a1 Public Health Laboratory, Dulwich Hospital, East Dulwich Grove, London SE22 8QF
a2 Antibiotic Reference Laboratory, Division of Hospital Infection, Central Public Health Laboratory
a3 Streptococcus Reference Laboratory, Division of Hospital Infection, Central Public Health Laboratory
Nosocomial infection or colonization due to enterococci with high-level resistance to vancomycin (minimal inhibitory concentrations [MICs] between 64 and > 2000 mg/L) has occurred in 41 patients with renal disease. These vancomycin-resistant enterococci were cultured from many sources including blood. All but one strain contained one or more plasmids ranging in molecular weight from 1·0 to 40 Megadaltons (MDa). Vancomycin resistance was transferable by conjugation to a susceptible recipient strain of Enterococcus faecalis but this was not always associated with plasmid DNA. The emergence of transferable high-level vancomycin resistance in enterococci causing significant clinical infections is of particular importance since vancomycin is widely regarded as a reserve drug for the management of infections with multi-resistant Gram-positive organisms.
(Accepted March 12 1989)