Abstract
C. albicans has recently been described as a secondary colonizer associated with periodontal infections. This study aimed to determine the expression patterns of ALS and SAP family genes in C. albicans strains isolated from patients with periodontal disease (n = 268), and a control group of healthy individuals without any clinical signs of periodontal disease (n = 100) was included. C. albicans and the ALS and SAP genes were identified using polymerase chain reaction (PCR). An in vitro infection model was used with the strains using the human gingival fibroblast cell line. RNA was extracted using a QIAcube robotic workstation (Qiagen). A QuantiTect Reverse Transcription Kit (Qiagen) was used for first-strand cDNA synthesis. ALS and SAP gene expression in the strains was determined using real-time PCR. A total of 82.5% (n = 66) of the C. albicans strains were isolated from patients with moderate periodontitis, 10% (n = 8) from patients with chronic periodontitis, and 7.5% (n = 6) from patients with gingivitis. In the group of healthy individuals, C. albicans was identified in 9% (9/100). Overall, the most frequently expressed ALS genes in the strains from the three diagnoses were ALS1 (77/80), ALS3 (67/80), ALS4 (67/80), ALS6 (77/80), ALS7 (62/80), and ALS9 (73/80), while the most frequently expressed SAP genes were SAP1 (76/80), SAP6 (57/80), SAP9 (78/80), and SAP10 (77/80). The overall frequencies of expression of the ALS4, ALS9, SAP2, SAP3, SAP6, and SAP genes in the strains were statistically different across the three diagnoses. We identified different profiles of expression of the ALS and SAP genes in the strains of C. albicans that contribute directly to the degree of periodontal disease. Therefore, our findings may contribute to improving our knowledge of the molecular mechanisms of C. albicans in the pathogenesis of periodontal disease.