Clonal profile and pathogenicity factors of Staphylococcus spp. on the prognostic of peritonitis in peritoneal dialysis

Abstract

Peritonitis remains as the main complication of peritoneal dialysis (DP) and Staphylococcus spp. are the most frequent causative microorganism of this complication. S. aureus is an etiologic agent associated to bad clinical course, possibly due to the production of pathogenic factors such as toxins, enzymes and biofilm. On the other hand, coagulase negative staphylococcus (CoNS) show higher tendency to bacterial resistance to methicillin and oxacillin. The clonal ancestrality of some strains can be related to higher incidence of pathogenic factors or antimicrobial resistance. Thus, the objective of this study is to evaluate the clonal distribution of S.aureus and CoNS from peritonitis in PD patients as well as to determine if the presence of virulence and resistance factors of these clones influence the peritonitis prognosis. For that, we will evaluate samples of Staphylococcus spp. from PD peritonitis treated in the University Hospital of Botucatu Medical School-UNESP, Brazil. All the strains will be tested regarding in vitro susceptibility and mecA gene for oxacillin resistance by PCR method. Enzymes and hemolysin production will be phenotypically determined. S. aureus and CoNs clones will be identified by pulsed field gel electrophoresis and after genotypically characterized for biofilm and toxins production and for type of chromosomal cassette associated to mecA gene (SCCmec). Finally, associations between microbiological characteristics of causative agent and the clinical course and complications of peritonitis episodes will be determined.