Biofilm formation by basidiomycete and ascomycete yeasts in the intestines under different temperature and oxygen conditions

Prokopiev V.V., Karabasova Е.B., Kraft L.A., Kuklina N.V., Yurova V.A.

Clinical and diagnostic laboratory«Zdorovie», Barnaul, Russia
Altai State Medical University, Barnaul, Russia

Aims. To evaluate the ability of biofilm formation by basidiomycete (Rhodotorula mucilaginosa, Trichosporon asahii) and ascomycete (Geotrichum candidum, Pichia kudriavzevii, Candida albicans) yeast isolated from the human intestine at different temperatures, under aerobic, anaerobic and hypercapnic conditions.
Methods. Evaluation of biofilm formation was performed by measuring optical density. Flat-bottom plastic plates with test strains were incubated for 96 hours under aerobic conditions at 37°C and 25°C, under hypercapnic conditions (10% CO2) at 37°C, and under anaerobic conditions at 25°C. After incubation, the plates were washed three times with physiological saline, and the optical density of the formed microbial aggregates was check investigated photometrically.
Results. It was found that C. albicans and P. kudriavzevii are capable of forming biofilms in all studied temperature and oxygen regimes. T. asahii formed biofilms only under aerobic conditions at the specified temperature regimes. G. candidum and Rh. mucilaginosa formed films under aerobic conditions only at 25°C.
Conclusions. The ability of C. albicans and P. kudriavzevii to biofilm formation under temperature-oxygen conditions similar to the conditions of various biotopes of the human body allows substantiating the high pathogenic potential of these fungi. The need for aerobic conditions for T. asahii will partially explain its predominant parasitism on the skin and their appendages. The failure of G. candidum and Rh. mucilaginosa to biofilm formation under human conditions may indicate their low pathogenic potential.