A Novel Adjuvant "Sublancin" Enhances Immune Response in Specific Pathogen-Free Broiler Chickens Inoculated with Newcastle Disease Vaccine

Bacillus subtilis expressing duck Tembusu virus E protein induces immune protection in ducklings

Duck Tembusu virus (DTMUV) is an infectious disease that emerged in China in 2010. It has caused serious economic losses to the poultry industry and may pose a threat to public health. We aimed to develop a new Bacillus subtilis (B. subtilis)-based oral vaccine to control DTMUV transmission among poultry; to this end, we constructed a B. subtilis strain that can secrete DTMUV E protein. Ducklings were orally immunized, and serum antibodies, mucosal antibodies, and splenic cytokines were detected. The results showed that, in addition to high levels of specific IgG, there were also high levels of specific secretory immunoglobulin A (sIgA) in ducklings orally treated with recombinant B. subtilis. In addition, the levels of IFN-γ, IL-2, IL-4, and IL-10 in spleens were significantly boosted by recombinant B. subtilis. Recombinant B. subtilis could effectively enhance ducklings resistance to DTMUV and significantly reduce viral load (p<0.01), along with pathological damage in the brain, heart, and spleen. This is the first study to apply a B. subtilis live-vector vaccine platform for DTMUV disease prevention and control, and our results suggest that B. subtilis expressing DTMUV E protein may be a candidate vaccine against DTMUV.

Study on the mechanism of Fufang E'jiao Jiang on precancerous lesions of gastric cancer based on network pharmacology and metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Fufang E'jiao Jiang (FEJ) is a prominent traditional Chinese medicine prescription, which consists of Asini Corii Colla (Donkey-hide gelatin prepared by stewing and concentrating from the hide of Equus asinus Linnaeus., ACC), Codonopsis Radix (the dried roots of Codonopsis pilosula (Franch.) Nannf., CR), Ginseng Radix et Rhizoma Rubra (the steamed and dried root of Panax ginseng C.A. Mey., GRR), Crataegi Fructus (the mature fruits of Crataegus pinnatifida Bunge., CF), and Rehmanniae Radix Praeparata (the steamed and sun dried tuber of Rehmannia glutinosa (Gaertn.) Libosch. ex Fisch. & C.A. Mey., RRP). It is a popularly used prescription for "nourishing Qi and nourishing blood".

AIM OF THE STUDY

To explore the potential mechanism of FEJ on precancerous lesion of gastric cancer in rats by combining network pharmacology and metabolomics.

METHODS

Traditional Chinese Medicine Systems Pharmacology and Bioinformatics Analysis Tool for Molecular mechanism of Traditional Chinese Medicine were used to identify the ingredients and potential targets of FEJ. GeneCards database was used to define PLGC-associated targets. We built a herb-component-disease-target network and analyzed the protein-protein interaction network. Underlying mechanisms were identified using Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. In addition, 40% ethanol, N-methyl-N'-nitro-N-nitroguanidine and irregular eating were used to establish PLGC rats model. We also evaluated the efficacy of FEJ on MNNG-induced PLGC rats by body weight, histopathology, blood routine and cytokine levels, while the predicted pathway was determined by the Western blot. Ultra-performance liquid chromatography-tandem mass spectrometry-based serum non-targeted metabolomics was used to select potential biomarkers and relevant pathways for FEJ in the treatment of PLGC.

RESULTS

Network pharmacology showed that FEJ exhibited anti-PLGC effects through regulating ALB, TNF, VEGFA, TP53, AKT1 and other targets, and the potential pathways mainly involved cancer-related, TNF, PI3K-AKT, HIF-1, and other signaling pathways. Animal experiments illustrated that FEJ could suppress inflammation, regulate gastrointestinal hormones, and inhibit the expression of PI3K/AKT/HIF-1α pathway-related proteins. Based on serum non-targeted metabolomics analysis, 12 differential metabolites responding to FEJ treatment were identified, and metabolic pathway analysis showed that the role of FEJ was concentrated in 6 metabolic pathways.

CONCLUSION

Based on network pharmacology, animal experiments and metabolomics, we found that FEJ might ameliorate gastric mucosal injury in PLGC rats by regulating gastrointestinal hormones and inhibiting inflammation, and its mechanism of action is related to the inhibition of excessive activation of PI3K/AKT/HIF-1α signaling pathway and regulation of disorders of body energy metabolism. This comprehensive strategy also provided a reasonable way for unveiling the pharmacodynamic mechanisms of multi-components, multi-targets, and multi-pathways in Traditional Chinese Medicine.

Effects of Bacillus methylotrophicus SY200 Supplementation on Growth Performance, Antioxidant Status, Intestinal Morphology, and Immune Function in Broiler Chickens

The present study was focused on evaluating the effects of Bacillus methylotrophicus SY200 in broiler production. A total of 120 healthy 7-day-old broiler chicks were randomly assigned to four dietary treatments, which included basal diet supplemented with 0%, 0.10%, 0.25%, or 0.50% (w/w) B. methylotrophicus SY200 preparation (1.0 × 10⁹ cfu/g), regarded as negative control group (NC), low-dose group (BML), medium-dose group (BMM), and high-dose group (BMH), respectively. Each treatment was fed the corresponding experimental diet for 35 days. Results showed that dietary supplementation of B. methylotrophicus SY200 could improve broiler weight gain, especially the finisher phase. Further studies suggested that a certain amount of B. methylotrophicus SY200 enhanced the broiler antioxidant status and improved the morphological development of jejunum. Besides, dietary supplementation of B. methylotrophicus SY200 especially in 0.50% levels significantly increased the relative weight of immune organs and Newcastle disease virus antibody titer, similarly, increased mRNA expression levels of claudin-1, claudin-3, zonula occluden-1, and zonula occluden-2 were observed in the jejunum of BMM group. Moreover, B. methylotrophicus SY200 also showed beneficial effects in improving broilers microbiota homeostasis by increasing the number of beneficial bacteria. Conclusively, B. methylotrophicus SY200 could effectively improve the antioxidant status, modulate the intestinal structure, enhance the intestinal mucosal barrier function, and regulate the immune function of broilers, which finally improves the performance of the chicken in the finisher period.

Antimicrobial Bacillus: Metabolites and Their Mode of Action

The agricultural industry utilizes antibiotic growth promoters to promote livestock growth and health. However, the World Health Organization has raised concerns over the ongoing spread of antibiotic resistance transmission in the populace, leading to its subsequent ban in several countries, especially in the European Union. These restrictions have translated into an increase in pathogenic outbreaks in the agricultural industry, highlighting the need for an economically viable, non-toxic, and renewable alternative to antibiotics in livestock. Probiotics inhibit pathogen growth, promote a beneficial microbiota, regulate the immune response of its host, enhance feed conversion to nutrients, and form biofilms that block further infection. Commonly used lactic acid bacteria probiotics are vulnerable to the harsh conditions of the upper gastrointestinal system, leading to novel research using spore-forming bacteria from the genus Bacillus. However, the exact mechanisms behind Bacillus probiotics remain unexplored. This review tackles this issue, by reporting antimicrobial compounds produced from Bacillus strains, their proposed mechanisms of action, and any gaps in the mechanism studies of these compounds. Lastly, this paper explores omics approaches to clarify the mechanisms behind Bacillus probiotics.

Probiotic supplementation containing Bacillus velezensis enhances expression of immune regulatory genes against pigeon circovirus in pigeons (Columba livia)

AIMS

In this study, we aimed to isolate and evaluate the efficacy of Bacillus velezensis as a probiotic and to assess its activity towards pigeons infected with pigeon circovirus (PiCV).

METHODS AND RESULTS

Bacillus velezensis, isolated from pigeon faeces, was orally administered to pigeons for 60 days. After pigeons were challenged with PiCV, the PiCV viral load and expression of indicator genes for innate immunity were detected in spleen tissue and faeces of pigeons. Bacillus velezensis significantly reduced the PiCV viral load in the faeces and spleen of pigeons 5 days post-challenge (dpc). The mRNA expression levels of treated pigeons showed that interferon-gamma (IFN-γ), myxovirus resistance 1 (Mx1), and signal transducers and activators of transcription 1 (STAT1) genes were upregulated, whereas no expression of interleukin-4 (IL-4) was detected. Moreover, toll-like receptor 2 (TLR2) and 4 (TLR4) were significantly upregulated in probiotic-treated pigeons (P < 0·05).

CONCLUSIONS

This is the first report showing that probiotic supplementation can effectively enhance the T-helper type 1 immune response and decrease the PiCV viral loads in pigeons.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study proposes that the administration of a probiotic strain, B. velezensis, to pigeons can protect against PiCV infection.

Application of Bacillus subtilis as a live vaccine vector: A review

Bacillus subtilis is widely used as a probiotic in various fields as it regulates intestinal flora, improves animal growth performance, enhances body immunity, has short fermentation cycle, and is economic. With the rapid development of DNA recombination technology, B. subtilis has been used as a potential vaccine expression vector for the treatment and prevention of various diseases caused by bacteria, viruses, and parasites as it can effectively trigger an immune response in the body. In this review, we refer to previous literature and provide a comprehensive analysis and overview of the feasibility of using B. subtilis as a vaccine expression vector, with an aim to provide a valuable reference for the establishment of efficient vaccines.