Density and susceptibility pattern of aspergillus in the air and on the surfaces of a tertiary hospital

P Giakkoupi, A Kanta, GL Petrikkos, S Adamidou, A Aviami, D Fasouli.


Introduction:Aspergillus sp, a common inhabitant of soil, releases a high number of conidia to the atmosphere.As such, an increase in the concentration of airborne spores resulting from construction work has been implicated in outbreaks of nosocomial aspergillosis. Objectives: To investigate the epidemiology of fungi in the air inside our hospital and on clinically important surfaces of the hospital during a building reconstruction period. Also the susceptibility pattern of the isolates to commonly used antifungal agents was detenmined. Materials & Methods: Environmental samples were always collected from the same locations (rooms with transplanted patients and with hematological malignansies) monthly, for 12 months (March 2000 to February 200 1).Aerial conidia were recovered using the airsampler BIOTEST RCS, which filters 1600L per sample. Spores were collected on Sabouraud medium strips supplemented with 0,05% chloramphenicol. To isolate spores deposited on surfaces a known area was swabbed with sterile cotton swaps, which were used to inoculate Sabouraud-chloramphenicol medium. Isolates were identified using culture characteristics, and morphology of conidiophores and conidia. Susceptibility testing of amphotericin B, itraconazole and voriconazole for 20A.niger, 20 A.flavus and 7 A.fumigatus was performed using the broth microdilution method according to the guidelines of NCCLS (M38-P). Results: 341 strains were collected from the air and 373 from the surfaces. The density of the Aspergillus conidia (A.niger, A.flavus and A.fumigatus) in the air showed a seasonal variation: higher densities were measured during the summer than during the winter (6-11,3CFU/m3 compared to 3,4-4,2CFU/m3). The density of non Aspergillus conidia (Rhizopus sp, Alternaria sp, Trichophyton sp) was higher in the period of high humidity (in autumn it raised to 7,7 CW1m3). Little variation was found in the numbers of Aspergillus conidia on the surfaces, from which 20-ST/G were Candida.The MIC values of amphotericin B for A.flavus (1 -4 g/L) were relatively higher than for A.niger (0,25- 1 g/L) and A.fumigatus (0,5-2g/L). ltraconazole had a cytostatic influence on A.niger isolates. A.fumigatus isolates (0, 125-0,25 g/L) were less susceptible than A.flavus (

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Full conference title: 

Trends in Invasive fungal Infections 6, 2001
    • TIFI 6th