Characterization of Bipolaris bicolor germination: effects of a physical factor on fungal adaptability.

Studies on physiological responses to stimuli from physical factors are essential for understanding the dynamics of the microorganisms and higly important for the management of plant diseases. Besides, the development of an epidemiological model for pathogen populations requires studying their physiological responses to physical stimuli. The objective of this study was to evaluate the germination dynamics of spores from six isolates of Bipolaris bicolor under effects of light at 25 °C. Suspensions of 1.6 × 105 conidia mL- 1 from the B. bicolor isolates were inoculated onto Petri dishes containing agar-water culture medium and incubated in a BOD chamber under two physical conditions: (a) constant darkness and (b) constant light for five hours. The study was conducted in a completely randomized design, with a 6 × 2 factorial arrangement (six B. bicolor isolates and two physical conditions) and five replications. The length of the germ tube was measured hourly. The constant darkness resulted in higher mean germ tube growth for the pathogen; however, differences in the final germination percentage were found among the isolates. The isolate F-24-02 exhibited the highest germination adaptability to constant darkness, presenting the longest germ tube length.

Colony Age of Trichoderma azevedoi Alters the Profile of Volatile Organic Compounds and Ability to Suppress Sclerotinia sclerotiorum in Bean Plants.

Common bean (Phaseolus vulgaris L.) is one of the most important crops in human food production. The occurrence of diseases, such as white mold, caused by Sclerotinia sclerotiorum can limit the production of this legume. The use of Trichoderma has become an important strategy in the suppression of this disease. The aim of the present study was to evaluate the effect of volatile organic compounds (VOCs) emitted by Trichoderma azevedoi CEN1241 in five different growth periods on the severity of white mold in common bean. The in vitro assays were carried out in double-plate and split-plate, and the in vivo assays, through the exposure of the mycelia of S. sclerotiorum to the VOCs of T. azevedoi CEN1241 and subsequent inoculation in bean plants. Chemical analysis by gas chromatography coupled to mass spectrometry detected 37 VOCs produced by T. azevedoi CEN1241, covering six major chemical classes. The profile of VOCs produced by T. azevedoi CEN1241 varied according to colony age and was shown to be related to the ability of the biocontrol agent to suppress S. sclerotiorum. T. azevedoi CEN1241 VOCs reduced the size of S. sclerotiorum lesions on bean fragments in vitro and reduced disease severity in a greenhouse. This study demonstrated in a more applied way that the mechanism of antibiosis through the production of volatile compounds exerted by Trichoderma can complement other mechanisms, such as parasitism and competition, thus contributing to a better efficiency in the control of white mold in bean plants.

BioSin UFMG Club: Engaging a multilevel and multidisciplinary community in synthetic biology.

Learning synthetic biology is often seen as a far distant possibility, restricted to those who have the privilege of an academic career. We propose a student-centered discussion group around synthetic biology, aimed at people from high school onwards with different backgrounds to interact and learn about synthetic biology. We developed a 14-week long program with three modules: "Leveling," "Introducing," and "Discussion." By completing the first two modules, the members should be more comfortable with biological names, structures, concepts, and techniques. The modules developed are available in Portuguese, Spanish, and English via the Open Lab Idea Real website (https://ideareal.org/clube-de-biologia-sintetica/) and can be used to implement the Club either in place or virtually around the world. We put it to practice at Universidade Federal de Minas Gerais (UFMG) creating the Club named BioSin. There are programs such as the International Genetically Engineered Machine (iGEM) competition focused on disseminating synthetic biology. Although iGEM is one fantastic way of learning about synthetic biology, there is a high cost. Because of that, a study and discussion Club is a tool to spread knowledge and engage with the study area.

Incidência e caracterização morfológica de Alternaria alternata e Bipolaris bicolor em sementes de trigo 'BRS 264' / Incidence and morphological characterization of Alternaria alternata e Bipolaris bicolor in wheat seeds 'BRS 264'

As sementes são consideradas importantes veículos de disseminação de patógenos. O objetivo deste estudo foi quantificar a incidência de A. alternata e B. bicolor em sementes de trigo ‘BRS 264’ e realizar a caracterização morfológica destes fungos. Para tanto, quatro avaliações sanitárias foram realizadas, empregando-se caixas acrílicas transparentes gerbox. Com finalidade de inibir a germinação, as sementes foram incubadas em BOD a 25ºC e regime de 12 h de luz durante 24 horas e, em seguida, transferidas para freezer a -20ºC e escuro por 24 horas. Posteriormente, as sementes foram incubadas em BOD a 25ºC e 12 horas de luz por mais 8 dias, onde a incidência foi estimada diariamente. Em seguida foram preparadas lâminas semi-permanentes para posterior registro de imagens e a mensuração de estruturas dos fungos pela obtenção de 30 medidas de cada componente estrutural avaliada em microscópio de luz Leica DM500, com auxílio do programa LAS EZ 2.0 (100x). Os resultados referentes às estruturas fúngicas e de incidência foram submetidos à análise de variância e de regressão, respectivamente. A partir disso, foi possível confirmar através da caracterização morfológica a presença de A. alternata e B. bicolor ̧ os quais apresentaram 41,5 e 16,5% de incidência nas sementes aos 8 dias de avaliação, respectivamente.

The seeds are considered important spread vehicles of pathogens. This study aimed to quantify the incidence of A. alternata and B. bicolor in wheat seeds ‘BRS 264’ and to perform morphological characterization of these fungi. Therefore, four sanitary evaluations were performed in gerbox transparent acrylic boxes. In order to inhibit germination, the seeds were incubated in a BOD at 25ºC and 12-hour light period for 24 hours and, then, transferred to freezer at -20ºC and dark period for 24 hours. Just after, the seeds were incubated in BOD chamber at 25ºC and 12-hour light period during 8 days, which the incidence was estimated daily. Then, semi-permanent slide mountings were prepared for subsequent capturing images and measurement of fungi structures by obtaining 30 measurements of each structural component evaluated under a Leica DM500 light microscope, using the LAS EZ 2.0 (100x) software. The results concerning fungal structures and incidence were submitted to variance and regression analysis, respectively. From this, it was possible to confirm A. alternata and B. bicolor presence through morphological characterization, which presented 41.5 and 16.5% of incidence on the seeds at 8 days of evaluation, respectively.

Incidência e caracterização morfológica de Alternaria alternata e Bipolaris bicolor em sementes de trigo 'BRS 264' / Incidence and morphological characterization of Alternaria alternata e Bipolaris bicolor in wheat seeds 'BRS 264'

As sementes são consideradas importantes veículos de disseminação de patógenos. O objetivo deste estudo foi quantificar a incidência de A. alternata e B. bicolor em sementes de trigo ‘BRS 264 e realizar a caracterização morfológica destes fungos. Para tanto, quatro avaliações sanitárias foram realizadas, empregando-se caixas acrílicas transparentes gerbox. Com finalidade de inibir a germinação, as sementes foram incubadas em BOD a 25ºC e regime de 12 h de luz durante 24 horas e, em seguida, transferidas para freezer a -20ºC e escuro por 24 horas. Posteriormente, as sementes foram incubadas em BOD a 25ºC e 12 horas de luz por mais 8 dias, onde a incidência foi estimada diariamente. Em seguida foram preparadas lâminas semi-permanentes para posterior registro de imagens e a mensuração de estruturas dos fungos pela obtenção de 30 medidas de cada componente estrutural avaliada em microscópio de luz Leica DM500, com auxílio do programa LAS EZ 2.0 (100x). Os resultados referentes às estruturas fúngicas e de incidência foram submetidos à análise de variância e de regressão, respectivamente. A partir disso, foi possível confirmar através da caracterização morfológica a presença de A. alternata e B. bicolor ̧ os quais apresentaram 41,5 e 16,5% de incidência nas sementes aos 8 dias de avaliação, respectivamente.(AU)

The seeds are considered important spread vehicles of pathogens. This study aimed to quantify the incidence of A. alternata and B. bicolor in wheat seeds ‘BRS 264 and to perform morphological characterization of these fungi. Therefore, four sanitary evaluations were performed in gerbox transparent acrylic boxes. In order to inhibit germination, the seeds were incubated in a BOD at 25ºC and 12-hour light period for 24 hours and, then, transferred to freezer at -20ºC and dark period for 24 hours. Just after, the seeds were incubated in BOD chamber at 25ºC and 12-hour light period during 8 days, which the incidence was estimated daily. Then, semi-permanent slide mountings were prepared for subsequent capturing images and measurement of fungi structures by obtaining 30 measurements of each structural component evaluated under a Leica DM500 light microscope, using the LAS EZ 2.0 (100x) software. The results concerning fungal structures and incidence were submitted to variance and regression analysis, respectively. From this, it was possible to confirm A. alternata and B. bicolor presence through morphological characterization, which presented 41.5 and 16.5% of incidence on the seeds at 8 days of evaluation, respectively.(AU)

Clinical pathology differences in laboratory utilization in hospice and nonhospice units.

A significant difference can be observed between hospice and nonhospice philosophy. Nonhospice units direct its effort to cure and sustain patient's life using disease-modifying therapeutic procedures, while hospice units focus on patient's quality of life. However, despite the differences between the 2 basic philosophies in question, both approaches share 1 aspect in common: the correct diagnosis of the patient. In any case above, laboratory analysis is a valuable tool. This work aims to compare the laboratory utilization between nonhospice cancer and hospice cancer units. Laboratory requests from patients within a 1-year period were evaluated and the hospice laboratory profile was presented. We demonstrated that nonhospice unit had a major volume of requested laboratory test than hospice unit, but for inpatients this difference was not so dramatic.

Determinaçao de especies de estafilococos coagulase-negativos de significado clinico / Species identification of coagulase-negative staphylococci of clinical significance

Uma coleçao de 141 amostras de estafilococos coagulase-negativos, isoladas de especimes clinicos, assim como de portadores e ambiente hospitalar, foram analisadas quanto as caracteristicas fisiologicas e propriedades biologicas. Oito especies foram identificadas pelos metodos convencionais segundo Kloos & Schleifer, e corresponderam a S. saprophyticus, S. epidermis, S. cohnil, S. simulans, S. hominis, S. warneri, S. haemolyticus e S. xylosus. Quatorze amostras nao foram identificadas. Atraves da aplicaçao da tecnica de taxonomia numerica se observou uma tendencia para a separaçao em dois grandes grupos, compreendendo S. saprophyticus e S. epidermidis. A partir dai as amostras restantes se identificaram com as outras especies de referencia de diferentes graus de similaridade. O emprego do micrometodo API no estudo de 39 das amostras ja identificadas so permitiu a classificaçao de 17 cepas em especies.

Cinética da sensibilidade bacteriana: proposta de uma função de sensibilidade bacteriana aos antimicrobianos

O comportamento de 52 cepas bacterianas: foi analisado frente a concentrações regularmente crescentes de antibiótico (G). Utilizou-se técnica turbidimétrica, através da medida da densidade ótica (DO). Foram estudadas 40 cepas de enterobactérias, 11 cepas de bactérias anaeróbias estritas e 1 cepa de mycobacterium como representante de gênero de crescimento lento. Uma função de sensibilidade (F sa) é proposta e designada “curva de sensibilidade cinética (CSC). A partir da medida experimental da DO j para cada concentração de antibiótico Cj, j = 0,1...10,5 parâmetros foram estimados para caracterização do comportamento de cada cepa individualmente ao antibiótico (cefalotina para enterobactérias, cloranfenicol para anaeróbios estritos e estreptomicina para micobactéria). A comparação dos parâmetros da CSC com os valores da concentração inibitória mínima (CIM) sugere tratar-se de fenomenologia diferenciada apesar de apresentarem aspectos correlacionáveis. A comparação da CSC utilizando-se os parâmetros estimados ou mesmo diretamente a medida da DO j revelou boa correlação com os resultados obtidos pela técnica de difusão em ágar com disco. Comportamento não regular quanto a dinâmica da CSC foi observado em algumas cepas estudadas. Este fenômeno parece estar relacionado a uma heterogeneidade intrínseca” e uma indeterminação na medida da CIM. As possíveis implicações desta “heterogeneidade” foram analisadas através de simulação. Os resultados obtidos forneceram hipóteses quanto aos mecanismos implicados na dissociação dos testes in vitro e as observações clínicas

The behavior of 52 bacterial strains : was analysed against regular increasing antibiotic concentrations (Cj) by measuring the optical density (Odj). We studied 40 strains of Enterobacteriaceae Mycobacterium tuberculosis. A sensibility function (Fsa) is proposed and designated as “Kinetic Sensibility Curve”. Sttarting from the experimental measure of the OD j to each antibiotic concentration Cj (j = 0,1, … 10), 5 parameters were estimated to characterize the individual response of each strain to the antibiotic. The comparison of the Kinetic Sensibility Curve using the estimated parameters with the values of the minimum inibitory concentration (MIC) obtained by the dilution technique suggests different instrinsic phenomenon, although one can show some similar aspects. The comparison of the estimated parameters or even the experimental DO (j = 10) with the results obtained by the disk diffusion technique revealed good correlation. Some of the strains studied have showed a non-regular dynamics of the Kinetic Sensibility Curve. This phenomenous seems to be related to an intrinsic population heterogeneity of the bacterial population and a MIC indetermination. The possible implications of this heterogeneity was analysed using simulation technique. The obtained results give us some hipotheses about the mechanism implicated in the dissociation between the in vitro tests and the clinical observations