Prospective analysis of the genotypic diversity and dynamics of the Candida albicans flora Colonizing in neutropenic de novo acute leukemia patients

Dalle F., C. The Ollivier, I. Lafon, E. Ferrant, P. Sicard, C. Labruère, A. Gibran, A. Laubriet, O. Vagner, D. Clot, A. Bonnin


Objective: The yeast Candida albicans is an ubiquitous eukaryotic organism That Develops as a saprophyte of the mucosae in humans. In immunocompromised patients or intensive-care, this organism May Overcome host defenses, resulting and in Increased mucosal colonization and invasion into the bloodstream Sometimes through epithelial and endothelial layers. Genotyping Studies Reported heterogeneity of C. albicans Colonizing flora in HIV patients, with the possible coexistence of multiple clones with distinct resistance patterns. We report a prospective study avocation at highlighting the dynamics and heterogeneity of the C. albicans flora in de novo acute leukemia patients.

Methods: Between 2001 and 2003, 66 consecutive adults with newly Diagnosed acute leukemia Were Monitored for Candida colonization. For patients with repeated multi-site C. albicans colonization, multiple isolates Were genotyped from Each individual website and mucosal Sequentially over time using microsatellite markers.

Results: DESPITE topical use of polyenes, 60.6% of the patients colonized Were Repeatedly and one multiple sites. Altogether, 2730 Were cultured peripheral samples, 379 (13.9%) of qui yielded yeasts. C. albicans Was The Most common species: recovered (68%). In 8 patients colonized with C. albicans , 429 isolates Were genotyped. Seven patients the carried a single genotype qui Was identiques in all niches body and over the time course. In one case, minor genotypic differences Were Observed. None of the patients shared C. albicans clones with identiques genotypic profiles. Occurred candidemia in 1/8 patient and the blood strain genotype Did not Differ from Those of Colonizing isolates. In no patient Was the genotypic profile altered upon topical and / or systemic use of antifungal.

Conclusions: In patients with de novo acute leukemia, genetic Evolution of the Colonizing C. albicans flora and selection of variants or replacement of the original strain upon antifungal drug pressure or nosocomial transmission are uncommon events.


Full conference title: 

Réunion Interdisciplinaire de Chimiothérapie Anti Infectieuse
    • RICAI 27th (2007)