Immunomodulatory effect of Bacillus toyonensis BCT-7112 supplementation in puppies vaccinated against canine parvovirus / Efeito imunomodulador da suplementação de Bacillus toyonensis BCT-7112 em cachorros vacinados contra o parvovírus canino

Bacillus toyonensis is a probiotic microorganism that for decades has been used in animal nutrition around the world. The objective of this work was to evaluate the immunomodulatory effect of oral B. toyonensis supplementation in dogs vaccinated against canine parvovirus. Puppies were randomly selected and divided in two groups, one received B. toyonensis at a concentration of 2x10 8 viable spores per day and another group without supplementation was left as control. The puppies were vaccinated against canine parvovirus type 2. B. toyonensis supplementation was efficient in stimulating specific IgG for parvovirus with titers of 2, 3, and 2.5-fold higher than controls at 7, 21, and 35 pos-vaccination days respectively. Peripheral blood mononuclear cells (PBMCs) from dogs were cultured and stimulated with B. toyonensis DNA, vegetative cell and spores. The mRNA transcription of cytokines IL-4, IL-17, and IFN-γ up modulated by the stimuli. Thus, we conclude in this study that B. toyonensis supplementation may amplify the vaccine immune response against canine parvovirus.(AU)

Bacillus toyonensis é um micro-organismo probiótico que há décadas é utilizado na nutrição animal em todo o mundo. O objetivo deste trabalho foi avaliar o efeito imunomodulador da suplementação oral de B. toyonensis em cães vacinados contra o parvovírus canino. Os filhotes foram selecionados aleatoriamente e divididos em dois grupos, um recebeu B. toyonensis na concentração de 2 × 10 8 esporos viáveis por dia e outro grupo sem suplementação como controle. Os filhotes foram vacinados contra o parvovírus canino tipo 2. A suplementação com B. toyonensis foi eficiente em estimular IgG específica para parvovírus com títulos de 2, 3 e 2,5 vezes maior que os controles aos 7, 21 e 35 dias pós-vacinação, respectivamente. Células mononucleares do sangue periférico (PBMCs) de cães foram cultivadas e estimuladas com DNA de B. toyonensis, células vegetativas e esporos. A transcrição do mRNA das citocinas IL-4, IL-17 e IFN-γ foi modulada pelos estímulos. Assim, concluímos neste estudo que a suplementação com B. toyonensis pode amplificar a resposta imune da vacina contra o parvovírus canino.(AU)

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. Leptospirosis is caused by pathogenic Leptospira spp. and is spread through direct contact with infected animals, their urine or contaminated water and soil. Inactivated leptospirosis vaccines, or bacterins, are approved in only a handful of countries due to the lack of heterologous protection (there are > 250 pathogenic Leptospira serovars) and the serious side-effects associated with vaccination. Currently, research has focused on recombinant vaccines, a possible solution to these problems. However, due to a lack of standardised animal models, rigorous statistical analysis and poor reproducibility, this approach has met with limited success. We evaluated a subunit vaccine preparation, based on a conserved region of the leptospiral immunoglobulin-like B protein (LigB(131-645)) and aluminium hydroxide (AH), in the hamster model of leptospirosis. The vaccine conferred significant protection (80.0-100%, P < 0.05) against mortality in vaccinated animals in seven independent experiments. The efficacy of the LigB(131-645)/AH vaccine ranged from 87.5-100% and we observed sterile immunity (87.5-100%) among the vaccinated survivors. Significant levels of IgM and IgG were induced among vaccinated animals, although they did not correlate with immunity. A mixed IgG1/IgG2 subclass profile was associated with the subunit vaccine, compared to the predominant IgG2 profile seen in bacterin vaccinated hamsters. These findings suggest that LigB(131-645) is a vaccine candidate against leptospirosis with potential ramifications to public and veterinary health.

Highly specific fiber optic immunosensor coupled with immunomagnetic separation for detection of low levels of Listeria monocytogenes and L. ivanovii.

BACKGROUND: Immunomagnetic separation (IMS) and immunoassays are widely used for pathogen detection. However, novel technology platforms with highly selective antibodies are essential to improve detection sensitivity, specificity and performance. In this study, monoclonal antibodies (MAbs) against Internalin A (InlA) and p30 were generated and used on paramagnetic beads of varying diameters for concentration, as well as on fiber-optic sensor for detection. RESULTS: Anti-InlA MAb-2D12 (IgG2a subclass) was specific for Listeria monocytogenes and L. ivanovii, and p30-specific MAb-3F8 (IgM) was specific for the genus Listeria. At all bacterial concentrations (10³-108 CFU/mL) tested in the IMS assay; the 1-µm diameter MyOne beads had significantly higher capture efficiency (P < 0.05) than the 2.8-µm diameter M-280 beads with both antibodies. The highest capture efficiency for MyOne-2D12 (49.2% for 105 CFU/mL) was significantly higher (P < 0.05) than that of MyOne-3F8 (16.6 %) and Dynabeads anti-Listeria antibody (9 %). Furthermore, capture efficiency for MyOne-2D12 was highly specific for L. monocytogenes and L. ivanovii. Subsequently, we captured L. monocytogenes by MyOne-2D12 and MyOne-3F8 from hotdogs inoculated with mono- or co-cultures of L. monocytogenes and L. innocua (10-40 CFU/g), enriched for 18 h and detected by fiber-optic sensor and confirmed by plating, light-scattering, and qPCR assays. The detection limit for L. monocytogenes and L. ivanovii by the fiber-optic immunosensor was 3 × 10² CFU/mL using MAb-2D12 as capture and reporter antibody. Selective media plating, light-scattering, and qPCR assays confirmed the IMS and fiber-optic results. CONCLUSIONS: IMS coupled with a fiber-optic sensor using anti-InlA MAb is highly specific for L. monocytogenes and L. ivanovii and enabled detection of these pathogens at low levels from buffer or food.