Saccharomyces boulardii reduces the vertical transmission of Toxocara canis larvae in mice.

Probiotics have been shown to reduce the intensity of Toxocara canis infection in mice. However, larval transmission of this nematode also occurs via transplacental and transmammary routes. Thus, the aim of this study was to evaluate the effect of the Saccharomyces boulardii probiotic on the vertical transmission of T. canis in Swiss mice. The mice received 107S. boulardii colony-forming units per gram of food. The supplementation began 15 days before mating and was maintained throughout pregnancy and lactation. The animals were inoculated with 300 T. canis embryonated eggs on the 14th day of pregnancy. The presence of larvae was examined in the organs of the females and their offspring. The examined organs included the following: brain, liver, lungs, heart, kidneys, spleen, eye, skeletal muscle (carcass) and mammary glands of lactating females. There was a 42% (P = 0.041) reduction in the number of larvae transmitted to offspring in the group that received probiotic-supplemented food (GI). Additionally, there was a 50% reduction (P = 0.023) in the number of larvae found in the brains of lactating offspring in the GI group. These results reveal the potential of S. boulardii probiotic use as an auxiliary method of controlling visceral toxocariasis.

Bacillus toyonensis BCT-7112T transient supplementation improves vaccine efficacy in ewes vaccinated against Clostridium perfringens epsilon toxin.

AIM: The aim of the present study was to examine the vaccine immune response in ewes supplemented with Bacillus toyonensis BCT-7112T during a period of 5-day supplementation before vaccination against a recombinant Clostridium perfringens epsilon toxin (rETX). METHODS AND RESULTS: Ewes were vaccinated with 200 µg of rETX adjuvanted with 10% aluminium hydroxide. The treat group was orally supplemented with B. toyonensis BCT-7112T (3 × 108 viable spores) for 5 days prior to the first and second vaccination. Ewes supplemented with B. toyonensis BCT-7112T showed higher neutralizing antibody titres than the non-supplemented ewes (P < 0·05), with an increase in serum levels for total IgG anti-rETX by 3·2-fold (P < 0·0001), and for both IgG isotypes IgG1 and IgG2 by 2·1-fold and 2·3-fold (P < 0·01), respectively, compared with the control group. The peripheral blood mononuclear cells of ewes in the supplemented group had a higher (P < 0·05) cytokine mRNA transcription levels for IL-2 (6·4-fold increase), IFN-γ (2·9-fold increase) and transcription factor Bcl6 (2·3-fold increase) compared with the control group. CONCLUSION: We conclude that a 5 days of supplementation with B. toyonensis BCT-7112T prior vaccination is sufficient to significantly improve the humoral immune response of ewes against C. perfringens recombinant ETX vaccine. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings open a new perspective in the utilization of B. toyonensis BCT-7112T as an immunomodulator since a 5 days period of probiotic supplementation is sufficient to improve the vaccine immune response.

Toxocara canis infection may impair bovine herpesvirus type 5 immunization.

Helminths have developed complex mechanisms to suppress the host immune response. These mechanisms may impair the host vaccine response. This study aimed to evaluate the effect of Toxocara spp. infection on the vaccine immune response to bovine herpesvirus type 5 (BoHV-5). First, 30 heifers received two doses of an experimental BoHV-5 vaccine. At 42nd days after the primo vaccination the vaccine efficacy was evaluated, and the presence of anti-Toxocara antibodies. Second, 20 Balb/c mice were divided into two groups, one infected with T. canis and the other without infection. After infection, both groups received two doses of vaccine. The vaccine immune response was assessed by BoHV-5 serum neutralization and splenic cytokines transcription by qPCR. All heifers positive for Toxocara spp. (40%) showed BoHV-5 SN titer ≤1:32, whereas heifers negative for Toxocara spp. (60%) had BoHV-5 SN titer ≥1: 128. Infected T. canis mice showed BoHV-5 SN titer ≤1:2, whereas mice not infected with T. canis BoHV-5 SN titer ≥1:8. Splenocytes from control mice stimulated with BoHV-5 had a significant (p < .05) mRNA transcription for the cytokines IL-12, IL-17, and IL-23, whereas the same cytokines were down-regulated in T. canis infected mice. These results suggest that Toxocara spp. infection may impair BoHV-5 immunization and should be considered for efficient herd immunization.

Imunogenicidade da proteína M recombinante de Streptococcus equi subsp. equi coadministrada com um adjuvante molecular / Immunogenicity of recombinant M protein of Streptococcus equi subsp. equi co administered with a molecular adjuvant

The strangles is an infectious disease that affects horses from all ages and causes important economic losses in the equine-related business. The aim of this work was to evaluate the immunogenicity of the recombinant M protein from Streptococcus equi (rSeM) co-administered with the recombinant heat-labile enterotoxin B subunit from Escherichia coli (rLTB) in mice and horses. A total of 72 female Balb-c mice were divided into eight groups and 18 horses were divided into six groups. The animals were inoculated by intramuscular (IM) or intranasal (IN) routes with different treatments of rSeM, rLTB and/or Al(OH)3. The results obtained in both species, independent of administration routes, demonstrated that rSeM + rLTB had higher levels of specific serum immunoglobulins, however, in mucosal immunity the increase was not identified. Thus, the use of rSeM as vaccine antigen and rLTB as adjuvant can be a potential tool in the control of equine strangles.(AU)

Cloning, expression and characterization of SeM protein of Streptococcus equi subsp. equi and evaluation of its use as antigen in an indirect ELISA / Clonagem, expressão e caracterização de proteína SeM de Streptococcus equi subsp. equi e avaliação de sua utilização como antígeno em um ELISA indireto

Strangles is an economically important horse disease caused by Streptococcus equi subsp. equi. The diagnosis can be confirmed either directly by bacterial isolation and PCR or by ELISA, which is an indirect method based on the detection of serum antibodies. The aim of this study was to clone, express and characterize the SeM protein of Streptococcus equi subsp. equi, evaluate its use as antigen in indirect ELISA and determine its performance to distinguish sera of negative, vaccinated and positive animals. This was initially performed by cloning the gene encoding the SeM protein and its expression in Escherichia coli. Subsequently, the protein produced was characterized and used as antigen in ELISA. Serum samples for evaluation were taken from 40 negative foals, 46 horses vaccinated with a commercial vaccine against strangles and 46 horses diagnosed with the disease. The test showed high specificity and sensitivity, allowing discrimination between negative and positive, positive and vaccinated animals, and vaccinated animals and negative sera. Thus, it was concluded that the protein produced rSeM, which can be used as antigen for disease diagnosis, and the described ELISA might be helpful to evaluate the immune status of the herd...

A adenite equina é uma enfermidade economicamente importante de equinos, causada por Streptococcus equi subsp. equi. Seu diagnóstico pode ser confirmado de forma direta, por meio de isolamento bacteriano e de PCR, ou de forma indireta, por meio de ELISA, método baseado na detecção de anticorpos séricos. O objetivo deste estudo foi clonar, expressar e caracterizar a proteína SeM de Streptococcus equi subsp. equi, avaliar sua utilização como antígeno em um ELISA indireto e determinar a capacidade do teste de distinguir soros de animais negativos, vacinados e positivos. Para tal, foi inicialmente realizada a clonagem do gene que codifica para a proteína SeM e sua expressão em Escherichia coli. Posteriormente, a proteína produzida foi caracterizada e utilizada como antígeno em um teste de ELISA indireto. Para avaliação do teste, foram utilizadas amostras de soro de 40 potros negativos, de 46 equinos vacinados com uma vacina comercial contra adenite equina e de 46 equinos com diagnóstico da doença. O teste demonstrou alta sensibilidade e especificidade, permitindo discriminar entre soros negativos e positivos, positivos e de animais vacinados, e negativos e de animais vacinados. Assim, conclui-se que a proteína rSeM produzida pode ser usada como antígeno para o diagnóstico da enfermidade e que o ELISA descrito pode ser útil para avaliar o estado imunológico do rebanho...

Production of recombinant botulism antigens: a review of expression systems.

Botulism is a paralytic disease caused by intoxication with neurotoxins produced by Clostridium botulinum. Despite their similar mechanism of action, the botulinum neurotoxins (BoNT) are classified in eight serotypes (A to H). As to veterinary medicine, the impact of this disease is essentially economic, since different species of production animals can be affected, especially by BoNT/C and D. In human health, botulism is feared in a possible biological warfare, what would involve mainly the BoNT/A, B, E and F. In both cases, the most effective way to deal with botulism is through prevention, which involves vaccination. However, the current vaccines against this disease have several drawbacks on their process of production and, besides this, can be dangerous to producers since it requires certain level of biosafety. This way, recombinant vaccines have been shown to be a great alternative for the development of vaccines against both animal and human botulism. All BoNTs have a 50-kDa light chain (LC) and a 100-kDa heavy chain (HC). The latter one presents two domains of 50 kDa, called the N-terminal (HN) and C-terminal (HC) halves. Among these regions, the HC alone seem to confer the proper immune response against intoxication. Since innumerous studies describe the expression of these distinct regions using different systems, strategies, and protocols, it is difficult to define the best option for a viable vaccine production. Thereby, the present review describes the problematic of botulism and discusses the main advances for the viable production of vaccines for both human and veterinary medicine using recombinant antigens.

Immunisation of mice with Mycoplasma hyopneumoniae antigens P37, P42, P46 and P95 delivered as recombinant subunit or DNA vaccines.

Porcine enzootic pneumonia (PEP), which is caused by the fastidious bacterium Mycoplasma hyopneumoniae, is one of the most economically important diseases in the pig industry worldwide. Commercial bacterins provide only partial protection; therefore, the development of more efficient vaccines against PEP is necessary. In this study, the cellular and humoral immune responses elicited by DNA and recombinant subunit vaccines based on the P37, P42, P46 and P95 antigens of M. hyopneumoniae were evaluated after the intramuscular inoculation of BALB/c mice. The expression of the cytokines INFγ, TNFα and IL1 was evaluated by real-time RT-PCR in splenocytes from vaccinated mice. All antigens delivered as subunit vaccines, especially P42 and P95, and the pcDNA3/P46 DNA vaccine were able to elicit strong immune responses. These vaccines induced cellular immune responses and the production of antibodies able to react with native M. hyopneumoniae proteins. Because both cellular and humoral immune responses were induced, P42 and P95 are promising candidates for a recombinant subunit vaccine and P46 is a promising candidate for a DNA vaccine against PEP.

Production and characterization of recombinant transmembrane proteins from Mycoplasma hyopneumoniae.

Mycoplasma hyopneumoniae is the etiological agent of swine enzootic pneumonia (EP), a chronic respiratory disease which causes significant economic losses to the swine industry worldwide. More efficient strategies for controlling this disease are necessary. In this study, we cloned17 genes coding for transmembrane proteins from M. hyopneumoniae, among which six were successfully expressed in Escherichia coli and had their immunogenic and antigenic properties evaluated. All proteins were immunogenic in mice and sera from naturally infected pigs reacted with the recombinant proteins, suggesting that they are expressed during infection. These antigens may contribute for the development of new recombinant vaccines and diagnostic tests against EP.

Expression of the B-cell and T-cell epitopes of the rabies virus nucleoprotein in Mycobacterium bovis BCG and induction of an humoral response in mice.

Expression vectors containing rabies virus nucleoprotein B-cell and T-cell epitopes in Mycobacterium bovis BCG were constructed. The epitopes were subcloned into the M. leprae 18-kDa gene to ensure correct presentation to the host immune system. Expression of the 18-kDa::B+T epitope fusion protein was driven by either the hsp60 promoter, which is constitutively activated at a high level in M. bovis BCG, or the 18-kDa promoter, which is strongly induced in vivo. Mice were immunised intra-peritoneally with the recombinant BCG cultures and compared to a control group vaccinated with the commercial rabies vaccine Rai-SAD. Both of the expression vectors elicited a higher antibody titre than that of the rabies vaccine, with the highest response shown by M. bovis BCG (pUP203), expression controlled by the 18-kDa promoter. Immunisation with M. bovis BCG (pUP202), expression controlled by the hsp60 promoter, resulted in a continuously increasing antibody titre up to 60 days post immunisation. The mice antibodies were also capable of recognising the whole rabies virus and not only the synthetic peptide epitopes.