The European Confederation of Medical Mycology (ECMM) survey of candidaemia in Italy: in vitro susceptibility of 375 Candida albicans isolates and biofilm production.
OBJECTIVE
To investigate the in vitro antifungal susceptibility pattern of 375 Candida albicans bloodstream isolates recovered during the European Confederation of Medical Mycology survey of candidaemia performed in Lombardia, Italy and to test the ability to form biofilm.


METHODS
In vitro susceptibility to flucytosine, fluconazole, itraconazole, posaconazole, voriconazole and caspofungin was performed by broth microdilution following the NCCLS guidelines. Biofilm production was measured using the XTT reduction assay in 59 isolates selected as representative of different patterns of susceptibility to flucytosine and azoles.


RESULTS
MICs (mg/L) at which 90% of the strains were inhibited were < or =0.25 for flucytosine, 0.25 for caspofungin, 4 for fluconazole and 0.06 for itraconazole, voriconazole and posaconazole. Flucytosine resistance was detected in five isolates and was associated with serotype B in 2/29 and serotype A in 3/346. Resistance to fluconazole was detected in 10 isolates; nine of these exhibited reduced susceptibility to the other azoles. Among the 10 patients with fluconazole-resistant C. albicans bloodstream infection, only one, an AIDS patient, had been previously treated with fluconazole. Biofilm production was observed in 23 isolates (39%) and was significantly associated with serotype B. No relationship was detected with the pattern of antifungal susceptibility.


CONCLUSIONS
Resistance is uncommon in C. albicans isolates recovered from blood cultures, while biofilm production is a relatively frequent event. Periodic surveillance is warranted to monitor the incidence of in vitro antifungal resistance as well as of biofilm production.
Tortorano
Anna Maria
AM
Istituto di Igiene e Medicina Preventiva, Università degli Studi di Milano, via Pascal 38, 20133 Milano, Italy. annamaria.tortorano@unimi.it
Prigitano
Anna
A
Biraghi
Emanuela
E
Viviani
Maria Anna
MA
D000935:Antifungal Agents / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D002176:Candida albicans / Q000187:drug effects* / Q000502:physiology; D002177:Candidiasis / Q000453:epidemiology* / Q000382:microbiology*; D003625:Data Collection; D025141:Drug Resistance, Fungal; D005060:Europe; D016469:Fungemia / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D009172:Mycology
D000935:Antifungal Agents