Diagnóstico e epidemiologia da Entamoeba histolytica em residentes do município de Juruti-Pará

Amebíase é a infecção no homem causada pelo protozoário Entamoeba histolytica, apresentam quadros sem manifestações clínicas até graves de elevada morbimortalidade e sendo responsável por milhões de casos de disenteria e abscessos hepáticos a cada ano. Os dados epidemiológicos da amebíase no Brasil estão sendo reavaliados desde que a Entamoeba histolytica (patogênica) foi considerada espécie distinta da Entamoeba dispar (não patogênica). Neste estudo, realizou- se o diagnóstico da amebíase por meio de métodos parasitológicos, pesquisa de antígenos e método molecular em amostras fecais de pacientes residentes no município de Juruti, Pará, Brasil. Foram analisadas 188 amostras, com positividade em 28 (14,89 %) no método imunológico, que foi considerado como padrão ouro. A infecção por E. histolytica foi maior no grupo etário acima de 14 anos (8,51%) que no grupo de 0-14 anos (6,38%), porém sem significância estatística (p > 0,05). Houve discordância nos resultados dos métodos ELISA e coproscópico em 41 amostras (21,81%), com maior número de positivos no teste imunoenzimático. O diagnóstico pelo método de PCR apresentou positividade de 5,88% (3/51), resultado inferior ao observado na microscopia (7,84% - 4/51) e teste de ELISA (11,76% - 6/51). Assim, nossos resultados sugerem que a amebíase intestinal é um problema de saúde pública no município de Juruti.

Plamodiophora brassicae x brassicaceas: variabilidade genética e patogênica, epidemiologia da doença e efeito de exsudatos radiculares e plantas não brassicaceas no controle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prozone effects in microscopic agglutination tests for leptospirosis in the sera of mice infected with the pathogenic Leptospira interrogans serovar Canicola

Mice experimentally infected with a pathogenic strain of Leptospira interrogans serovar Canicola produced false negative results (prozone effect) in a microscopic agglutination test (MAT). This prozone effect occurred in several serum samples collected at different post-infection times, but it was more prominent in samples collected from seven-42 days post-infection and for 1:50 and 1:100 sample dilutions. This phenomenon was correlated with increased antibody titres in the early post-infection phase. While prozone effects are often observed in serological agglutination assays for the diagnosis of animal brucellosis and human syphilis, they are not widely reported in leptospirosis MATs.

Molecular and Pathogenic Diversity Among Brazilian Isolates of Xanthomonas albilineans Assessed with SSR Marker Loci

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

Highlights in pathogenic fungal biofilms

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

Potentially pathogenic Escherichia coli in healthy, pasture-raised sheep on farms and at the abattoir in Brazil

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

Antifungal Activity of Decyl Gallate against Several Species of Pathogenic Fungi

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

Overlapped Sequence Types (STs) and Serogroups of Avian Pathogenic (APEC) and Human Extra-Intestinal Pathogenic (ExPEC) Escherichia coli Isolated in Brazil

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

Occurrence of pathogenic environmental mycobacteria on surfaces in health institutions

The presence of environmental mycobacteria on surfaces in two public health institutions, namely a health center and a hospital in upstate São Paulo (Brazil), was identified by polymerase chain reaction-restriction enzyme analysis (PRA). The possible sources of contamination by these microorganisms were evaluated, contributing to epidemiology studies. Methods: From June 2005 to June 2006, a total of 632 samples were collected from exposed surfaces, such as washbasins, drinking fountains, and other accessible sites, and the mycobacteria present in the samples were isolated and cultured. Results: Sixty-five mycobacteria were isolated from the 632 samples; 47 of which were detected in samples from the health center and 18 in samples collected from the hospital. The isolates were identified by DNA restriction patterns obtained by PRA, and potentially pathogenic species were found to be prevalent among the identified mycobacteria. This study shows that the PRA technique can be employed as a fast and easy method for identification of nontuberculous mycobacteria in public areas. Conclusions: The isolation of environmental mycobacteria from the two health institutions demonstrates that these surfaces are reservoirs of potentially pathogenic mycobacteria and indicates the need for continuous maintenance and monitoring. These data will add to the study of the epidemiology of these microorganisms.

Antimicrobial photodynamic therapy against pathogenic bacterial suspensions and biofilms using chloro-aluminum phthalocyanine encapsulated in nanoemulsions

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

In vitro antibacterial and chemical properties of essential oils including native plants from Brazil against pathogenic and resistant bacteria

The antimicrobials products from plants have increased in importance due to the therapeutic potential in the treatment of infectious diseases. Therefore, we aimed to examine the chemical characterisation (GC-MS) of essential oils (EO) from seven plants and measure antibacterial activities against bacterial strains isolated from clinical human specimens (methicillin-resistant Staphylococcus aureus (MRSA) and sensitive (MSSA), Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) and foods (Salmonella Enteritidis). Assays were performed using the minimal inhibitory concentration (MIC and MIC90%) (mg/mL) by agar dilution and time kill curve methods (log CFU/mL) to aiming synergism between EO. EO chemical analysis showed a predominance of terpenes and its derivatives. The highest antibacterial activities were with Cinnamomun zeylanicum (0.25 mg/mL on almost bacteria tested) and Caryophyllus aronzaticus EO (2.40 mg/mL on Salmonella Enteritidis), and the lowest activity was with Eugenia uniflora (from 50.80 mg/mL against MSSA to 92.40 mg/mL against both Salmonella sources and P aeruginosa) EO. The time kill curve assays revealed the occurrence of bactericide synergism in combinations of C. aromaticus and C. zeylanicum with Rosmarinus. officinalis. Thus, the antibacterial activities of the EO were large and this can also be explained by complex chemical composition of the oils tested in this study and the synergistic effect of these EO, yet requires further investigation because these interactions between the various chemical compounds can increase or reduce (antagonism effect) the inhibitory effect of essential oils against bacterial strains.

Molecular characterization of intestinal protozoa in two poor communities in the State of São Paulo, Brazil

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

Risk Assessment of the Introduction of H5N1 Highly Pathogenic Avian Influenza as a Tool to be Applied in Prevention Strategy Plan

Risks of the introduction of highly pathogenic avian influenza (HPAI) H5N1 through migratory birds to the main wintering site for wild birds in southern Brazil and its consequences were assessed. Likelihoods were estimated by a qualitative scale ranging from negligible to high. Northern migrants that breed in Alaska and regularly migrate to South America (primary Charadriiformes) can have contact with birds from affected areas in Asia. The likelihood of the introduction of HPAI H5N1 through migratory birds was found to be very low as it is a probability conditioned to successful transmission in breeding areas and the probabilities of an infected bird migrating and shedding the virus as far as southern Brazil. The probability of wild species becoming exposed to H5N1-infected birds is high as they nest with northern migrants from Alaska, whereas for backyard poultry it is moderate to high depending on proximity to wetlands and the presence of species that could increase the likelihood of contact with wild birds such as domestic duck. The magnitude of the biological and economic consequences of successful transmission to poultry or wild birds would be low to severe depending on the probability of the occurrence of outbreak scenarios described. As a result, the risk estimate is greater than negligible, and HPAI H5N1 prevention strategy in the region should always be carefully considered by the veterinary services in Brazil.

Pathogenic Mycobacterium bovis strains differ in their ability to modulate the proinflammatory activation phenotype of macrophages

Background: Tuberculosis, caused by Mycobacterium tuberculosis or Mycobacterium bovis, remains one of the leading infectious diseases worldwide. The ability of mycobacteria to rapidly grow in host macrophages is a factor contributing to enhanced virulence of the bacteria and disease progression. Bactericidal functions of phagocytes are strictly dependent on activation status of these cells, regulated by the infecting agent and cytokines. Pathogenic mycobacteria can survive the hostile environment of the phagosome through interference with activation of bactericidal responses. To study the mechanisms employed by highly virulent mycobacteria to promote their intracellular survival, we investigated modulating effects of two pathogenic M. bovis isolates and a reference M. tuberculosis H37Rv strain, differing in their ability to multiply in macrophages, on activation phenotypes of the cells primed with major cytokines regulating proinflammatory macrophage activity. Results: Bone marrow- derived macrophages obtained from C57BL/6 mice were infected by mycobacteria after a period of cell incubation with or without treatment with IFN-gamma, inducing proinflammatory type-1 macrophages (M1), or IL-10, inducing anti-inflammatory type-2 cells (M2). Phenotypic profiling of M1 and M2 was then evaluated. The M. bovis strain MP287/03 was able to grow more efficiently in the untreated macrophages, compared with the strains B2 or H37Rv. This strain induced weaker secretion of proinflammatory cytokines, coinciding with higher expression of M2 cell markers, mannose receptor (MR) and arginase-1 (Arg-1). Treatment of macrophages with IFN-gamma and infection by the strains B2 and H37Rv synergistically induced M1 polarization, leading to high levels of inducible nitric oxide synthase (iNOS) expression, and reduced expression of the Arg-1. In contrast, the cells infected with the strain MP287/03 expressed high levels of Arg-1 which competed with iNOS for the common substrate arginine, leading to lower levels of NO production. Conclusions: The data obtained demonstrated that the strain, characterized by increased growth in macrophages, down- modulated classical macrophage activation, through induction of an atypical mixed M1/M2 phenotype.

Synthesis and Photodynamic Effect of New Highly Photostable Decacationically Armed [60]- and [70]Fullerene Decaiodide Monoadducts To Target Pathogenic Bacteria and Cancer Cells

Novel water-soluble decacationically armed C-60 and C-70 decaiodide monoadducts, C-60- and C-70[>M(C3N6+C3)(2)], were synthesized, characterized, and applied as photosensitizers and potential nano-PDT agents against pathogenic bacteria and cancer cells. A high number of cationic charges per fullerene cage and H-bonding moieties were designed for rapid binding to the anionic residues displayed on the outer parts of bacterial cell walls. In the presence of a high number of electron-donating iodide anions as parts of quaternary ammonium salts in the arm region, we found that C-70[>M(C3N6+C3)(2)] produced more HO center dot than C-60[>M(C3N6+C3)(2)], in addition to O-1(2). This finding offers an explanation of the preferential killing of Gram-positive and Gram-negative bacteria by C-60[>M(C3N6+C3)(2)] and C-70[>M(C3N6+C3)(2)], respectively. The hypothesis is that O-1(2) can diffuse more easily into porous cell walls of Gram-positive bacteria to reach sensitive sites, while the less permeable Gram-negative bacterial cell wall needs the more reactive HO center dot to cause real damage.