Shortened derivatives from native antimicrobial peptide LyeTx I: and biological activity assessment.

In the continuing search for novel antibiotics, antimicrobial peptides are promising molecules, due to different mechanisms of action compared to classic antibiotics and to their selectivity for interaction with microorganism cells rather than with mammalian cells. Previously, our research group has isolated the antimicrobial peptide LyeTx I from the venom of the spider . Here, we proposed to synthesize three novel shortened derivatives from LyeTx I (LyeTx I mn; LyeTx I mnΔK; LyeTx I mnΔKAc) and to evaluate their toxicity and biological activity as potential antimicrobial agents.

Thiosemicarbazone of lapachol acts on cell membrane in Paracoccidioides brasiliensis.

Paracoccidioidomycosis (PCM) is the most prevalent systemic mycosis in Latin American countries. Amphotericin B, sulfonamides, and azoles may be used in the treatment of PCM. However, the high toxicity, prolonged course of treatment, and significant frequency of disease relapse compromise their use.

Identification and characterization of expressed retrotransposons in the genome of the Paracoccidioides species complex.

Background: Species from the Paracoccidioides complex are thermally dimorphic fungi and the causative agents of paracoccidioidomycosis, a deep fungal infection that is the most prevalent systemic mycosis in Latin America and represents the most important cause of death in immunocompetent individuals with systemic mycosis in Brazil. We previously described the identification of eight new families of DNA transposons in Paracoccidioides genomes. In this work, we aimed to identify potentially active retrotransposons in Paracoccidioides genomes.

Melanin protects Paracoccidioides brasiliensis from the effects of antimicrobial photodynamic inhibition and antifungal drugs.

Paracoccidioidomycosis (PCM) is a public health concern in Latin America and South America that when not correctly treated can lead to patient death. In this study, the influence of melanin produced by Paracoccidioides spp. on the effects of treatment with antimicrobial photodynamic inhibition (aPI) and antifungal drugs was evaluated.

Transposable elements and two other molecular markers as typing tools for the genus Paracoccidioides.

Studies comparing Paracoccidioides brasiliensis and Paracoccidioides lutzii have shown that these fungi have significant genomic differences that may have implications in the clinical manifestation, diagnosis, and treatment of paracoccidioidomycosis caused by them. Thus, molecular typing methods are required that can distinguish between various species of Paracoccidioides. The aim of this study was to explore the potential use as molecular markers of the transposable elements Trem A-H recently identified and characterized in the genus Paracoccidioides as a means of differentiating the species.

IFN-γ impairs Trichophyton rubrum proliferation in a murine model of dermatophytosis through the production of IL-1β and reactive oxygen species.

Trichophyton rubrum is the main etiological agent of dermatophytosis, an infection of the skin that affects millions of people worldwide. In this study, we developed a murine model of the dermatophytosis caused by T. rubrum in which C57BL/6 wild-type, interleukin (IL)-12(-/-), and interferon-gamma (IFN-γ(-/-)) mice were inoculated with 1 × 10(6) conidia/animal.

The pivotal role of 5-lipoxygenase-derived LTB4 in controlling pulmonary paracoccidioidomycosis.

Leukotrienes (LTs) produced from arachidonic acid by the action of 5-lipoxygenase (5-LO) are classical mediators of inflammatory responses. However, studies published in the literature regarding these mediators are contradictory and it remains uncertain whether these lipid mediators play a role in host defense against the fungal pathogen Paracoccidioides brasiliensis. To determine the involvement of LTs in the host response to pulmonary infection, wild-type and LT-deficient mice by targeted disruption of the 5-lipoxygenase gene (knockout mice) were studied following intratracheal challenge with P.

Traffic of leukocytes and cytokine up-regulation in the central nervous system in a murine model of neuroparacoccidioidomycosis.

Background: Paracoccidioidomycosis is the most important systemic mycosis in South America. In the last decades, it was observed that central nervous system involvement is frequent, occurring in 12.5 % of the cases.

The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives.

Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.

Photodynamic inhibition of Trichophyton rubrum: in vitro activity and the role of oxidative and nitrosative bursts in fungal death.

Objectives: Antimicrobial photodynamic inhibition (aPI) is based on the use of a light source and a photosensitizer to kill pathogens. Little is known about aPI of dermatophytic fungi and its mechanism of action. We aimed to evaluate aPI of Trichophyton rubrum.

In vitro antifungal activity of fatty acid methyl esters of the seeds of Annona cornifolia A.St.-Hil. (Annonaceae) against pathogenic fungus Paracoccidioides brasiliensis.

Introduction: Fatty acids are abundant in vegetable oils. They are known to have antibacterial and antifungal properties.

Methods: Antifungal susceptibility was evaluated by broth microdilution assay following CLSI (formerly the NCCLS) guidelines against 16 fungal strains of clinical interest.

MIF induces osteoclast differentiation and contributes to progression of periodontal disease in mice.

Periodontal disease (PD) is a chronic inflammatory and alveolar bone destructive disease triggered by microorganisms from the oral biofilm. Oral inoculation of mice with the periodontopathogen Aggregatibacter actinomycetemcomitans (Aa) induces marked alveolar bone loss and local production of inflammatory mediators, including Macrophage Migration Inhibitory Factor (MIF). The role of MIF for alveolar bone resorption during PD is not known.

Quinolinyl and quinolinyl N-oxide chalcones: synthesis, antifungal and cytotoxic activities.

A series of new 6-quinolinyl and quinolinyl N-oxide chalcones were efficiently prepared. All chalcones were tested by minimal inhibitory concentration (MIC) against three species of Candida, Cryptococcus gattii and Paracoccidioides brasiliensis. The effect of these compounds was also tested on the survival and growth of the human cancer cell lines UACC-62 (melanoma), MCF-7 (breast), TK-10 (renal) and leukemic cells, Jurkat and HL60.

Cryptococcus gattii: in vitro susceptibility to photodynamic inactivation.

Cryptococus gattii is an emergent primary human pathogen that causes meningismus, papilledema, high intracranial pressure and focal involvement of the central nervous system in immunocompetent hosts. Prolonged antifungal therapy is the conventional treatment, but it is highly toxic, selects for resistant strains, contributes to therapy failure and has a poor prognosis. Photodynamic inactivation (PDI) offers a promising possibility for the alternative treatment of cryptococcosis.

Antifungal activity of extracts of some plants used in Brazilian traditional medicine against the pathogenic fungus Paracoccidioides brasiliensis.

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by Paracoccidioides brasiliensis Almeida (Onygenales) that requires 1-2 years of treatment. In the absence of drug therapy, the disease is usually fatal, highlighting the need for the identification of safer, novel, and more effective antifungal compounds. With this need in mind, several plants employed in Brazilian traditional medicine were assayed on P.

Antifungal activity of trichothecenes from Fusarium sp. against clinical isolates of Paracoccidioides brasiliensis.

Paracoccidioidomycosis (PCM), a human mycosis caused by the dimorphic fungus Paracoccidioides brasiliensis, is a serious public health problem in several countries of Latin America. In our search we found that the crude extract of the endophytic fungus UFMGCB 551 was able to inhibit several clinical strains of P. brasiliensis, and was also active in the bioautographic assay against Cladosporium sphaerospermum.

Coordination to gallium(III) strongly enhances the potency of 2-pyridineformamide thiosemicarbazones against Cryptococcus opportunistic fungi.

A family of 2-pyridineformamide-derived thiosemicarbazones and their gallium(III) complexes were tested against several isolates of pathogenic Cryptococcus strains. On complexation the antifungal activity significantly increases, suggesting coordination to gallium(III) to be an interesting strategy of antifungal dose reduction.

Trichophyton rubrum and Trichophyton interdigitale: genetic diversity among species and strains by random amplified polymorphic DNA method.

Onychomycosis is a common condition that represents up to 50% of all nail problems and 30% of all cases of dermatophytoses. Trichophyton rubrum and Trichophyton interdigitale are the most common agents involved in this condition. In cases of recurrent post-treatment onychomycosis, strain fingerprinting could reveal whether the original isolate is responsible, a new strain has been acquired or if multiple strains are involved.

Cerebral infection caused by Cryptococcus gattii: a case report and antifungal susceptibility testing.

We report a clinical case of cerebral infection caused by Cryptococcus gattii in a 10 year-old boy. Clinical and laboratory exams did not demonstrate any apparent immunosuppressed state (HIV antibody and the tuberculin skin tests, both negative, were performed; blood cells count and immunoglobulin levels were within normality). Treatment was begun with amphotericin B-deoxycholate but renal toxicity signs led to its substitution by fluconazole.

In vitro photodynamic inactivation of Candida spp. growth and adhesion to buccal epithelial cells.

In this study, photodynamic inactivation (PDI) was used to inhibit in vitro growth and adhesion of different Candida isolates to buccal epithelial cells (BEC). Experimental conditions were optimized and 25muM toluidine blue O (TBO) and 15min of irradiation time by light emitting diode (LED) (energy density of 180J/cm(2)) were selected due to higher reductions in cellular viability obtained after treatment. Reduction media of Log(10) 3.

Molecular typing and antifungal susceptibility of Trichophyton rubrum isolates from patients with onychomycosis pre- and post-treatment.

Forty sequential isolates of Trichophyton rubrum were obtained from patients suffering from onychomycosis at two time points, before and after antifungal oral therapy. Strain differentiation by specific amplification of the two tandemly repeated elements (TRS-1 and TRS-2) of the ribosomal DNA of T. rubrum was performed.

[Laboratory evolutive aspects of children under paracoccidioidomycosis treatment].

The study of 38 children with paracoccidioidomycosis, aged up to 14, treated for 24 to 30 months with either a sulfonamide derivative or ketoconazole either alone or, after the use of amphotericin B. Laboratory data at admission were analyzed and compared with those of sequential tests after up to 30 months follow-up. Anemia, eosinophilia, increased bilirubin and aminotransferases normalized, in most patients, after three months treatment and hypoalbuminemia normalized after six months, suggesting that these laboratory findings are useful for monitoring early therapeutic response.