title: Change in colony morphology of Candida lusitaniae in association with development of amphotericin B resistance.
abstract: It is not uncommon to see amphotericin B treatment failure in patients with systemic infection caused by Candida lusitaniae. We report a patient with stage IV ovarian carcinoma and C. lusitaniae sepsis whose treatment with amphotericin B failed. The initial blood isolate was susceptible to amphotericin B in vitro; however, the MIC for a blood isolate recovered 7 weeks after treatment began showed a fourfold increase. Direct subculture of two positive blood samples obtained within a week of the patient's death showed the coexistence of two distinct colony color variants on CHROMagar Candida (CAC). One variant was susceptible to amphotericin B, and one was resistant. These results emphasize the importance of repeat amphotericin B susceptibility testing for patients with persistent C. lusitaniae infection. The presence of colony variants on CAC may signal the emergence of amphotericin B resistance in C. lusitaniae and should be investigated.
authors.affiliation: Clinical Microbiology/Virology Laboratory, Stanford University Medical Center, Stanford, California 94305, USA. nancy.mcclenny@medcenter.stanford.edu
authors.forename: Nancy B
authors.initials: NB
authors.lastname: McClenny
authors.forename: Haihua
authors.initials: H
authors.lastname: Fei
authors.forename: Ellen J
authors.initials: EJ
authors.lastname: Baron
authors.forename: Ana C
authors.initials: AC
authors.lastname: Gales
authors.forename: Allison
authors.initials: A
authors.lastname: Houston
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Hollis
authors.forename: Michael A
authors.initials: MA
authors.lastname: Pfaller
mesh_terms: D000368:Aged; D000666:Amphotericin B / Q000494:pharmacology* / Q000627:therapeutic use; D000935:Antifungal Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001769:Blood / Q000382:microbiology; D002175:Candida / Q000145:classification / Q000187:drug effects* / Q000254:growth & development*; D002177:Candidiasis / Q000188:drug therapy / Q000382:microbiology; D002863:Chromogenic Compounds / Q000378:metabolism; D003470:Culture Media; D025141:Drug Resistance, Fungal; D016521:Electrophoresis, Gel, Pulsed-Field; D017809:Fatal Outcome; D005260:Female; D016469:Fungemia / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D017211:Treatment Failure
chemical_list: D000935:Antifungal Agents; D002863:Chromogenic Compounds; D003470:Culture Media; D000666:Amphotericin B