Evaluation of Toxoplasma gondii placental transmission in BALB/c mice model

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

Microbiological evaluation of milk samples positive to California Mastitis Test in dairy buffalo cows (Buballus bubalis)

In order to observe the microbiological status of CMT positive samples, 734 apparently health mammary quarters from buffalo cows were submitted to physical evaluation, strip cup test and CMT. After milk samples inoculation in 10% ovine blood agar base media and in MacConkey agar and incubation under aerobic condition for 72 hours at 37 degrees C, identification was proceeded. According to CMT, 227 quarters (30,93%) were positive, among them 73 (32,16%) presented 1+ reaction, 53 (23,35%) were 2+ and 101 (44,49%) were 3+. Microbiological exams of such samples were positive in 147 (64,76%) out of 227 CMT positive samples and among the remaining 72 (31,72%) were negative and 8 (3,52) were contaminated. In the 147 microbiological positive samples 204 bacteria were found in pure or associated growth and the most frequent agents were: Corynebacterium sp (59,25%); Staphylococcus sp (17,65%) among which 86,11% were coagulase negative and 13,89% were coagulase positive; and Micrococcus sp (6,37%). The results revealed that, excluding the eight contaminated samples, 147 (67,12%) quarters out of 219 CMT positive could be considered as bacteria-carrier and that even in a smaller percentage false-positive results can cause problems in a sanitary program for mastitis control in dairy buffalo cows.

Experimental infection of pregnant queens with two major Brazilian clonal lineages of Toxoplasma gondii

Toxoplasma gondii isolates from Brazil are biologically and genetically different from European and North America isolates. Recently, four genotypes were considered the common clonal lineages in Brazil and were designated as types BrI, BrII, BrIII, and BrIV. The pathogenicity of two major Brazilian lineages was investigated after oral inoculation of queens in the middle third of their pregnancies with T. gondii cysts. Twelve pregnant queens without T. gondii antibodies were distributed in group A (infected with a type BrI isolate); group 2 (infected with type BrIII isolate), and group 3 (non-infected control). Infection with type BrI isolate caused toxoplasmosis manifestations and abortion from one litter. Toxoplasmosis manifestations besides premature stillbirth of one litter were observed in queens infected with type BrIII isolate. Indirect fluorescence antibody test showed T. gondii antibodies in all eight infected queens at 30 days after inoculation. In two 10-day-old kittens of the same litter (group 1), titers of 16 and 64 were detected. At the same time, titers of 16, 32, and 32 were detected in three kittens from the same litter (group 2). Experimental infection with tissue cysts from a type BrI and type BrIII isolates of T. gondii developed similar reproductive disturbance in primary infected pregnant queens.

Perfil epidemiológico da raiva na região Noroeste do Estado de São Paulo no período de 1993 a 2007

The epidemiology of animal rabies in the region of Aracatuba, in the northwest of São Paulo State, from 1993 to 2007, is described according to the results from diagnoses made at laboratories in the region, using the fluorescent antibody and mouse inoculation tests. Out of 10,579 samples analyzed, 4.9% were positive (518/10,579). Dogs accounted for 67% of the cases (346/518) and these occurred between 1993 and 1997. Among the other positive samples, 16% (84/518) were in cattle and 9.7% (50/518) were in bats. Among the 42 municipalities in the region, 23 (55%) presented at least one rabies-positive case, while 13 of them had cases in bats. Three distinct cycles of rabies were identified in the northwestern region of the State of São Paulo: the urban cycle characterized predominantly by canine rabies (1993 to 1997); and the aerial and rural cycles starting in 1998, with predominance of cases in bats in urban areas and in herbivores.

Biological studies and molecular characterization of a Cryptosporidium isolate from ostriches (Struthio camelus)

There are many reports of cryptosporidial infection in ostriches, but none with molecular characterization of the isolates. A study was undertaken for the characterization of a Brazilian Cryptosporidium sp. ostrich isolate by using molecular phylogenetic analysis of fragments of the 18S ribosonial DNA. heat-shock Protein (lisp) 70 coding gene, and actin coding gene. Biological studies were accomplished by the experimental inoculation of chickens via oral or intratracheal routes with fresh ostrich Cryptosporidium sp. oocysts. Molecular analysis of nuceotide sequences of the 3 genes by using neighbor-joining and parsimony methods grouped the ostrich isolate as a sister taxon of Crypiosporidium badeyi and showed that the os(rich isolate is genetically distinct from all other known Cryptosporidium species or genotypes. None of the inoculated chickens developed infection as determined by mucosal smears. histology, and fecal screening for oocysts. Although biological and molecular Studies indicate that the ostrich Cryptosporidium is a new species, further Studies regarding morphological. biological, and molecular characteristics of other ostrich isolates are required to confirm the species status of the ostrich Cryprosporidium.

Histopathology of the reproductive system of male sheep experimentally infected with Toxoplasma gondii

The aim of this study was to investigate the histopathological changes in reproductive system (testicles, epididymis, seminal vesicles, and prostate) of small male ruminants after Toxoplasma gondii infection. Eight sheep were inoculated with T. gondii: group I, four sheep (2.0 x 10(5) P-strain oocysts); group II, four sheep (1.0 x 10(6) RH-strain tachyzoites); and group III, two uninfected sheep maintained as control. Infection with T. gondii was confirmed by seroconversion (indirect fluorescent antibody test-IgG) in all the infected animals beginning on post-inoculation day (PID) 7. on PID 70, all the animals were euthanized and tissue samples (testicles, epididymis, seminal vesicles, and prostate) were collected and processed for histological analysis. The main changes detected were a focal mononuclear interstitial inflammatory infiltrate in the prostate and seminal vesicles; diffuse testicular degeneration associated with calcification foci and a multifocal mononuclear interstitial inflammatory infiltrate; and a mononuclear interstitial infiltrate and focal necrotic areas of the muscle fibers surrounding the seminal vesicles. The histopathological findings of this work, along with the detection of T. gondii in the examined parenchyma tissues (immunohistochemistry) and the results obtained by other authors examining different tissues, suggest that histological changes diagnosed in the reproductive system of rams infected with T. gondii are strongly suggestive of toxoplasmatic infection.

Immunotherapy with the saponin enriched-Leishmune (R) vaccine versus immunochemotherapy in dogs with natural canine visceral leishmaniasis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Susceptibility of Candida albicans to photodynamic therapy in a murine model of oral candidosis

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

Alterações anatômicas induzidas por Meloidogyne enterolobii (=M. mayaguensis) e Meloidogyne javanica em tomateiros resistentes a meloidoginose

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

Effects of extracts from Brazilian sun-mushroom (Agaricus blazei) on the NK activity and lymphoproliferative responsiveness of Ehrlich tumor-bearing mice

Agaricus blazei Murrill, is an edible and medicinal mushroom which is popularly consumed due to its antitumoral properties. The immunomodulatory effects of methanol (METH), dichloromethane (DM) and n-hexane (HEX) extracts of this mushroom were evaluated in Ehrlich tumor-bearing mice. Subcutaneous inoculation of Ehrlich tumor cells inhibited the natural killer (NK) activity of spleen cells (specific lysis = 6.18 +/- 2.56%) compared with normal mice (17.59 +/- 7.77%). Treatment of tumor-bearing mice with the extracts for 10 days restored the natural killer activity against Yac-1 target cells and the best results were observed by treatment with the HEX extract (21.48 +/- 15.26%). Treatment of the animals with the HEX extract for 10 days was also able to stimulate the mitogen-induced lymphoproliferative activity of spleen cells. Thirty days after the treatment, all groups presented low proliferative activity. Specific antibody production was observed to be higher in the groups treated with the DM or METH extract 30 days after the treatment. Analysis of the 3 extracts by gas chromatography mass spectrum (GCMS) and magnetic nuclear resonance (MNR) showed that the HEX extract contains mainly sugar and fatty acids and that the METH extract also contains sugar and possibly amino acids. (C) 2004 Elsevier Ltd. All rights reserved.

Variabilidade genética de Sugarcane mosaic virus, causando mosaico em milho no Brasil

O objetivo deste trabalho foi caracterizar biológica e molecularmente três isolados de Sugarcane mosaic virus (SCMV) de lavouras de milho, analisá-los filogeneticamente e discriminar polimorfismos do genoma. Plantas com sintomas de mosaico e nanismo foram coletadas em lavouras de milho, no Estado de São Paulo e no Município de Rio Verde, GO, e seus extratos foliares foram inoculados em plantas indicadoras e submetidos à análise sorológica com antissoros contra o SCMV, contra o Maize dwarf mosaic virus (MDMV) e contra o Johnsongrass mosaic virus (JGMV). Mudas de sorgo 'Rio' e 'TX 2786' apresentaram sintomas de mosaico após a inoculação dos três isolados, e o DAS-ELISA confirmou a infecção pelo SCMV. O RNA total foi extraído e usado para amplificação por transcriptase reversa seguida de reação em cadeia de polimerase (RT-PCR). Fragmentos específicos foram amplificados, submetidos à análise por polimorfismo de comprimento de fragmento de restrição (RFLP) e sequenciados. Foi possível discriminar os genótipos de SCMV isolados de milho de outros isolados brasileiros do vírus. Alinhamentos múltiplos e análises dos perfis filogenéticos corroboram esses dados e mostram diversidade nas sequências de nucleotídeos que codificam para a proteína capsidial, o que explica o agrupamento separado desses isolados e sugere sua classificação como estirpes distintas, em lugar de simples isolados geográficos.

Caracterização de um isolado do Sugarcane mosaic virus que quebra a resistência de variedades comerciais de cana-de-açúcar

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

Genome-Wide Analysis of Differentially Expressed Genes During the Early Stages of Tomato Infection by a Potyvirus

Plant responses against pathogens cause up-and downward shifts in gene expression. To identify differentially expressed genes in a plant-virus interaction, susceptible tomato plants were inoculated with the potyvirus Pepper yellow mosaic virus (PepYMV) and a subtractive library was constructed from inoculated leaves at 72 h after inoculation. Several genes were identified as upregulated, including genes involved in plant defense responses (e. g., pathogenesis-related protein 5), regulation of the cell cycle (e. g., cytokinin-repressed proteins), signal transduction (e. g., CAX-interacting protein 4, SNF1 kinase), transcriptional regulators (e. g., WRKY and SCARECROW transcription factors), stress response proteins (e. g., Hsp90, DNA-J, 20S proteasome alpha subunit B, translationally controlled tumor protein), ubiquitins (e. g., polyubiquitin, ubiquitin activating enzyme 2), among others. Downregulated genes were also identified, which likewise display identity with genes involved in several metabolic pathways. Differential expression of selected genes was validated by macroarray analysis and quantitative real-time polymerase chain reaction. The possible roles played by some of these genes in the viral infection cycle are discussed.

CaPrx, a Coffea arabica gene encoding a putative class III peroxidase induced by root-knot nematode infection

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

Experimental paracoccidioidomycosis of the Syrian hamster: fungicidal activity and production of inflammatory cytokines by macrophages

Phagocytic cells play an important role in nonspecific resistance to fungal infection by mediating an inflammatory response and by a direct fungicidal action. In this study, the functional activity of peritoneal macrophages obtained from hamsters experimentally infected with strain Pb18 of Paracoccidioides brasiliensis was evaluated during 16 weeks of infection. The results showed that macrophages had a higher spreading ability associated with increased production of tumor necrosis factor alpha (TNF-alpha) and enhanced fungicidal activity during the early periods of infection. TNF-alpha levels remained elevated during all periods studied, while low levels of interleukin-1 beta (IL-1 beta) were produced during the infection. A necrotic area with dead fungi was observed at the inoculation site and the infection disseminated only to liver and lymph nodes in a few animals. These results suggest that during the early stages of infection with P. brasiliensis, macrophage activation by the high levels of TNF-alpha limited fungal dissemination. In contrast, in the later stages of infection, high levels of TNF-alpha were observed while the fungicidal activity of macrophages was lower and the animals presented loss of vitality resulting in their death. These observations suggest a complex role of TNF-alpha in experimental paracoccidioidomycosis of Syrian hamsters, involving not only resistance but also pathogenesis.