Amphotericin B-resistant yeast infection in severely immunocompromised patients.
Systemic yeast infections are a major cause of morbidity and mortality in severely immunocompromised patients. The in vitro susceptibility to amphotericin B of 29 yeasts causing fungemia was examined in 26 patients undergoing allogeneic or autologous bone marrow transplantation and/or myelosuppressive chemotherapy. The minimal inhibitory concentrations (MICs) of amphotericin B observed with blood isolates from these patients were significantly higher than those observed with blood, sputum, or skin isolates from non-immunocompromised patients (p less than 0.01). All episodes (10 of 10) of bloodstream infection in immunocompromised patients caused by isolates with MICs greater than 0.8 micrograms/ml were fatal, versus eight of 17 episodes of bloodstream infection caused by yeasts with MICs of 0.8 micrograms/ml or less (p = 0.04). Although 15 of 26 patients received empiric treatment with amphotericin B before laboratory evidence of fungemia developed, the amphotericin B susceptibilities of their isolates were not significantly different from those of patients who had not received empiric amphotericin B treatment. It is concluded that yeast fungemia in severely immunocompromised patients is often caused by organisms resistant to the usual concentrations of amphotericin B obtainable in vivo, and that this finding is clinically significant.
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Washington University School of Medicine, Department of Medicine, St. Louis, Missouri 63110.
Kobayashi
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Herzig
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Medoff
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D000328:Adult; D000666:Amphotericin B / Q000494:pharmacology / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects; D016026:Bone Marrow Transplantation; D002175:Candida / Q000187:drug effects; D002177:Candidiasis / Q000188:drug therapy* / Q000209:etiology; D004352:Drug Resistance, Microbial; D006801:Humans; D007108:Immune Tolerance; D008826:Microbial Sensitivity Tests; D009503:Neutropenia / Q000209:etiology
D000666:Amphotericin B