Vancomycin has been ordered to treat a patient's infection. Which is true regarding vancomycin (Select all that apply)

Only effective against gram negative bacteria

Oral vancomycin can be used to treat pseudomembranous colitis (C. diff)

IV vancomycin too quickly may cause flushing, or "red man syndrome"

Slow IV infusion is recommended, over at least 1 hour

Effective against vancomycin resistant enterococcus (VRE)