The killer effect of Saccharomyces cerevisiae , Saccharomyces bayanus and Hansenula anomala on Candida albicans

C. albicans is a commensal yeast which asymptomatically colonizes mucosal surfaces; however, any disruption in the host environment or under conditions of immune dysfunction, C. albicans can proliferate and invade virtually any site in the host. S. cerevisiae is found in nature associated with man and, more rarely, found on the skins of grapes. S.bayanus can be found in locations remote from humans, which is not in common with S. cerevisiae . H. anomala ecological traits include: fermentation contaminant, soil, grain, ensilage, water, plants (especially fruits and fermenting matter), sewage, warm blooded animals. The scope of this study was to see if S. cerevisiae, S.bayanus, and H. anomala have any killer effect on C. albicans strains. We have realized it at Phytotoxin Laboratory, Department of Plant Protection, Durrës, Albania. We have analyzed 20 positive samples of C. albicans, isolated in the Microbiological Laboratory of Durrës, Albania. It has resulted that Hansenula anomala has the greatest killer effect of these three yeasts on Candida albicans strains, while the effect of Saccharomyces cerevisiae and Saccharomyces bayanus is almost rough, with minor differences between C. albicans strains. Keywords— Candida albicans, Saccharomyces cerevisiae, Saccharomyces bayanus, Hansenula anomala, killer


INTRODUCTION
Candida albicans is the most common human fungal pathogen causing diseases ranging from mucosal to systemic infections.As a commensal, C. albicans asymptomatically colonizes mucosal surfaces; however, any disruption in the host environment or under conditions of immune dysfunction, C. albicans can proliferate and invade virtually any site in the host.The ability of this highly adaptable fungal species to transition from commensal to pathogen is due to a repertoire of virulence factors (Christina Tsui et al., 2016).Saccharomyces cerevisiae belongs to the phylum Ascomycota and can be reproduced in these ways: Spore: Spherical often in groups of four; Zygote: dumbell-shaped; Ascus: group of four spores arranged in a tetrad conformation S. cerevisiae is found in nature associated with man and, more rarely, found on the skins of grapes (H.Konig et al., 2009).Saccharomyces bayanus belongs to the phylum Ascomycota.S. bayanus reproduction has three possible ways: Spore: spheroidal and smooth; Zygote: diploid vegetative cell; Ascus: typically four spores per ascus, ascus persistent S.bayanus can be found in locations remote from humans, which is not in common with S. cerevisiae (Naumov et al., 2001).Hansenula anomala is an Ascomycete fungus.H. anomala can be in two different forms: cells, spheroidal to elongate (1.9-4.1)X(2.1-6.1)µmsingly, pairs, small clusters; ovoid, ellipsoidal, or cylindrical, multilateral buddin or pseudohyphae form as chains of ovoid or cylindroidal cells.H. anomala ecological traits include: fermentation contaminant, soil, grain, ensilage, water, plants (especially fruits and fermenting matter), sewage, warm blooded animals (Kurtzman 1998).

II. MATERIALS AND METHODS
We have realized this study at Phytotoxin Laboratory, Department of Plant Protection, Durrës, Albania.We have study the effect of the three supposed "killer" yeasts: Saccharomyces cerevisiae, Saccharomyces bayanus, Hansenula anomala, on C. albicans strains.The same steps were taken with Saccharomyces cerevisiae, Saccharomyces bayanus, Hansenula anomala.We have taken S. bayanus and H. anomala in the Biotechnology Laboratory, Biotechnology Faculty, Tirana, Albania, but to take the isolated colonies we plated them in solid YEPD medium.

International Journal of
Each isolate of C. albicans was then incubated in 10 ml of liquid YEPD medium, for 18 hours in 25 °C in a rotary shaker (120 rpm). 1 ml of this culture was diluted in 10 ml fresh liquid YEPD medium. 1 ml of the diluted culture has been mixed with 20 ml fresh solid YEPD medium and then plated in Petri dishes, to get an Agar-C.albicans medium.
In this medium we have plated S. cerevisiae, S. bayanus dhe H. anomala and we have incubated them in 25°C, for 72 hours.
For compare propose, we have deluted the 48 hours culture of C. albicans in 10 ml distilled water. 1 ml of this suspention was mixed with 20 ml fresh solid YEPD medium and then plated in Petri dishes, to get an Agar-C.albicans medium.Then we have incubated the dishes in 25°C for 72 hours.

III. RESULTS AND DISCUSSION
We have determined the effect of the three "killer" yeasts by counting the colonies on each C. albicans strains (C1A-C20A).In the case of positive control, since the number of C. albicans colonies was very large and evenly spread throughout the plate, we first made the division of the plate into 8 equal parts, we counted the colonies in one of them and we multiplied by 8.After the effect of the "killer" yeasts, counting the remaining C. albicans colonies was very easy.
The results are shown in table 1

International Journal of Medical, Pharmacy and Drug Research (IJMPD) [Vol-2, Issue-2, Mar-Apr, 2018] https://dx.doi.org/10.22161/ijmpd.2.2.1 ISSN: 2456-8015
Therefore, we can say that Hansenula anomala has the greatest killer effect of these three yeasts on Candida albicans strains, while the effect of Saccharomyces cerevisiae and Saccharomyces bayanus is almost rough, with minor differences between C. albicans strains.Characteristic of H. anomala on C. albicans strains was that this yeast clouded the medium, while S. cerevisiae clarified it.The killer effect of S. cerevisiae, S. bayanus dhe H. anomala on C. albicans strains are shown in Figure1.1.Fig.1.1:The killer effect of S. cerevisiae, S. bayanus dhe H. anomala on C. albicans strains