Effects of helium-neon (HeNe) laser on Paracoccidioides brasiliensis yeast cells

Author(s)

Rosaria Di Gangi

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2012-04-07

Examining board members

Liana Maria Cardoso Verinaud; Dagmar Ruth Stach Machado; Edmilson Ricardo Gonçalves

• Advisor: Luciana Campos Paulino; Liana Maria Cardoso Verinaud

Abstract

Paracoccidioidomycosis (PMC), caused by the fungus Paracoccidioides brasiliensis (Pb), mainly affects the lungs and also causes painful lesions in the skin and mucous membranes that can remain active for months even after the beginning of antifungal treatment. In this work, we evaluated the effects of laser treatment on fungal cells, aiming to provide support for the use of this therapy during PCM. Pb yeast cells were exposed to laser for three consecutive days and then analyzed for growth inhibition, viability, 43-kDa glycoprotein (gp43) expression, infectivity, and ultra-structural alterations. HeNe laser treatment reduced the growth capacity and the viability of fungal cells, and increased gp43 expression. Laser-treated cells also showed pronounced structural alterations, since they were collapsed and presented deep folds. Additionally, remarkable changes were observed in the nucleus that presented a very electrondense form. The pathogenicity of P. brasiliensisafter laser treatment was also evaluated,and no differences were observed in pulmonary lesions comparing animals infected with laser-treated and non-treated yeast cells. Possibly HeNe laser is able to modify fungal structures involved in resistance and virulence mechanisms and therefore can be considered as an adjunctive therapy in the treatment of skin lesions observed during PCM (AU)

• FAPESP's process: 10/02239-2 - In vitro action of HeNe laser on the fungus Paracoccidioides brasiliensis
• Grantee: Rosária Di Gangi
• Support Opportunities: Scholarships in Brazil - Master