Pathogenic Leptospires Modulate Protein Expression and Post-translational Modifications in Response to Mammalian Host Signals.

Pathogenic species of cause leptospirosis, a bacterial zoonotic disease with a global distribution affecting over one million people annually. Reservoir hosts of leptospirosis, including rodents, dogs, and cattle, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil.

A Universal Vaccine against Leptospirosis: Are We Going in the Right Direction?

Leptospirosis is the most widespread zoonosis in the world and a neglected tropical disease estimated to cause severe infection in more than one million people worldwide every year that can be combated by effective immunization. However, no significant progress has been made on the leptospirosis vaccine since the advent of bacterins over 100 years. Although protective against lethal infection, particularly in animals, bacterin-induced immunity is considered short term, serovar restricted, and the vaccine can cause serious side effects.

LigB subunit vaccine confers sterile immunity against challenge in the hamster model of leptospirosis.

Neglected tropical diseases, including zoonoses such as leptospirosis, have a major impact on rural and poor urban communities, particularly in developing countries. This has led to major investment in antipoverty vaccines that focus on diseases that influence public health and thereby productivity. While the true, global, impact of leptospirosis is unknown due to the lack of adequate laboratory diagnosis, the WHO estimates that incidence has doubled over the last 15 years to over 1 million cases that require hospitalization every year.

Reverse Vaccinology: An Approach for Identifying Leptospiral Vaccine Candidates.

Leptospirosis is a major public health problem with an incidence of over one million human cases each year. It is a globally distributed, zoonotic disease and is associated with significant economic losses in farm animals. Leptospirosis is caused by pathogenic spp.

Secretory expression of bovine herpesvirus type 1/5 glycoprotein E in Pichia pastoris for the differential diagnosis of vaccinated or infected cattle.

Bovine herpesvirus (BoHV) glycoprotein E (gE) is a non-essential envelope glycoprotein and the deletion of gE has been used to develop BoHV-1 and BoHV-5 differential vaccine strains. The DIVA (Differentiation of Infected from Vaccinated Animals) strategy, using marker vaccines based on gE-negative BoHV strains, allows the identification of vaccinated or infected animals in immunoassays designed to detect anti-gE antibodies. In this study a codon optimized synthetic sequence of gE containing highly conserved regions from BoHV-1 and BoHV-5 was expressed in Pichia pastoris.

Draft genome of the Leptospira interrogans strains, Acegua, RCA, Prea, and Capivara, obtained from wildlife maintenance hosts and infected domestic animals.

In the present paper, we announce new draft genomes of four Leptospira interrogans strains named Acegua, RCA, Prea, and Capivara. These strains were isolated in the state of Rio Grande do Sul, Brazil, from cattle, dog, Brazilian guinea pig, and capybara, respectively.

Infection with Leptospira kirschneri Serovar Mozdok: First Report from the Southern Hemisphere.

Leptospirosis is a global zoonosis caused by pathogenic Leptospira spp. In this study, we characterized two Leptospira kirschneri serogroup Pomona serovar Mozdok isolates, one obtained from a dog and the other from a patient with severe leptospirosis, 4 years later. Histopathological analysis showed that both isolates caused severe tissue damage when used to infect hamsters.

Evaluation of the Leptospira interrogans Outer Membrane Protein OmpL37 as a Vaccine Candidate.

The identification of potential vaccine candidates against leptospirosis remains a challenge. However, one such candidate is OmpL37, a potentially surface-exposed antigen that has the highest elastin-binding ability described to date, suggesting that it plays an important role in host colonization. In order to evaluate OmpL37's ability to induce a protective immune response, prime-boost, DNA and subunit vaccine strategies were tested in the hamster model of lethal leptospirosis.

Generation of Mammalian Host-adapted by Cultivation in Peritoneal Dialysis Membrane Chamber Implantation in Rats.

can infect a myriad of mammalian hosts, including humans (Bharti , 2003; Ko , 2009). Following acquisition by a suitable host, leptospires disseminate the bloodstream to multiple tissues, including the kidneys, where they adhere to and colonize the proximal convoluted renal tubules (Athanazio , 2008). Infected hosts shed large number of spirochetes in their urine and the leptospires can survive in different environmental conditions before transmission to another host.

Human toxocariasis: current advances in diagnostics, treatment, and interventions.

Toxocariasis is a neglected zoonosis caused by the nematodes Toxocara canis and Toxocara cati. This disease is widespread in many countries, reaching high prevalence independently of the economic conditions. However, the true number of cases of toxocariasis is likely to be underestimated owing to the lack of adequate surveillance programs.

Xanthan gum as an adjuvant in a subunit vaccine preparation against leptospirosis.

Leptospiral immunoglobulin-like (Lig) proteins are of great interest due to their ability to act as mediators of pathogenesis, serodiagnostic antigens, and immunogens. Purified recombinant LigA protein is the most promising subunit vaccine candidate against leptospirosis reported to date, however, as purified proteins are weak immunogens the use of a potent adjuvant is essential for the success of LigA as a subunit vaccine. In the present study, we compared xanthan pv.

Mannosylated LigANI produced in Pichia pastoris protects hamsters against leptospirosis.

The C-terminal region of the Leptospiral immunoglobulin-like A protein (LigA) contains six carboxy-terminal Ig-like repeat domains (LigANI). Subunit vaccine preparations based on recombinant LigANI produced in Escherichia coli, are promising vaccine candidates, albeit with variable efficacy. In the present study, LigANI was expressed in the methylotrophic yeast Pichia pastoris using a 12 L bioreactor to produce mannosylated LigANI (mLigANI) for use in a vaccine preparation against leptospirosis.

Structure predictions of two Bauhinia variegata lectins reveal patterns of C-terminal properties in single chain legume lectins.

Bauhinia variegata lectins (BVL-I and BVL-II) are single chain lectins isolated from the plant Bauhinia variegata. Single chain lectins undergo post-translational processing on its N-terminal and C-terminal regions, which determines their physiological targeting, carbohydrate binding activity and pattern of quaternary association. These two lectins are isoforms, BVL-I being highly glycosylated, and thus far, it has not been possible to determine their structures.

Characterization of a virulent Leptospira interrogans strain isolated from an abandoned swimming pool.

Pathogenic Leptospira spp. are the etiological agents of leptospirosis, an important disease of both humans and animals. In urban settings, L.

Seroprevalence of Toxocara infection in children from southern Brazil.

The seroprevalence of Toxocara canis antibodies in children aged from 1 to 12 yr old was evaluated in Pelotas City, Rio Grande do Sul, Brazil. Human toxocariasis or visceral larva migrans (VLM) was diagnosed with the use of an ELISA based on the T. canis excretory-secretory (TES) antigens; Western blotting was used to confirm the ELISA-positive results.

Concentration regimes of biopolymers xanthan, tara, and clairana, comparing dynamic light scattering and distribution of relaxation time.

The aim of this work was to evaluate the utilization of analysis of the distribution of relaxation time (DRT) using a dynamic light back-scattering technique as alternative method for the determination of the concentration regimes in aqueous solutions of biopolymers (xanthan, clairana and tara gums) by an analysis of the overlap (c*) and aggregation (c**) concentrations. The diffusion coefficients were obtained over a range of concentrations for each biopolymer using two methods. The first method analysed the behaviour of the diffusion coefficient as a function of the concentration of the gum solution.

A prime-boost strategy using the novel vaccine candidate, LemA, protects hamsters against leptospirosis.

Toward developing an effective vaccine capable of conferring heterologous protection, the putative lipoprotein LemA, which presents an M3 epitope similar to that of Listeria, was evaluated as a vaccine candidate in the hamster model of leptospirosis. LemA is conserved (>70% pairwise identity) among the pathogenic Leptospira spp., indicating its potential in stimulating a cross-protective immune response.

Substituted diaryl diselenides: cytotoxic and apoptotic effect in human colon adenocarcinoma cells.

Aims: To investigate the effects and study the underlying cell death mechanisms of diaryl diselenides, including: diphenyl diselenide (C(6)H(5)Se)(2); 4-chlorodiphenyl diselenide (4-ClC(6)H(4)Se)(2); 3-(trifluoromethyl)-diphenyl diselenide (3-CF(3)C(6)H(4)Se)(2) and 4-methoxydiphenyl diselenide (4-MeOC(6)H(4)Se)(2), on the human colon adenocarcinoma cell line HT-29.

Main Methods: The viability of HT-29 cells after exposure to the diaryl diselenides and its substituted structures was based on the MTT assay. To verify if cell death was mediated throughout apoptosis mechanisms, flow cytometry and real-time PCR (qPCR) analyses were conducted.

Neuropeptide Y gene expression around meal time in the Brazilian flounder Paralichthys orbignyanus.

Neuropeptide Y (NPY) is considered the major stimulant for food intake in mammals and fish. Previous results indicate that NPY is involved in the feeding behaviour of the Brazilian flounder, Paralichthys orbignyanus. In this study, we evaluated hypothalamic NPY expression before (-2 h), during (0 h) and after feeding (+2 h) in two independent experiments: (1) during a normal feeding schedule and (2) in fish fasted for 2 weeks.

Detection and quantification of Leptospira interrogans in hamster and rat kidney samples: immunofluorescent imprints versus real-time PCR.

A major limitation in the clinical management and experimental research of leptospirosis is the poor performance of the available methods for the direct detection of leptospires. In this study, we compared real-time PCR (qPCR), targeting the lipL32 gene, with the immunofluorescent imprint method (IM) for the detection and quantification of leptospires in kidney samples from the rat and hamster experimental models of leptospirosis. Using a virulent strain of Leptospira interrogans serovar Copenhageni, a chronic infection was established in the rat model, which were euthanized 28 days post-infection, while the hamster model simulated an acute infection and the hamsters were euthanized eight days after inoculation.

Recombinant vaccines against leptospirosis.

Leptospirosis is an important neglected infectious disease that occurs in urban environments, as well as in rural regions worldwide. Rodents, the principal reservoir hosts of pathogenic Leptospira spp., and other infected animals shed the bacteria in their urine.

Attenuated nephritis in inducible nitric oxide synthase knockout C57BL/6 mice and pulmonary hemorrhage in CB17 SCID and recombination activating gene 1 knockout C57BL/6 mice infected with Leptospira interrogans.

The aims of this study were to investigate the frequency of pulmonary hemorrhage (PH) in mice unable to produce functional B and T lymphocytes and to explore the effect of an inducible nitric oxide synthase gene (Inos) knockout (KO) on the frequency/severity of interstitial nephritis in vivo. We studied the outcome of infection by the virulent Leptospira interrogans serovar Copenhageni strain Cop. The animals used were Inos KO mice, recombination activating gene 1 (Rag1) KO mice, CB17 severe combined immunodeficiency (SCID) mice, and the respective wild-type (WT) C57BL/6 and BALB/c controls.

Characterization of the immunogenic and antigenic potential of putative lipoproteins from Leptospira interrogans.

The search for a vaccine capable of conferring heterologous protection, through the identification of conserved and cross-protective antigens, remains an ongoing priority in leptospirosis research. In the present study, an in silico analysis was used to identify potentially protective lipoproteins from Leptospira interrogans serovar Copenhageni. Eight putative lipoproteins were selected (LIC10009, LIC10054, LIC10091, LIC11058, LIC11567, LIC13059, LIC13305, and LIC20172), cloned and expressed in Escherichia coli and purified by affinity chromatography.

High yield expression of leptospirosis vaccine candidates LigA and LipL32 in the methylotrophic yeast Pichia pastoris.

Background: Leptospirosis, a zoonosis caused by Leptospira spp., is recognized as an emergent infectious disease. Due to the lack of adequate diagnostic tools, vaccines are an attractive intervention strategy.

Bioinformatics describes novel Loci for high resolution discrimination of leptospira isolates.

Background: Leptospirosis is one of the most widespread zoonoses in the world and with over 260 pathogenic serovars there is an urgent need for a molecular system of classification. The development of multilocus sequence typing (MLST) schemes for Leptospira spp. is addressing this issue.