To determine whether the restriction of 3rd generation cephalosporins and carbapenems contribute to the reduction of intestinal colonization or infection with vancomycin-resistant enterococci (VRE) in a medical intensive care unit (MICU).

Inclusion Criteria:

• All patients admitted to or transferred to the MICU.
• Patients 18 years of age or older.
• Provide written informed consent.

Exclusion Criteria:

• Patients known to be infected or colonized by VRE or ESBL-producing E.coli, K.pneumoniae.
• Patients who have hypersensitivity to penicillin.
• Any underlying conditions or diseases that will be ultimately fatal within 48 hours.
• Any concurrent condition or medication which would interfere with absorption or metabolism of study drugs.