Ecophysiology of environmental Aspergillus fumigates and comparison with clinical strains on gliotoxin production and elastase activity.

ALONSO V; AMINHAUEL C; DÍAZ VERGARA L; PEREYRA C; POLONI V; DALCERO A C; CAVAGLIERI L

LETTERS IN APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 62 p. 160 - 168

0266-8254

The aim of this manuscript was to study the influence of water activity (aW)and pH in the ecophysiological behaviour of Aspergillus fumigatus strains athuman body temperature. In addition, gliotoxin production and enzymaticability among environmental (n = 2) and clinical (n = 5) strains werecompared. Ecophysiological study of environmental strains was performed onagar silage incubated at 37°C, studying the interaction at eight aW levels (08,085, 09, 092, 094, 096, 098 and 099) and eight pH levels (35, 4, 45, 5, 6,7, 75 and 8). Considering the influence of the assumed lung conditions ongrowth of A. fumigatus (aW 098/099 and pH of 7/75), the optimal conditionfor the development of A. fumigatus RC031 was at aW 099 at pH 7. At aW098/099 and pH of 7/75, the highest growth rate and the lowest lag phasewas reported, whereas there were no significant differences at aW 098/099 andpH 7/75 interactions on growth of A. fumigatus RC032. Gliotoxin productionof A. fumigatus strains was evaluated. The gliotoxin production was similar inclinical and environmental strains. Elastin activity was studied in solidmedium, highest elastase activity index was found for clinical strainA. fumigatus RC0676, followed by the environmental strain A. fumigatusRC031. Opportunistic environmental strains can be considered as pathogenicin some cases when rural workers are exposed constantly to handling silage.