Decreased antimicrobial resistance after changes in antibiotic use

Vancomycin-resistant enterococci (VRE) and methicillin-oxacillin-resistant Staphylococcus aureus (MRSA) originally predominated in large medical cente rs; however, these isolates are now common in community hospitals and commu nity clinics. No simple answer is available regarding control of antimicrob ial-resistant bacteria, especially VRE and MRSA, as their numbers increase and pose a more serious threat to patient care. The source of colonization is often difficult to identify because of transport of patients among diffe rent locations on the continuum of care (e.g., hospital to extended care fa cility to home and back). At one hospital, control strategies greatly reduc ed the occurrence of gram-negative bacteria such as VRE. Since 1994, VRE de clined from 16% to 5%. Similarly, the number of MRSA isolates declined from 35% to 23%. These declines are attributed to a cohesive working relationsh ip among pharmacists, microbiologists, and infectious disease physicians an d personnel, and to a decision to decrease administration of cephalosporins in favor of piperacillin-tazobactam.