Nosocomial Spread of Linezolid-Resistant, Vancomycin-ResistantEnterococcus faecium

Abstract

Vancomycin-resistant enterococci have become important nosocomial pathogens in the United States. Since November 1995, rectal swabs for surveillance for vancomycin-resistant enterococci have been collected twice weekly from adult patients admitted to the liver, kidney, and pancreas transplantation unit at our institution.¹ Recently, linezolid-resistant, vancomycin-resistant Enterococcus faecium was isolated from seven patients at our institution. All isolates carried the vanA gene and were resistant to linezolid (minimal inhibitory concentration [MIC], 16 μg per milliliter), ampicillin, penicillin, gentamicin, streptomycin, and vancomycin and were susceptible to quinupristin–dalfopristin and the investigational agents oritavancin (MIC, 1 μg per milliliter) and tigecycline (MIC, Escherichia coli numbering), (GenBank accession number, AF432914),² and all exhibited indistinguishable patterns on SmaI pulsed-field gel electrophoresis.