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Maria Sueli Soares Felipe

Publications and source records attributed to Maria Sueli Soares Felipe.

7 recordsLinked to original sources
PubMed2006

Differential gene expression by Paracoccidioides brasiliensis in host interaction conditions: representational difference analysis identifies candidate genes associated with fungal pathogenesis.

Paracoccidioides brasiliensis causes infection by the host inhalation of airborne propagules of the mycelia phase of the fungus. These particles reach the lungs, and disseminate to virtually all organs. Here we describe the identification of differentially expressed genes in studies of host-fungus interaction. We analyzed two cDNA populations of P. brasiliensis, one obtained from infected animals and the other an admixture of fungus and human blood thus mimicking the hematologic events of the fungal dissemination. Our analysis identified transcripts differentially expressed. Genes related to iron acquisition, melanin synthesis and cell defense were specially upregulated in the mouse model of infection. The upregulated transcripts of yeast cells during incubation with human blood were those predominantly related to cell wall remodeling/synthesis. The expression pattern of genes was independently confirmed in host conditions, revealing their potential role in the infection process. This work can facilitate functional studies of novel regulated genes that may be important for the survival and growth strategies of P. brasiliensis in humans.

Adaptation, Physiological↗
PubMed2006

Multilocus sequence typing of hospital-associated Enterococcus faecium from Brazil reveals their unique evolutionary history.

We studied the genetic relationships between vancomycin-susceptible (n = 11) and -resistant Enterococcus faecium (VRE, n = 20) recovered from Brazil using a multilocus sequence typing (MLST) scheme. Grouping of allelic profiles revealed six clusters of related sequence types (STs) that differ in no more than two of the seven alleles. Of these, one cluster harbored 16 of the 20 isolates recovered during the first VRE outbreak in Brazil. The ampicillin and gentamicin resistance profiles were stable in the isolates that clustered within the groups I-III. Comparison with the allelic profiles of 139 E. faecium from different geographical regions and origins found in the international database http://www.mlst.net revealed that the Brazilian outbreak clone did not cluster in the previously named complex-17. This genetic complex contains hospital epidemic and clinical isolates recovered from different countries and continents. Twenty two of the 31 Brazilian isolates, including the VRE outbreak clone, clustered apart from the E. faecium isolates from the database, suggesting that these Brazilian isolates have a distinct evolutionary history.

Alleles↗
PubMed2005

Bioinformatics of the Paracoccidioides brasiliensis EST Project.

Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, an endemic mycosis of Latin America. This fungus presents a dimorphic character; it grows as a mycelium at room temperature, but it is isolated as yeast from infected individuals. It is believed that the transition from mycelium to yeast is important for the infective process. The Functional and Differential Genome of Paracoccidioides brasiliensis Project--PbGenome Project was developed to study the infection process by analyzing expressed sequence tags--ESTs, isolated from both mycelial and yeast forms. The PbGenome Project was executed by a consortium that included 70 researchers (professors and students) from two sequencing laboratories of the midwest region of Brazil; this project produced 25,741 ESTs, 19,718 of which with sufficient quality to be analyzed. We describe the computational procedures used to receive process, analyze these ESTs, and help with their functional annotations; we also detail the services that were used for sequence data exploration. Various programs were compared for filtering and grouping the sequences, and they were adapted to a user-friendly interface. This system made the analysis of the differential transcriptome of P. brasiliensis possible.

Brazil↗
PubMed2005

Therapeutic targets in Paracoccidioides brasiliensis: post-transcriptome perspectives.

The rise in antifungal resistance, observed as a result of the increasing numbers of immunocompromised patients, has made the discovery of new targets for drug therapy imperative. The description of the Paracoccidioides brasiliensis transcriptome has allowed us to find alternatives to refine current therapy against paracoccidioidomycosis. We used comparative analysis of expressed sequence tags to find promising drug targets that have been addressed in other pathogens. We divided the analysis into six different categories, based on the involvement of the targeted mechanisms in the cell: i) cell wall construction, ii) plasma membrane composition, iii) cellular machinery, iv) cellular metabolism, v) signaling pathways, and vi) other essential processes. Through this approach, it has been possible to infer strategies to develop alternative drugs against this pathogen.

Antifungal Agents↗
PubMed2005

Comparative analysis of the cDNA encoding a ClpA homologue of Paracoccidioides brasiliensis.

A cDNA encoding a chaperone ClpA homologue of Paracoccidioides brasiliensis was isolated and characterized. The ClpA belongs to a group of ClpATPAses proteins, which are highly conserved, and include several heat inducible molecular chaperones. In this study, a 2879 bp cDNA designated as Pbclpa was obtained which encodes a predicted protein of 927 amino acids. Characteristic consensus motifs of the ClpATPases family are present. The PbClpA middle region was compared to other related ClpA and ClpB proteins from fungi and bacteria. Comparative analysis demonstrated in the middle region the presence of a heptad repeat sequence, characteristic of ClpBs from prokaryotes and fungi, which are absent in ClpAs from prokaryotes but were present in all described fungal ClpAs. Our comparative analysis reveals that one of the criteria typically used to distinguish the prokaryotic subfamilies ClpA and ClpB, the size of the middle sequence, may not be useful in fungi. Phylogenetic analyses were performed with the complete sequences of ClpAs from fungi and bacteria and with the middle regions of those ClpAs present at NCBI and Pfam databases. Our results indicated that both types of analysis can be useful as a tool in the determination of phylogenetic relationships.

Amino Acid Sequence↗
PubMed2004

Molecular epidemiology and antimicrobial susceptibility of Enterococci recovered from Brazilian intensive care units.

We studied the antimicrobial resistance and the molecular epidemiology of 99 enterococcal surveillance isolates from two hospitals of Brasilia, Brazil. Conventional biochemical tests were used to identify the enterococcal species and the disk diffusion method was used to determine their resistance profiles. Enterococcus faecalis (76%) and E. faecium (9%) were the most prevalent species. No enterococci showed the vanA or vanB vancomycin resistance phenotypes or genotypes. Only the intrinsically resistant species E. gallinarum (n=2) and E. casseliflavus (n=3) harbored the vancomycin-resistance genes vanC1 and vanC2/3, respectively. We found E. faecalis isolates with high-level resistance to gentamicin (22%) and streptomycin (8%) and both E. faecalis and E. faecium isolates with resistance to more than two antimicrobials (84% and 67%, respectively). Nine E. faecalis isolates (12%) were resistant to ampicillin; the minimal inhibitory concentration (MIC) values were 16 microg/mL (n=6) and 32 microg/mL (n=3). Among these ampicillin-resistant E. faecalis, seven were also resistant to gentamicin, ciprofloxacin, rifampin, penicillin, chloramphenicol, tetracycline and erythromycin. Pulsed-field gel electrophoresis classified those isolates in three different genotypes, suggesting dissemination of genetically related ampicillin-resistant E. faecalis strains among different patients.

Anti-Bacterial Agents↗