Experimental infection of commercial layers with wild or attenuated Salmonella Gallinarum mutant strains: Anatomic pathology, total blood cell count and serum protein levels

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microsatellite marker-based assessment of the biodiversity of native bioethanol yeast strains

Although many Brazilian sugar mills initiate the fermentation process by inoculating selected commercial Saccharomyces cerevisiae strains, the unsterile conditions of the industrial sugar cane ethanol fermentation process permit the constant entry of native yeast strains. Certain of those native strains are better adapted and tend to predominate over the initial strain, which may cause problems during fermentation. In the industrial fermentation process, yeast cells are often exposed to stressful environmental conditions, including prolonged cell recycling, ethanol toxicity and osmotic, oxidative or temperature stress. Little is known about these S. cerevisiae strains, although recent studies have demonstrated that heterogeneous genome architecture is exhibited by some selected well-adapted Brazilian indigenous yeast strains that display high performance in bioethanol fermentation. In this study, 11 microsatellite markers were used to assess the genetic diversity and population structure of the native autochthonous S. cerevisiae strains in various Brazilian sugar mills. The resulting multilocus data were used to build a similarity-based phenetic tree and to perform a Bayesian population structure analysis. The tree revealed the presence of great genetic diversity among the strains, which were arranged according to the place of origin and the collection year. The population structure analysis revealed genotypic differences among populations; in certain populations, these genotypic differences are combined to yield notably genotypically diverse individuals. The high yeast diversity observed among native S. cerevisiae strains provides new insights on the use of autochthonous high-fitness strains with industrial characteristics as starter cultures at bioethanol plants. © 2013 John Wiley & Sons, Ltd.

The role of leukotriene B4 in early stages of experimental paracoccidioidomycosis induced in phenotypically selected mouse strains

Paracoccidioidomycosis is a human systemic mycosis caused by the fungus Paracoccidioides brasiliensis. The mechanisms involved in innate immune response to this fungus are not fully elucidated. Leukotrienes are known to be critical for the clearance of various microorganisms, mainly by mediating the microbicidal function of phagocytes. We investigated the involvement of leukotriene B4 in the early stages of experimental paracoccidioidomycosis, which was induced by intratracheal inoculation of the fungus in selected mouse lines. The mouse lines utilized were produced through bi-directional phenotypic selection, endowed with maximal or minimal acute inflammatory reactivity, and designated AIRmax and AIRmin, respectively. AIRmax mice were more resistant to the infection, which was demonstrated by reduced lung fungal loads. However, the two lines produced similar amounts of leukotriene B4, and pharmacological inhibition of this mediator provoked similar fungal load increases in the two lines. The lower fungal load in the AIRmax mice was associated with a more effective inflammatory response, which was characterized by enhanced recruitment and activation of phagocytic cells and an increased production of activator cytokines. This process resulted in an increased release of fungicidal molecules and a diminution of fungal load. In both lines, leukotriene production was associated with a protective response in the lung that was consequent to the effect of this eicosanoid on the influx and activation of phagocytes. © 2013 ISHAM.

Differential arthritogenicity of Staphylococcus aureus strains isolated from biological samples

Background: Staphylococcus aureus is the most common agent of septic arthritis that is a severe, rapidly progressive and destructive joint disease. Superantigens produced by S. aureus are considered the major arthritogenic factors. In this study, we compared the arthritogenic potential of five superantigen-producing staphylococcal strains.Methods: Male C57BL/6 mice were intravenously infected with ATCC 19095 SEC+, N315 ST5 TSST-1+, S-70 TSST-1+, ATCC 51650 TSST-1+ and ATCC 13565 SEA+ strains. Clinical parameters as body weight, arthritis incidence and clinical score were daily evaluated. Joint histopathological analysis and spleen cytokine production were evaluated at the 14th day after infection.Results: Weight loss was observed in all infected mice. ATCC 19095 SEC+, N315 ST5 TSST-1+ and S-70 TSST-1+ were arthritogenic, being the highest scores observed in ATCC 19095 SEC+ infected mice. Intermediate and lower clinical scores were observed in N315 ST5 TSST-1+ and S-70 TSST-1+ infected mice, respectively. The ATCC 13565 SEA+ strain caused death of 85% of the animals after 48 h. Arthritis triggered by the ATCC 19095 SEC+ strain was characterized by accentuated synovial hyperplasia, inflammation, pannus formation, cartilage destruction and bone erosion. Similar joint alterations were found in N315 ST5 TSST-1+ infected mice, however they were strikingly more discrete. Only minor synovial proliferation and inflammation were triggered by the S-70 TSST-1+ strain. The lowest levels of TNF-α, IL-6 and IL-17 production in response to S. aureus stimulation were found in cultures from mice infected with the less arthritogenic strains (S-70 TSST-1+ and ATCC 51650 TSST-1+). The highest production of IL-17 was detected in mice infected with the most arthritogenic strains (ATCC 19095 SEC+ and N315 ST5 TSST-1+).Conclusions: Together these results demonstrated that S. aureus strains, isolated from biological samples, were able to induce a typical septic arthritis in mice. These results also suggest that the variable arthritogenicity of these strains was, at least in part, related to their differential ability to induce IL-17 production. © 2013 Colavite-Machado et al.; licensee BioMed Central Ltd.

Comportamento estrutural de lajes pré-moldadas treliçadas com adição de resíduos de borracha de pneu

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Simulação numérica do comportamento da madeira de Eucalytus citrodora ao cisalhamento através do ensaio de tração Off-Axis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Growth curves of Nile tilapia (Oreochromis niloticus) strains cultivated at different temperatures

Growth of Red, GIFT and Supreme Nile tilapia strains were evaluated. Fish were cultivated in indoor recirculation systems in 0.5 m³ tanks with controlled temperatures of 22, 28 and 30°C. Random samples of 20 fish from each strain (10 fish tank-1) were weighed at day 7, 30, 60, 90 and 120. Exponential model (y=AeKx) and Gompertz model (y = Aexp(-Be-Kx)) were fitted and the estimates parameters were obtained by Weighted Least Squares. At 22°C, Red, GIFT and Supreme strain presented similar growth and fit of exponential model. GIFT and Supreme strain presented higher growth rate at 30°C of cultivation when compared to Red strain. Temperature influences weight and age at the inflection point. The temperature of cultivation influences the growth description of Red, GIFT and Supreme tilapia strains. It changes the age and weight at inflection point and the qualities of growth model fits, changing the variation of the batch.

Alloxan diabetes alters the tensile strength, morphological and morphometric parameters of abdominal wall healing in rats

PURPOSE:To investigate the effects of alloxan diabetes on the abdominal wall healing of rats undergoing laparotomy.METHODS:Ninety-six male Wistar rats weighing between 200 and 300 grams, divided into two groups: non-diabetic group (G1) and another with untreated diabetes (G2). Three months after diabetes induction, the animals underwent a 5cm-long- laparotomy and 5.0 nylon monofilament suture. After the surgery, 12 animals from each group were euthanized on days 4, 14, 21 and 30 corresponding to the moments M1, M2, M3 and M4. In each moment a fragment of the abdominal wall containing the scar was removed for tensile strength measurement, histological and morphometric study. Clinical and biochemical parameters were also analyzed.RESULTS:G2 animals showed parameters compatible with severe diabetes and decreased plasma levels of insulin. The tensile strength in G2 was significantly smaller in M2 and M4, with a tendency to fall in the other two. Through light microscope, diabetic animals showed more difficulty to increase collagen density and contraction. G2 animals showed high cellularity of fibroblasts in later healing moments, with collagen thinning in M2 and M4.CONCLUSION:The abdominal wound healing in untreated diabetic animals was altered and led to a higher incidence of dehiscence and infections.

Coagulase-negative staphylococci strains resistant to oxacillin isolated from neonatal blood cultures

Coagulase-negative staphylococci (CoNS) are the microorganisms most frequently isolated from clinical samples and are commonly found in neonatal blood cultures. Oxacillin is an alternative treatment of choice for CoNS infections; however, resistance to oxacillin can have a substantial impact on healthcare by adversely affecting morbidity and mortality. The objective of this study was to detect and characterise oxacillin-resistant CoNS strains in blood cultures of newborns hospitalised at the neonatal ward of the University Hospital of the Faculty of Medicine of Botucatu. One hundred CoNS strains were isolated and the mecA gene was detected in 69 of the CoNS strains, including 73.2% of Staphylococcus epidermidis strains, 85.7% of Staphylococcus haemolyticus strains, 28.6% of Staphylococcus hominis strains and 50% of Staphylococcus lugdunensis strains. Among these oxacillin-resistant CoNS strains, staphylococcal cassette chromosome mec (SCCmec) type I was identified in 24.6%, type II in 4.3%, type III in 56.5% and type IV in 14.5% of the strains. The data revealed an increase in the percentage of CoNS strains isolated from blood cultures from 1991-2009. Furthermore, a predominant SCCmec profile of the oxacillin-resistant CoNS strains isolated from neonatal intensive care units was identified with a prevalence of SCCmec types found in hospital-acquired strains.

Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dynamics of the chemical composition and productivity of composts for the cultivation of Agaricus bisporus strains

Two compost formulations based on oat straw (Avena sativa) and brachiaria (Brachiaria sp.) were tested for the cultivation of three Agaricus bisporus strains (ABI-07/06, ABI-05/03, and PB-1). The experimental design was a 2 x 3 factorial scheme (composts x strains) with 6 treatments and 8 repetitions (boxes containing 12 kg of compost). The chemical characterization of the compost (humidity, organic matter, carbon, nitrogen, pH, raw protein, ethereal extract, fibers, ash, cellulose, hemicellulose, and lignin) before and after the cultivation of A. bisporus and the production (basidiomata mass, productivity, and biological efficiency) were evaluated. Data were submitted to variance analysis, and averages were compared by means of the Tukey's test. According to the results obtained, the chemical and production characteristics showed that the best performances for the cultivation of A. bisporus were presented by the compost based on oat and the strain ABI-07/06.

Mycelial growth of two Lentinula edodes strains in culture media prepared with sawdust extracts from seven eucalyptus species and three eucalyptus clones

The in vitro mycelial growth of Lentinula edodes strains LE-95/01 and LE-96/18 were evaluated in solid culture media prepared with sawdust extracts from seven eucalyptus species (E. saligna, E. grandis, E. urophylla, E. pellita, E. paniculata, E. citriodora, and E. camaldulensis) and three eucalyptus clones (E. grandis × E. urophylla hybrids). Evaluations were made every 48 hours by means of colony diameter measurements (mean of four transversely-oriented measurements), during ten days of incubation in the dark at 25ºC ±1°C. The experimental design consisted of randomized blocks, and treatment means were compared by Tukey test. The culture medium prepared from E. citriodora sawdust extract was the most promising to grow L. edodes strains LE-96/18 and LE-95/01. L. edodes strain LE-96/18 presented the fastest mycelial growth after incubation for ten days, regardless of sawdust extract type used in the culture medium.

TENSILE AND CREEP BEHAVIOR OF GEOSYNTHETICS USING CONFINED-ACCELERATED TESTS

A major aspect in geosynthetics creep analysis is the load level applied to the specimen, usually referred as a percentage of the geosynthetic ultimate tensile strength (UTS). Since both tensile and creep standard tests are performed with in-isolation specimens, they may not reproduce the possibly significant effect of soil-geosynthetic interaction. A new creep testing machine was recently developed and successfully addressed this concern. However, further developments allowed tensile tests to be performed in the same conditions used in nonconventional creep ones. This paper presents the results of nonconventional tensile tests performed with a woven biaxial polyester geogrid. They were used to define its UTS in the same conditions employed in creep tests performed with the new equipment. Despite changes in tensile curves shapes were found, the UTS from confined, accelerated and confined-accelerated tensile tests were quite similar to those obtained with standard tensile test procedure.

Invasion of differentiated intestinal caco-2 cells is a sporadic property among atypical enteropathogenic escherichia coli strains carrying common intimin subtypes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification of pathogens and virulence profile of Rhodococcus equi and Escherichia coli strains obtained from sand of parks

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)