Developmental study of the morphogenesis of the yeast candida albicans in response to some inducers and inhibitors.

number: 
609
English
Degree: 
Imprint: 
Biotechnology
Author: 
Ahmed Abdul Jabbar Suliaman
Supervisor: 
Dr. Mohammed A. K. Ibrahim
year: 
2002

This work was aimed to study the developmental patterns of the pathogenic yeast Candida albicans,therefore fifty isolates of Candida spp. were collected from different sources such as oral thrush,vagina,skin,hair and nail. These isolates were identified by biochemical and morphological tests,and it was found that the most isolates were belong to Calbicans(30isolates),the other identified species were :- C. dubliniesis, C. tropicalis, C. krusei, C.parapsilosis, C.stelloidea and C.glabrdta The minimum inhibitory cocentration for nystatin, cycloheximide, and acridine orange were 80,1500,25 ug/ml respectively,and the used concentration for the inhibition of morphogenesis were 35,1000,13ug/ml respectively. The optimum parameters for germ tube formation in sabouraud dextrose broth were 37°C at pH 7, and at cell density of l06 cell/ml. Ten of C. albicans isolates were classified according to their efficiency for germ tube formation in sabouraud dextrose broth at 37°C and pH 7 for and at cell density of 106 cell/ml . Two pure cell line of C. albicans for both high effecient and low efficient isolates for germ tube formation were isolated by micromanipulation.Then different media were used to study the morphogenesis in C.albicans The more efficient media for bud formation were sabouraud dextrose broth andyeast extract glucose broth, and all isolates had same efficiency for budding. Germ tube formation, pseudohyphal formation , and true hyphal "formation were studied in plasma containing medium, Zhang medium, and SDB medium. It was found that the high effecient isolate(l) was more efficient for germ tube and hyphae formation and ail isolates had same efficiency forpseudohyphae formation. The better medium for pseudohyphal formation was sabouraud dextrose broth while plasma containing medium was more efficient medium for germ tube and hyphal formation. The com meal agar was the suitable medium for chlamydospore formation and the high effecient isolate(l) formed chlamydospores more than other isolates . The presence of nystatin, cycloheximide, and acridine orange at sub-inhibitory concentrations in induction media of different forms of C. albicans led to approximately complete inhibition of hyphae and chlamydospore formation, inhibition of germ tube at different proportion, whereas their effects on bud and pseudehyphae formation were undetectable. The results of protein profile study showed that the C albicans have different proteins involved exoressed in different media for germ tube formation. Moreover plasma induce multiple proteins responsible for germ tube formation.