In Vitro and In Vivo Activities of Ruthenium(II) Phosphine/Diimine/Picolinate Complexes (SCAR) against Mycobacterium tuberculosis

Rifampicin, discovered more than 50 years ago, represents the last novel class of antibiotics introduced for the first-line treatment of tuberculosis. Drugs in this class form part of a 6-month regimen that is ineffective against MDR and XDR TB, and incompatible with many antiretroviral drugs. Investments in R&D strategies have increased substantially in the last decades. However, the number of new drugs approved by drug regulatory agencies worldwide does not increase correspondingly. Ruthenium complexes (SCAR) have been tested in our laboratory and showed promising activity against Mycobacterium tuberculosis. These complexes showed up to 150 times higher activity against MTB than its organic molecule without the metal (free ligand), with low cytotoxicity and high selectivity. In this study, promising results inspired us to seek a better understanding of the biological activity of these complexes. The in vitro biological results obtained with the SCAR compounds were extremely promising, comparable to or better than those for first-line drugs and drugs in development. Moreover, SCAR 1 and 4, which presented low acute toxicity, were assessed by Ames test, and results demonstrated absence of mutagenicity. © 2013 Pavan et al.

Photodynamic inactivation of biofilm: Taking a lightly colored approach to stubborn infection

Microbial biofilms are responsible for a variety of microbial infections in different parts of the body, such as urinary tract infections, catheter infections, middle-ear infections, gingivitis, caries, periodontitis, orthopedic implants, and so on. The microbial biofilm cells have properties and gene expression patterns distinct from planktonic cells, including phenotypic variations in enzymic activity, cell wall composition and surface structure, which increase the resistance to antibiotics and other antimicrobial treatments. There is consequently an urgent need for new approaches to attack biofilm-associated microorganisms, and antimicrobial photodynamic therapy (aPDT) may be a promising candidate. aPDT involves the combination of a nontoxic dye and low-intensity visible light which, in the presence of oxygen, produces cytotoxic reactive oxygen species. It has been demonstrated that many biofilms are susceptible to aPDT, particularly in dental disease. This review will focus on aspects of aPDT that are designed to increase efficiency against biofilms modalities to enhance penetration of photosensitizer into biofilm, and a combination of aPDT with biofilm-disrupting agents. © 2013 Informa UK Ltd.

Atividade antimicrobiana in vitro de extrato de Punica granatum L. sobre staphylococcus aureus isolado em leite bovino

Bovine mastitis is considered important disease causing major economic losses in dairy herds. Antimicrobial drug can promote resistance, chemical residues in food and environmental contamination. The purpose of this study was to evaluate the antibacterial activity in vitro of pomegranate extract on Staphylococcus aureus isolated from bovine milk, evaluate its antioxidant activity, and quantify levels of total phenols and fravonoides of the different extracts used. Aqueous extracts were used in nature and dry, from the peel of the fruit (EAC) and leaves (EAF). Additionally, it was evaluated the antioxidant activity (AA%), total phenols and flavonoids. Milk samples were inoculated, incubated, and the colonies were characterized as Staphylococcus aureus were adjusted to 1.0x106 UFC/mL in the 6 standard of the MacFarland scale. The sensitivity of the microbial isolates were determined in quintuplicate, in disk diffusion test. The minimum inhibitory concentration was determined by visible inhibition zone greater than 15mm. The results were evaluated by ANOVA, Tukey 5%, using the program SISVAR 5.3 - DEX/UFLA. Results implied that the aqueous extract from the bark of dried fruit was capable of inhibiting bacterial growth at concentrations of 3%. The other treatments only showed this activity, from the concentrations of 15%, 20% and 30% for dry EAF, in nature EAC and in nature EAF, respectively. Regarding the action antioxidant of dry EAC, was not correlated with total phenols and flavonoids. Probably other alkaloids substances present in the extract studied, may have been responsible for this activity. It is concluded that extracts of Punica granatum L., especially those obtained by the shell of the fruit, showed inhibitory activity against S. aureus, indicating your use potential for the control of bovine mastitis.

Antimicrobial Brazilian propolis (EPP-AF) containing biocellulose membranes as promising biomaterial for skin wound healing

Among remarkable discoveries concerning propolis, such as antifungal, antiviral, and antioxidant activities, its anti-inflammatory, and mainly its antibacterial, properties deserve special attention when skin wound healing is concerned. Based on this and knowing the distinctive performance of bacterial (BC) membranes on wound healing, in this work it is proposed to demonstrate the potent antimicrobial activity and wound healing properties of a novel propolis containing biocellulose membrane. The obtained propolis/BC membrane was able to adsorb propolis not only on the surface, but also in its interstices demonstrated by scanning electron microscopy, X-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy, and thermogravidimetric assays. Additionally, the polyphenolic compounds determination and the prominent antibacterial activity in the membrane are demonstrated to be dose dependent, supporting the possibility of obtaining propolis/BC membranes at the desired concentrations, taking into consideration its application and its skin residence time. Finally, it could be suggested that propolis/BC membrane may favor tissue repair in less time and more effectively in contaminated wounds. © 2013 Hernane da Silva Barud et al.

Contribuição eletrostática e não eletrostática na interação de peptídeos líticos com membranas modelo

Pós-graduação em Biofísica Molecular - IBILCE

Óleos essenciais: verificação da ação antimicrobiana in vitro, na água e sobre a microbiota da pele humana

Pós-graduação em Biologia Geral e Aplicada - IBB

Estudos de adsorção do ácido clavulânico

Pós-graduação em Biotecnologia - IQ

Atividade antibacteriana de óleos essenciais de especiarias em alimentos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação histológica e microbiológica de curativos de demora à base de hidróxido de cálcio usados em endodontia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Peperomia blanda (Piperaceae): avaliação das atividades antibacteriana e antioxidante

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo agronômico, químico e biológico de Cochlospermum regium (mart. ex. Scharank): uma planta medicinal do Cerrado

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Potencial de atividade antimicrobiana in vitro de extratos vegetais do cerrado frente estirpes de Staphylococcus aureus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da quercetina sobre alguns fatores relacionados com a virulência de Staphylococcus aureus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção, purificação e ação antimicrobiana do extrato fúngico do Trichosporon asahii

Pós-graduação em Microbiologia - IBILCE