Ganciclovir susceptibility studies were done on the last cytomegalovirus (CMV) isolate available from 42 solid organ transplant recipients with CMV viremia who were enrolled in a prospective CMV prophylactic trial. Viruses were categorized as follows: 13 isolates (group 1) from patients who received ganciclovir prophylaxis; 9 isolates (group 2) from patients who received acyclovir prophylaxis; 8 isolates (group 3) from patients who received acyclovir prophylaxis and ganciclovir treatment; and 12 isolates (group 4) from patients who received prophylaxis and treatment with ganciclovir. All CMV isolates were sensitive to ganciclovir (mean 50% inhibitory concentration [IC50] = 1.7 µM; range, 0.2-5.3 µM). Mean IC50 values (in µM) were 1.7 for group 1 isolates, 1.2 for group 2 isolates, 2.2 for group 3 isolates, and 1.7 for group 4 isolates (P>.05). Thus, acyclovir or ganciclovir prophylaxis in solid organ transplant patients did not select ganciclovir- resistant isolates of CMV.
Bibliographical noteFunding Information:
Received 22 January 1993: revised I April 1993. Presented in part: 32nd Interscience Conference on Antimicrobial Agents and Chemotherapy. 14 October 1992. Anaheim. California (abstract 1429). Financial support: Minnesota Medical Foundation: National Institutes of Health (AM-13083): Le Fonds de la Recherche en Sante du Quebec (G.B.). Reprints or correspondence: Dr. Henry H. Balfour. Jr.. Dept. of Laboratory Medicine and Pathology. Box 437 UMHC, 15-144 Phillips-Wangensteen Bldg.. Harvard Street at East River Road. Minneapolis, MN 55455.