Association Between Antecedent Intravenous Antimicrobial Exposure and Isolation of Vancomycin-Resistant Enterococci

• Published in: Microbial drug resistance (Larchmont, N.Y.) Vol. 9; no. 1, Supplement 1; pp. 69 - 77
• Main Authors: Chavers, L.S., Moser, S.A., Funkhouser, E., Benjamin, W.H., Chavers, P., Stamm, A.M., Waites, K.B.
• Format: Journal Article
• Language: English
• Published: United States Mary Ann Liebert, Inc 01.01.2003
• Subjects: Adult; Aged; Anti-Bacterial Agents - administration & dosage; Anti-Bacterial Agents - therapeutic use; Case-Control Studies; Ceftazidime - administration & dosage; Ceftazidime - therapeutic use; Cross Infection - microbiology; Cross Infection - prevention & control; Disease; Enterococcus - drug effects; Enterococcus - isolation & purification; Female; Gram-Positive Bacterial Infections - microbiology; Gram-Positive Bacterial Infections - prevention & control; Hospitals, Urban; Humans; Imipenem - administration & dosage; Imipenem - therapeutic use; Infusions, Intravenous; Male; Middle Aged; Severity of Illness Index; Vancomycin - pharmacology; Vancomycin Resistance
• ISSN: 1076-6294; 1931-8448
• DOI: 10.1089/107662903322541928

Vancomycin-resistant enterococci (VRE) have become important causes of nosocomial infections. This study evaluated the association between a variety of intravenous antimicrobial exposures and the isolation of VRE using two control groups: (1) a vancomycin-susceptible enterococci (VSE) group, to assess factors associated with development of VRE, and (2) a nonenterococci control group, to assess factors associated with positive cultures for enterococci without regard to vancomycin resistance. After adjusting for the effect of other antimicrobials, time at risk, and patient morbidity, compared to vancomycin-susceptible enterococci controls, exposures to imipenem (OR = 4.9, 95% CI = 1.6-14.1) and ceftazidime (OR = 2.6, 95% CI = 1.1-6.1) were significant predictors of VRE. When compared to nonenterococci controls, exposures to ampicillin (OR = 20.1, 95% CI = 1.5-263.1) and imipenem (OR = 5.1, 95% CI = 1.5-17.1) were significantly associated with VRE. Neither piperacillin nor vancomycin was associated with VRE compared to either control group. This study offers further evidence that the replacement of broad-spectrum cephalosporins by extended-spectrum penicillins, specifically piperacillin, may be effective in reducing VRE.