RCAAP Repository

Toxoplasmosis is a worldwide zoonosis, caused by the protozoan Toxoplasma gondii. Although it is an usuall asymptomatic infection, the toxoplasmosis can manifest as a potentially serious disease in immunocompromised individuals and when acquired during pregnancy. The treatment of toxoplasmosis during pregnancy when the fetal infection is confirmed is based in the association of pyrimethamine, sulfadiazine and folinic acid (PSA). Pyrimethamine is potentially toxic and should not be used in the first trimester of pregnancy. The azalide antibiotic azithromycin presents efficacy in a wide range of bacterial infections and antimalarial activity, and it is considered safe for use during pregnancy. The objective of the present study was to evaluate the efficacy of azithromycin in controlling T. gondii infection in human placentas from third trimester. The placental villi were infected or not with tachyzoites of T. gondii and treated with various concentrations of azithromycin or PSA. The villous placenta were processed for morphological analysis, T. gondii intracellular proliferation and immunohistochemistry; and supernatants were evaluated for measuring the activity of LDH, cytokine, hormone production and nitrite. In non-cytotoxic doses (200 and 1000 ug/ml), treatment with azithromycin or PSA did not alter the morphology of the placental villi. Both antibiotics were able to reduce significantly the T. gondii intracellular proliferation, and the treatment with PSA promoted increase of IL-12 and IL-10 reduce, whereas azithromycin induced an increase in IL-2 and IL-6 in the groups infected with T. gondii, and reduced production of estradiol, progesterone and hCG. Moreover, the previous treatment of T. gondii with antibiotics was able to control the replication of the parasite, showing direct action of drugs on T. gondii. Thus, our data suggest that azithromycin, as PSA, was able to control the infection with T. gondii in an experimental model of human placental explants of third trimester. Additionally our data suggest that azithromycin may be an alternative selection for treatment of congenital toxoplasmosis, expanding the therapeutic strategies to control the parasite in maternal fetal interface.

Background: Blomia tropicalis (Bt) is a common house dust mite in tropical regions and important source of allergens for the induction of respiratory allergic diseases. Most Bt allergens identified so far, however, have shown sequence homology to other dust mite allergens, such as Dermatophagoides spp. The aim of this study was to investigate major IgE-binding isoforms for screening Bt allergens. Methods: We used two-dimensional (2D)-gel electrophoresis of crude Bt extract and sera from mite-sensitized patients with positive skin prick test to Bt that were screened for specific IgE antibodies in ELISA, followed by one-dimensional (1D-) and 2D-immunoblots. Inhibition 1D-immunoblot was performed to visualize the crossreactivity with Dermatophagoides spp. From 2D gels, corresponding IgE-binding spots were excised and identified by mass spectrometry. Results: IgE-binding Bt allergens with low molecular weight (LMW, 14-16 and 25 kDa) and high molecular weight (HMW, 54-134 kDa) showed >50% recognition and were considered immunodominant bands. A high homologous inhibition rate (>80%) was demonstrated with all immunodominant bands. Nearly all HMW immunodominant components showed an expressive rate of heterologous inhibition. However, the low heterologous inhibition was found to LMW immunodominant compounds (25 and 14 kDa). More than 50 spots were identified by stained 2D gel of Bt extract, from which 15 allergens showed IgE reactivity in 2D-immunoblot. Blo t 3 isoforms with enzymatic molecular function of trypsin were identified by mass spectrometry. Blo t 11 was considered as a hypothetical allergen. Other IgE-binding isoforms, such as the enzymes aldehyde dehydrogenase (Blo t ALDH), hexosaminidase (Blo t HEXM), and unknown function (Blo t 2) were also identified. Conclusions: The results indicate several isoforms (Blo t 11, Blo t 3, Blo t 2 and probably Blo t ALDH and Blo t HEXM ) from B. tropicalis recognized by IgE antibodies in Brazilian mite-allergic patients as potential candidates for diagnosis and allergen-specific immunotherapy of allergic diseases.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Acute respiratory infection (ARI) have an important disease burden for humans and viruses are causes of 50-90% of these infections in children up to five years of age who usually presents 6 to 9 infections per year. The objectives of this study was to describe the clinical aspects and its clinical-etiological correlation, assessment of severity and clinical progressives outcomes of viral ARI in children under five years of age; to assess patient´s risk factors related to the frequency and severity of viral ARI, and outline preventive measures and appropriate treatment for these infections. From 2000 to 2010, nasopharyngeal aspirate (NPA) from children up to five years old with ARI was collected within the 5th day of symptoms. Demographic data, signs and symptoms, comorbidities, clinical evaluation, assessment of severity and discharge diagnosis were obtained through a questionnaires and review of medical records. The specimens were analyzed by indirect immunofluorescence assay for the detection of common respiratory viruses and/orpolymerase chain reaction (RT)-PCR. During the study period 535 specimens of NPA were collected: 46.5% inpatients (mean age 6.6 months) and 53.5% outpatients (mean age 17.8 months). Upper respiratory tract infection (URTI) represented 28% of the cases whereas lower respiratory tract infection (LRTI) for 72%. In 430 of the viral positive samples, single infection were 85.1% and 14.9% were codetections cases. Rhinovirus (HRV) was detected in 37.9% of the samples (either in single or codetections), followed by respiratory syncytial virus (RSV - 35.6%), parainfluenza virus (PIV - 9.3%), influenza virus (FLU - 7.3%), adenovirus (AdV- 6.3 %) and human metapneumovirus (hMPV- 3.4%). In 64 codetections, HRV was present 62 times, half of it with RSV. For either outpatients or inpatients, HRV and RSV were the most common respiratory virus identified. Young children showed to be the group with more frequent ARI, more severe diseases and, therefore, are those that are more frequently hospitalized. RSV and HRV in single infections and coinfections were the most important agents identified. Moderate to severe disease has been linked to RSV, HRV and coinfections in a similar frequency. Our data could reinforce the importance of respiratory viruses in children causing serious nosocomial infection or aggravating coexisting disease. Identify groups of patients at high risk for severe disease may allow the implementation of preventive measures and the adoption of appropriate care assistance, reduzing the burden of viral ARI in children. Caregivers of inpatients should be alerted to the unnecessary use of antibiotics in many situations.

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Human cysticercosis is caused by installation of metacestodes of Taenia solium. The most serious condition is the infection of the central nervous system, which leads to neurocysticercosis. Despite attempts to eradicate the disease, cysticercosis remains a serious public health issue, and the development of a vaccine may be an alternative to control the disease. The aim of this study was to test the feasibility of mimotope Cc48 from T. solium to control of experimental murine cysticercosis. Peptide Cc48 was tested as expressed in bacteriophage M13 (mCc48) and as a synthetic peptide (sCc48). A total of 160 BALB/c mice were used, being divided into four groups: G1 (n = 40): mice immunized with mCc48, G2 (n = 40): immunized with peptide Cc48, G3 (n = 40) and G4 (n = 40): inoculated with saline. After immunization, mice from groups G1, G2 and G3 were challenged with Taenia crassiceps metacestodes, while those in group G4 did not received cysticercus for being the negative control of the experiment. The animals were sacrificed at four points: 15, 30, 45 and 60 days after infection (dai), to collect blood samples and perform cysticerci count. The count of cysticerci was used to analyze the protection achieved by immunization. Serum samples were obtained from collected blood and were tested by ELISA to verify the production of antibodies (IgM, IgG, IgA, and IgE), test IgG avidity and quantify cytokines (IL-4, INF-gamma). Total and differential leukocyte counts were performed in blood samples. Indirect immunofluorescence tests were done with sera from mice against cysticerci of T. crassiceps and T. solium. Immunization with sCc48 decreased the number of cysticerci and infected animals, inducing 90% of protection and efficacy of 98% in point 60 dai. G1 had higher IgM and IgG production and presence of IgE, while in G2 IgG was the main antibody detected. G1 presented significant increase in leukocytes production. IL-4 production was detected in all groups, and some animals in groups G1, G2 and G3 presented IFN-gamma. Cross-reactivity of antibodies produced with both tested species was observed through immunofluorescence. The ability of synthetic peptide sCc48 to induce protection makes it a potential compound against cysticercosis.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Physical exercise has been implicated in several immunophysiological improvements especially during the aging process when an immunocompromised status could be established. Toxoplasma gondii is a protozoan parasite that causes a widespread opportunistic infection, which may present severe consequences, particularly to the fetus and immunocompromised patients. It is estimated that one-third of the human population worldwide has been infected by this parasite, being the reactivation during immunesenescence an unexplored public health issue. The present study was designed to assess the immunophysiological differences between exercised versus sedentary C57BL/6 male mice that have been infected by T. gondii. Before the two key set of experiments, several other sets were carried out to the prospection of the main found data of this study. There were two main sets of experiments: in the first set, the animals were infected after exercising and three groups were formed: experimental groups - infected sedentary (IS, n=6); infected exercised (IEx, n=6) and control group - non-infected sedentary (NIS, n=6). When splenocytes were stimulated by T. gondii-soluble tachyzoite antigens, it was found an significant increasing (P<0.0001) in interferon-gamma (IFN-) production concomitant with any changes in IL-10, allowing a greater IFN-/IL-10 ratios, produced by the cells from exercised group compared to sedentary one. However, there was no difference concerning quantification of T. gondii genomic DNA by qPCR and immunohistochemistry analysis in brain cysts (P>0.05). In order to further investigate the consequences of these data for the host, a second set of experiments was performed, when the animals were infected before exercising and four groups of animals were established for comparison purpose, as follows: experimental groups - infected sedentary (IS, n=7); infected exercised (IEx, n=6) and control groups - non-infected sedentary (NIS, n=6) and non-infected exercised (NIEx, n=6). It was found that exercised group survived longer (P<0.05) than sedentary one. In both sets of experiments, mice have been submitted to moderate exercises: running (14m/min; 3x/week) and strength (60-80% of one-repetition maximum; 2x/week). In summary, moderated aerobic and strength exercises are able to modulate immune responses against T. gondii infection, being these immunological features beneficial to the host.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais