Search for biological control agents against Candida yeasts and other dermatomycetes

Abstract

The objective of this work was to screen the killer action of the bacterial isolates T1x, T2x, T3x, Ux and Ux308 against some dermatomycetes and the genus Candida yeast. The bacterial isolates T1x, T2x, T3x, Ux were recovered from spontaneous fruit and berry fermentations and the Ux308 isolate from soil. The raw materials were gathered in Lithuania. The dermatomycetes and Candida yeast were isolated from morbid material of patients with diagnosed dermatomycosis and onychomycosis at the Vilnius University Hospital Santariškių Klinikos Diagnostic Centre. The killer ability was tested using routine methods and standard yeast Saccharomyces cerevisiae strains. In the course of screening bacterial isolates for killer activity we found that the bacterial isolate T1x exhibited a very strong antifungal action against the dermatomycetes Trichophyton rubrum. Extracts of the bacterial isolates T1x, T2x, T3x, Ux and Ux308 showed a killer effect against Candida yeast. The growth of dermatomycete Microsporum canis was fungistatically affected by bacterial Ux isolate. The results of investigation showed that there is essential to study the biochemical properties of substances which are secreted of the bacterial isolates T1x, T2x, T3x, Ux and Ux308. The fact that the substances from bacterial isolates kill some pathogenic microorganisms allows us to expect their use in medicine. It is possible that the toxins secreted of bacterial isolates could kill also other genera of yeast and micromycetes. Keywords: dermatomycetes, Candida, bacteria, killer activity