Caracterização de cepas hospitalares de enterococcus resistentes à vancomicina (VRE) : resistência aos antimicrobianos e fatores de virulência

• Autor(a) principal: Coelho, Marcela Rodrigues
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/4574
• topic: Enterococci vancomycin-resistant; Virulence factors; Resistance to antimicrobials; Enterococo resistente à vancomicina; Fatores de virulência; PCR Multiplex; Resistência aos antimicrobianos; Doenças Infecciosas e Parasitárias; Enterococcus; Virulência (Microbiologia); Agentes antiinfecciosos; 61

Enterococcus are Gram-positive cocci commonly found in the gastrointestinal tract of humans and animals as well as in soil, water and food. The members of the genus Enterococcus have a remarkable ability to acquire new mechanisms of resistance to antimicrobials, and are considered one of the most versatile bacteria in the current scenario of bacterial resistance and a major cause of hospital acquired infections. Vancomycin-resistant enterococci (VRE) were first identified in the late 1980s in a few European countries. In the present study, hundred VRE isolated from different hospital of Vitória-ES were examined for their resistance genotype and the virulence factors encoded by ace, efaA, gelE, agg and esp genes. The presence of vancomycin resistance genes and species was determined by a polymerase chain reaction using different specific primers (vanA, vanB, ddl E. faecalis and ddl E. faecium). The in vitro susceptibility to ampicillin, penicillin, streptomycin, gentamicin, tetracycline, erythromycin, nitrofurantoin, norfloxacin, ciprofloxacin, teicoplanin, vancomycin and linezolid was evalueted by disk diffusion method. The Minimal Inhibitory Concentration (MIC) to vancomycin was determined by E-test and agar dilution method. All isolates were identified as VRE are the species Enterococcus faecium. All isolates showed MIC to vancomycin >32 µg/ml and proved to harbor the vanA gene in the PCR multiplex. The most in vitro active compound was linezolid. The occurrence of a high frequency of multiple antimicrobial-resistance was detected among these isolates and this phenotype was independent of the origin from they were recovered. Several virulence factors were described for enterococcus, but little is known about the virulence of Enterococcus faecium. The virulence factors were investigated by molecular. The prevalence of the virulence genes was as follows: ace (2%), efaA (5%), gelE (3%), agg (2% and esp (62%). These results showed the low virulence of nosocomial multiple-resistant E. faecium. The knowledge about the role of them on its pathogenesis can contribute to develop new strategies for enterococcus infection combat.