Association between virulence factors and clinical outcome of patients with health care infection by Stenotrophomonas maltophilia

• Grant number: 09/02281-1
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2009
• End date: August 31, 2011
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Silvia Figueiredo Costa
• Grantee: Silvia Figueiredo Costa
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Stenotrophomonas maltophilia is a non fermentative, gram-negative bacillus, long recognized as a cause of infectious in debilitated patients, usually in immunocompromised and critical ill patients. Earlier studies in the 80s and 90s, suggested low patogenicity in S. maltophilia. Some studies did not find association between infcetion due to this bacteria and unfavorable outcome. However more recent studies found high mortality in association with S. maltophilia infection. Biofilm formation as described in others gram-negative bacterias, is caused by bacterial adherence, structural appendages and hidrophobicity of the bacterial surface. Many "in vitro" studies investigated a biofilm production and adherences to surfaces in isolates of S. maltophilia, however these are not studies comparing the relation ship between forming and non forming biofilms S. maltophilia and clinical outcome in infected patients. The aim of this study is through a prospective cohort assess of the association between virulence factors with the clinical course (mortality) of patients with infections caused by S. maltophilia associated of health care. It will also be performed molecular typing of all isolates from patients infected by S. maltophilia identified during the study period to understand the clonality of the strains on the expression of virulence factors and resistance (expression of genes for resistance to trimethoprim-sulfamethoxazole and quinolones). (AU)