Arbitrarily primed polymerase chain reaction for fingerprinting the genotype identification of mutans streptococci in children with Down syndrome

This study investigated the possible intrafamilial similarity of mutans streptococcal strains in some families with a child with Down syndrome using chromosomal DNA fingerprinting. The isolates were genotyped using arbitrarily primed polymerase chain reaction with the OPA 02 and OPA 03 primers. The results showed that five children with Down syndrome harbored mutans streptococci genotypes different from those of their mothers. A matching of genotypes was observed within the control pair (mother/child without Down syndrome). After six months, new samples were collected from all participants. Analysis showed that samples from children with Down syndrome were colonized by a new strain of Streptococcus mutans that did not match the previously collected one. The results suggest the S. mutans indigenous bacteria change more than once in children with Down syndrome.

Age-age correlation for early selection of rubber tree genotypes in São Paulo State, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

RAPD optimization for genetic studies with Citrulus lanatus and Sesamum indicum genotypes

The Random Amplified Polymorphic DNA (RAPD) technique is powerful for DNA polymorphism determinations and is widely used in research involving different organisms, but it is known that RAPD can be affected by many factors that may result in false positive bands and non-reproducible assays. In this study, we analyzed the effect of several factors such as DNA template, primer and Taq DNA polymerase concentrations to optimize and standardize the RAPD technique for further genetic studies with Citrulus lanattus and Sesamum indicum L. The best combination of DNA, Taq DNA polymerase enzyme and primer concentrations in RAPD amplification procedures for sesame and watermelon genotypes was established.

Preliminary selection of acerola genotypes in Brazil

Introduction. Breeding studies for acerola (Malpighia glabra) improvement aim at obtaining plants that produce fruits with uniform chemical and physical attributes, including high levels of vitamin C, which can provision the market with fresh fruit and frozen pulp. High variability in fruit quality is observed in Brazilian acerola crops, especially those propagated by seeds. In this context, the objective of our research was to evaluate the physical and chemical characteristics of Brazilian acerola genotype fruits. Materials and methods. Sixteen acerola genotypes were studied in Jaboticabal, São Paulo State, Brazil. A completely randomized design with sixteen treatments and six replications was adopted. Each treatment was represented by one genotype. Several parameters related to fruit quality, such as width, length, weight, pulp percentage, soluble solids (SS), titratable acidity (TA), [SS / TA] ratio and vitamin C content, were evaluated in fruits of the acerola genotypes. The results were submitted to variance analyses, the Tukey test and cluster analysis. Results and discussion. There was a statistical difference between the acerola genotypes studied. Three of them stood out as natural sources of vitamin C. In spite of fruit size, two acerola genotypes were found to have potential for fresh fruit production. In a general form, genotypes that presented a high [SS / TA] ratio had low vitamin C content. Conclusion. The acerola genotypes studied in Jaboticabal presented high variability, forming eleven groups in relation to fruit quality parameters. © 2007 Cirad/EDP Sciences All rights reserved.

Determination of crude protein, crude fiber and crude fat in twenty-five genotypes of kale (B. oleracea var. acephala)

The aim of the study was to determine the percentage of crude protein, crude fiber and crude fat (ether extract) of 25 genotypes of kale from the Germplasm Bank of Instituto Agronômico de Campinas and of one genotype grown in the region of Jaboticabal-SP. The plants were cultivated in the field, and the leaves after collection were pre-dried in a convection oven at 65°C for 72 h. Afterward, the leaves were analyzed for crude protein, crude fiber and crude fat (ether-soluble materials). Significant differences were detected among the different genotypes for all the characteristics examined. Of the genotypes studied, six showed more than 30% crude protein: HS-20 (32.56%), Comum (31.70%), Couve de Arthur Nogueira 2 (31.16%), Pires 2 de Campinas (30.63%), Manteiga I-916 (30.36%), and Manteiga de Ribeirao Pires I-2446 (30.03%). In relation to crude fiber, the highest percentage was seen in the genotype Manteiga de Mococa (10.92%), differing significantly from the other genotypes studied. With regard to crude fat, the highest percentage was found in the genotype HS-20 (3.72%), and Pires 1 de Campinas (3.34%). Of the genotypes tested, HS-20 stood out among the others, showing both the highest percentage of protein and fat.

Performance of different genotypes of vegetable soybeans in Jaboticabal-SP

The study was conducted in the field, in the experimental area of the Section of Crop Production and Aromatic Medicinal Plants, belonging to the Faculty of Agricultural and Veterinary Sciences, Jaboticabal Campus-SP. The aim of the study was to assess the performance of seven genotypes of vegetable soybeans in Jaboticabal-SP. The experiment was carried out in a complete randomized block design with seven treatments (genotypes) and four replications. The genotypes examined were: CNPSOI, JLM003, JLM010, JLM018, JLM019, JLM024 and BRS216. The seeds were obtained from EMBRAPA-Soja and EMBRAPA- Hortaliças, and planted in Styrofoam trays with 128 cells containing Plantmax Hortaliças® as substrate. Transplanting occurred 10 d after seeding when the seedlings showed 2 or 3 definitive leaves and about 12 cm in height, demonstrating that the soil had been properly prepared according to the recommendations for this crop. Pests and diseases were adequately controlled in the event of their occurrence in the experimental area and in accordance with technical recommendations for the chemical products utilized. Collections were carried out based on the maturation of the pods, according to the scale of Fehr and Caviness (1977) adapted by Costa and Marchezan (1982), when the pods reached the reproductive stage R6. The parameters determined were mean precocity, height of the first pod, mean number of pods per plant, mean number of seeds per pod, fresh weight of 100 seeds and total yield of immature grains. Based on the results obtained, the genotypes JLM003 and JLM010 were found to be most indicated for growing vegetable soybeans, because of their capacity to produce immature grains of 1090 and 848 g·m-2, respectively, and fresh weights for 100 seeds of 62.20 and 68.19 g, respectively.

Use of Physiological Parameters in Screening Drought Tolerance in Sugarcane Genotypes

The physiological response of four commercial sugarcane genotypes to water stress was evaluated by measuring the photochemical efficiency of the photosystem II (chlorophyll a fluorescence ratio, F v/F m), estimated chlorophyll content (SPAD unit), leaf temperature (LT) and leaf relative water content (RWC). A field trial was established in the subtropical area with well-watered and water-stressed genotypes, in completely randomized blocks with four replicates in a 4 × 2 × 3 factorial design (genotype × irrigation × evaluation date). Physiological measurements were done during a 90 day-period of formative stage of plants. The analysis of variance showed that the interaction of genotype × irrigation × evaluation date had a significant effect for three physiological markers tested, F v/F m, SPAD unit and RWC. Under non-stressed conditions, all genotypes showed similar responses for the four markers. Under water deficiency stress, two drought-tolerant genotypes, HOCP01-523 and TCP89-3505 displayed higher values for F v/F m, SPAD unit and RWC, and lower values for LT, and could be classified as tolerant. It is therefore possible to use these physiological water stress associated traits as scorable marker traits for selecting drought-tolerant sugarcane genotypes in future breeding programs. © 2011 Society for Sugar Research & Promotion.

Salmonella enterica serovar typhimurium colonizing the lumen of the chicken intestine grows slowly and upregulates a unique set of virulence and metabolism genes

The pattern of global gene expression in Salmonella enterica serovar Typhimurium bacteria harvested from the chicken intestinal lumen (cecum) was compared with that of a late-log-phase LB broth culture using a whole-genome microarray. Levels of transcription, translation, and cell division in vivo were lower than those in vitro. S. Typhimurium appeared to be using carbon sources, such as propionate, 1,2-propanediol, and ethanolamine, in addition to melibiose and ascorbate, the latter possibly transformed to D-xylulose. Amino acid starvation appeared to be a factor during colonization. Bacteria in the lumen were non- or weakly motile and nonchemotactic but showed upregulation of a number of fimbrial and Salmonella pathogenicity island 3 (SPI-3) and 5 genes, suggesting a close physical association with the host during colonization. S. Typhimurium bacteria harvested from the cecal mucosa showed an expression profile similar to that of bacteria from the intestinal lumen, except that levels of transcription, translation, and cell division were higher and glucose may also have been used as a carbon source. © 2011, American Society for Microbiology.

Caracterização molecular de isolados de Paracoccidioides brasiliensis obtidos de Dasypus novemcinctus (tatu) e sua correlação com virulência e origem geográfica

Pós-graduação em Patologia - FMB

Distribution of hepatitis C virus genotypes among different exposure categories in the State of Pará, Brazilian Amazon

INTRODUÇÃO: Estudos epidemiológicos sobre a distribuição genotípica do HCV na Amazônia Brasileira são escassos. Baseado nisto, determinamos o padrão de distribuição genotípica do HCV em diferentes categorias de exposição no Estado do Pará, Amazônia Brasileira. MÉTODOS: Estudo transversal foi realizado com 312 indivíduos infectados pelo HCV, pertencentes a diferentes categorias de exposição atendidas pelo HEMOPA, CENPREN e uma clínica privada de hemodiálise em Belém. Eles foram testados quanto à presença de anticorpos anti-HCV por teste imunoenzimático, RNA-HCV utilizando PCR em tempo real e genotipados através de análise filogenética da 5' UTR. Os grupos de populações foram caracterizados epidemiologicamente de acordo com dados coletados em breve entrevista ou consulta de prontuários médicos. RESULTADOS: Em todas as diferentes categorias de exposição ao HCV, foram encontrados predomínio do genótipo 1. A distribuição genotípica do HCV em doadores de sangue (BD) foi constituída pelos genótipos 1 (94%) e 3 (6%). Todos os pacientes com doenças hematológicas crônicas (PCHD) possuíam genótipo 1. A distribuição genotípica em usuários de drogas ilícitas (DU) foi constituída pelos genótipos 1 (59,6%) e 3 (40,4%). Em pacientes em hemodiálise (PUH) foram detectados os genótipos 1 (90,1%), 2 (3,3%) e 3 (6,6%). Finalmente, a frequência entre os genótipos 1 e 3 foi significativamente diferente entre os grupos: BD e DU, PUH e DU, PUH e PCHD, e PCHD e DU. CONCLUSÕES: A frequência genotípica e distribuição de HCV em diferentes categorias de exposição no Estado do Pará mostraram predominância do genótipo 1, independentemente do possível risco de infecção.

Genetic parameters and simultaneous selection for root yield, adaptability and stability of cassava genotypes

O objetivo deste trabalho foi estimar parâmetros genéticos e avaliar a seleção simultânea quanto à produtividade de raízes e à adaptabilidade e estabilidade de genótipos de mandioca. Os efeitos dos genótipos foram considerados como fixos e aleatórios, e a metodologia de modelos mistos (REML/Blup) foi utilizada para estimar os parâmetros genéticos e a média harmônica do desempenho relativo dos valores genotípicos (MHPRVG), para seleção simultânea. Dez genótipos foram avaliados em delineamento de blocos ao acaso, com quatro repetições. O experimento foi realizado nos municípios de Altamira, Santarém e Santa Luzia do Pará, PA, nos anos agrícolas de 2009/2010, 2010/2011 e 2011/2012. As raízes foram colhidas 12 meses após o plantio, em todos os locais testados. A produtividade de raízes apresentou baixo coeficiente de variação genotípica (4,25%) e herdabilidade de parcelas individuais no sentido amplo (0,0424), o que resultou em baixo ganho genético. Em razão da baixa correlação genotípica (0,15), a classificação dos genótipos quanto à produtividade de raízes variou de acordo com o ambiente. Os genótipos CPATU 060, CPATU 229 e CPATU 404 destacaram-se quanto à produtividade, adaptabilidade e estabilidade.

Virulence of entomopathogenic nematodes (Rhabditida: Steinernematidae, Heterorhabditidae) to spittlebug Mahanarva spectabilis (Hemiptera: Cercopidae)

A cigarrinha-das-pastagens pode causar sérias limitações na produção de forragens, e o uso de produtos químicos para o controle é caro, além de poder prejudicar o ambiente. Então, existe a necessidade de reduzir o uso de agentes químicos através do desenvolvimento de novas estratégias de controle dessa praga. A virulência de nove isolados de nematoides entomopatogênicos (NEPs) sobre a cigarrinha-das-pastagens foi avaliada em condições de laboratório e casa-de-vegetação. Ninfas de quarto/quinto ínstar de Mahanarva spectabilis foram expostas aos isolados de NEPs em laboratório, e os mais virulentos foram aplicados sobre as ninfas em casa-de-vegetação sob as concentrações de 2000 e 4000 JIs/mL. A eficácia do agente patogênico foi confirmada pela dissecação dos hospedeiros mortos. Todos os isolados testados foram patogênicos às ninfas da cigarrinha-das-pastagens em laboratório, particularmente Steinernema carpocapsae, S. feltiae, S. riobrave e Heterorhabditis amazonensis RSC1, cada um deles causando mortalidade maior que 80%. A concentração não influenciou a eficiência, exceto para S. carpocapsae, o qual não foi tão efetivo como os demais em casa-de-vegetação. Nematoides entomopatogênicos podem ser incluídos em programas de manejo integrado de M. spectabilis.