Genetic relatedness and antifungal susceptibility profile of Candida albicans isolates from fungaemia patients.
A prospective study to assess fungaemia was conducted for 12 months at a Portuguese University Hospital. A total of 35 Candida albicans isolates obtained from 12 patients with fungaemia were compared by a multiplex PCR system using four microsatellite loci. Blood isolates were evaluated against concomitant isolates from urine, lower respiratory secretions and central venous catheters, as well as with successive isolates recovered from recurrent episodes of fungaemia. The data analyzed included the department of admission, underlying diseases and antifungal therapy. The susceptibility phenotypes of all isolates to amphotericin B, fluconazole, itraconazole, voriconazole and caspofungin were determined according to the CLSI M27-A3 protocol. We observed a high degree of similarity between successive blood isolates and between blood and concomitant isolates from other sites of the same patient. This is suggestive of the recurrence of fungaemia and was due to the same strain, possibly as a result of the failure of antifungal therapy. The genetic similarity observed between some strains isolated from different patients suggested the likelihood that they were hospital acquired. Distinct patients were infected by the same strain at different time periods, and an increase in antifungal resistance was observed over time for some of these strains. Hospital-acquired exogenous nosocomial infections can be associated with higher risks of antifungal resistance and need to be closely monitored. Particular attention should also be given to endogenous non-blood Candida isolates which can be critical in high risk patients, as they often can become invasive in immunodeficient individuals.
Costa-de-Oliveira
Sofia
S
Department of Microbiology, Faculty of Medicine, University of Porto, Porto. Portugal. sqco@med.up.pt
Sousa
Inês
I
Correia
Alexandra
A
Sampaio
Paula
P
Pais
Célia
C
Rodrigues
Acácio Gonçalves
AG
Pina-Vaz
Cidália
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000935:Antifungal Agents / Q000494:pharmacology; D002176:Candida albicans / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D058387:Candidemia / Q000453:epidemiology* / Q000382:microbiology*; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000235:genetics; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D018895:Microsatellite Repeats; D008875:Middle Aged; D017720:Molecular Epidemiology; D058889:Molecular Typing; D016533:Mycological Typing Techniques; D016133:Polymerase Chain Reaction; D011174:Portugal / Q000453:epidemiology; D011446:Prospective Studies; D012008:Recurrence
D000935:Antifungal Agents; D004271:DNA, Fungal