RESUMO
In this work we compare the antifungal capacity of zinc oxide nanoparticles (ZnO-NPs) synthesized by a chemical route and a ZnO-based nanobiohybrid obtained by green synthesis in an extract of garlic (Allium sativum). To find out the characteristics of the materials synthesized, X-ray diffraction (XRD), IR spectroscopy and absorption in UV-Vis were used, as well as both scanning (SEM) and transmission (TEM) electron microscopy. The results showed that the samples obtained were of nanometric size (<100â¯nm), with a predominance of the wurtzite crystal phase of ZnO and little crystallization of the nanobiohybrids. Their antifungal capacity on two pathogenic fungi of coffee, Mycena citricolor (Berk and Curt) and Colletotrichum sp. was also evaluated. Both nanomaterials showed an efficient antifungal capacity, particularly the nanobiohybrids, with ~97% inhibition in growth of M. citricolor, and ~93% for Colletotrichum sp. The microstructural study with high resolution optical (HROM) and ultra-structural microscopy (using TEM) carried out on the fungi treated with the synthesized nanomaterials showed a strong nanofungicidal effect on the vegetative and reproductive structures and fungal cell wall, respectively. The inhibition of the growth of the fungi and micro and ultra-structural affectations were explained considering that the size of the nanomaterials allows them to pass easily through the cell membranes. This indicates that they can be absorbed easily by the fungi tested here, causing cellular dysfunction. Nanofungicide effects are also attributable to the unique properties of nanomaterials, such as the high surface-to-bulk ratio of atoms and their surface physicochemical characteristics that could directly or indirectly produce reactive oxygen species (ROS), which affect the proteins of the cell wall.
Assuntos
Antifúngicos/farmacologia , Basidiomycota/efeitos dos fármacos , Café/microbiologia , Colletotrichum/efeitos dos fármacos , Nanopartículas/química , Óxido de Zinco/farmacologia , Basidiomycota/crescimento & desenvolvimento , Basidiomycota/ultraestrutura , Colletotrichum/crescimento & desenvolvimento , Colletotrichum/isolamento & purificação , Colletotrichum/ultraestrutura , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Cebolas/química , Tamanho da Partícula , Extratos Vegetais/química , Espectrofotometria Ultravioleta , Difração de Raios XRESUMO
OBJECTIVE: The purpose of this study is to determine the seroprevalence of blood borne transmissible diseases of the orthopaedic trauma surgical patients who deny or did not have knowledge of having disease or risk factors, but are positive for either human immunodeficiency virus, hepatitis B virus, and hepatitis C virus. BACKGROUND: Orthopaedic surgeons practicing in areas with a high prevalence of HIV infection may expect that up to 7% of their patients who undergo emergency procedures and 1% to 3% of those who undergo elective surgery will be HIV-positive. METHOD: All conscious adult patients consecutively admitted for surgical management by the orthopaedic service were evaluated. A detailed questionnaire was completed asking the patient of knowledge of having a transmissible disease and documenting certain risk factors. Blood samples were taken to test for HIV, HBV and HCV and all positive patients were sent to a follow up clinic. RESULTS: Out of 100 patients the following results were found: 7% were positive for HIV, 12% positive for HBV, 12% positive for HCV, 19% were positive to at least one test, and 9% were positive in more than one test. Of the one hundred patients, 6% had a positive test in spite of denying having a disease or any risk factors. None of the patients with HBV and/or HCV knew they were positive and three (43%) of the seven with HIV were also unaware of their condition. CONCLUSIONS: This study suggests that a worrisome number of patients are seropositive for a blood borne transmissible disease, even though they had no knowledge of such disease and claimed they had no risk factors. In order to protect orthopaedic surgeons from the unreliability of some patients' histories, all trauma orthopaedic surgical patients should be managed with universal precautions.