Dynamics of ex vivo cytokine transcription during experimental Toxocara canis infection in Balb/c mice.

The cytokine microenvironment is crucial in generating and polarizing the immune response. A means of monitoring this environment would be of great value for better understanding Toxocara canis immune modulation. The aim of this study was to analyze the dynamics of cytokine transcription ex vivo, during early (24-48 hours) and late (15-30 days) times post-infection, in the mesenteric lymph nodes, spleen and intestinal mucosa of Balb/c mice experimentally infected with T. canis larvae. Mice in the treated group were infected with 100 third-stage larvae (L3), whereas mice in the control group were not infected. Analyses were performed at different times: 24-48 hours post-infection (HPI), 15-30 days post-infection (DPI). IL4, IL10, IL12 and Ym1 mRNA transcriptions were analyzed through qPCR. This study showed cytokine transcription mediated by migrating larvae in the mesenteric lymph nodes and spleen at 24-48 HPI, whereas cytokine transcription in the intestinal mucosa was observed only at late times (15-30 DPI). These results suggest that the T. canis larvae migration during infection might play a role in cytokine dynamics. Since the cytokine microenvironment is crucial in modulating immune response, knowledge of cytokine dynamics during T. canis infections pave the way to better understand its interaction with the host.

Immunomodulatory effect of Lacticaseibacillus casei CB054 supplementation in calves vaccinated against infectious bovine rhinotracheitis.

Probiotics are live microorganisms that, confer health benefits to the host when supplemented in adequate amounts. They can promote immunomodulation by inducing phagocyte activity, leukocyte proliferation, antibody production, and cytokine expression. Lactic acid bacteria (BAL) are important probiotic specimens with properties that can improves ruminant nutrition, productivity and immunity. The aim of the present study was to evaluate the immunomodulatory effect of the supplementation with Lacticaseibacillus casei CB054 in calve vaccinated against bovine infectious rhinotracheitis (IBR). Calve were vaccinated with a commercial IBR vaccine, on day 0 and received a booster dose on day 21. L. casei CB054 was orally administered (4 ×109 UFC) for 35 days, while a non-supplemented control group received Phosphate Buffer Saline (PBS). Stimulation of bovine splenocytes with L. casei CB054 markedly enhanced mRNA transcription levels of cytokines IL2, IL4, IL10 and IL17 genes. Calves supplemented with L. casei CB054 showed significantly higher (p < 0.05) specific anti-BoHV-1 IgG levels, higher serum neutralization, as well as higher mRNA transcription for IL2, IL4, IL10 and IL17 genes in Peripheral Blood Mononuclear Cells (PBMCs) comparing with control calves. Supplemented calve had an average weight gain of ∼14 kg more than non-supplemented during the experimental period. These results suggest that L. casei CB054 supplementation increase immunogenicity of a commercial IBR vaccine in cattle and improve weight gain.

High Seroprevalence of Lawsonia intracellularis in Thoroughbred Farms in Southern Brazil.

The aim of the present study was to carry out a serological survey to identify the seroprevalence of Lawsonia intracellularis in six Thoroughbred farms in the Southern region of the state of Rio Grande do Sul, Brazil. During 2019 and 2020, blood samples from 686 Thoroughbred horses were obtained from six different breeding farms. Horses were divided into groups according to age: (1) broodmares (>5 years), (2) two-year-old foals, (3) yearlings, and (4) 0-6 months-old foals. Blood samples were collected by venipuncture of the external jugular vein. The detection of antibodies (IgG) against L. intracellularis was performed by Immunoperoxidase Monolayer Assay. The detection of specific antibodies (IgG) against L. intracellularis in the evaluated population was 51%. The highest detection (86.8%) of IgG was in the broodmares category, while the lowest (5.2%) was in foals of 0-6 months of age. Regarding the farms, the Farm 1 had the highest (67.4%) prevalence of seropositivity against L. intracellularis, while Farm 4 had the lowest (30.6%). There was no record of clinical manifestation of Equine Proliferative Enteropathy in the sampled animals. The results of this study show the high seroprevalence of L. intracellularis in Thoroughbred farms in the Southern of Rio Grande do Sul, suggesting a large and continuous exposure to the agent.

Application of the solid-state fermentation process and its variations in PHA production: a review.

Solid-state fermentation (SSF) is a type of fermentation process with potential to use agro-industrial by-products as a carbon source. Nonetheless, there are few studies evaluating SSF compared to submerged fermentation (SmF) to produce polyhydroxyalkanoates (PHAs). Different methodologies are available associating the two processes. In general, the studies employ a 1st step by SSF to hydrolyze the agro-industrial by-products used as a carbon source, and a 2nd step to produce PHA that can be carried out by SmF or SSF. This paper reviewed and compared the different methodologies described in the literature to assess their potential for use in PHA production. The studies evaluated showed that highest PHA yields (86.2% and 82.3%) were achieved by associating SSF and SmF by Cupriavidus necator. Meanwhile, in methodologies using only SSF, Bacillus produced the highest yields (62% and 56.8%). Since PHA (%) does not necessarily represent a higher production by biomass, the productivity parameter was also compared between studies. We observed that the highest productivity results did not necessarily represent the highest PHA (%). C. necator presented the highest PHA yields associating SSF and SmF, however, is not the most suitable microorganism for PHA production by SSF. Concomitant use of C. necator and Bacillus is suggested for future studies in SSF. Also, it discusses the lack of studies on the association of the two fermentation methodologies, and on the scaling of SSF process for PHA production. In addition to demonstrating the need for standardization of results, for comparison between different methodologies.

Sheep immune-stimulated with Saccharomyces boulardii show reduced prolificacy of Haemonchus contortus.

Haemonchus contortus is the most pathogenic parasite for sheep. The objective was to evaluate immunomodulation of the probiotic Saccharomyces boulardii in sheep experimentally infected with H. contortus. Twenty-four sheep were divided into three groups: one infected with 500 H. contortus larvae/day for 26 days and supplemented with S. boulardii (40 ml with 1 × 108 CFU/ml/day); a control group only infected with H. contortus but not supplemented; and a naïve group that never came into contact with either parasites or S. boulardii. To assess the humoral immune response, production of specific serum IgG anti-somatic H. contortus antigen was evaluated through indirect ELISA. To assess the cellular immune response, cell populations and cytokine (IL-4, IL-5 and IL-10) production were evaluated through flow cytometry. For parasitological analyses, the counts of eggs per gram of faeces (EPG) and larvae per faecal culture were assessed. At all the study points, the concentration of IgG anti-H. contortus was higher (p < .05) in the S. boulardii group than in the other groups. The cell analysis revealed that there were significantly higher numbers (p < .05) of cells expressing MHC-II and significantly higher numbers (p < .05) of eosinophils in the mucosa in the S. boulardii group. Significant expression of IL-10 was observed only in the control infected group. There were significant reductions (p < .05) in EPG and larval counts in the S. boulardii supplemented group. These results show that S. boulardii supplementation modulated the immune response against H. contortus, thereby reducing its infection.

Effect of oral administration of Bacillus thuringiensis var. oswaldocruzi to sheep on the development of larvae in fecal cultures.

Haemonchus contortus is one of the most important gastrointestinal nematodes infecting sheep, being a production-limiting factor in sheep herds. Biological control has been used for many years either in combination with traditional parasiticides or as an alternative treatment itself. Bacillus thuringiensis can be a promising tool for an integrate control of H. contortus in sheep herds by disrupting nematode's life cycle, thus decontaminating pasture. This study aims to evaluate the larvicidal efficacy of Bacillus thuringiensis var. oswaldocruzi (Bto) on the development of H. contortus larvae in fecal sheep cultures. Bto concentrations (~1010 colony forming units, CFU / mL) were orally administered to thirty-six ewes naturally infected with H. contortus in three different pharmaceutical forms: hard gelatin capsule, mucoadhesive gel or suspension. The different treatments were carried out in a single oral administration (SOA). All formulations were effective in inhibiting larvae development compared with control groups in all time points studied (p < 0.05). The mucoadhesive gel showed ~90% of efficacy on inhibiting larvae development during all the time points post SOA. The suspension had 85% efficacy on inhibiting larvae development at 24-48 h and 96% at 72-96 h. The hard gelatin capsule was 57%, 62%, 73% and 96% effective inhibiting larvae development at 24, 48, 72 and 96 h, respectively. This study highlights that disrupting the infective larval stage in the environment Bacillus thuringiensis var. oswaldocruzi is a promising prophylactic alternative in the H. contortus control.

Immune response of adult horses, pregnant mares and foals to an experimental vaccine with recombinant EMA-2 protein of Theileria equi.

Equine theileriosis, caused by the Theileria equi protozoan, is a disease of worldwide importance. T. equi expresses surface proteins, of which the EMA-2 protein is a promising antigen for vaccine use. The aim of this study was to evaluate the immune response of adult horses, pregnant mares, and foals to an experimental EMA-2 protein of recombinant T. equi vaccine. A total of 46 horses were used in this study for vaccine trials and challenges. Twelve geldings, 14 pregnant mares, and 14 foals were divided into vaccinated and control groups. Total serum specific anti-rEMA-2 IgG, IgG subclasses, and transcription of cytokines related to the immune response were evaluated. For the vaccine challenge, six six-month-old foals were divided into vaccinated and control groups. For the challenge, blood from a horse with theileriosis was transfused to the foals. Geldings and pregnant mares maintained anti-rEMA-2 IgG levels at 130 and 140 days after vaccination, respectively. The most-detected IgG subclasses in vaccinated were IgG3/5, IgG4/7, and IgG1. IL2, IL10, IL12, IL17, IFN-γ, and TNF-α were the most-transcribed cytokines in PBMCs of vaccinated horses stimulated with rEMA-2. Challenge with T. equi demonstrated that vaccinated foals had an increase of 33% in total IgG four days after blood transfusion, while control foals had no significant response, suggesting that vaccine antibodies may have recognized EMA-2 protein of the native T. equi antigen. T. equi recombinant EMA-2 was shown to be a promising vaccine antigen by inducing humoral and cellular immunity similar to that observed in natural parasite infections.

Expression cassette and plasmid construction for Yeast Surface Display in Saccharomyces cerevisiae.

OBJECTIVES: Develop a Cell Surface Display system in Saccharomyces cerevisiae, based on the construction of an expression cassette for pYES2 plasmid. RESULTS: The construction of an expression cassette containing the α-factor signal peptide and the C-terminal portion of the α-agglutinin protein was made and its sequence inserted into a plasmid named pYES2/gDαAgglutinin. The construction allows surface display of bovine herpesvirus type 5 (BoHV-5) glycoprotein D (gD) on S. cerevisiae BY4741 strain. Recombinant protein expression was confirmed by dot blot, and indirect immunofluorescence using monoclonal anti-histidine antibodies and polyclonal antibodies from mice experimentally vaccinated with a recombinant gD. CONCLUSIONS: These results demonstrate that the approach and plasmid used represent not only an effective system for immobilizing proteins on the yeast cell surface, as well as a platform for immunobiologicals development.

Immunomodulatory effect of short-term supplementation with Bacillus toyonensis BCT-7112T and Saccharomyces boulardii CNCM I-745 in sheep vaccinated with Clostridium chauvoei.

The bacterium Clostridium chauvoei is the causative agent of blackleg in livestock, and vaccination is the most effective means of prevention. The aim of this study was to assess the effect of short-term supplementation with Bacillus toyonensis and Saccharomyces boulardii on the immune response to a C. chauvoei vaccine in sheep. Sheep were vaccinated subcutaneously on day 0 and received a booster dose on day 21, with 2 mL of a commercial vaccine formulated with inactivated C. chauvoei bacterin adsorbed on aluminum hydroxide. Probiotics were orally administered B. toyonensis (3 × 108 cfu) and S. boulardii (3 × 108 cfu) over five days prior to the first and second doses of the vaccine. Sheep supplemented with B. toyonensis and S. boulardii showed significantly higher specific IgG, IgG1, and IgG2 titers (P<0.05), with approximately 24- and 14-fold increases in total IgG levels, respectively, than the nonsupplemented group. Peripheral blood mononuclear cells from the supplemented group had increased mRNA transcription levels of the IFN-γ, IL2, and Bcl6 genes. These results demonstrate an adjuvant effect of short-term supplementation with B. toyonensis and S. boulardii on the immune response against the C. chauvoei vaccine in sheep.

Recombinant bovine IL17A acts as an adjuvant for bovine herpesvirus vaccine.

The Bovine herpes virus type 5 glycoprotein D (gD) is essential for viral penetration into host permissive cells. The Herpes virus gD glycoprotein has been used for bovine immunization, being efficient in reduction of viral replication, shedding and clinical signs, however sterilizing immunity is still not achieved. Recombinant subunit vaccines are, in general, poorly immunogenic requiring additional adjuvant components. Interleukin 17A (IL17A) is a pro-inflammatory cytokine produced by T helper 17 cells that mediate mucosal immunity. IL17 production during vaccine-induced immunity is a requirement for mucosal protection to several agents. In this study, we investigated the potential of a recombinant IL17A to act as an adjuvant for a recombinant BoHV-5 glycoprotein D vaccine in cattle. Three cattle groups were divided as: group 1) rgD5 + alumen + rIL-17A; 2) rgD5 + alumen; and 3) PBS + alumen. The cattle (3 per group) received two doses of their respective vaccines at an interval of 21 days. The group that received rIL17 in its vaccine formulation at the 7th day after the prime immunization had significant higher levels of specific rgD-IgG than the alumen group. Addition of rIL17 also led to a significant fold increase in specific anti-rgD IgG and neutralizing antibodies to the virus, respectively, when compared with the alumen group. Cells stimulated with rIL17A responded with IL17 transcription, as well IL2, IL4, IL10, IL15, Bcl6 and CXCR5. Our findings suggest that the rIL17A has adjuvant potential for use in vaccines against BoHV-5 as well as potentially other pathogens of cattle.

Bacillus Toyonensis BCT-7112T Spores as Parenteral Adjuvant of BoHV-5 Vaccine in a Murine Model.

Bacterial spores of the genus Bacillus are being evaluated as adjuvant molecules capable of improving the immune response to vaccines. In this study, we investigate whether subcutaneously administered spores of B. toyonensis BCT-7112T could enhance a vaccine immune response in mice. Three groups of mice were subcutaneously vaccinated on day 0 and received a booster on day 21 of the experiment, with the following vaccine formulations: 40 µg of recombinant glycoprotein D (rgD) from bovine herpesvirus type 5 (BoHV-5) adsorbed in 10% aluminum hydroxide (alum) without B. toyonensis spores (group 1) and B. toyonensis (1 × 106 viable spores) + 40 µg of rgD adsorbed in 10% alum (group 2); and B. toyonensis (1 × 106 viable spores) without rgD (group 3). Group 2 showed significantly higher titers (P < 0.05) of total specific serum IgG, IgG2a, and neutralizing antibodies, when compared with the groups 1 and 3. A significantly higher (P < 0.05) transcription level of cytokines IL-4, IL-12, and IFN-γ was observed in splenocytes from mice that received the B. toyonensis spores in the vaccine formulation. In addition, stimulation of the macrophage-like cell line RAW264.7 with spores of B. toyonensis markedly enhanced the cell proliferation and mRNA transcription levels of IL-4, and IL-12 cytokines in these cells. Our findings indicated that the subcutaneous administration of B. toyonensis BCT-7112T spores enhanced the humoral and cellular immune response against BoHV-5 in mice.

RA92A recombinant protein as immunogen to protect cattle against tick challenge in Brazil and Uganda

In this study, the recombinant gut protein rRa92A produced in Pichia pastoris yeast cells was used to immunize cattle in two experiments, one in Brazil and the other in Uganda. In both experiments, the animals were intramuscularly (IM) injected with 200 µg of recombinant protein in Brazil on days 0, 30 and 51 and in Uganda on days 0, 30. Blood samples for sera separation were collected from different days in both experiments. These samples were analyzed by ELISAs. In Brazil, ticks collected from the animals during the experimental period were analyzed for biological parameters. At Uganda, blood was collected to assess blood parameters, clinical signs were recorded and adult tick (Rhipicephalus appendiculatus) counts were performed. All animals of the vaccinated groups were shown to produce antibodies, and it was not possible to detect an effect on Rhipicephalus microplus. All the clinical parameters were considered within the normal ranges for both the experimental and control groups in Uganda. Antibody absorbance was elevated after each immunization and remained high until the end of the experiments, remaining low in the control animals. The results of stall test carried out in Brazil using R. microplus tick showed efficacy of 21.95%. The rRa92A immunization trial experiments in Uganda showing a decrease of 55.2% in the number of engorged adult ticks, which was statistically significant (p<0.05). Assessment of the immunogenicity of Ra92A produced in the P. pastoris expression system in bovines is reported for the first time, and the protein acted as a concealed antigen.

Immunogenicity of Escherichia coli Expressing Streptococcus equi subsp. equi Recombinant SeM

Abstract The Equine Strangles, caused by Streptococcus equi subs. equi, is a contagious disease, causing high rates of morbidity been responsible for important economic losses. The M protein synthesized by S. equi plays an important role in the pathogenesis and is a promising candidate for a vaccine antigen. The innate immune system is responsible for the first immune response against microorganisms, this response is mediated by receptors that detect PAMPs and their activation trigger crucial modulation of the adaptative immune response. This work describes the immune response of S. equi subs. equi. recombinant SeM protein, using Escherichia coli BL21 (DE3) as an expression and delivery vaccine system. To characterize and to determine the vaccine efficacy, mice were vaccinated as followed: 1. Recombinant E. coli expressing rSeM protein; 2. The same recombinant E. coli, inactivated adsorbed in Alumen; 3. Purified rSeM protein adsorbed in Alumen; 4. Inactivated S. equi whole cells adsorbed in Alumen; 5. Control group. All vaccinated mice developed protective response against S. equi infection, however the groups that received the E. coli expressing rSeM presented significant higher IgG level than other vaccinated groups. The recombinant E. coli delivery vaccine system also induced a highest IgG response than inactivated S. equi or purified rSeM vaccines in horses. This study evidence that the recombinant E. coli, live or inactivated, enhanced the humoral response, reaching significant higher antibodies levels than those obtained in the vaccination with the bacterin or purified antigen, showing the feasibility of producing low-cost vaccines against strangles.

Immunogenicity of a Recombinant Gonadotropin-releasing Hormone Associated to the B Subunit of Escherichia coli Heat-labile Enterotoxin Expressed in Pichia pastoris and Escherichia coli Platforms

Abstract Gonadotropin-releasing hormone (GnRH) is one of the main targets for the development of immunocontraceptives vaccines. The aim of this study was to clone and express the recombinant GnRH fused to the B subunit of Escherichia coli heat-labile enterotoxin (LTB) molecule in Pichia pastoris and Escherichia coli platforms and evaluate their immunogenicity in mice. P. pastoris (pGnRH/LTB) and E. coli (eGnRH/LTB) platforms were able to express GnRH/LTB expected band with ~ 21 kDa. Both constructions were immunogenic in mice. Similar IgG kinetics was observed for both construction when it was used as ELISA antigen respectively, showing significant (p<0.05) IgG levels 5-fold higher than a commercial vaccine and 14-fold higher than the controls. The histological effects of pGnRH/LTB as well as eGnRH/LTB proteins demonstrated a significant effect on the gonads, characterized by atrophy of seminiferous tubules, absence of spermatogenesis and reduction of Leydig cells. Both constructions were able to induce antibodies that block the hormone effect, suggesting the potential of GnRH/LTB, independently of the P. pastoris or E. coli platform used, as a vaccine candidate for immunocontraception.

Eimeria bateri Natural Infection: Oocysts Reductions in Grey Quail (Coturnix coturnix) Treated with Bacillus thuringensis var. israelensis

Abstract Coccidiosis, a disease caused by the parasitic Eimeria spp., affects birds of all ages, particularly young birds more intensely. Infected poultry presents significant economic losses. Bacillus thuringiensis var israelensis (Bti) is a Gram-positive, spore-forming bacterium that produces proteins with high specific parasiticidal activity against various orders of parasites. Thus, the aim of the present study was to evaluate the parasiticidal potential of Bti in quails that were naturally infected with Eimeria bateri. Twenty 12-week-old male quails (Coturnix coturnix coturnix), naturally infected with Eimeria bateri, were randomly divided into two groups of 10 birds: Bti treated and control. The treated group was supplemented with Bti (1×108 spores∙g-1) in the feed, while; the control group received the same feed without Bti. To evaluate the occurrence of oocysts, samples of feces were collected every week for four weeks. Significant (P < 0.05) oocysts reductions of 56.64% and 94.51% were noted in the Bti treated group at 2nd and 4th week of study, respectively. The Bti supplementation may contribute to the reduction of oocysts in quails and environmental contamination. Bacillus thuringiensis var israelensis appeared to be a promising complementary alternative in E. bateri control.

Association of Bacillus toyonensis spores with alum improves bovine herpesvirus 5 subunit vaccine immune response in mice.

Spores of the genus Bacillus are molecules capable of increasing the vaccine adjuvanticity. Bovine herpesvirus type 5 (BoHV-5) is responsible for meningoencephalitis that causes important economic losses in cattle. BoHV-5 glycoprotein D (gD) is a target of vaccine antigen and plays an important role in host cell penetration. The present study aimed to evaluate the adjuvanticity of Bacillus toyonensis (B.t) spores, live and heat-killed, associated with a vaccine formulated with aluminum hydroxide (alum) and the recombinant BoHV-5 glycoprotein D (rgD) in an experimental murine model. Six experimental groups of mice were subcutaneously vaccinated on day 0 and received a booster on day 21 of the experiment, with the following vaccine formulations: rgD (40 µg) + live spores (2 × 109 CFU); rgD + killed spores; rgD + live spores + alum (2.0 mg); rgD + killed spores + alum; rgD + alum, and rgD + PBS. Mice from rgD + live spores group showed an increase in rgD IgG titers from the 21st day until the end of the experiment. The groups of live and killed spores, associated to alum, had similar levels of IgG titers with no significant difference between each other; however, by the 14th and 28th day until the end of the experiment, presented higher IgG titers in comparison to the rgD + alum group. Moreover, increased serum levels of IgG1, IgG2a, and IgG2b were detected in mice that received spores in the vaccine formulation. The spores associated with alum groups showed neutralizing BoHV-5 antibodies and high mRNA transcription of the cytokines IFN-γ (66-fold), IL-17 (14-fold), and IL-12 (2.8-fold). In conclusion, our data demonstrated that the B. toyonensis spores, live or killed, associated with alum increased the adjuvanticity for BoHV-5 rgD in mice, suggesting the use of B. toyonensis spores as a promising component for vaccine formulations.

An assessment of the impacts of litter treatments on the litter quality and broiler performance: A systematic review and meta-analysis.

OBJECTIVE: The choice of the most suitable litter treatment should be based on scientific evidence. This systematic review assessed the effectiveness of litter treatments on ammonia concentration, pH, moisture and pathogenic microbiota of the litter and their effects on body weight, feed intake, feed conversion and mortality of broilers. METHODS: The systematic literature search was conducted using PubMed (Medline), Google Scholar, ScienceDirect and Scielo databases to retrieve articles published from January 1998 to august 2019. Means, standard deviations and sample sizes were extracted from each study. The response variables were analyzed using the mean difference (MD) or standardized mean difference (SMD), (litter treatment minus control group). All variables were analyzed using random effects meta-analyses. RESULTS: Subgroup meta-analysis revealed that acidifiers reduce pH (P<0.001), moisture (P = 0.002) ammonia (P = 0.011) and pathogenic microbiota (P <0.001) of the litter and improves the weight gain (P = 0.019) and decreases the mortality rate of broilers (P<0.001) when compared with controls. Gypsum had a positive effect on ammonia reduction (P = 0.012) and improved feed conversion (P = 0.023). Alkalizing agents raise the pH (P = 0.035), worsen feed conversion (P<0.001), increase the mortality rate (P <0.001), decrease the moisture content (P<0.001) and reduce the pathogenic microbiota of the litter (P<0.001) once compared to controls. Superphosphate and adsorbents reduce, respectively, pH (P<0.001) and moisture (P = 0.007) of the litter compared to control groups. CONCLUSION: None of the litter treatments influenced the feed intake of broilers. Meta-analyses of the selected studies showed positive and significant effects of the litter treatments on broiler performance and litter quality when compared with controls. Alkalizing was associated with worse feed conversion and high mortality of broilers.

Ovicidal and larvicidal potential of Rosmarinus officinalis to control gastrointestinal nematodes of sheep / Potencial ovicida e larvicida de Rosmarinus officinalis para controle de nematódeos gastrintestinais de ovinos

Abstract Gastrointestinal Nematode Infection (GIN) are the main constraint to the production of small ruminants. Studies of medicinal plants have been an important alternative in the effort to control these parasites. Therefore, the purpose of this study was to evaluate the in vitro ovicidal and larvicidal activity of essential oil of Rosmarinus officinalis. The oil was extracted, analyzed by gas chromatography and tested on GIN eggs and larvae in six concentrations, 227.5mg/mL, 113.7mg/mL, 56.8mg/mL, 28.4mg/mL, 14.2mg/mL and 7.1mg/mL. To determine the ovicidal activity, GIN eggs were recovered from sheep feces and incubated for 48h with different concentrations of the oil. For the evaluation of larval migration, third-stage larvae (L3) were obtained by fecal culture, and associated with the essential oil for 24h at the same concentrations, after which they were left for another 24 hours on microsieves, followed by the count of migrating and non-migrating larvae. The assays of R. officinalis oil showed a significant (p<0.05) 97.4% to 100% inhibition of egg hatching and a significant (p<0.05) 20% to 74% inhibition of larval migration. The main constituent revealed by gas chromatography was Eucalyptol. The results indicate that R. officinalis essential oil has ovicidal and larvicidal activity on sheep GINs.

Resumo As infecções por nematódeos gastrintestinais (ING) constituem a maior limitação à produção de pequenos ruminantes. Na busca do controle desses parasitos, estudos com plantas medicinais têm sido uma importante alternativa. Visto isto, o estudo desenvolvido teve como objetivo avaliar a ação ovicida e larvicida in vitro do óleo essencial de Rosmarinus officinalis. O óleo foi extraído, analisado por cromatografia gasosa e testado sobre ovos e larvas de ING em seis concentrações, 227,5mg/mL; 113,7mg/mL; 56,8mg/mL; 28,4mg/mL; 14,2mg/mL; 7,1mg/mL. Para determinar a ação ovicida, ovos de ING foram recuperados de fezes de ovinos e incubados por 48h com as diferentes concentrações do óleo. Na avaliação da migração das larvas, as larvas de terceiro estágio (L3) foram obtidas por coprocultura, e associadas ao óleo essencial por 24h nas mesmas concentrações, permanecendo por mais 24h em microtamises, seguindo-se a contagem de larvas que migraram e que não migraram. Os testes in vitro com o óleo de R. officinalis mostraram o nível de significância (p<0.05) 97,4% a 100% na inibição da eclodibilidade e 20% a 74% na inibição da migração das larvas. Na análise por cromatografia gasosa o constituinte majoritário foi o eucaliptol. Os resultados apresentados mostram que o óleo essencial de R. officinalis possui ação ovicida e larvicida sobre ING de ovinos.

O probiótico Saccharomyces boulardii modula a resposta de IgG2a em camundongos expostos aos antígenos de Leishmania infantum / Probiotic Saccharomyces boulardii modulates IgG2a response in miceexposed to Leishmania infantum antigens

O objetivo do presente estudo foi avaliar os efeitos do probiótico Saccharomyces boulardii na modulação da resposta imune humoral de animais expostos a antígenos de Leishmania infantum. Para isso, 16 camundongos BALB/c foram imunizados com antígeno particulado de Leishmania infantum e divididos em dois grupos experimentais, um composto por animais suplementados e outro por animais não suplementados com o probiótico. Amostras de sangue dos animais foram colhidas semanalmente durante o período experimental e submetidas ao Ensaio da Imunoabsorbância Ligado à Enzima indireto para avaliação dos títulos de IgG totais e o perfil dos isotipos de IgG produzidos (IgG1 e IgG2a). A suplementação com o probiótico não exacerbou a produção de IgG total em comparação ao grupo controle, não havendo diferenças significativas entre os dois grupos. Porém, as soroconversões de IgG2a foram mais elevadas no grupo suplementado, no qual registrou-se um aumento de 1,46 vezes no final do experimento. Assim, a suplementação com S. boulardii foi capaz de modular a resposta de IgG2a/IgG1 nos animais expostos aos antígenos de Leishmania infantum.

The aim of the present study was to evaluate the effects of the Saccharomyces boulardii probiotic on the modulation of humoral immune response in animals exposed to Leishmania infantum antigens. For this, 16 BALB/c mice were immunized with Leishmania infantum particulate antigen and divided into two experimental groups, one consisting of supplemented animals and the other not probiotic supplemented animals. Blood samples from the animals were taken weekly during the experimental period and subjected to the Indirect Enzyme-Linked Immunosorbance Assay for evaluation of total IgG titers and the profile of the produced IgG isotypes (IgG1 and IgG2a). Probiotic supplementation did not exacerbate total IgG production compared to the control group, with no significant differences between the two groups. However, IgG2a seroconversions were higher in the supplemented group, which showed a 1.46-fold increase at the end of the experiment. Thus, supplementation with S. boulardii was able to modulate the IgG2a/IgG1 response in animals exposed to Leishmania infantum antigens.

O probiótico Saccharomyces boulardii modula a resposta de IgG2a em camundongos expostos aos antígenos de Leishmania infantum / Probiotic Saccharomyces boulardii modulates IgG2a response in mice exposed to Leishmania infantum antigens

O objetivo do presente estudo foiavaliar os efeitos do probiótico Saccharomyces boulardii na modulação da resposta imune humoral de animais expostos a antígenos de Leishmania infantum. Para isso, 16 camundongos BALB/c foram imunizados com antígeno particulado de Leishmania infantum e divididos em dois grupos experimentais, um composto por animais suplementados e outro por animais não suplementados com o probiótico. Amostras de sangue dos animais foram colhidas semanalmente durante o período experimental e submetidas ao Ensaio da Imunoabsorbância Ligado à Enzima indireto para avaliação dos títulos de IgG totais e o perfil dos isotipos de IgG produzidos (IgG1 e IgG2a). A suplementação com o probiótico não exacerbou a produção de IgG total em comparação ao grupo controle, não havendo diferenças significativas entre os dois grupos. Porém, as soroconversões de IgG2a foram mais elevadas no grupo suplementado, no qual registrou-se um aumento de 1,46 vezes no final do experimento. Assim,a suplementação com S. boulardii foi capaz de modular a resposta de IgG2a/IgG1 nos animais expostos aos antígenos de Leishmania infantum.

The aim of the present study was to evaluate the effects of the Saccharomyces boulardii probiotic on the modulation of humoral immune response in animals exposed to Leishmania infantum antigens. For this, 16 BALB/c mice were immunized with Leishmania infantum particulate antigen and divided into two experimental groups, one consisting of supplemented animals and the other not probiotic supplemented animals. Blood samples from the animals were taken weekly during the experimental period and subjected to the Indirect Enzyme-Linked Immunosorbance Assay for evaluation of total IgG titers and the profile of the produced IgG isotypes (IgG1 and IgG2a). Probiotic supplementation did not exacerbate total IgG production compared to the control group, with no significant differences between the two groups. However, IgG2a seroconversions were higher in the supplemented group, which showed a 1.46-fold increase at the end of the experiment. Thus, supplementation with S. boulardii was able to modulate the IgG2a/IgG1 response in animals exposed to Leishmania infantum antigens.