EVALUATION OF WATER QUALITY FOR CONSUMPTION AND PREVALENCE OF ANTIBIOTIC-RESISTANT BACTERIA:

Resumo: O consumo inadequado de água representa um risco para a saúde, porque leva a um aumento na incidência de doenças infecciosas propagadas pela água. Amostras de água coletadas em torneiras foram avaliadas quanto à presença de coliformes e outras bactérias, testes fenotípicos foram realizados para identificá-los e definir seus padrões de susceptibilidade antimicrobiana. Também foram analisadas a presença de metais potencialmente tóxicos e os padrões físico-químicos estabelecidos para a água consumida pelo homem. Por meio da avaliação microbiológica foi possível observar que a quantidade de coliformes na maioria das amostras é superior à recomendada pelos órgãos que regulam os padrões de potabilidade da água. Além disso, através da análise microbiológica foi possível identificar a presença de bactérias relacionadas a doenças comuns em humanos, das quais muitas apresentavam resistência a múltiplos antibacterianos. Os resultados das análises físico-químicas e dos metais potencialmente tóxicos demonstraram que esses parâmetros estão de acordo com os padrões estabelecidos para água potável pelas instituições normativas. Assim, o presente trabalho alerta para o problema da contaminação bacteriana em água para consumo de regiões quilombolas e também para o crescente problema da transmissão de genes de resistência antimicrobiana em água. Palavras chave: Coliformes. Água subterrânea. Multidroga-resistente. Físico-químico. Metais tóxicos.   Abstract: Inappropriate water consumption represents a health risk because it leads to an increase in the incidence of infectious diseases propagated by water. Samples of water collected in taps were evaluated for the presence of coliforms and other bacteria, phenotypic tests were performed to identify them and define their patterns of antimicrobial susceptibility. Were also analyzed for the presence of potentially toxic metals and for the physico-chemical standards established for human consumed water. By means of the microbiological evaluation it was possible to observe that the quantity of coliforms in the majority of the samples is superior to that recommended by the organs that regulate the water potability standards. In addition, through the microbiological analysis it was possible to identify the presence of bacteria related to common diseases in humans, of which many presented resistance to multiple antibacterial. Physico-chemical analyzes and potentially toxic metals were performed, the results demonstrated that these parameters are in agreement with the standards established for potable water by the normative institutions. Thus, the present work alerts to the problem of bacterial contamination in water for consumption of quilombola regions and also to the growing problem of the transmission of antimicrobial resistance genes in water. Keywords: Coliform. Groundwater. Multidug-resistance. Physico-chemical. Toxic metals. &nbsp

Characterization of Monoclonal Antibodies against Bovine herpesvirus type 1 selected by Phage Display Technology

The specificity of monoclonal antibodies (mAbs) to desired targets makes these molecules suitable for therapeutic and diagnostic uses against a wide range of pathogens. Phage display antibody libraries offer one method by which mAbs can be selected for, without the use of conventional hybridoma technology. In this work, phage display technology was used to construct, select and characterize a combinatorial single chain fragment variable (scFv) antibody library against bovine herpesvirus type 1 (BoHV-1) from the immune repertoire of chickens immunized with the virus. In silico analysis of the hypervariable domains of the antibody heavy chains revealed a high frequency of scFv fragments with low variability, suggesting that selection had probably been carried out and favored by a few im-munogenic viral antigens. The reactivity of the scFv fragments selected against BoHV-1 was demon-strated by Phage-ELISA. A significant increase in antibody reactivity to the target was observed after six rounds of library selection, showing its potential use as a molecule for BoHV-1 diagnosis. The strategy described here opens up a field for the use of phage display as a tool for selection of mono-clonal antibodies that could be used for theranostic applications against infectious and parasitic dis-eases of veterinary interest

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

VARIABILIDADE GENÉTICA DA RÃ-TOURO GIGANTE (Rana catesbeiana) PROVENIENTE DE POPULAÇÕES DOS ESTADOS DE GOIÁS, PARÁ E PARANÁ, CRIADAS EM SISTEMA INTENSIVO DE CULTIVO

Durante os meses de julho a outubro de 2001 foi realizado um experimento a fim de verificar a variabilidade genética entre os animais Rana catesbeiana de ranários dos estados de Goiás, Pará e Paraná. A diversidade genética foi avaliada utilizando-se marcador molecular tipo RAPD. Ensaios tipo RAPD resultaram em 105 marcadores (bandas), os quais foram todos polimórficos. Procedendo-se à análise de divergência genética calculada pelo software WINAMOVA, a variação genética intrapopulacional (65,15%) foi maior que a variação entre populações (34,85%). Utilizou-se a soma dos quadrados internos para estimar a variabilidade interna de cada população, e os dados mostraram que os animais do estado de Goiás apresentaram a maior diversidade interna (148,4167). A análise das distâncias genéticas entre populações (pelo teste PhiST) mostrou que os animais provenientes dos estados de Goiás e Paraná formaram um grupo (distância genética de 0,2002) e os do estado do Pará formaram um grupo à parte (distância Pará e Goiás 0,3783, Pará e Paraná 0,4283).
 PALAVRAS-CHAVE: Divergência genética, marcador molecular, populações, Rana catesbeiana

Hypothesis testing of genetic similarity based on RAPD data using Mantel tests and model matrices

Clustering and ordination procedures in multivariate analyses have been widely used to describe patterns of genetic distances. However, in some cases, such as when dealing with Jaccard coefficients based on RAPD data, these techniques may fail to represent genetic distances because of the high dimensionality of the genetic distances caused by stochastic variation in DNA fragments among the units analyzed (species or populations). In this note, we show how Mantel tests can be used to test hypotheses about genetic distances and avoid problems with multivariate data representation. The procedure is illustrated with RAPD data comparing 20 anuran species from the cerrado, in which Jaccard genetic distances were compared to three model matrices linking the species at distinct taxonomic levels

Hypothesis testing of genetic similarity based on RAPD data using Mantel tests and model matrices

Abstract Clustering and ordination procedures in multivariate analyses have been widely used to describe patterns of genetic distances. However, in some cases, such as when dealing with Jaccard coefficients based on RAPD data, these techniques may fail to represent genetic distances because of the high dimensionality of the genetic distances caused by stochastic variation in DNA fragments among the units analyzed (species or populations). In this note, we show how Mantel tests can be used to test hypotheses about genetic distances and avoid problems with multivariate data representation. The procedure is illustrated with RAPD data comparing 20 anuran species from the cerrado, in which Jaccard genetic distances were compared to three model matrices linking the species at distinct taxonomic levels

Improvement of bread making quality by supplementation with a recombinant xylanase produced by Pichia pastoris.

Xylanases (EC 3.2.1.8) are hydrolytic enzymes, which randomly cleave the β-1,4-linked xylose residues from xylan. The synthetic gene xynBS27 from Streptomyces sp. S27 was successfully cloned and expressed in Pichia pastoris. The full-length gene consists of 729 bp and encodes 243 amino acids including 51 residues of a putative signal peptide. This enzyme was purified in two steps and was shown to have a molecular weight of 20 kDa. The purified r-XynBS27 was active against beechwood xylan and oat spelt xylan as expected for GH 11 family. The optimum pH and temperature values for the enzyme were 6.0 and 75 °C, respectively. The Km and Vmax were 12.38 mg/mL and 13.68 μmol min/mg, respectively. The r-XynBS27 showed high xylose tolerance and was inhibited by some metal ions and by SDS. r-XynBS27 was employed as an additive in the bread making process. A decrease in firmness, stiffness and consistency, and improvements in specific volume and reducing sugar content were recorded

Dificuldades na identificação laboratorial da talassemia alfa Difficulty on laboratory identification of alpha thalassemia

Introdução: Talassemia alfa é uma síndrome associada à redução da síntese de cadeias de globina do tipo alfa. A gravidade das manifestações clínicas está relacionada com a quantidade de globinas produzida e a estabilidade das cadeias beta presentes em excesso. A talassemia alfa mínima resulta da deleção de apenas um dos quatro genes a (-&#945;/&#945;&#945;). Clinicamente apresenta anemia leve com microcitose ou ausência de anemia, sendo o diagnóstico realizado por meio de visualização da hemoglobina (Hb) H por eletroforese alcalina em acetato de celulose ou por identificação de inclusões celulares de Hb H coradas pelo azul de crezil brilhante. Objetivo: Avaliar portadores de talassemia alfa e seus respectivos progenitores, correlacionando perfil hematológico e presença de Hb H, utilizando procedimentos laboratoriais clássicos em três diferentes amostragens. Discussão e conclusão: Os dados obtidos mostram que a presença de Hb H, indicativo de talassemia alfa, pode não ser confirmada em uma análise posterior. Entre os fatores que podem influenciar no não aparecimento de Hb H em pessoa comprovadamente com talassemia alfa está a deficiência de ferro. A talassemia alfa está associada a defeitos envolvendo os genes codificadores da cadeia alfa, mas também pode estar relacionada com desbalanciamento temporário na expressão dos genes globina, diminuição de alfa ou aumento de beta, o que poderia explicar o aparecimento de tetrâmeros de cadeia beta (Hb H), sugerindo diagnóstico de talassemia alfa mínima.<br>Introduction: Alpha thalassemia is a syndrome with associated with the reduction of alpha globin chain synthesis. The severity of clinical manifestations is related to the amount of globins produced and the stability of beta chains that are present in excess. Alpha thalassemia minor is caused by the deletion of one of the four genes a (-&#945;/&#945;&#945;). Clinically, it presents mild anemia with microcytosis or absence of anemia. The diagnosis is made by the visualization of Hb H through alkaline electrophoresis on cellulose acetate or by the identification of inclusion bodies stained with brilliant cresyl blue. Objective: Evaluate alpha thalassemia carriers and their respective progenitors, correlating their hematology profile and the presence of Hb H by means of standard laboratory procedures in three different samplings. Discussion and conclusion: The results show that the presence of Hb H, which is indicative of alpha thalassemia, may not be confirmed in a subsequent analysis. Iron deficiency in Hb H carriers is among the factors that may influence on the absence of Hb H in alpha thalassemia proven patients. Alpha thalassemia is associated with genetic defects involving alpha chain encoding genes, but may be also associated with a temporary imbalance of globin gene expression, alpha chain reduction or beta increase, which could explain the presence of beta chain tetramer (Hb H) leading to the diagnosis of alpha thalassemia minor