A GENETIC STUDY ON ENTEROCIN – PRODUCTION FROM Enterococcus faecalis ISOLATED FROM DIFFERENT CLINICAL SOURCES

Abstract

This study include genetic investigation Locally isolated Enterococcus. faecalis ability to produce enterocin, Hemolysin and cytolysin (production hemolysin and enterocin). The results of detection virulence factor showed that E.faecalis isolates possessed 14% hemolysin, of which 8% from clinical sources, and 6% of these isolates showed ability to produce cytolysin , 6% of normal flora isolates produced hemolycin was distributed between 4% isolates produce cytolycin and 2% non-produced. The results of plasmid content showed that selected isolates E.faecalis (EFU32 and EFU36) from Urinary Tract Infection and E.faecalis EFUW47 from Wound infection contained large plasmid bands; while other selected isolates E. faecalis EFW46 from Wound infection and normal flora did not exhibit this band. It was also observed that clinical and non-clinical isolates have homogenous plasmid profile in spite of the variation in their ability in producing enterocin, hemolysin and resistance to antibiotics. The results of plasmid curing by using physical and chemical agents showed the physical agents (heating at 48ºC) was more efficient to curied small and large plasmid completely together with the lots of hemolysin and enterocin production ability, and resistance to some antibiotics. the results of the treatment with chemical agents like mitomycin – c and ethidium bromide, showed the abilty of mitomycin – c agent to cure all small and large plasmid bands for all isolates at concentration of 80 µgml, also lose the ability to produce enterocin and hemolycin was observed. while the results showed variety when treated with eithidium bromide. In order to investigate the role of the large plasmid for enterocin production and whether it is a conjugative plasmid or not, an experiment on conjugation was carried out between cured EFU36 which harbor large plasmid as donor cell and cured EFW46 that did not harbor large plasmid, as a recipient cell. The results of conjugation experiment revealed that genes encoding for the production of enterocin, resistant to vancomycin may located on conjugative large plasmid.