Differences in immune responses against Leishmania induced by infection and by immunization with killed parasite antigen: implications for vaccine discovery.

The leishmaniases are a group of diseases caused by different species of the protozoan genus Leishmania and transmitted by sand fly vectors. They are a major public health problem in almost all continents. There is no effective control of leishmaniasis and its geographical distribution is expanding in many countries. Great effort has been made by many scientists to develop a vaccine against leishmaniasis, but, so far, there is still no effective vaccine against the disease. The only way to generate protective immunity against leishmaniasis in humans is leishmanization, consisting of the inoculation of live virulent Leishmania as a means to acquire long-lasting immunity against subsequent infections. At present, all that we know about human immune responses to Leishmania induced by immunization with killed parasite antigens came from studies with first generation candidate vaccines (killed promastigote extracts). In the few occasions that the T cell-mediated immune responses to Leishmania induced by infection and immunization with killed parasite antigens were compared, important differences were found both in humans and in animals. This review discusses these differences and their relevance to the development of a vaccine against leishmaniasis, the major problems involved in this task, the recent prospects for the selection of candidate antigens and the use of attenuated Leishmania as live vaccines.

Evaluation of the anti-inflammatory action of curcumin analog (DM1): Effect on iNOS and COX-2 gene expression and autophagy pathways.

This work describes the anti-inflammatory effect of the curcumin-analog compound, sodium 4-[5-(4-hydroxy-3-methoxyphenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate (DM1), and shows that DM1 modulates iNOS and COX-2 gene expression in cultured RAW 264.7 cells and induces autophagy on human melanoma cell line A375.

Intestinal helminth coinfection is associated with mucosal lesions and poor response to therapy in American tegumentary leishmaniasis.

The most severe clinical form of American tegumentary leishmaniasis (ATL) due to Leishmania braziliensis is mucosal leishmaniasis (ML), characterized by destructive lesions in the facial mucosa. We performed a retrospective cohort study of 109 ATL patients from Rio de Janeiro State, Brazil, where ATL is caused by L. braziliensis, to evaluate the influence of intestinal parasite coinfections in the clinical course of ATL. Parasitological stool examination (PSE) was performed with samples from all patients by the sedimentation, Kato-Katz and Baermann-Moraes methods. The diagnosis of ATL was made from lesion biopsies by direct observation of amastigotes in Giemsa-stained imprints, isolation of Leishmania promastigotes or histopathological examination. All patients were treated with meglumine antimoniate. Patients with positive PSE had a frequency of mucosal lesions significantly higher than those with negative PSE (p<0.005). The same was observed for infections with helminths in general (p<0.05), with nematodes (p<0.05) and with Ascaris lumbricoides (p<0.05), but not for protozoan infections. Patients with intestinal parasites had poor response to therapy (therapeutic failure or relapse) significantly more frequently than the patients with negative stool examination (p<0.005). A similar difference (p<0.005) was observed between patients with positive and negative results for intestinal helminths, but not for intestinal protozoa. Patients with positive PSE took significantly longer to heal than those with negative PSE (p<0.005). A similar difference was observed for intestinal helminth infections (p<0.005), but not for protozoan infections. Our results indicate a deleterious influence of intestinal helminth infections in the clinical course of ATL and evidence for the first time an association between ML and these coinfections, particularly with nematodes and A. lumbricoides.

Kinetoplastid Membrane Protein-11 as a Vaccine Candidate and a Virulence Factor in Leishmania.

Kinetoplastid membrane protein-11 (KMP-11), a protein present in all kinetoplastid protozoa, is considered a potential candidate for a leishmaniasis vaccine. In Leishmania amazonensis, KMP-11 is expressed in promastigotes and amastigotes. In both stages, the protein was found in association with membrane structures at the cell surface, flagellar pocket, and intracellular vesicles. More importantly, its surface expression is higher in amastigotes than in promastigotes and increases during metacyclogenesis. The increased expression of KMP-11 in metacyclic promastigotes, and especially in amastigotes, indicates a role for this molecule in the parasite relationship with the mammalian host. In this connection, we have shown that addition of KMP-11 exacerbates L. amazonensis infection in peritoneal macrophages from BALB/c mice by increasing interleukin (IL)-10 secretion and arginase activity while reducing nitric oxide production. The doses of KMP-11, the IL-10 levels, and the intracellular amastigote loads were strongly, positively, and significantly correlated. The increase in parasite load induced by KMP-11 was inhibited by anti-KMP-11 or anti-IL-10-neutralizing antibodies, but not by isotype controls. The neutralizing antibodies, but not the isotype controls, were also able to significantly decrease the parasite load in macrophages cultured without the addition of KMP-11, demonstrating that KMP-11-induced exacerbation of the infection is not dependent on the addition of exogenous KMP-11 and that the protein naturally expressed by the parasite is able to promote it. All these data indicate that KMP-11 acts as a virulence factor in L. amazonensis infection.

T-cell receptor Vβ repertoire of CD8+ T-lymphocyte subpopulations in cutaneous leishmaniasis patients from the state of Rio de Janeiro, Brazil

In human cutaneous leishmaniasis (CL), the immune response is mainly mediated by T-cells. The role of CD8⁺ T-lymphocytes, which are related to healing or deleterious functions, in affecting clinical outcome is controversial. The aim of this study was to evaluate T-cell receptor diversity in late-differentiated effector (LDE) and memory CD8⁺ T-cell subsets in order to create a profile of specific clones engaged in deleterious or protective CL immune responses. Healthy subjects, patients with active disease (PAD) and clinically cured patients were enrolled in the study. Total CD8⁺ T-lymphocytes showed a disturbance in the expression of the Vβ2, Vβ9, Vβ13.2, Vβ18 and Vβ23 families. The analyses of CD8⁺T-lymphocyte subsets showed high frequencies of LDE CD8⁺T-lymphocytes expressing Vβ12 and Vβ22 in PAD, as well as effector-memory CD8⁺ T-cells expressing Vβ22. We also observed low frequencies of effector and central-memory CD8⁺ T-cells expressing Vβ2 in PAD, which correlated with a greater lesion size. Particular Vβ expansions point to CD8⁺ T-cell clones that are selected during CL immune responses, suggesting that CD8⁺ T-lymphocytes expressing Vβ12 or Vβ22 are involved in a LDE response and that Vβ2 contractions in memory CD8⁺T-cells are associated with larger lesions.

T-cell receptor Vß repertoire of CD8+ T-lymphocyte subpopulations in cutaneous leishmaniasis patients from the state of Rio de Janeiro, Brazil.

In human cutaneous leishmaniasis (CL), the immune response is mainly mediated by T-cells. The role of CD8+ T-lymphocytes, which are related to healing or deleterious functions, in affecting clinical outcome is controversial. The aim of this study was to evaluate T-cell receptor diversity in late-differentiated effector (LDE) and memory CD8+ T-cell subsets in order to create a profile of specific clones engaged in deleterious or protective CL immune responses. Healthy subjects, patients with active disease (PAD) and clinically cured patients were enrolled in the study. Total CD8+ T-lymphocytes showed a disturbance in the expression of the Vß2, Vß9, Vß13.2, Vß18 and Vß23 families. The analyses of CD8+T-lymphocyte subsets showed high frequencies of LDE CD8+T-lymphocytes expressing Vß12 and Vß22 in PAD, as well as effector-memory CD8+ T-cells expressing Vß22. We also observed low frequencies of effector and central-memory CD8+ T-cells expressing Vß2 in PAD, which correlated with a greater lesion size. Particular Vß expansions point to CD8+ T-cell clones that are selected during CL immune responses, suggesting that CD8+ T-lymphocytes expressing Vß12 or Vß22 are involved in a LDE response and that Vß2 contractions in memory CD8+T-cells are associated with larger lesions.

Apoptosis and frequency of total and effector CD8+ T lymphocytes from cutaneous leishmaniasis patients during antimonial therapy.

BACKGROUND: Leishmaniasis is an important parasitic disease affecting millions worldwide. Human cutaneous leishmaniasis (CL) is endemic in Rio de Janeiro, Brazil, where is caused by Leishmania braziliensis. The adaptive immune response is accountable for the healing of CL and despite of key role of CD8+ T cells in this immune response little is known about the CD8+ T lymphocytes frequencies, apoptosis and antigen-responsive CD8+ T lymphocytes of CL patients during antimonial therapy. METHODS: Using flow cytometry, we examined total and effector CD8+ T cells from CL patients before (PBT), during (PDT) and after (PAT) treatment for apoptosis and frequencies upon isolation and after in vitro L. braziliensis antigens (LbAg)-stimulation culture. Besides, a correlation study between immunological findings and lesion size was done. RESULTS: PDT showed lower frequencies of total CD8+ T lymphocytes and higher levels of apoptosis of these cells, which were also observed following LbAg-stimulation culture. Regarding effector CD8+ T cells, high frequencies were observed in PDT, while lower frequencies were observed in PAT. Interestingly, PDT showed higher frequencies of apoptotic-effector CD8+ T lymphocytes. Similar results were seen after in vitro antigenic-stimulation assays. Correlation analysis showed that the greater the size of lesion, the smaller the frequency of effector CD8+ T lymphocytes in PDT and PAT, as well as a positive correlation between apoptotic-effector CD8+ T cells frequency and lesion size of PDT. CONCLUSIONS: Changes in effector CD8+ T-lymphocyte frequencies, during and after treatment, seem to represent a critical stage to generate an efficient immune response and suggest that these cells would be evolved in the triggering or in the resolution of lesion, under the influence of therapy. This hypothesis opens new perspectives to clarify controversial statements about the protective or deleterious role of CD8+ T cells in the cure or aggravation of CL and the new approach of evaluating patients during treatment proved to be of utmost importance for understanding the immune response in the healing process of human CL.

Avaliação do risco epidemiológico e do desempenho dos programas de controle de tuberculose nas Regiões de Saúde do estado de Santa Catarina, 2003 a 2010* / Evaluation of epidemiologic risk and Tuberculosis Control Program performance by health regions, State of Santa Catarina, Brazil, 2003-2010

Avaliar o risco epidemiológico e o desempenho dos programas de controle de tuberculose segundo Regiões de Saúde do estado de Santa Catarina, Brasil, no período de 2003 a 2010. Métodos: estudo ecológico com dados fornecidos pela vigilância epidemiológica estadual, compreendendo 4 indicadores de risco e 11 de desempenho do programa; calculou-se a mediana de cada indicador por Região e atribuiu-se pontos conforme a distribuição percentilar, permitindo-se a criação de um índice de gravidade. Resultados: verificou-se a existência de diferentes níveis de risco de morbimortalidade e distintos índices de desempenho das ações de controle da tuberculose nas Regiões de Saúde; o índice de gravidade permitiu identificar 6 Regiões de maior gravidade, 9 intermediárias e 6 de menor gravidade, com diferenças nos escores de risco e desempenho (p<0,001). Conclusão: evidenciou-se grande variedade de nichos de gravidade distribuídos nas diversas Regiões, bem como diversidade no empenho da gestão administrativa para seu enfrentamento...

To evaluate epidemiologic risk and Tuberculosis Control Program performance by Health Region in Santa Catarina State, Brazil, 2003-2010. Methods: this was an ecological study using state epidemiologic surveillance data comprising 4 risk indicators and 11 Tuberculosis Program performance indicators; we calculated the median for each indicator by region and gave scores according to percentile ranking. A severity index was thus created. Results: different levels of morbi-mortality risk and distinct Tuberculosis control performance indexes were found in the regions; the severity index created allowed us to identify six regions with high severity, nine intermediate and six with low severity, although there were differences in risk and performance scores (p<0.001). Conclusion: a great variety was found in the distribution of pockets of disease severity in the different regions, as was diversity in health management efforts to overcome them...

Effects of typified propolis on mutans streptococci and lactobacilli: a randomized clinical trial.

OBJECTIVE: The aim of this study was to determine in a randomized, double-blind, placebo-controlled clinical trial the effects of typified propolis and chlorhexidine rinses on salivary levels of mutans streptococci (MS) and lactobacilli (LACT). METHODS: One hundred patients were screened for salivary levels of MS >100,000 CFUs/mL of saliva. All patients presented with at least one cavitated decayed surface. Sixty patients met entry criteria. Subjects were adults 18-55 years old. After restoration of cavitated lesions patients were randomized to 3 experimental groups: 1) PROP-alcohol-free 2% typified propolis rinse (n = 20); 2) CHX- 0.12% chlorhexidine rinse; 3) PL-placebo mouthrinse. Patients rinsed unsupervised 15 mL of respective rinses twice a day for 1 min for 28 days. Patients were assessed for the salivary levels of MS (Dentocult SM) and LACT (Dentocult LB) at baseline, 7-day, 14-day, and at 28-day visits (experimental effects) and at 45-day visit (residual effects). General linear models were employed to analyze the data. RESULTS: PROP was superior to CHX at 14-day and 28-day visits in suppressing the salivary levels of MS (p < .05). PROP was superior to PL at all visits (p < .01). The residual effects of PROP in suppressing the salivary levels of MS could still be observed at the 45-day visit, where significant differences between PROP and CHX (p < .05), were demonstrated. PROP was significantly superior than CHX in suppressing the levels of salivary LACT at the 28-day visit (p < .05). CONCLUSION: Typified propolis rinse was effective in suppressing cariogenic infections in caries-active patients when compared to existing and placebo therapies.

Effects of typified propolis on mutans streptococci and lactobacilli: a randomized clinical trial / Efeitos da própolis tipificada nos estreptococcos do grupo mutans e lactobacilos: ensaio clínico randomizado

Objective: The aim of this study was to determine in a randomized, double-blind, placebo-controlled clinical trial the effects of typified propolis and chlorhexidine rinses on salivary levels of mutans streptococci (MS) and lactobacilli (LACT). Methods: One hundred patients were screened for salivary levels of MS >100,000 CFUs/mL of saliva. All patients presented with at least one cavitated decayed surface. Sixty patients met entry criteria. Subjects were adults 18-55 years old. After restoration of cavitated lesions patients were randomized to 3 experimental groups:1) PROP-alcohol-free 2% typified propolis rinse (n= 20); 2) CHX- 0.12% chlorhexidine rinse; 3) PLplacebo mouthrinse. Patients rinsed unsupervised 15 mL of respective rinses twice a day for 1 min for 28 days. Patients were assessed for the salivary levels of MS (Dentocult SM) and LACT (Dentocult LB) at baseline, 7-day, 14-day, and at 28-day visits (experimental effects) and at 45-day visit (residual effects). General linear models were employed to analyze the data. Results: PROP was superior to CHX at 14-day and 28-day visits in suppressing the salivary levels of MS (p < .05). PROP was superior to PL at all visits (p < .01). The residual effects of PROP in suppressing the salivary levels of MS could still be observed at the 45-day visit, where significant differences between PROP and CHX (p < .05), were demonstrated. PROP was significantly superior than CHX in suppressing the levels of salivary LACT at the 28-day visit (p < .05). Conclusion: Typified propolis rinse was effective in suppressing cariogenic infections in caries-active patients when compared to existing and placebo therapies.

Objetivo: O objetivo deste estudo foi determinar, em um estudo randomizado, duplo-cego, placebo-controlado os efeitos da própolis tipificada e clorexidina sobre os níveis salivares de estreptococos do grupo mutans (EM) e lactobacilos (LACT). Métodos: Cem pacientes foram selecionados para níveis salivares de MS > 100.000 UFC/mL de saliva. Todos os pacientes apresentaram pelo menos uma superfície cariada com cavitação. Sessenta pacientes preencheram os critérios de inclusão. Os indivíduos eram adultos com 18-55 anos de idade. Após a restauração das lesões cavitadas, os pacientes foram randomizados para três grupos experimentais: 1) PROP- bochecho livre de álcool de 2% de própolis tipificada (n = 20), 2) CHX- bochecho de clorexidina 0,12%, 3) PL- bochecho placebo. Os participantes bochecharam sem supervisão 15 mL dos enxaguatórios duas vezes por dia, durante 1 minuto, durante 28 dias. Os pacientes foram avaliados para os níveis salivares de MS (Dentocult SM) e LACT (Dentocult LB) na linha de base, e após 7 dias, 14 dias, 28 dias (efeitos experimentais) e 45 dias (efeitos residuais). Modelos lineares foram utilizados para analisar os dados. Resultados: PROP foi superior ao CHX nas visitas de 14 dias e de 28 dias na supressão dos níveis salivares de SM (p < 0,05). PROP foi superior ao PL em todas as visitas (p < 0,01). Os efeitos residuais de PROP na supressão dos níveis salivares de MS ainda foi observado na visita de 45 dias, onde diferenças significativas entre PROP e CHX (p < 0,05) foram demonstradas. PROP foi significativamente superior a CHX na supressão dos níveis salivares de LACT na visita de 28 dias (p < 0,05). Conclusão: O enxaguatório de própolis tipificada foi eficaz na supressão de infecções cariogênicas em pacientes com atividade de cárie quando comparado a terapias existentes e ao placebo

Kinetoplastid membrane protein-11 exacerbates infection with Leishmania amazonensis in murine macrophages.

In Leishmania amazonensis, kinetoplastid membrane protein-11 (KMP-11) expression increases during meta-cyclogenesis and is higher in amastigotes than in promastigotes, suggesting a role for this protein in the infection of the mammalian host. We show that the addition of KMP-11 exacerbates L. amazonensis infection in peritoneal macrophages from BALB/c mice by increasing interleukin (IL)-10 secretion and arginase activity while reducing nitric oxide (NO) production. The doses of KMP-11, the IL-10 levels and the intracellular amastigote loads were strongly, positively and significantly correlated. The increase in parasite load induced by KMP-11 was inhibited by anti-KMP-11 or anti-IL-10 neutralising antibodies, but not by isotype controls. The neutralising antibodies, but not the isotype controls, were also able to significantly decrease the parasite load in macrophages cultured without the addition of KMP-11, demonstrating that KMP-11-induced exacerbation of the infection is not dependent on the addition of exogenous KMP-11 and that the protein naturally expressed by the parasite is able to promote it. In this study, the exacerbating effect of KMP-11 on macrophage infection with Leishmania is for the first time demonstrated, implicating it as a virulence factor in L. amazonensis. The stimulation of IL-10 production and arginase activity and the inhibition of NO synthesis are likely involved in this effect.

Kinetoplastid membrane protein-11 exacerbates infection with Leishmania amazonensis in murine macrophages

In Leishmania amazonensis, kinetoplastid membrane protein-11 (KMP-11) expression increases during metacyclogenesis and is higher in amastigotes than in promastigotes, suggesting a role for this protein in the infection of the mammalian host. We show that the addition of KMP-11 exacerbates L. amazonensis infection in peritoneal macrophages from BALB/c mice by increasing interleukin (IL)-10 secretion and arginase activity while reducing nitric oxide (NO) production. The doses of KMP-11, the IL-10 levels and the intracellular amastigote loads were strongly, positively and significantly correlated. The increase in parasite load induced by KMP-11 was inhibited by anti-KMP-11 or anti-IL-10 neutralising antibodies, but not by isotype controls. The neutralising antibodies, but not the isotype controls, were also able to significantly decrease the parasite load in macrophages cultured without the addition of KMP-11, demonstrating that KMP-11-induced exacerbation of the infection is not dependent on the addition of exogenous KMP-11 and that the protein naturally expressed by the parasite is able to promote it. In this study, the exacerbating effect of KMP-11 on macrophage infection with Leishmania is for the first time demonstrated, implicating it as a virulence factor in L. amazonensis. The stimulation of IL-10 production and arginase activity and the inhibition of NO synthesis are likely involved in this effect.

Indicação da prova tuberculínica e infecção latente da tuberculose em HIV-positivos, Município de Blumenau, Estado de Santa Catarina, Brasil, 2004-2009 / Tuberculin skin test prescription and tuberculosis latent infection treatment in HIV-positive, Municipality of Blumenau, State of Santa Catarina, Brazil, 2004-2009

OBJETIVO: determinar a indicação à prova tuberculínica (PT) e tratamento para infecção latente da tuberculose (ILTB) pelo Serviço de Atendimento Especializado em DST/aids (SAE-DST/aids) do município de Blumenau, estado de Santa Catarina, Brasil. MÉTODO: estudo transversal, em prontuários de pacientes HIV-positivos ingressantes entre 2004 e 2009; análises estatísticas foram estabelecidas pelos testes exato de Fisher, t de Student e qui-quadrado. RESULTADOS: dos 693 pacientes, 56,6 por cento tinham aids e 96,23 por cento tinham indicação para PT, embora somente 16,29 por cento realizaram-na; a prescrição da PT foi de 23,46 por cento mas apenas 1,31 por cento realizou tratamento; fatores clínicos, como comorbidades relacionadas ao HIV, tiveram associação estatística com a prescrição da PT em 19,58 por cento dos não prescritos e 14,01 por cento dos prescritos (p<0,01); houve diferença estatística na frequência de indicação pelos médicos do serviço avaliado. CONCLUSÃO: os dados evidenciam que as recomendações para prescrição da PT em pacientes HIV-positivos e o tratamento da ILTB não estão sendo cumpridas pelo SAE/DST/aids de Blumenau-SC.

OBJECTIVE: to evaluate the indication of Tuberculin Skin Test (TST) and Latent Tuberculosis Infection (LTBI) treatment by the Specialized HIV/AIDS Healthcare Services (SHS-STD/AIDS) in Blumenau, state of Santa Catarina, Brazil. METHODS: cross-sectional study with records of HIV-positive patients admitted between 2004 and 2009; statistical analysis were established using Fisher exact, t Student and chi-squared tests. RESULTS: among 693 patients, 56.6 per cent had aids and 96.23 per cent had indication to TST, although only 16.29 per cent performed it; TST prescription was 23.46 per cent but only 1.31 perc ent did the treatment; clinical featuressuch as HIV-related comorbidities were statistically associated with TST prescription in 19.58 per cent non-prescribed and 14.01 per cent prescribed (p<0.01); there was statistical difference in the proportion of indication among the physicians of the assessed service. CONCLUSION: data indicates that the recommendations to TST prescription in patients HIV-positiveand LTBI treatment are not being accomplished by the SHS-STD/AIDS of Blumenau-SC.

Kinetoplastid membrane protein-11 is present in promastigotes and amastigotes of Leishmania amazonensis and its surface expression increases during metacyclogenesis.

Kinetoplastid membrane protein-11 (KMP-11), a protein present in all kinetoplastid protozoa, is considered a potential candidate for a leishmaniasis vaccine. A suitable leishmaniasis vaccine candidate molecule must be expressed in amastigotes, the infective stage for mammals. However, the expression of KMP-11 in Leishmania amastigotes has been a subject of controversy. We evaluated the expression of this molecule in logarithmic and stationary growth phase promastigotes, as well as in amastigotes, of Leishmania amazonensis by immunoblotting, flow cytometry and immunocytochemistry, using a monoclonal antibody against KMP-11. We found that KMP-11 is present in promastigotes and amastigotes. In both stages, the protein was found in association with membrane structures (at the cell surface, flagellar pocket and intracellular vesicles). More importantly, its surface expression is higher in amastigotes than in promastigotes and increases during metacyclogenesis. The increased expression of KMP-11 in metacyclic promastigotes, and especially in amastigotes, indicates a role for this molecule in the parasite relationship with the mammalian host. The presence of this molecule in amastigotes is consistent with the previously demonstrated immunoprotective capacity of vaccine prototypes based on the KMP-11-coding gene and the presence of humoral and cellular immune responses to KMP-11 in Leishmania-infected humans and animals.

Kinetoplastid membrane protein-11 is present in promastigotes and amastigotes of Leishmania amazonensis and its surface expression increases during metacyclogenesis

Kinetoplastid membrane protein-11 (KMP-11), a protein present in all kinetoplastid protozoa, is considered a potential candidate for a leishmaniasis vaccine. A suitable leishmaniasis vaccine candidate molecule must be expressed in amastigotes, the infective stage for mammals. However, the expression of KMP-11 in Leishmania amastigotes has been a subject of controversy. We evaluated the expression of this molecule in logarithmic and stationary growth phase promastigotes, as well as in amastigotes, of Leishmania amazonensis by immunoblotting, flow cytometry and immunocytochemistry, using a monoclonal antibody against KMP-11. We found that KMP-11 is present in promastigotes and amastigotes. In both stages, the protein was found in association with membrane structures (at the cell surface, flagellar pocket and intracellular vesicles). More importantly, its surface expression is higher in amastigotes than in promastigotes and increases during metacyclogenesis. The increased expression of KMP-11 in metacyclic promastigotes, and especially in amastigotes, indicates a role for this molecule in the parasite relationship with the mammalian host. The presence of this molecule in amastigotes is consistent with the previously demonstrated immunoprotective capacity of vaccine prototypes based on the KMP-11-coding gene and the presence of humoral and cellular immune responses to KMP-11 in Leishmania-infected humans and animals.

Composition and biological activity of the essential oil from leaves of Plinia cerrocampanensis, a new source of alpha-bisabolol.

The essential oil from fresh leaves of Plinia cerrocampanensis Barrie (Myrtaceae), obtained by hydrodistillation, was analysed by GC-FID and GC-MS. Forty components, representing more than 91% of the oil, were identified. Oxygenated sesquiterpenes represented the main fraction with alpha-bisabolol (42.8%) as the major constituent, making this plant a new and good source of this substance. Biological activity of the essential oil was evaluated against several bacterial and fungal strains as well as larvae from Aedes aegypti. The highest activity was found against Staphylococcus aureus, Pseudomonas aeruginosa, Microsporum gypseum, Trichophyton mentagrophytes and Trichophyton rubrum with MIC values from 32 to 125 microg/ml. The essential oil also showed potent inhibitory and bactericidal activities against three H. pylori strains, with MIC and MBC values of 62.5 microg/ml, and caused 100% mortality of A. aegypti larvae at a concentration of 500 microg/ml.

The C-terminal extension of Leishmania pifanoi amastigote-specific cysteine proteinase Lpcys2: a putative function in macrophage infection.

Cysteine proteinases have been implicated in many aspects of protozoan parasite pathogenesis. These hydrolases are normally found as zymogens, and some classes in trypanosomatids possess a long C-terminal extension (CTE), for which no function has been assigned. In this paper we hypothesize that the CTE domain of Lpcys2, the abundant lysosomal cysteine proteinase of Leishmania pifanoi amastigotes, is involved in host cell infection. Confirming previous reports that this peptide is highly immunogenic in Trypanosoma cruzi, we detected antibodies against CTE in sera of leishmaniasis patients. We produced a polyclonal antibody specific to Lpcys2 CTE and determined that this antibody was capable of recognizing both L. pifanoi and Leishmania amazonensis cysteine proteinases. Using this antibody, we detected a predominant localization of Lpcys2 CTE in the lysosome and flagellar pocket of cultured axenic amastigotes of both parasite species; however, its location was shifted towards the surface of the parasites during macrophage infection. We examined the role of Lpcys2 CTE in macrophage infection and found a significant reduction in the percentage of infected cells when macrophages were infected with L. pifanoi and L. amazonensis in the presence of anti-CTE antibody. This study suggests a role for leishmanial cysteine proteinases CTE at early stages of infection.

[Analysis of molecular fingerprint and virulence factors of Helicobacter pylori strains]. / Análise das impressões digitais de DNA e de fatores de virulência de linhagens de Helicobacter pylori.

BACKGROUND: Helicobacter pylori is now accepted as the most important agent of gastritis in humans, as well as a risk factor for peptic ulcer disease and gastric carcinoma. The outcome of the infection is related to several factors, among them bacterial ones such as cagA and vacA s1m1 genotype. Random amplified polymorphic DNA (RAPD)-PCR, has been used to generate DNA fingerprints to evaluate similarity among strains within a bacterial species. AIM: To assess the association between RAPD fingerprinting, virulence factors and the disease. METHODS: H. pylori was isolated from 112 patients (41 with gastritis; 19 with gastric ulcers; 38 with duodenal ulcer disease; and 14 with gastroesophageal reflux disease). Allelic variants of cagA and vacA were identified using the polymerase chain reaction (PCR) and the fingerprints were generated by RAPD-PCR. RESULTS: There was a strong association between the genotype vacA s1m1 and duodenal ulcers. Although RADP-PCR is a very useful tool in genotyping H. pylori, no significant correlation between the diseases studied and DNA fingerprint was detected neither with fingerprint and different vacA and, cagA genotypes. CONCLUSIONS: The extension of our analysis to patients with well-characterized gastric diseases may provide significant information on the relationship between vacA genotypes and clinical outcomes of H. pylori infection.

Sensitivity of Leishmania braziliensis promastigotes to meglumine antimoniate (glucantime) is higher than that of other Leishmania species and correlates with response to therapy in American tegumentary leishmaniasis.

The first line drugs for the treatment of leishmaniasis are antimonial derivatives. Poor clinical response may be credited to factors linked to the host, the drug, or the parasite. We determined the sensitivity of Leishmania sp. promastigotes and amastigotes by counting parasites exposed to increasing concentrations of meglumine antimoniate (Glucantime). Leishmania braziliensis promastigotes were significantly more sensitive than those belonging to other species. The sensitivity of L. braziliensis isolates from patients with unfavorable clinical outcome, such as therapeutic failure or relapse, was significantly lower than those from patients who had clinical cure. Poor clinical response to therapy (therapeutic failure or relapse) was also associated with inadequate antimonial therapy. We also found a significant and positive correlation between promastigotes and intracellular amastigotes with regard to their in vitro susceptibilities to meglumine antimoniate. Our data provide evidence for an association between the sensitivity of promastigotes to antimonials in vitro and clinical response to therapy in American tegumentary leishmaniasis. The high sensitivity of the local L. braziliensis to meglumine antimoniate in vitro provides an explanation for the good clinical response of cutaneous leishmaniasis in the municipality of Rio de Janeiro, Brazil, even when low-dose regimens are employed.