Biocontrol mechanisms of the Antarctic yeast Debaryomyces hansenii UFT8244 against post-harvest phytopathogenic fungi of strawberries.

The use of yeasts has been explored as an efficient alternative to fungicide application in the treatment and prevention of post-harvest fruit deterioration. Here, we evaluated the biocontrol abilities of the Antarctic yeast strain Debaryomyces hansenii UFT8244 against the post-harvest phytopathogenic fungi Botrytis cinerea and Rhizopus stolonifer for the protection and preservation of strawberry fruit. The strongest inhibition of germination of B. cinerea (57%) was observed at 0 °C, followed by 40% at 25 °C. In addition, germ tubes and hyphae of B. cinerea were strongly surrounded and colonized by D. hansenii. Production of the enzymes ß-1,3-glucanase, chitinase and protease by D. hansenii was detected in the presence of phytopathogenic fungus cell walls. The activity of ß-1,3-glucanase was highest on day 12 of incubation and remained high until day 15. Chitinase and protease activities reached their highest levels on the day 15 of incubation. D. hansenii additionally demonstrated the ability to resist oxidative stress. Our data demonstrated that the main biocontrol mechanisms displayed by D. hansenii were the control of phytopathogenic fungal spore germination, production of antifungal enzymes and resistance to oxidative stress. We conclude that isolate D. hansenii UFT8422 should be further investigated for use at commercial scales at low temperatures.

Aspectos epidemiológicos e terapêuticos das infecções oculares em serviços de referência / Epidemiology and therapy of ocular infections in eye's hospitals

Introdução: As infecções oculares são um desafio constante na prática oftalmológica diária. Material e Métodos: Foram analisados 155 casos de infecções oculares supostamente bacterianas, atendidos nos serviços do Instituto/Fundação Hilton Rocha, de janeiro de 1996 a dezembro de 1999. Resultados: O quadro clínico predominante foi a conjuntivite (29,6 por cento), seguido pela blefarite (27,09 por cento) e úlcera de córnea (21,29 por cento). Nos casos de cultura positiva, os microorganismos mais comumente isolados foram o estafilococos epidermidis (48,12 por cento) e o estafilococos aureus (38,34 por cento). Dentre os agentes patológicos detectados, o estafilococos aureus foi o que apresentou maior resistência aos antibióticos utilizados na prática oftalmológica (41,18 por cento a ofloxacina). Conclusão: A análise laboratorial rigorosa e a escolha criteriosa dos medicamentos, muitas vezes com associação de drogas, são passos fundamentasis para o sucesso nestes casos.