MEDICAL INTELLIGENCE 
PLASM ID-MEDIATED RESISTANCE TO 
VANCOMYCIN AND TEICOPLANIN IN 
EXTEROCOCCUS FAECIUM 
Roland Leci.f.rcq, M.D., Eliane Derlot, 
Jf.an Dcval, M.D., and Patrice Courvai in, M.D. 
T HE glycopcpiidc antibiotic agents vancomycin 
and tcicuplanin arc useful in the treatment of 
severe infections due to gram-positive bacteria. 1 ' 3 
Staphylococci, streptococci, and enterococci arc al- 
most always susceptible to these agents, which consti- 
tute an alternative to the penicillins in cases of resist- 
ance or intolerance. 
Resistance to glycopeplides is extremely common in 
Icuconostoc species 4 and pediococcus species and also 
From the Service itc B-jCtci iologic - Virol.sgie Hygiene. Hopiul Henri Mon- 
due. I'niverMte P_r.s XII. Crcteil (R L.. J D ), and I'niti dec Agents Amibacter- 
ienc. Instilnt Pasteur. Pone (E D . PC ). France AdJro'S reprint regue'ts to Dr 
Courvalin at the Unite .tec Agents Antihacllricns. Inctitut Paclcur. 25 R.ic Ju Dr. 
Roue. 75724 Pans Cede* 15. Trance. 
Presented in part at the 27th Interccicncc Conference on Antimicrobial Agents 
anj (Tieinothcrapv . Neve York, October 4 -7, 1987. 
occurs in Lactobacilli. 5 0 These gram-positive bacteria 
rarely cause infections and arc considered opportunis- 
tic pathogens. The emergence of strains of Staphylococ- 
cus hacmolylicus that became resistant during vancomy- 
cin therapy has recently been reported.' Resistance to 
vancomycin is rare in streptococci. 8 Enicrococcal iso- 
lates with minimal inhibitors concentrations above 
100 mg per liter base been described. 9 l0 Recently, an 
outbreak of infections due to strains of Enterococcus fae- 
cium and Enterococcus faecalis resistant to vancomycin 
has been reported." However, the biochemical mech- 
anism and the genetic basis for vancomycin resistance 
in these organisms have not been studied. 
We report resistance to high levels of vancomycin 
and teicoplanin in two clinical isolates of E. faecium. 
The resistance genes were carried by plasmids that arc 
structurally related. This report of plasmid-mediated 
resistance to glycopeplides is of importance because of 
the risk of dissemination to microorganisms consid- 
ered universally susceptible. 
Methods 
Bacterial Strains 
The properties of the strains used in this studs arc listed in Ta- 
ble I. E /iifuum strains BM 1 1 47 and BM H52 were isolated in I98G 
from the feces of two patients with acute leukemia who had not been 
treated w ith vancoiny cin and w ho had undergone selective digcstic e 
tract decontamination with oral kananiycin, sisomicin. nitrofurans, 
and colis'in flee days before a bone marrow transplantation. The 
patients I :d been hospitalized in a hematology unit where vanco- 
mycin was included in a regimen of empirical antibiotic therapy of 
febrile patients with neutropenia. The strains were isolated as pure 
cultures from the stools of the patients with neutroprnia but did not 
provoke infection. They were identified as enterococci by Gram s 
Reprinted from the Vi a England Journal of W- Heine 
J i 9: 1 57 IM i July 21). 19S8 
Recombinant DNA Research, Volume 13 
[409] 
