SAN DIEGO-A strain of Enterococcus faecium is emerging that can’t live without vancomycin.
A University of Wisconsin team has seen the vancomycin-dependent organism in a cluster of three women who developed nosocomial infections soon after, respectively, a bone-marrow, kidney, and liver transplant. Nine individual cases have been reported before.
Dr. Dennis Maki, who calls E. faecium’s versatility scary, says it progresses rapidly from resistant to dependent. All three Wisconsin patients had had serious underlying disease and heavy exposure to systemic antibiotics, especially vancomycin.
In the 60 days before the onset of their nosocomial infections the patients had been given antibiotics for a mean 103 days, vs. 86 days for 10 infected with vancomycin-resistant E. faecium and 31 days for 10 with vancomycin-susceptible infections. Mean days of vancomycin exposure were 31 for the first group, 9.0 for the second, and 0.1 for the third, Dr. Maki’s team told the Interscience Conference on Antimicrobial Agents and Chemotherapy here.
Two of the three patients were given investigational quinupristin/dalfopristin (Synercid, Rhône-Poulenc Rorer), which has been effective in some methicillin- and vancomycin-resistant infections. All three died.
Dr. Alexander Tomasz of Rockefeller University says the organisms, in effect, “become addicted to the antibiotic.” Such addiction has been reported in other organisms that were treated with streptomycin, tetracycline, and chloramphenicol. -Elsie Rosner
SAN DIEGO-A strain of Enterococcus faecium is emerging that can’t live without vancomycin.
