Uptake of clinical yeast isolates by human epithelial cell line.

OBJECTIVE: The occurrence of yeast infections in humans has increased, with the species belonging to genus Candida still being the most common cause of infection. Nevertheless, infections caused by less common yeasts have been widely reported in recent years. The main objective of this study was to assess the potential of these less common saprophytic yeasts to invade the host cell, which is essential for causing systemic infections. MATERIAL AND METHODS: Various yeast isolates were identified by DNA sequence information of PCR amplified ITS region. The purported saprophytic yeasts were characterized for internalization by mammalian cells in vitro, by staining the F-actin. CONCLUSION: The identification of different yeast isolates from various patients revealed that 70% of the isolates belonged to the genus Candida, while remaining 30% of the isolates were yeasts not belonging to genus Candida. These non-Candida clinical isolates, either in yeast or hyphal forms, were efficiently internalized by human epithelial cells. The internalization was marked by a process of actin polymerization surrounding the invading yeast. Such uptake by epithelial cells signifies traversal of cell barrier by yeast cells during infection in vivo.

Immune response modulation to DPT vaccine by aqueous extract of Withania somnifera in experimental system.

Immunopotentiation on oral feeding of standardized aqueous extract of Withania somnifera (Linn. Dunal, Family Solanaceae) was evaluated in laboratory animals immunized with DPT (Diphtheria, Pertussis, Tetanus) vaccine. The immunostimulation was evaluated using serological and hematological parameters. Treatment of immunized animals with test material (100 mg/kg/day) for 15 days resulted in significant increase of antibody titers to B. pertussis (P=0.000007). Immunized animals (treated and untreated) were challenged with B. pertussis 18,323 strain and the animals were observed for 14 days. Results indicate that the treated animals did show significant increase in antibody titers as compared to untreated animals after challenge (P=0.000003). Immunoprotection against intracerebral challenge of live B. pertussis cells was evaluated based on degree of sickness, paralysis and subsequent death. Reduced mortality accompanied with overall improved health status was observed in treated animals after intracerebral challenge of B. pertussis indicating development of protective immune response. Present study indicates application of the test material as potential immunopotentiating agent possible applications in immunochemical industry. The test material also offers direct therapeutic benefits resulting in reduced morbidity and mortality of experimental animals.