Anaphylactoid reaction caused by sodium ceftriaxone in two horses experimentally infected by Borrelia burgdorferi

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

Effect of biotransformation by liver S9 enzymes on the mutagenicity and cytotoxicity of melanin extracted from Aspergillus nidulans

A mutant that exhibited increased melanin pigment production was isolated from Aspergillus nidulans fungus. This pigment has aroused biotechnological interest due to its photoprotector and antioxidant properties. In a recent study, we showed that melanin from A. nidulans also inhibits NO and TNF-α production. The present study evaluates the mutagenicity and cytotoxicity of melanin extracted from A. nidulans after its exposure to liver S9 enzymes. The cytotoxicity of multiple concentrations of melanin (31.2-500 μg/mL) against the McCoy cell line was evaluated using the Neutral Red assay, after incubation for 24 h. Mutagenicity was assessed using the Ames test with the Salmonella typhimurium strains TA98, TA97a, TA100, and TA102 at concentrations ranging from 125 μg/plate to 1 mg/plate after incubation for 48 h. The cytotoxicity of A. nidulans melanin after incubation with S9 enzymes was less than (CI50 value= 413.4 ± 3.1 μg/mL) that of other toxins, such as cyclophosphamide (CI50 value = 15 ± 1.2 μg/mL), suggesting that even the metabolised pigment does not cause significant damage to cellular components at concentrations up to 100 μg/mL. In addition, melanin did not exhibit mutagenic properties against the TA 97a, TA 98, TA 100, or TA 102 strains of S. typhimurium, as shown by a mutagenic index (MI)  <2 in all assays. The significance of these results supports the use of melanin as a therapeutic reagent because it possesses low cytotoxicity and mutagenic potential, even when processed through an external metabolising system.

TNF-alpha and IL-6 immunohistochemistry in rat renal tissue experimentaly infected with Leptospira interrogans serovar Canicola

Leptospirosis is a public health problem worldwide and its etiology remains unclear. Its pathogenesis involves a complex interaction between host and infecting microorganism. The inflammatory reaction that controls the infection process also underscores many pathophysiological events occurring in leptospirosis. We investigated the presence of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in renal tissues by immunohistochemical and histopathological examination in animals experimentally inoculated with Leptospira serovar Canicola. All the tests were carried out 2, 7, 14, 21 or 28 days after inoculation. Although TNF-alpha and IL-6 had been detected in tissues throughout the observation period, these cytokines appeared more intensely during the initial phase of infection. Therefore, both TNF-alpha and IL-6 were associated with the immunopathogenesis of leptospirosis. This profile suggests a high immunocellular response throughout the early infection stages followed by subsequent humoral response.

Comparison of diferent diagnostic tests in dogs uninfected and naturally infected with visceral leishmaniasis

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

The genome sequence of the plant pathogen Xylella fastidiosa: The Xylella fastidiosa consortium of the organization for nucleotide sequencing and analysis, Sao Paulo, Brazil

Xylella fastidiosa is a fastidious, xylem-limited bacterium that causes a range of economically important plant diseases. Here we report the complete genome sequence of X. fastidiosa clone 9a5c, which causes citrus variegated chlorosis - a serious disease of orange trees. The genome comprises a 52.7% GC-rich 2,679,305-base-pair (bp) circular chromosome and 'two plasmids of 51,158 bp and 1,285 bp. We can assign putative functions to47% of the 2,904 predicted coding regions. Efficient metabolic functions are predicted, with sugars as the principal energy and carbon source, supporting existence in the nutrient-poor xylem sap. The mechanisms associated with pathogenicity and virulence involve toxins, antibiotics and ion sequestration systems, as well as bacterium-bacterium and bacterium-host interactions mediated by a range of proteins. Orthologues of some of these proteins have only been identified in animal and human pathogens; their presence in X. fastidiosa indicates that the molecular basis for bacterial pathogenicity is both conserved and independent of host. At least 83 genes are bacteriophage-derived and include virulence-associated genes from other bacteria, providing direct evidence of phage-mediated horizontal gene transfer.

Ocorrência de Clostridium botulinum tipos C e D em criatórios de bovinos no município de Cocalinho, Vale do Araguaia, Mato Grosso

In order to assess the occurrence and distribution of spores and toxins of Clostridium botulinum types C and D in three farms in Cocalinho, at the Araguaia River valley, State of Mato Grosso, Brazil, we analyzed sediment samples from 40 water holes, soil and cattle feces, collected around water holes. Sediments were analyzed by direct method, whilst feces, soil and also sediment samples were individually analyzed by indirect method. The detection of spores and botulinum toxins in the filtered material was performed by bioassay in Swiss Webster mice strain, as well as the serum-neutralization of the positive materials for typing. Samples of cattle feces showed the largest positive rate for C. botulinum, with 25/40 (62.5%), followed by soil, 12/40 (30%), and by sediment, 13/40 (32.5%). From the 40 cattle feces samples, 25 (62.00%) were positive for Clostridium botulinum; six samples were identified as type C, other six as type D, and 13 samples were classified as CD complex. From the equal number (40) of soil samples, 12 (30%) were positive for C. botulinum; two samples were identified as type C, other three as type D, and seven samples were classified as CD complex. Regarding the 40 sediment samples, 13 (32.5%) were positive for C. botulinum; two samples were identified as type C, other three as type D, and eight samples were classified as CD complex. No botulism toxin was detected by indirect method.

Efeito do soro de cães portadores de insuficiência renal sobre a apoptose e o metabolismo oxidativo dos polimorfonucleares

In recent years, uremic toxins have been widely investigated as an immunosuppressive factor for nephropathic patients. This study aimed to test the hypothesis that, as it was similarly observed in humans, the rate of apoptosis and superoxide production in polymorphonuclear leukocytes are changed in dogs treated with uremic serum. The superoxide production of polymorphonuclear leukocytes and apoptotic index of 10 healthy dogs incubated with autologous and homologous serum from healthy and uremic dogs was compared. Thus, there was an effect of partial inhibition of oxidative metabolism in uremia without correlation with the acceleration of polymorphonuclear leukocytes apoptosis in dogs.

Efeito do plasma rico em uréia na apoptose de neutrófilos de cães

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

Uprecycling leater waste

Incorporating contaminated leather waste into natural rubber improves the rubber's mechanical properties and avoids improper disposal of toxins.

Patógenos bacterianos isolados de fezes de felinos domésticos, sem sinais entéricos, de ambiente urbano e rural

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interações moleculares das proteínas CRY1 e VIP3 no controle de lepidópteros em cana-de-açúcar

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

Síntese e caracterização de pequenos peptídeos lineares do veneno de Tityus serrulatus (Buthidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Staphylococcal enterotoxins: molecular aspects and detection methods

Members of the Staphylococcus genus, especially Staphylococcus aureus, are the most common pathogens found in hospitals and in community-acquired infections. Some of their pathogenicity is associated with enzyme and toxin production. Until recently, S. aureus was the most studied species in the genus; however, in last few years, the rise of infections caused by coagulase-negative staphylococci has pointed out the need for further studies on virulence factors that have not yet been completely elucidated so as to better characterize the pathogenic potential of this group of microorganisms. Several staphylococcal species produce enterotoxins, a family of related proteins responsible for many diseases, such as the toxic-shock syndrome, septicemia and food poisoning. To this date, 23 different enterotoxin types have been identified besides toxic-shock syndrome toxin-1 (TSST-1), and they can be divided into five phylogenetic groups. The mechanism of action of these toxins includes superantigen activity and emetic properties, which can lead to biological effects of infection. Various methods can detect genes that encode enterotoxins and their production. Molecular methods are the most frequently used at present. This review article has the objective to describe aspects related to the classification, structure and regulation of enterotoxins and toxic-shock syndrome toxin-1 detection methods.

Estudo peptídico e determinação do perfil de metabólitos de venenos de escorpiões da família buthidae: Tityus serrulatus, Tityus bahiensis e Tityus obscurus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito de compostos inorgânicos, herbicidas e extratos foliares no desenvolvimento de microcystis aeruginosa e produção de microcistina

Pós-graduação em Agronomia (Proteção de Plantas) - FCA