Antibiotic- resistant infection has become a serious health threat, and its incidence is rising at unprecedented rate. Statistics show that about 2 million patients in the United States acquire a nosocomial infection with more than 70 percent of the causative agents being resistant to at least one of the commonly used antibiotics. Studies also show that more than 50 percent of Staphylococcus aureus isolates in the ICU today are resistant to oxacillin, nafcillin or methicillin. Also about 25 percent of enterococcus isolates are resistant to vancomycin and 87 percent of coagulase-negative staphylococci are resistant to methicillin.