Browsing by Author "Cuenca-Estrella, Manuel"

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    Transient Fungemia Caused by an Amphotericin B-Resistant Isolate of Candida haemulonii
    (2002-06-01) Rodero, Laura; Cuenca-Estrella, Manuel; Córdoba, Susana; Cahn, Pedro; Davel, Graciela; Kaufman, Sara; Guelfand, Liliana; Rodríguez-Tudela, Juan L
    A bloodstream infection due to Candida haemulonii afflicting a patient with fever and a medical history of megaloblastic anemia is reported. The clinical isolate was misidentified by the API 20C and VITEK identification systems. The results of susceptibility tests showed that the MIC of amphotericin B for C. haemulonii was 4 μg/ml. Additional susceptibility testing procedures based on the use of antibiotic medium 3 and Iso-Sensitest broth were performed, and killing curves were determined. Two collection strains of C. haemulonii were employed as controls. The three isolates exhibited resistance to amphotericin B in vitro regardless of the antifungal susceptibility testing method employed. In addition, the MICs of fluconazole for the three isolates were high. Further studies are needed in order to ascertain whether this species exhibits innate or acquired resistance to amphotericin B and other antifungal agents. Candida haemulonii (Van Uden & Kolipinski) S. A. Meyer & Yarrow (Yarrow and Meyer 1978) (syn. Torulopsis haemulonii) is a yeast species that has been reported in the scales of animals and in seawater and has been recently associated with an epidemic disease afflicting laboratory animals (Ornithodoros moubata) in the Czech Republic (5, 10, 11). This fungus is also involved in human infections such as onychia, ulcers of the feet or legs, and candidemia (10). Identification of C. haemulonii is difficult because it is phenotypically very similar to Candida famata (teleomorph, Debaryomyces hansenii) and Candida guilliermondii (teleomorph, Pichia guilliermondii), although it can be distinguished by its inability to assimilate cellobiose and its negative or weak assimilation of raffinose (8, 10). In addition, commercial yeast identification systems have failed to identify C. haemulonii isolates (16). Lehmann et al. studied 25 clinical isolates of C. haemulonii and described two genetically distinct groups within the species (group I and group II) on the basis of isoenzyme profiles, DNA reassociations, and physiological characteristics (9, 10, 16). No differences in clinical associations between the groups were described, but it was determined that C. haemulonii constitutes a species complex. The susceptibility pattern of C. haemulonii is unknown, but an anecdotal report has suggested that it could be resistant to amphotericin B (AMB) and other antifungal agents (4). Here, we describe a case of transient fungemia due to a C. haemulonii strain which exhibited resistance to AMB and fluconazole in vitro. Killing curves were determined and additional susceptibility tests were performed to assess the activity of AMB against the isolate.