Publications by authors named "Andre Luiz Pedrosa"

Biofilm formation is a key factor in the pathogenesis of enterococcal infections. Thus, the biofilm-forming ability and frequency of biofilm-related genes in (PRASEF) compared to penicillin- and ampicillin-susceptible (PSASEF) were assessed in the present study. In addition, the effect of sub-inhibitory concentrations (sub-MICs) of antibiotics on biofilm formation and expression of virulence genes was evaluated.

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parasites are the causative agents of a group of neglected tropical diseases known as leishmaniasis. The molecular mechanisms employed by these parasites to adapt to the adverse conditions found in their hosts are not yet completely understood. DNA repair pathways can be used by to enable survival in the interior of macrophages, where the parasite is constantly exposed to oxygen reactive species.

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Introduction: Blastocystis is an intestinal protozoan that may play a role in the pathogenicity of humans. This study aimed to (i) genetically characterize Blastocystis isolates obtained from human fecal samples and the water supply of the city of Uberaba, Minas Gerais, Brazil, and (ii) to verify the phylogenetic relationship between these isolates.

Methods: Blastocystis species present in 26 fecal samples obtained from humans and animals from Uberaba were genetically characterized by polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction-sequence-tagged sites.

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is an avirulent flagellate protozoan that could mislead correct diagnosis of infection, the causative agent of Chagas' disease, given their high similarity. Besides, presents two genetic groups, whose differentiation is achieved mainly by molecular approaches. In this context, ribosomal DNA (rDNA) is a useful target for intra and interspecific molecular differentiation.

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Diabetes mellitus (DM) may lead to gastrointestinal motility disorders. Rodent models of DM indicate the presence of morpho-functional abnormalities of the enteric nervous system. Here, we evaluated whether experimental DM can cause changes in the excitatory cholinergic fibers, neuronal density, and voltage-gated sodium channel (Nav) expression in the myenteric plexus of the ileum.

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All cellular processes, including those involved in normal cell metabolism to those responsible for cell proliferation or death, are finely controlled by cell signaling pathways, whose core proteins constitute the family of phosphatidylinositol 3-kinase-related kinases (PIKKs). Ataxia Telangiectasia Mutated (ATM) and Ataxia Telangiectasia and Rad3 related (ATR) are two important PIKK proteins that act in response to DNA damage, phosphorylating a large number of proteins to exert control over genomic integrity. The genus Leishmania belongs to a group of early divergent eukaryotes in evolution and has a highly plastic genome, probably owing to the existence of signaling pathways designed to maintain genomic integrity.

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Introduction: Currently, there are few studies regarding Blastocystis epidemiology. This study aimed to evaluate the occurrence of Blastocystis in animals in Uberaba, Brazil.

Methods: Fecal samples were examined by parasitological methods and screened for Blastocystis by polymerase chain reaction.

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Several bat species can be infected by trypanosomes, but there is not much information about which of these parasites infect bats from Triângulo Mineiro and Alto Paranaíba, Minas Gerais state, Brazil, a formerly endemic region for Trypanosoma cruzi, the causative agent of Chagas disease. The aim of this study was to describe, characterize, and identify the presence of trypanosomes in bats. The captured bats (448) belong to four families and to 19 different species.

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Trypanosoma cruzi, a human protozoan parasite, is the causative agent of Chagas disease. Currently the species is divided into six taxonomic groups. The genome of the CL Brener clone has been estimated to be 106.

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Introduction: This work shows that 3% (v/v) human urine (HU) in semisolid Liver Infusion Tryptose (SSL) medium favors the growth of Trypanosoma cruzi and T. rangeli.

Methods: Parasites were plated as individual or mixed strains on SSL medium and on SSL medium with 3% human urine (SSL-HU).

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Intestinal parasites are a problem for public health all over the world. The infection with Blastocystis, a protozoan of controversial pathogenicity, is one of the most common among them all. In this study, the occurrence of intestinal parasites, with emphasis on Blastocystis, in patients at the Universidade Federal do Triângulo Mineiro was investigated in Uberaba (MG) through microscopy of direct smears and fecal concentrates using Ritchie's method.

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Trypanosoma cruzi and Trypanosoma rangeli are kinetoplastid parasites which are able to infect humans in Central and South America. Misdiagnosis between these trypanosomes can be avoided by targeting barcoding sequences or genes of each organism. This work aims to analyze the feasibility of using species-specific markers for identification of intraspecific polymorphisms and as target for diagnostic methods by PCR.

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Cryptococcus neoformans and C. gattii are the etiologic agents of cryptococcosis, a life-threatening disease in both immunocompromised and immunocompetent hosts. Antifungal resistance has been evaluated using different methods, breakpoints, and sizes of test populations and it is an emerging as a significant issue worldwide.

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Different methods have been used to perform the molecular characterization of Cryptococcus neoformans. Among them, RAPD analysis is able to separate isolates of the same species and genotypes. This study aimed to evaluate clinical and environmental C.

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Cryptococcus laurentii has been classically considered a saprophytic species, although several cases of human infection have been already reported. This study aimed to evaluate the phospholipase, proteinase and hemolysins activity, the antifungal susceptibility profile, the genetic variability by M13 and (GACA)(4) fingerprinting and the internal transcribe spacer (ITS) sequencing of 38 C. laurentii isolates recovered from captive bird droppings and surrounding hospital areas.

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Cryptococcosis is a common opportunistic fungal infection that is mainly caused by the species Cryptococcus neoformans and Cryptococcus gattii, but there have recently been several reports of infection by non-neoformans Cryptococcus species. The aims of this study were to genetically characterize Cryptococcus spp. isolated from external hospital areas in Minas Gerais State, Brazil, and to evaluate their pathogenic potential, analyzing their phospholipase and melanin production and the capacity for capsule enlargement.

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The aim of this study was to investigate the genetic variability of sequences present in the chromosome ends of Trypanosoma rangeli strains defined by the presence (+) or absence (-) of KP1 minicircles, and to compare the mean terminal restriction fragment (TRF) lengths to those of Trypanosoma cruzi populations representative of groups TcI, TcII, TcIV, and TcVI. Southern blots containing RsaI-digested genomic DNA of T. rangeli KP1(+) strains, T.

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To evaluate Cryptococcus spp. molecular types isolated from captive birds' droppings, an epidemiological survey was carried out in Uberaba, Minas Gerais, Brazil, from December 2006 to September 2008. A total of 253 samples of bird excreta (120 fresh and 133 dry) were collected from pet shop cages and houses in different neighbourhoods.

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We molecularly characterized 81 cryptococcal isolates recovered from cerebrospinal fluid samples of 77 patients diagnosed between 1998 and 2007 as having cryptococcal meningitis in Uberaba Minas Gerais, Brazil. Fifty-seven (74%) were male with a mean age 35.6 years.

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In the present study, the molecular karyotypes of 12 KP1(+) and KP1(-) Trypanosoma rangeli strains were determined and 10 different molecular markers were hybridized to the chromosomes of the parasite, including seven obtained from T. rangeli [ubiquitin hydrolase (UH), a predicted serine/threonine protein kinase (STK), hexose transporter, hypothetical protein, three anonymous sequences] and three from Trypanosoma cruzi [ubiquitin-conjugating enzyme E2 (UBE2), ribosomal RNA methyltransferase (rRNAmtr), proteasome non-ATPase regulatory subunit 6 (PSMD6)]. Despite intraspecific variation, analysis of the karyotype profiles permitted the division of the T.

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The clinical course of Chagas' disease varies widely among different patients and geographic regions. For reasons that are not completely understood but involve host and parasite factors, some patients never develop the disease while others present cardiac and/or gastrointestinal symptoms. Many studies have been conducted in order to correlate the genetic variability of the parasites with the clinical forms of the disease, but no conclusive data have been obtained.

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Trypanosoma rangeli is a kinetoplastid protozoan parasite that has been found in the majority of Latin American countries, overlapping its distribution area with that of Trypanosoma cruzi, the causative agent of Chagas disease. This parasite shares the same reservoirs and vectors as T. cruzi.

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