiotics. Clonal distribution was assessed by pulsed-field gel electrophoresis (PFGE). Minimum inhibitory concentrations (MICs) of antibiotics were evaluated via broth microdilution method. Polymerase chain reaction (PCR) assays were performed to detect <i>mec</i>A, <i>ica</i>A, <i>aap</i>, <i>atl</i>E, <i>atl</i> and <i>fbp</i> genes. <i>S.haemolyticus</i> strains grown in the presence of the antibiotics tested and were investigated for biofilm formation on glass, polystyrene and catheter surfaces. The neonate strains blood isolates were confirmed as <i>S. haemolyticus</i> by sequencing of the 16S gene and clustered in 6 pulsed-field gel electrophoresis types, in the adults stains, 12 pulsed-field gel electrophoresis types and for strains fomites isolates 5 pulsed-field gel electrophoresis types. Antimicrobial susceptibility tests identified most strains as MDR phenotype. Biofilm formation were independent of the presence of the <i>ica</i>A and <i>mec</i>A genes and PFGE type. On abiotic surfaces, antibiotics tested, including vancomycin and oxacillin did not inhibit the biofilm formation. Fomites isolated strains were characterized as MDR showing susceptibility only to linezolid and vancomycin. The affinity and ability of this species on biofilm-formation may contribute to the establishment and dissemination of nosocomial infection. The molecular mechanisms of biofilm formation in this specie have not been elucidated, particularly in the presence of antimicrobial agents. A sub-lethal dose of vancomycin may favor biofilm formation by ORSH on fomites and catheter surfaces. Further studies related to the presence and expression of ica gene may elucidate different mechanisms of adhesion related to the pathogenesis of infections caused by <i>S. haemolyticus</i>, including cases associated with medical devices.