Utilização de porfirinas na inativação fotodinâmica do Herpesvírus bovino 1

• Autor(a) principal: Teles, Amanda Vargas
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5698
• topic: BoHV-1; Fotoinativação; Fotodegradação; Fotossensibilizadores; BoHV-1; Photoinactivation; Fotodegradation; Photossensitizer; MEDICINA VETERINARIA PREVENTIVA::SAUDE ANIMAL (PROGRAMAS SANITARIOS)

Bovine herpesvirus 1 (BoHV-1) is a virus of the family Herpesviridae and the subfamily Alphaherpesvirinae, known to cause several diseases worldwide in cattle, including rhinotracheitis, vaginitis, balanoposthitis, abortion, conjunctivitis, and enteritis. O BoHV-1 is a source of economic loss for both dairy and beef producer due to a decrease in dairy production, decrease in animal weight gain, a higher susceptibility to secondary infections, and the occurrences of abortions. Aiming at new alternatives for the treatment and disposal of these cattle pathogen, the photoinactivation becomes a viable alternative because this treatment has shown to be effective against animal and human microorganisms. The technique is based on the synergistic combination of a photosensitizer (PS), oxygen, and light. When irradiated by a light source, the photosensitizer undergoes a series of photophysical processes, which culminate in the generation of reactive oxygen species (ROS), which in large amounts are toxic to pathogens. Aiming at a better efficiency of photoinactivation is necessary to know the characteristics of each photosensitizer, analyzing the molecular structure, quantum yield, lifetime, toxicity, stability, and absorption at specific wavelengths. The irradiation time has shown to be very important because each PS reacts differently at a given time. To evaluate the effect of the electrical charges present on PS, zinc insert ring in the central ring of the molecule and the irradiation time in the photodynamic inactivation, BoHV-1 aliquots were used with initial viral titer from 105.75 incubated for one hour with four different photosensitizers: TPPS4, ZnTPPS4, TMPyP, and ZnTMPYP. Subsequently, they we irradiated for two hours and sampled every 15 minutes. As control, we used virus without any treatment, virus irradiated in the absence of PS, and virus with PS without radiating. After irradiation, the sample was added to cultures of cells permissive to the virus, which was analyzed for the presence of cytopathic effect (CPE), and the results were expressed as viral titers. Although all treatments had significant differences, all PSs used in the study were effective in the treatment of BoHV-1. The ZnTMPYP was the most efficient, fully inactivating the virus with 30 minutes of irradiation, and the TPPS4 showed the worst result unable to inactivate the virus after the period of irradiation, but considerably reduced the viral load of BoHV -1. We also analyzed the photodegradation of a plasmid DNA using the same photosensitizers. Again, ZnTMPYP showed better results.