Virulence profile of vancomycin resistant Enterococci (VRE) samples isolated during a surveillance program ina Brazilian hospital

• Grant number: 10/09609-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2010
• End date: August 31, 2011
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Ilana Lopes Baratella da Cunha Camargo
• Grantee: Rafaela Francini Corrêa
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Virulence factor is any component of the microorganism that is required to cause the disease or that enhance its ability to cause the disease. According to this, even a substance that purified is not toxic to the host tissue would be consider a virulence factor if, in its absence, the microorganism become considerably less capable to infect or to cause the disease (less virulent). In Enterococcus faecalis, an important nosocomial pathogen, virulence factors may be acquired by genetic transference and disseminate among the strains. Examples of virulence factors found in E. faecalis are: Aggrefation substance (Agg), gelatinase (GelE), Enterococci surface protein (Esp), Cytolysin (Cyl), and Enterococcal rich-leucin protein A (ErlA). On the other hand, different virulence factors are found in E. faecium such as: adhesin (Acm), hyalorunidase (HyL) and extracelullar surface protein (Esp). Those factors have been shown by other investigators to aggregate cells, to contribute to biofilm formation and to be particularly important in the dissemination or acquisition of resistances by promoting cell-cell contact and the conjugal transfer of plasmids harboring resistance and virulence genes. In general, mobile genetic elements such as insertion elements (IS) and transposons, are common components on the microbial genome and promote the genotypic and phenotypic variation. IS may disrupt genes, but also may alter the expression of downstream genes. Recently, the IS16 was described as a hospital E. faecium strains marker and probable play a role in genome plasticity contributing to the adaptation to highly competitive niches such as hospital environment. Besides, IS elements also may increase the propensity of acquiring further adaptive mechanisms. The main objective of this study is to characterize the virulence profile of VRE samples isolated from a surveillance program at the Hospital Risoleta Tolentino Neves, Belo Horizonte, MG and verify if IS16 is present in the samples as hospital marker such as in other countries. (AU)