Genotyping of Candida albicans isolates from patients with fungemia using a microsatellite multiplex PCR system

Oliveira S, Correia A, Sampaio P, Pais C, Pina-Vaz C, G Rodrigues A

Author address: 

1 Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal, 2 Department of Biology, Minho University, Braga, Portugal

Abstract: 

The purpose of the study was to compare genetic similitude between Candida albicans isolates from blood cultures and simultaneous isolates from different sites of the same patient. Fungemia represents an important cause of septicemia with considerable mortality. All the yeasts isolated from blood cultures at a University Hospital of Porto, Portugal were collected during 24 months (2002-2004). Additionally, yeasts simultaneously isolated from distinct body sites of the same patient were collected. The strains were biochemically characterized with Vitek system (BioMerieux, Paris) and the susceptibility profile to antifungals (fluconazole, itraconazole, voriconazole, amphoterine B and caspofungin) was determined according to NCCLS M27-A2. Antifungal susceptibility patterns were identical among the different isolates of the same patients, in most cases. C. albicans strains were genotyped with microsatellite markers to assess the genetic relatedness among isolates from the same patient (Sampaio et al., 2003). Multilocus genotypes from blood culture isolates were compared with the ones obtained from urine, upper respiratory tract and/or catheter isolates. Application of these markers indicated that the majority of strains isolated from different body sites of the same patient shared the same multilocus genotype. In two patients slight differences were observed, in only one microsatellite marker, suggesting microevolution events and in three patients, strains isolated from urine were genetically distinct from those isolated from blood. These results indicated that isolates from the upper respiratory tract and blood were exactly the same strain or the same strain undergoing microevolutionary processes, which support that in patients with high risk of fungemia, the isolation of C. albicans from other body sites represents a clinical precursor that should raise the alert for earlier therapeutical intervention. Sampaio et al., 2003 Highly Polymorphic Microsatellite for the Identification of Candida albicans strains. J Clin Microbiol 41:552-557, 2003.
2005

abstract No: 

54

Full conference title: 

15th Annual Focus on Fungal Infections
    • FFI 15th (2005)