High-frequency, in vitro reversible switching of Candida lusitaniae clinical isolates from amphotericin B susceptibility to resistance

Stephanie A. Yoon, Jose A. Vazquez, Paul E. Steffan, Jack D. Sobel, Robert A. Akins

Research output: Contribution to journalArticle

64 Scopus citations


Recent studies have revealed an increase in the incidence of serious infections caused by non-albicans Candida species. Candida lusitaniae is of special interest because of its sporadic resistance to amphotericin B (AmB). The present in vitro study demonstrated that, unlike other Candida species, C. lusitaniae isolates frequently generated AraB-resistant lineages form previously susceptible colonies. Cells switching from a resistant colony to a susceptible phenotype were also detected after treatment with either UV light, heat shock, or exposure to whole blood, all of which increased the frequency of switching. In some C. lusitaniae lineages, after a cell switched to a resistant phenotype, the resistant phenotype was stable; in other lineages, colonies were composed primarily of AmB-susceptible cells. Although resistant and susceptible lineages were identical in many aspects, their cellular morphologies were dramatically different. Switching mechanisms that involve exposure to antifungals may have an impact on antifungal therapeutic strategies as well as on standardized susceptibility testing of clinical yeast specimens.

Original languageEnglish (US)
Pages (from-to)836-845
Number of pages10
JournalAntimicrobial Agents and Chemotherapy
Issue number4
StatePublished - Jan 1 1999
Externally publishedYes


ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)
  • Infectious Diseases

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