Potentially functional lactose-free ice cream with Lacticaseibacillus casei CSL3, ginger, and honey.

AIMS: To develop and characterize a functional lactose-free ice cream with added ginger and honey, evaluate the survival of Lacticaseibacillus casei CSL3 under frozen storage and the simulated gastrointestinal tract (GIT), as well as antioxidant activity and product acceptability. METHODS AND RESULTS: The survival of Lacticaseibacillus casei CSL3 was evaluated for 180 days, under frozen storage, and GIT at 60 days. At 15 days of storage, proximal composition, antioxidant activity, color, pH, acidity, fusion, density, overrun, and sensory analysis were performed. Ice cream was an effective food matrix for maintaining the viability of CSL3, with concentrations > 7 log CFU g- 1 during storage and GIT. In addition, the analysis showed overrun and prebiotic characteristics through high values of antioxidant activity and phenolic compounds, good acceptability, and purchase intention. CONCLUSIONS: The product has satisfactory market potential (acceptance rate of 95.19% and purchase intention rate > 96%), and it could become another means of inserting probiotics in food.

Combined antibodies against internalins A and B proteins have potential application in immunoassay for detection of Listeria monocytogenes.

Listeria monocytogenes is a food-borne bacterium that causes listeriosis upon the ingestion of contaminated food. Traditional methods to detect L. monocytogenes require pre-enrichment broths to increase its concentration. To improve the screening of contaminated food and prevent listeriosis outbreaks, rapid, specific and sensitive assays are needed to detect L. monocytogenes. This study developed a prototype lateral flow immunochromatographic assay (LFIA) employing antibodies against L. monocytogenes Internalin A (InlA) and Internalin B (InlB) proteins, that are involved in non-phagocytic cell invasion. The following antibodies were used to capture L. monocytogenes antigenic targets: mouse anti-Internalin A monoclonal antibody (MAb-2D12) conjugated to colloidal gold nanoparticles and a mouse anti-Internalin B polyclonal antibody. This test was able to detect pure L. monocytogenes from culture with a limit of detection (LOD) ranging from 5.9 × 103 to 1.5 × 104 CFU/mL. In milk artificially contaminated with L. monocytogenes, the LOD was 1 × 105 CFU/mL. This prototype test discriminated L. monocytogenes from other bacterial species (Listeria innocua, Enterobacter cloacae, Bacillus cereus). Results indicate that this LFIA developed using antibodies against L. monocytogenes InlA and InlB proteins is a sensitive and specific tool that can be potentially useful to rapidly detect L. monocytogenes in contaminated food. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05597-9.

Phage Display-Derived Monoclonal Antibodies Against Internalins A and B Allow Specific Detection of Listeria monocytogenes.

Listeria monocytogenes is the causative agent of listeriosis, a highly lethal disease initiated after the ingestion of Listeria-contaminated food. This species comprises different serovars, from which 4b, 1/2a, and 1/2b cause most of the infections. Among the different proteins involved in pathogenesis, the internalins A (InlA) and B (InlB) are the best characterized, since they play a major role in the enterocyte entry of Listeria cells during early infection. Due to their covalent attachment to the cell wall and location on the bacterial surface, along with their exclusive presence in the pathogenic L. monocytogenes, these proteins are also used as detection targets for this species. Even though huge advancements were achieved in the enrichment steps for subsequent Listeria detection, few studies have focused on the improvement of the antibodies for immunodetection. In the present study, recombinant InlA and InlB produced in Escherichia coli were used as targets to generate antibodies via phage display using the human naïve antibody libraries HAL9 and HAL10. A set of five recombinant antibodies (four against InlA, and one against InlB) were produced in scFv-Fc format and tested in indirect ELISA against a panel of 19 Listeria strains (17 species; including the three main serovars of L. monocytogenes) and 16 non-Listeria species. All five antibodies were able to recognize L. monocytogenes with 100% sensitivity (CI 29.24-100.0) and specificity (CI 88.78-100.0) in all three analyzed antibody concentrations. These findings show that phage display-derived antibodies can improve the biological tools to develop better immunodiagnostics for L. monocytogenes.

Evaluation of the expression and immunogenicity of four versions of recombinant Clostridium perfringens beta toxin designed by bioinformatics tools.

Beta toxins (CPB) produced by Clostridium perfringens type B and C cause various diseases in animals, and the use of toxoids is an important prophylactic measure against such diseases. Promising recombinant toxoids have been developed recently. However, both soluble and insoluble proteins expressed in Escherichia coli can interfere with the production and immunogenicity of these antigens. In this context, bioinformatics tools have been used to design new versions of the beta toxin, and levels of expression and solubility were evaluated in different strains of E. coli. The immunogenicity in sheep was assessed using the molecule with the greatest potential that was selected on analyzing these results. In silico analyzes, greater mRNA stability (-169.70 kcal/mol), solubility (-0.755), and better tertiary structure (-0.12) were shown by rCPB-C. None of the strains of E. coli expressed rFH8-CPB, but a high level of expression and solubility was shown by rCPB-C. Higher levels of total and neutralizing anti-CPB antibodies were observed in sheep inoculated with bacterins containing rCPB-C. Thus, this study suggests that due to higher productivity of rCPB-C in E. coli and immunogenicity, it is considered as the most promising molecule for the production of a recombinant vaccine against diseases caused by the beta toxin produced by C. perfringens type B and C.

Pyruvate dehydrogenase complex-enzyme 2, a new target for Listeria spp. detection identified using combined phage display technologies.

The genus Listeria comprises ubiquitous bacteria, commonly present in foods and food production facilities. In this study, three different phage display technologies were employed to discover targets, and to generate and characterize novel antibodies against Listeria: antibody display for biomarker discovery and antibody generation; ORFeome display for target identification; and single-gene display for epitope characterization. With this approach, pyruvate dehydrogenase complex-enzyme 2 (PDC-E2) was defined as a new detection target for Listeria, as confirmed by immunomagnetic separation-mass spectrometry (IMS-MS). Immunoblot and fluorescence microscopy showed that this protein is accessible on the bacterial cell surface of living cells. Recombinant PDC-E2 was produced in E. coli and used to generate 16 additional antibodies. The resulting set of 20 monoclonal scFv-Fc was tested in indirect ELISA against 17 Listeria and 16 non-Listeria species. Two of them provided 100% sensitivity (CI 82.35-100.0%) and specificity (CI 78.20-100.0%), confirming PDC-E2 as a suitable target for the detection of Listeria. The binding region of 18 of these antibodies was analyzed, revealing that ≈ 90% (16/18) bind to the lipoyl domains (LD) of the target. The novel target PDC-E2 and highly specific antibodies against it offer new opportunities to improve the detection of Listeria.

Evaluation of Toxocara canis Glycosylated TES Produced in Pichia pastoris for Immunodiagnosis of Human Toxocariasis

Abstract Recombinant proteins are a suggested alternative for the diagnosis of toxocariasis. The current Escherichia coli recombinant protein overexpression system usually produces insoluble products. As an alternative, yeast such as Pichia pastoris have secretory mechanisms, which could diminish the cost and time for production. This study aimed to produce recombinant proteins in Pichia pastoris and verify their sensibility and specificity in an indirect ELISA assay. Two sequences (rTES-30 and rTES-120) of Toxocara canis excretory-secretory antigens were cloned in a pPICZαB vector and expressed in P. pastoris KM71H. Sera samples collected from human adults infected by Toxocara spp. were tested by indirect ELISA using rTES-30 and rTES-120 as antigens. Recombinant proteins were detected at 72 hours after induction, in the supernatant, as pure bands between 60~70 kDa with hyperglycosylation. Regarding diagnosis potential, recombinant antigens had high specificity (95.6%); however, sensitivity was 55.6% for rTES-30 and 68.9% for rTES-120. Further deglycosylation of the P. pastoris antigens did not seem to affect ELISA performance (p>0.05). The low sensitivity in the serodiagnosis diminished any advantage that P. pastoris expression could have. Therefore, we do not recommend P. pastoris recombinant TES production as an alternative for the diagnosis of toxocariasis.

Biopolymer Xanthan: A New Adjuvant for DNA Vaccines

Abstract DNA vaccines have been evaluated as an option to prevent several diseases. In this study, the capacity of the xanthan biopolymer to improve the DNA vaccines immune response, administered intramuscularly, was evaluated. The experimental vaccines consisted of genes encoding fragments of the proteins LigA and LigB of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Copenhageni strain Fiocruz L1-130. The humoral immune response was evaluated by indirect ELISA. Cytokine expression levels were determined by RT-qPCR. Compared to the control group, the IgG antibody levels of animals immunized with pTARGET/ligAni and pTARGET/ligBrep plasmids associated with xanthan biopolymer were significantly higher than the control group. Additionally, there was a significant increase in IL-17 expression in animals vaccinated with pTARGET/ligBrep and xanthan.

The serodiagnostic potential of recombinant proteins TES-30 and TES-120 in an indirect ELISA in the diagnosis of toxocariasis in cattle, horses, and sheep.

Toxocariasis is a zoonotic disease that affects humans and animals alike. Although recombinant proteins are widely used for its diagnosis in humans, their performance in companion and production animals remains unknown. This study aimed to investigate the serodiagnostic potential of the recombinant proteins rTES-30 and rTES-120 from Toxocara canis in an indirect ELISA for cattle, horses, and sheep. Serum samples collected from the animals were tested with indirect ELISA and Western Blotting using T. canis TES-30 and TES-120 recombinant proteins produced in Escherichia coli, as well as native-TES. In the ELISA, rTES-30 showed high serodiagnostic potential in sheep and horses (92.6% and 85.2%, respectively), while the sensitivity of rTES-120 was higher in cattle and horses (97.2% and 92.6%, respectively). Furthermore, a highly positive association was observed between native and recombinant proteins in seropositive samples, while a moderately positive association was observed in seronegative samples, probably due to the lower specificity of native TES. In conclusion, our study indicates that the use of recombinant proteins in an indirect ELISA is an effective tool for the serodiagnosis of toxocariasis in animals, with the choice of protein being species-dependent.

Avaliação do índice de conicidade como preditor de risco cardiometabólico e suas associações em pacientes adultos submetidos a atendimento ambulatorial no Sul do Brasil / Evaluation of the conicity index as a predictor of cardiometabolic risk and its associations in adult patients submitted to outpatient care in Southern Brazil

Objetivo: Avaliar índice de conicidade de pacientes adultos atendidos em um Ambulatório de Nutrição, associá-lo com presença de patologias e compará-lo a indicadores antropométricos quanto à sua eficácia como preditor de risco cardiometabólico. Metodologia: Estudo observacional com dados secundários de prontuários. Dados socioeconômicos, antropométricos (peso, índice de massa corporal, circunferência da cintura, do pescoço e índice de conicidade), número de consultas e hábitos de vida, foram obtidos e comparados entre a primeira e última consulta. As análises foram realizadas no pacote estatístico Stata® 11.1, com nível de significância de 5%. Resultados: Amostra constituída por 164 adultos, sendo 114 (70%) mulheres. A maioria apresentava hipertensão (45%), sedentarismo (48%), peso acima do ideal (90%) e valores de CC(82%), CP (82%) e IC (88%) acima do recomendado. A maioria apresentou perda de peso (77%), sendo que 29% perdeu mais de 5% do peso inicial, além de melhora significativa nos hábitos alimentares, principalmente pelas mulheres. O índice de conicidade associou-se significativamente com os indicadores antropométricos analisados; foi mais sensível nas mulheres quanto à classificação de risco de complicações metabólicas e cardiovasculares, e apresentou valores significativamente maiores nos hipertensos e diabéticos. Conclusão: É importante o acompanhamento nutricional para melhoria dos hábitos de vida dos pacientes, assim como a utilização do IC, que associou-se com hipertensão e diabetes,sendo mais sensível nas mulheres em relação ao risco de complicações cardiometabólicas do que a CC e CP, demonstrando ser um bom indicador antropométrico,capaz de possibilitar a detecção precoce da obesidade e da distribuição de gordura (AU)

Objective: Evaluate the conicity index of adult patients treated at a Nutrition Outpatient Clinic, to associate it with the presence of pathologies and to compare with anthropometric indicators as to its efficacy as a predictor of cardiometabolic risk. Methodology: Observational study with secondary data from medical records. Socioeconomic, anthropometric data (weight, body mass index, waist circumference, neck and conicity index), number of visits and life habits were obtained and compared between the first and last visit. The analyzes were performed in Stata® 11.1 statistical package, with a significance level of 5%. Results: Sample of 164 adults, 114 (70%) of whom were women. The majority had hypertension (45%), sedentarism (48%), weight above the ideal (90%) and values of CC (82%), CP (82%) and IC (88%) above recommended. The majority presented weight loss (77%), with 29% losing more than 5% of the initial weight, in addition to a significant improvement in eating habits, mainly by women. The taper index was significantly associated with the anthropometric indicators analyzed; was more sensitive in women regarding the risk classification of metabolic and cardiovascular complications, presented significantly higher values in hypertensive and diabetic patients. Conclusion: It is important nutritional monitoring to improve life habits of patients, as well as the use of HF, which was associated with hypertension and diabetes, being more sensitive in women in relation to the risk of cardiometabolic complications than CC and CP, proving to be a good anthropometric indicator, capable of making possible the early detection of obesity and fat distribution (AU)

Sensitivity and specificity of recombinant proteins in Toxocara spp. for serodiagnosis in humans: Differences in adult and child populations.

Toxocariasis is a neglected zoonosis that affects children and adults. Recombinant proteins have been widely investigated for diagnosis, achieving high sensitivity and specificity in an overall population; however, little is known about age as a factor in its application. This study aims to investigate the diagnostic potential of Toxocara canis TES-30 and TES-120 recombinant proteins in humans, differentiating between its performance in children and adults. Serum samples collected from children and adults seropositive to Toxocara spp. were tested with indirect ELISA using T. canis TES-30 and TES-120 recombinant proteins produced in Escherichia coli. While rTES-30 sensitivity was not affected by age (81.8% in children and 87% in adults), rTES-120 sensitivity severely decreased in children to only 63.6%, down from 95.7% in adults. Furthermore, the sensitivity of rTES-30 increased to 97.8% after Western blotting confirmation. High specificity (>94%) against other geohelminths was reported for both recombinant proteins. Our study favors the use of rTES-30 with total IgG as the primary antibody in an indirect ELISA assay as a tool for epidemiological human studies.

Bioremediation and biomass production from the cultivation of probiotic Saccharomyces boulardii in parboiled rice effluent.

The parboilization of rice generates 2 L of effluent per kilogram of processed grain. Several methodologies have previously been tested with the aim of reducing the environmental impact of this effluent. The objective of this study was to evaluate the bioremediation of parboiled rice effluent supplemented with sucrose or residual glycerol from the biodiesel during the cultivation of the Saccharomyces boulardii probiotic. In the first stage of the experiment, cultures were grown in orbital shaker, and five media compositions were evaluated: 1) parboiled rice effluent; 2) effluent supplemented with 1% sucrose; 3) effluent supplemented with 3% sucrose; 4) effluent supplemented with 15 g.L-1 of biodiesel glycerol and 5) standard yeast culture medium (YM). The addition of 1% of sucrose generated the most promising results in terms of cell viability, removal of nitrogen, phosphorus and chemical oxygen demand (COD). From these results, four independent cultures were grown in a bioreactor using effluent +1% of sucrose as the medium. This assays generated a mean of 3.8 g.L-1 of biomass, 1.8 × 1011 CFU.L-1, and removal of 74% of COD and 78% of phosphorus. Therefore, the cultivation of Saccharomyces boulardii in parboiled rice effluent supplemented with 1% sucrose may represent a viable method by which the environmental impact of this effluent can be reduced while simultaneously producing probiotic culture for use in animal production.

Reactivity of recombinant Toxocara canis TES-30/120 in experimentally infected mice.

AIM: While the use of recombinant antigens is being widely investigated in the diagnosis of human toxocariasis, relatively little attention has been given to animal diagnostic models. For this reason, this study aimed to investigate the diagnosis potential of Toxocara canis TES-30 and TES-120 recombinant antigens in mice, the animal model for toxocariasis studies. METHODS AND RESULTS: Serum samples obtained from mice infected with T. canis or Toxocara cati were tested by indirect ELISA using T. canis TES-30 and TES-120 recombinant antigens produced in Escherichia coli. 90% of the samples reacted with rTES-30, whereas there was almost no reactivity with rTES-120. CONCLUSION: Despite rTES-120 being a good antigen for diagnosis in humans, it could not reproduce its reactivity in this animal model. As rTES-30 has good reactivity in mice, it is a valuable tool for diagnosis.

Parenteral adjuvant potential of recombinant B subunit of Escherichia coli heat-labile enterotoxin.

BACKGROUND: The B subunit of Escherichia coli heat-labile enterotoxin (LTB) is a potent mucosal immune adjuvant. However, there is little information about LTB's potential as a parenteral adjuvant. OBJECTIVES: We aimed at evaluating and better understanding rLTB's potential as a parenteral adjuvant using the fused R1 repeat of Mycoplasma hyopneumoniae P97 adhesin as an antigen to characterise the humoral immune response induced by this construct and comparing it to that generated when aluminium hydroxide is used as adjuvant instead. METHODS: BALB/c mice were immunised intraperitoneally with either rLTBR1 or recombinant R1 adsorbed onto aluminium hydroxide. The levels of systemic anti-rR1 antibodies (total Ig, IgG1, IgG2a, and IgA) were assessed by enzyme-linked immunosorbent assay (ELISA). The ratio of IgG1 and IgG2a was used to characterise a Th1, Th2, or mixed Th1/Th2 immune response. FINDINGS: Western blot confirmed rR1, either alone or fused to LTB, remained antigenic; anti-cholera toxin ELISA confirmed that LTB retained its activity when expressed in a heterologous system. Mice immunised with the rLTBR1 fusion protein produced approximately twice as much anti-rR1 immunoglobulins as mice vaccinated with rR1 adsorbed onto aluminium hydroxide. Animals vaccinated with either rLTBR1 or rR1 adsorbed onto aluminium hydroxide presented a mixed Th1/Th2 immune response. We speculate this might be a result of rR1 immune modulation rather than adjuvant modulation. Mice immunised with rLTBR1 produced approximately 1.5-fold more serum IgA than animals immunised with rR1 and aluminium hydroxide. MAIN CONCLUSIONS: The results suggest that rLTB is a more powerful parenteral adjuvant than aluminium hydroxide when administered intraperitoneally as it induced higher antibody titres. Therefore, we recommend that rLTB be considered an alternative adjuvant, even if different administration routes are employed.

Parenteral adjuvant potential of recombinant B subunit of Escherichia coli heat-labile enterotoxin

BACKGROUND The B subunit of Escherichia coli heat-labile enterotoxin (LTB) is a potent mucosal immune adjuvant. However, there is little information about LTB's potential as a parenteral adjuvant. OBJECTIVES We aimed at evaluating and better understanding rLTB's potential as a parenteral adjuvant using the fused R1 repeat of Mycoplasma hyopneumoniae P97 adhesin as an antigen to characterise the humoral immune response induced by this construct and comparing it to that generated when aluminium hydroxide is used as adjuvant instead. METHODS BALB/c mice were immunised intraperitoneally with either rLTBR1 or recombinant R1 adsorbed onto aluminium hydroxide. The levels of systemic anti-rR1 antibodies (total Ig, IgG1, IgG2a, and IgA) were assessed by enzyme-linked immunosorbent assay (ELISA). The ratio of IgG1 and IgG2a was used to characterise a Th1, Th2, or mixed Th1/Th2 immune response. FINDINGS Western blot confirmed rR1, either alone or fused to LTB, remained antigenic; anti-cholera toxin ELISA confirmed that LTB retained its activity when expressed in a heterologous system. Mice immunised with the rLTBR1 fusion protein produced approximately twice as much anti-rR1 immunoglobulins as mice vaccinated with rR1 adsorbed onto aluminium hydroxide. Animals vaccinated with either rLTBR1 or rR1 adsorbed onto aluminium hydroxide presented a mixed Th1/Th2 immune response. We speculate this might be a result of rR1 immune modulation rather than adjuvant modulation. Mice immunised with rLTBR1 produced approximately 1.5-fold more serum IgA than animals immunised with rR1 and aluminium hydroxide. MAIN CONCLUSIONS The results suggest that rLTB is a more powerful parenteral adjuvant than aluminium hydroxide when administered intraperitoneally as it induced higher antibody titres. Therefore, we recommend that rLTB be considered an alternative adjuvant, even if different administration routes are employed.

Saccharomyces boulardii improves humoral immune response to DNA vaccines against leptospirosis.

PURPOSE: Saccharomyces boulardii may improve the immune response by enhancing the production of anti-inflammatory cytokines, T-cell proliferation and dendritic cell activation. The immunomodulator effect of this probiotic has never been tested with DNA vaccines, which frequently induce low antibody titers. This study evaluated the capacity of Saccharomyces boulardii to improve the humoral and cellular immune responses using DNA vaccines coding for the leptospiral protein fragments LigAni and LigBrep. BALB/c mice were fed with rodent-specific feed containing 108 c.f.u. of Saccharomycesboulardii per gram. METHODOLOGY: Animals were immunized three times intramuscularly with 100 µg of pTARGET plasmids containing the coding sequences for the above mentioned proteins. Antibody titers were measured by indirect ELISA. Expression levels of IL-4, IL-10, IL-12, IL-17, IFN-γ and TGF-ß were determined by quantitative real-time PCR from RNA extracted from whole blood, after an intraperitoneal boost with 50 µg of the recombinant proteins.Results/Key findings. Antibody titers increased significantly after the second and third application when pTARGET/ligAni and pTARGET/ligBrep were used to vaccinate the animals in comparison with the control group (P<0.05). In addition, there was a significant increase in the expression of the IL-10 in mice immunized with pTARGET/ligBrep and fed with Saccharomyces boulardii. CONCLUSION: The results suggested that Saccharomyces boulardii has an immunomodulator effect in DNA vaccines, mainly by stimulating the humoral response, which is often limited in this kind of vaccine. Therefore, the use of Saccharomyces boulardii as immunomodulator represents a new alternative strategy for more efficient DNA vaccination.

Fructose 1,6-Bisphosphate Aldolase, a Novel Immunogenic Surface Protein on Listeria Species.

Listeria monocytogenes is a ubiquitous food-borne pathogen, and its presence in food or production facilities highlights the importance of surveillance. Increased understanding of the surface exposed antigens on Listeria would provide potential diagnostic and therapeutic targets. In the present work, using mass spectrometry and genetic cloning, we show that fructose-1,6-bisphosphate aldolase (FBA) class II in Listeria species is the antigen target of the previously described mAb-3F8. Western and dot blot assays confirmed that the mAb-3F8 could distinguish all tested Listeria species from close-related bacteria. Localization studies indicated that FBA is present in every fraction of Listeria cells, including supernatant and the cell wall, setting Listeria spp. as one of the few bacteria described to have this protein on their cell surface. Epitope mapping using ORFeome display and a peptide membrane revealed a 14-amino acid peptide as the potential mAb-3F8 epitope. The target epitope in FBA allowed distinguishing Listeria spp. from closely-related bacteria, and was identified as part of the active site in the dimeric enzyme. However, its function in cell surface seems not to be host cell adhesion-related. Western and dot blot assays further demonstrated that mAb-3F8 together with anti-InlA mAb-2D12 could differentiate pathogenic from non-pathogenic Listeria isolated from artificially contaminated cheese. In summary, we report FBA as a novel immunogenic surface target useful for the detection of Listeria genus.

Protective potential of recombinant non-purified botulinum neurotoxin serotypes C and D.

Botulinum neurotoxin (BoNT) serotypes C and D are responsible for cattle botulism, a fatal paralytic disease that results in great economic losses in livestock production. Vaccination is the main approach to prevent cattle botulism. However, production of commercially available vaccines (toxoids) involves high risk and presents variation of BoNT production between batches. Such limitations can be attenuated by the development of novel nontoxic recombinant vaccines through a simple and reproducible process. The aim of this study was to evaluate the protective potential of recombinant non-purified botulinum neurotoxin serotypes C and D. Bivalent vaccines containing 200 µg rHCC and rHCD each were formulated in three different ways: (1) purified antigens; (2) recombinant Escherichia coli bacterins; (3) recombinant E. coli cell lysates (supernatant and inclusion bodies). Guinea pigs immunized subcutaneously with recombinant formulations developed a protective immune response against the respective BoNTs as determined by a mouse neutralization bioassay with pooled sera. Purified recombinant antigens were capable of inducing 13 IU/mL antitoxin C and 21 IU/mL antitoxin D. Similarly, both the recombinant bacterins and the cell lysate formulations were capable of inducing 12 IU/mL antitoxin C and 20 IU/mL antitoxin D. These values are two times as high as compared to values induced by the commercial toxoid used as control, and two to ten times as high as the minimum amount required by the Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA), respectively. Therefore, we used a practical, industry-friendly, and efficient vaccine production process that resulted in formulations capable of inducing protective immune response (neutralizing antitoxins) against botulism serotypes C and D.

Immunogenicity of a Trivalent Recombinant Vaccine Against Clostridium perfringens Alpha, Beta, and Epsilon Toxins in Farm Ruminants.

Clostridium perfringens is an anaerobic bacterium that produces several toxins. Of these, the alpha, beta, and epsilon toxins are responsible for causing the most severe C. perfringens-related diseases in farm animals. The best way to control these diseases is through vaccination. However, commercially available vaccines are based on inactivated toxins and have many production drawbacks, which can be overcome through the use of recombinant antigens. In this study, we produced recombinant alpha, beta, and epsilon toxins in Escherichia coli to formulate a trivalent vaccine. Its effectiveness was evaluated through a potency test in rabbits, in which the vaccine generated 9.6, 24.4, and 25.0 IU/mL of neutralizing antibodies against the respective toxins. Following this, cattle, sheep, and goats received the same formulation, generating, respectively, 5.19 ± 0.48, 4.34 ± 0.43, and 4.70 ± 0.58 IU/mL against alpha toxin, 13.71 ± 1.17 IU/mL (for all three species) against beta toxin, and 12.74 ± 1.70, 7.66 ± 1.69, and 8.91 ± 2.14 IU/mL against epsilon toxin. These levels were above the minimum recommended by international protocols. As such, our vaccine was effective in generating protective antibodies and, thus, may represent an interesting alternative for the prevention of C. perfringens-related intoxications in farm animals.

Pichia pastoris X-33 has probiotic properties with remarkable antibacterial activity against Salmonella Typhimurium.

Probiotics are live microorganisms which are beneficial for the host when ingested at high enough concentrations. The methylotrophic yeast Pichia pastoris is widely used as heterologous protein production platform. However, its use as probiotic is poorly studied. The objective of this study was to evaluate some probiotic properties of the P. pastoris strain X-33 wild type. The resistance to in vitro and in vivo gastrointestinal conditions, stability in feed, safety, and antibacterial activity against Salmonella Typhimurium were evaluated. The yeast remained viable and persisted at appropriate concentration in the diet for at least 2 months, survived the stresses of the gastrointestinal tract in vitro and in vivo, caused no behavioral changes or lesions when administered to mice, inhibited the growth of S. Typhimurium in culture media, and reduced adhesion of the bacteria to the intestinal cells HCT-116. In the challenge experiment with a LD50 of virulent S. Typhimurium strain, mice supplemented with the yeast had a higher survival rate (50 % when administered by gavage and 80 % via the diet, compared with 20 and 50 %, respectively, in the control group). In addition, the S. Typhimurium concentration in the intestine of the surviving mice was lower; the score of intestinal lesions, lower; and the pathogen, not detected in the liver, spleen, and feces when compared to the control group (p < 0.05). It was concluded that the yeast Pichia pastoris X-33 has probiotic properties with remarkable antibacterial activity against S. Typhimurium.

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. Although some diagnostic tests are available, their sensitivity and specificity need to be improved. In addition, treatment options for toxocariasis are limited and are non-specific. Toxocariasis is listed as one of the five most important neglected diseases by the CDC. This review presents recent advances related to the control of toxocariasis, including new immunodiagnostics, therapies, and drug formulations, as well as novel interventions using DNA vaccines, immunomodulators, and probiotics.