Occurrence of virulence genes among Enterococcus faecalis strains isolated from patients and hospital environment

The aim of this study was to evaluate occurrence of virulence genes among Enterococcus faecalis strains isolated from two hospitals in Łódź, during 2005-2006. The second goal was to determine possible relationship between presence of those genes, resistance to ampicillin and sources of isolation. Enterococcal strains were identified to the species by PCR with ddl primers. All 161 isolates were tested for the presence of aggregation substance gene (agg), cytolisine genes (cyl-L, cyl-S), esp protein gene, gelatinase gene (gelE), serine protease gene (sprE). Susceptibility to ampicillin was tested by microdillution method. Both cyl-L and cyl-S genes were found in 52,2% of strains, agg gene was present in 62,73% isolates, esp gene--in 71.2%. Most frequently found genes were gelE (85.1%) and sprE (82.6%). The presence of esp gene in isolates resistant to ampicillin was statistically higher than in susceptible strains, what might suggest appearance of epidemic strains. Besides, strains possessing both, cyl-L/S and esp genes, were found to be statistically more often isolated strains than those possessing only single genes.