Enterococcus faecalis and Enterococcus faecium are bacterial organisms commonly found in food, water, soil, plants, and animals. In a laboratory, they can be discerned from other bacteria by several important diagnostic clinical features including:
*morphologic appearance on Gram stain and culture (Gram-positive cocci that grow in chains, pairs, or singles)
*ability to react with group D antiserum
*PYR positive (L-pyrrolidonyl - beta- naphthylamide) and LAP positive (leucine- beta-naththylamide)
*hydrolyze esculin with 40% bile present
*can grow in 6.5% sodium chloride
*can grow at temps as high as 45 degrees C
E. faecalis and E. faecium are not as virulent as Staphylococcus aureus because they don't secrete exotoxins or produce superantigens.