الملخص

Objectives: To detect the virulence factors of yeasts which are proteinase and phospholipase                 which have important role in the pathogenesis of oral lesions.                                                                                               Patients and methods: This study included 120 children manifested with oral lesions admitted to the Consultating Clinic and Medical Wards of   Ibn – Sina and Ibn Al – Ather Teaching Hospitals in addition to Neonatal Care Unit of Al – Battol Teaching Hospital. Samples collected during the period from December 2012 – May 2013. Control group was 60 apparently healthy children from whom oral swabs 'were obtained.  Identification' of' the isolated yeasts were conceded by "direct examination, culture, biochemical tests and API – 20 C system, then detection of' protienase and phospholipase of yeasts isolated from oral lesions".                                                        Results: Candida albicans isolates have a high expression rate for the production of proteinase (95.3%) and phospholipase(97.1%) in comparison to the other candida and yeast species with a significant difference     (p = 0.001).  Conclusion: The isolates produce two important virulence factors namely proteinase and phospholipase significantly more in Candida albicans than other yeasts.