Trichosporon beigelii, an emerging pathogen resistant to amphotericin B.
Trichosporon beigelii caused fatal disseminated infections that were resistant to amphotericin B in two granulocytopenic patients. In vitro susceptibility studies demonstrated that both index strains of T. beigelii were inhibited but not killed by amphotericin B at achievable concentrations in serum. The minimum lethal concentration for both isolates was greater than or equal to 18 micrograms/ml. Five of seven other isolates were found to have a similar pattern of amphotericin B resistance. The fact that the minimum lethal concentration of T. beigelii was many times greater than its MIC was consistent with a resistance pattern of tolerance. We concluded that T. beigelii may be resistant in vitro to amphotericin B and that this in vitro resistance was correlated with refractory, disseminated trichosporonosis in granulocytopenic patients. T. beigelii should be included in the expanding list of amphotericin B-resistant fungi.
Walsh
T J
TJ
Infectious Diseases Section, National Cancer Institute, Bethesda, Maryland 20892.
Melcher
G P
GP
Rinaldi
M G
MG
Lecciones
J
J
McGough
D A
DA
Kelly
P
P
Lee
J
J
Callender
D
D
Rubin
M
M
Pizzo
P A
PA
D000293:Adolescent; D000368:Aged; D000380:Agranulocytosis / Q000150:complications; D000666:Amphotericin B / Q000494:pharmacology*; D000741:Anemia, Aplastic / Q000150:complications; D004352:Drug Resistance, Microbial; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D003904:Mitosporic Fungi / Q000187:drug effects*; D009181:Mycoses / Q000150:complications / Q000188:drug therapy*; D009894:Opportunistic Infections / Q000150:complications; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications; D014250:Trichosporon / Q000187:drug effects* / Q000472:pathogenicity
D000666:Amphotericin B