Chromobacterium violaceum as a potential biosurfactant‐producing microorganism

Chromobacterium violaceum is a Gram‐negative bacterium found in the soil and water in tropical and sub‐tropical environments. Its complete genome sequence revealed wide varying alternative pathways for energy generation, complex and extensive systems for stress adaptation, motility and widespread utilization of quorum sensing for control of its inducible systems. Biosurfactants are amphiphilic compounds produced by microorganisms, both intra and extracellularly, that reduce surface and interfacial tensions. In this work, C. violaceum UCP 1552 isolated from the contaminated area of Pernambuco, was used. Biosurfactant production was carried out in 500mL Erlenmeyer flasks containing 250mL of LB medium [tryptone – 10g/L, yeast extract – 5g/L, sodium chloride – 5g/L] plus 5g/L glucose and 1.6g/L soy oil, at 150 rpm and 30°C. Samples were collected at different fermentation times (from 0 to 188h) to evaluate cellular growth, glucose consumption and biosurfactant production (by reduction of surface tension and emulsification index determination). Biomass growth was observed during the first 96h and afterwards the cells entered the stationary phase. Moreover, glucose was consumed in the first 30h. Surface tension of the fermentation broth free of C. violaceum cells recovered after 188h was found to be 32 mN/m. The highest emulsification index was observed for 12h experiment, being 56 and 59% for sunflower oil and nhexadecane, respectively. Results gathered in this study reveal the C. violaceum potential as a biosurfactant‐producer opening novel perspectives for its application in the environmental area.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

The use of immunohistochemistry for diagnosis of prostate cancer

PURPOSE: Atypical glands (ASAP) are diagnosed in 5.0% of prostate biopsies, and cancer identification in a rebiopsy is higher than 40.0%. The use of antibodies to mark basal cells is currently a common practice, in order to avoid rebiopsies. There has been no reported study that has reviewed characteristics of radical prostatectomies (RPs) when immunohistochemistry (IHC) was necessary for definitive diagnosis. MATERIALS AND METHODS: Out of 4127 biopsies examined from 2004 to 2008, 144 (3.5%) were diagnosed with ASAP. IHC was performed using antibody anti-34ßE12 and p63. The results of surgical specimens of 27 patients treated by RP after the diagnosis of prostate cancer (PC) was made using IHC (Group 1) were compared with 1040 patients where IHC was not necessary (Group 2). RESULTS: IHC helped to diagnose PC in 103 patients (71.5%). Twenty-seven (26.2%) underwent RP. In Group 1, two (7.4%) adenocarcinomas were insignificant versus 29 (2.9%) for Group 2. Patients from Group 1 were younger (p = 0.039), had lower Gleason scores (GS) (p < 0.001), lower percentage of Gleason pattern 4 (p < 0.001), and smaller tumors (p < 0.001). CONCLUSION: The use of IHC did not lead to diagnosis of insignificant tumors as illustrated by absence of differences in pathological stage or positive surgical margins in men submitted to RP. Therefore, our results suggest that this modality should be routinely used for a borderline biopsy and ASAP cases

Rhizopus arrhizus ucp1295 como fonte econômica para produção de biopolímeros funcionais quitina e quitosana utilizando substratos renováveis / Rhizopus arrhizus ucp1295 as economic source for production of functional biopolymers chitin and chitosan using renewable substrates

Neste trabalho foi investigada a produção de quitina e quitosana por Rhizopus arrhizus UCP 1295 isolado do solo da Caatinga do Estado de Pernambuco, Brasil, utilizando o efluente industrial de doces e milhocina como substratos de baixo custo, considerando a versatilidade de aplicação das biomoléculas. O micro-organismo foi cultivado em diferentes concentrações dos substratos efluente da indústria de doces e milhocina (CSL) em diferentes valores de pH, de acordo com um planejamento fatorial completo 23. Após 96 h de fermentação, a biomassa produzida foi liofilizada e submetida ao tratamento com álcali- ácido-. Os polissacarídeos extraídos foram caracterizados por espectroscopia por transformada de Fourier (FTIR) na região do infravermelho. A maior produção de biomassa (14,11 g/L) foi obtida na condição 6 (8% de efluente industrial de doces, 5% de milhocina e pH 5), enquanto os maiores rendimentos de quitina (169,3 mg/g) e quitosana (239,1 mg/g) foram obtidos em meio contendo 4% de efluente da indústria de doces, sem milhocina, nas condições 3 (pH 7) e 1 (pH 5), respectivamente. A quitina apresentou grau de acetilação de 71,4% e a quitosana de 86,0%, de desacetilação, respectivamente. Além disso, foi demonstrado que o efluente industrial de balas e milhocina são substratos renováveis e alternativos na formulação de novos meios de produção de quitina e quitosana. A versatilidade das biomoléculas deve-se as suas propriedades bioquímicas únicas, como biocompatibilidade, biodegradabilidade, não toxicidade, capacidade de formar filmes e aplicações industriais promissoras

Mycobacterium tuberculosis Infection in Young Children: Analyzing the Performance of the Diagnostic Tests

This study evaluated the performance of the Tuberculin Skin Test (TST) and Quantiferon-TB Gold in-Tube (QFT) and the possible association of factors which may modify their results in young children (0-6 years) with recent contact with an index tuberculosis case. Materials and Methods: A cross-sectional study including 135 children was conducted in Manaus, Amazonas-Brazil. The TST and QFT were performed and the tests results were analyzed in relation to the personal characteristics of the children studied and their relationship with the index case. Results: The rates of positivity were 34.8% (TST) and 26.7% (QFT), with 14.1% of indeterminations by the QFT. Concordance between tests was fair (Kappa = 0.35 P<0.001). Both the TST and QFT were associated with the intensity of exposure (Linear OR = 1.286, P = 0.005; Linear OR = 1.161, P = 0.035 respectively) with only the TST being associated with the time of exposure (Linear OR = 1.149, P = 0.009). The presence of intestinal helminths in the TST+ group was associated with negative QFT results (OR = 0.064, P = 0.049). In the TST- group lower levels of ferritin were associated with QFT+ results (Linear OR = 0.956, P = 0.036). Conclusions: Concordance between the TST and QFT was lower than expected. The factors associated with the discordant results were intestinal helminths, ferritin levels and exposure time to the index tuberculosis case. In TST+ group, helminths were associated with negative QFT results suggesting impaired cell-mediated immunity. The TST-&QFT+ group had a shorter exposure time and lower ferritin levels, suggesting that QFT is faster and ferritin may be a potential biomarker of early stages of tuberculosis infection

Diversity of eukaryotic and prokaryotic microbiota revealed by metabarcoding in Neotropical floodplain lakes

Abstract The diversity of eukaryotic and prokaryotic communities has been assessed by morphological and genetic approaches, which are used to characterize the microbiota in different environments. Here, planktonic prokaryotic and eukaryotic communities of the Araguaia River, located in the Central region of Brazil, were analyzed based on metabarcoding analysis of rRNA genes to evaluate the diversity of these groups in tropical floodplain lakes. Also, we tested their spatial concordance throughout the Araguaia river. Water samples were collected from 8 floodplain lakes in Araguaia River. The 16S and 18S rRNA genes were amplified and sequenced using Illumina MiSeq. For eukaryotes, 34,242 merged reads were obtained and 225 distinct OTUs were delineated, of which 106 OTUs were taxonomically classified. For prokaryotes, 26,426 sequences were obtained and 351 OTUs were detected. Of them, 231 were classified in at least one taxonomic category. The most representative eukaryotes belonged to Ciliophora, Chlorophyta and Charophyta. The prokaryotic phylum with the most OTUs classified were Proteobacteria, Actinobacteria and Bacteroidetes. The lakes did not show spatial concordance when comparing the similarity between their microbiota. The knowledge of freshwater biodiversity using DNA sequencing for important rivers, such as Araguaia River, can improve microbiota inventories of tropical biodiversity hotspots

Proteins of Leishmania (Viannia) shawi confer protection associated with Th1 immune response and memory generation

<p>Abstract</p> <p>Background</p> <p><it>Leishmania (Viannia) shawi </it>parasite was first characterized in 1989. Recently the protective effects of soluble leishmanial antigen (SLA) from <it>L. (V.) shawi </it>promastigotes were demonstrated using BALB/c mice, the susceptibility model for this parasite. In order to identify protective fractions, SLA was fractionated by reverse phase HPLC and five antigenic fractions were obtained.</p> <p>Methods</p> <p>F1 fraction was purified from L. (V.) shawi parasite extract by reverse phase HPLC. BALB/c mice were immunized once a week for two consecutive weeks by subcutaneous routes in the rump, using 25 μg of F1. After 1 and 16 weeks of last immunization, groups were challenged in the footpad with L. (V.) shawi promastigotes. After 2 months, those same mice were sacrificed and parasite burden, cellular and humoral immune responses were evaluated.</p> <p>Results</p> <p>The F1 fraction induced a high degree of protection associated with an increase in IFN-γ, a decrease in IL-4, increased cell proliferation and activation of CD8⁺T lymphocytes. Long-term protection was acquired in F1-immunized mice, associated with increased CD4⁺central memory T lymphocytes and activation of both CD4⁺and CD8⁺T cells. In addition, F1-immunized groups showed an increase in IgG2a levels.</p> <p>Conclusions</p> <p>The inductor capability of antigens to generate memory lymphocytes that can proliferate and secrete beneficial cytokines upon infection could be an important factor in the development of vaccine candidates against American Tegumentary Leishmaniasis.</p

How genomics can help biodiversity conservation

The availability of public genomic resources can greatly assist biodiversity assessment, conservation, and restoration efforts by providing evidence for scientifically informed management decisions. Here we survey the main approaches and applications in biodiversity and conservation genomics, considering practical factors, such as cost, time, prerequisite skills, and current shortcomings of applications. Most approaches perform best in combination with reference genomes from the target species or closely related species. We review case studies to illustrate how reference genomes can facilitate biodiversity research and conservation across the tree of life. We conclude that the time is ripe to view reference genomes as fundamental resources and to integrate their use as a best practice in conservation genomics.info:eu-repo/semantics/publishedVersio

The era of reference genomes in conservation genomics

Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional genomics, and are expected to revolutionize conservation genomics