Analysis of virulence factors in cases of enterococcal endocarditis.

Eleven isolates of Enterococcus faecalis causing endocarditis were screened for possible virulence factors with PCR and phenotypic assays. The gene coding for the enterococcal surface protein (esp) was detected in one isolate only, and haemolysin was produced by two isolates. Aggregation substance, biofilm formation and gelatinase were present in seven, nine and eight isolates, respectively. Predisposing factors, particularly hospitalisation and multiple antibiotic therapy, appeared to be more relevant to the development of enterococcal endocarditis following bloodstream infections than the pattern of virulence factors.