Search Results (166)

Aquaculture has rapidly become a vital sector for ensuring global food security by meeting the growing demand for animal protein. Bangladesh, one of the world’s leading aquaculture producers, recorded a production of 4.91 million MT in 2022–2023, largely driven by inland farming systems. Despite this remarkable growth, the sector is highly vulnerable to disease outbreaks, which are aggravated by different factors. Pathogens such as bacteria, viruses, fungi, and parasites cause significant losses, while conventional disease diagnosis in Bangladesh still depends mainly on visual assessment and basic laboratory techniques, limiting early detection. This narrative review highlights recent advances in diagnostics as molecular tools, immunodiagnostics, nanodiagnostics, machine learning, and next-generation sequencing (NGS) that are widely applied globally but remain limited in Bangladesh due to infrastructure gaps, lack of skilled manpower, and resource constraints. Current treatment strategies largely rely on antibiotics and aquaculture medicinal products (AMPs), often misused without proper diagnosis, contributing to antimicrobial resistance (AMR). Promising alternatives, including probiotics, immunostimulants, vaccines, and enhanced biosecurity, require greater adoption and farmer awareness. The near-term priorities for Bangladesh include standardized disease and AMR surveillance, prudent antibiotic stewardship, phased adoption of validated rapid diagnostics, and investment in diagnostic and human capacity. Policy-level actions, including a national aquatic animal health strategy, stricter antimicrobial regulation, strengthening diagnostic infrastructure in institution, are crucial to achieve sustainable disease management and ensure long-term resilience of aquaculture in Bangladesh. Full article

Background and Objectives: Probiotics are live microorganisms that promote health when consumed in adequate amounts, ensure the balance of bacterial composition in the digestive system, and suppress harmful pathogenic bacteria, with overall implications for animal and human health, welfare and performance. However, a lot remains unclear about their functional mechanisms. Materials and Methods: In this study, 14 uncharacterized proteins of Lactobacillus acidophilus were analyzed for subcellular localization, structural and safety profiling and interleukin-6-(IL-6)-inducing potential. Results: Aliphatic index scores were generally high, ranging between 138.39 (LBA1705) and 78.39 (LBA1825). The instability index scores were less than 40 for all the query proteins except for LBA0995. All the proteins produced immunogenic IL-6-inducing peptides, except for LBA0037, LBA1825 and LBA1788. Conclusions: The findings provide insight into understanding the functional mechanism of probiotic Lactobacillus, laying a strong foundation for more experimental studies. Full article

Non-Saccharomyces yeasts are emerging as promising new probiotics with a beneficial effect equal to or greater than the reference probiotic yeast, Saccharomyces boulardii. Candida intermedia, a non-albicans species not considered a common human pathogen, previously demonstrated probiotic potential. In this work, our objective was to evaluate the immunomodulatory effects of C. intermedia ORQ001 in mice vaccinated with inactivated SARS-CoV-2, seeking further evidence of its probiotic activity. Murine macrophages were stimulated with C. intermedia, followed by mRNA transcription analysis via qPCR. Mice were supplemented with C. intermedia prior to SARS-CoV-2 vaccination. Antibody production was assessed by ELISA, and fecal microbiomes were analyzed using next-generation sequencing. C. intermedia significantly increased Il4 and Il13 expression while decreasing Stat3 in macrophages. Splenocytes from supplemented mice exhibited elevated transcription levels of Tnf, Ifng, Il4, Bcl6, and Stat3 after exposure to stimulatory molecules. These mice showed increased levels of anti-SARS-CoV-2 IgG and sIgA isotypes, along with higher abundances of Bacteroides spp. and Clostridium spp. in their gut microbiome. In conclusion, C. intermedia supplementation modulated the expression of key immune-related genes and enhanced humoral responses in mice. Furthermore, its influence on gastrointestinal microbiota suggests a synergistic effect on vaccine immunogenicity. These findings support the potential of C. intermedia as a novel probiotic candidate with immunomodulatory properties applicable to vaccine adjuvanticity. Full article

It is estimated that global meat production will show an upward trend, with the most dynamic growth projected in the poultry sector (it is estimated that poultry meat consumption will be 2.3 times higher by 2050 than in 2010). The expected increase in consumption of poultry meat, mainly from intensively reared broiler chickens, is associated with an increasing prevalence of diseases, particularly those affecting the digestive system. One important parasitic disease is coccidiosis, a gastrointestinal disease caused by widespread protozoa of the genus Eimeria. The occurrence of coccidiosis in broiler chicken flocks results in a significant deterioration of production rates. Coccidiostats are most commonly used in the prevention of this disease, which are introduced in rotation into the feed ration. However, long-term use of coccidiostats is associated with the risk of parasite resistance development and the possibility of residues in animal products. Therefore, there is a need to search for safe and effective alternatives to pharmacological coccidiostatic agents. This review aims to analyze the available literature data on the efficacy of vaccines and functional feed supplements, such as plant substances, probiotics, prebiotics, and organic acids, in the prevention of coccidiosis. Full article

Functional foods enriched with bioactive compounds—including vitamins, minerals, polyphenols, probiotics, fatty acids, and amino acids—have gained growing attention due to their ability to modulate immune responses. This review aims to summarize and critically evaluate evidence from both preclinical and clinical studies on the immunomodulatory effects of these compounds. A structured literature search was performed across major scientific databases in accordance with PRISMA 2020 guidelines. Seventy studies met the predefined eligibility criteria and were included. Evidence indicates that functional ingredients support immune function via antioxidant, anti-inflammatory, and microbiome-mediated pathways. Clinical trials further report benefits including a reduced risk of respiratory infections and enhanced vaccine responses. Nonetheless, important challenges remain regarding bioavailability, inter-individual variability, and the long-term safety of supplementation. Emerging research on precision nutrition and innovative delivery systems may further enhance the efficacy of these bioactive compounds. Overall, functional foods and nutraceuticals show strong potential as adjunct strategies for maintaining immune health; however, further well-designed clinical studies are required to confirm their translational applicability. Full article

Background: African swine fever (ASF) is a highly contagious and often deadly disease that poses a major threat to swine production worldwide. The lack of a commercially available vaccine underscores the critical need for innovative immunization strategies to combat ASF. Methods: Six ASFV antigenic proteins (K78R, A104R, E120R, E183L, D117L, and H171R) were fused with the Lactiplantibacillus plantarum WCFS1 surface anchor LP3065 (LPxTG motif) to generate recombinant Lactiplantibacillus plantarum NC8 (rNC8) strains. The surface expression was confirmed using immunofluorescence and Western blotting assays. Additionally, the dendritic cell-targeting peptides (DCpep) were co-expressed with each antigen protein. Mice were immunized at a dosage of 10⁹ colony-forming units (CFU) per strain per mouse via intragastric (I.G.), intranasal (I.N.), and intravenous (I.V.) routes. The bacterial mixture was heat-inactivated by boiling for 15 min to destroy viable cells while preserving antigenic structures. I.V. administration caused no hypersensitivity, confirming the method’s safety and effectiveness. Results: Following I.G. administration, rNC8-E120R, rNC8-E183L, rNC8-K78R, and rNC8-A104R induced significant levels of secretory immunoglobulin A (sIgA) in fecal samples, whereas rNC8-H171R and rNC8-D117L failed to induce a comparable response. Meanwhile, rNC8-D117L, rNC8-K78R, and rNC8-A104R also elicited significant levels of sIgA in bronchoalveolar lavage fluid (BALF). Following I.N. immunization, rNC8-E120R, rNC8-K78R, and rNC8-A104R significantly increased sIgA levels in both fecal and BALF immunization. In contrast, I.V. immunization with heat-inactivated rNC8-K78R and rNC8-A104R induced robust serum IgG titers, whereas the remaining antigens elicited minimal or insignificant responses. Flow cytometry analysis revealed expanded CD3⁺CD4⁺ T cells in mice immunized via the I.N. and I.G. and CD3⁺CD4⁺ T cells only in those immunized via the I.N. route. Th1 responses were also significant in the sera of mice immunized via the I.G. and I.N. routes. Conclusions: The rNC8 multiple-antigen cocktail elicited strong systemic and mucosal immune responses, providing a solid foundation for the development of a probiotic-based vaccine against ASF. Full article

Lactobacillus species play a fundamental role in maintaining a healthy vaginal microbiota and have been increasingly recognized for their protective effects against high-risk human papillomavirus (HR-HPV) infection and the progression of cervical intraepithelial neoplasia (CIN). These beneficial bacteria contribute to host defense through multiple mechanisms, including the production of lactic acid that sustains a low vaginal pH, enhancement of epithelial barrier integrity via E-cadherin regulation, and modulation of immune signaling pathways such as interferon responses and NF-κB activity. Lactobacillus strains exert anti-inflammatory effects by downregulating pro-inflammatory cytokines and interfering with oncogenic pathways including Wnt/β-catenin and the expression of HPV E6 and E7 proteins. Additionally, they may regulate tumor-suppressor microRNAs and modulate dendritic cell and macrophage activity, supporting antiviral immunity. Recent studies have explored their potential influence on CIN regression and HR-HPV clearance, particularly the strains Lactobacillus crispatus and L. gasseri, which are associated with favorable microbial community states. This review explores the potential mechanisms through which Lactobacillus species contribute to HR-HPV clearance and the regression of cervical dysplasia, integrating evidence from molecular studies, in vivo models, and clinical trials. The emerging role of probiotic interventions as adjunctive strategies in HPV management is also discussed, highlighting their possible synergy with conventional treatments and prophylactic vaccination. Full article

Background/Objectives: The ongoing evolution of SARS-CoV-2 has highlighted the limitations of parenteral vaccines in preventing viral transmission, largely due to their failure to elicit robust mucosal immunity. Methods: Here, we evaluated an intranasal (IN) vaccine formulation consisting of recombinant receptor-binding domain (RBD) adsorbed onto human probiotic Bacillus subtilis DG101 spores. Results: In BALB/c mice, IN spore-RBD immunization induced strong systemic and mucosal humoral responses, including elevated specific IgG, IgM, and IgA levels in serum, bronchoalveolar lavage fluid (BALF), nasal-associated lymphoid tissue (NALT), and saliva. It further promoted mucosal B cell and T cell memory, along with a Th1/Tc1-skewed T cell response, characterized by increased IFN-γ-expressing CD4⁺ and CD8⁺ T cells in the lungs. Conclusions: All in all, these findings highlight the potential of intranasal vaccines adjuvanted with probiotic B. subtilis spores in inducing sterilizing immunity and limiting SARS-CoV-2 transmission. Full article

CRISPR technology, which is derived from the bacterial adaptive immune system, has transformed traditional genetic engineering techniques, made strain engineering significantly easier, and become a very versatile genome editing system that allows for precise, programmable modifications to a wide range of microbial genomes. The economies of fermentation-based manufacturing are changing because of its quick acceptance in both academic and industry labs. CRISPR processes have been used to modify industrially significant bacteria, including the lactic acid producers, Clostridium spp., Escherichia coli, and Corynebacterium glutamicum, in order to increase the yields of bioethanol, butanol, succinic acid, acetone, and polyhydroxyalkanoate precursors. CRISPR-mediated promoter engineering and single-step multiplex editing have improved inhibitor tolerance, raised ethanol titers, and allowed for the de novo synthesis of terpenoids, flavonoids, and recombinant vaccines in yeasts, especially Saccharomyces cerevisiae and emerging non-conventional species. While enzyme and biopharmaceutical manufacturing use CRISPR for quick strain optimization and glyco-engineering, food and beverage fermentations benefit from starter-culture customization for aroma, texture, and probiotic functionality. Off-target effects, cytotoxicity linked to Cas9, inefficient delivery in specific microorganisms, and regulatory ambiguities in commercial fermentation settings are some of the main challenges. This review provides an industry-specific summary of CRISPR–Cas9 applications in microbial fermentation and highlights technical developments, persisting challenges, and industrial advancements. Full article

Livestock farming is a vital component of global food security, yet it remains a major contributor to greenhouse gas (GHG) emissions, particularly methane (CH₄), which has a global warming potential 28 times greater than carbon dioxide (CO₂). This review provides a comprehensive synthesis of current knowledge surrounding the sources, biological mechanisms, and mitigation strategies related to CH₄ emissions from ruminant livestock. We first explore the process of methanogenesis within the rumen, detailing the role of methanogenic archaea and the environmental factors influencing CH₄ production. A thorough assessment of both direct and indirect methods used to quantify CH₄ emissions is presented, including in vitro techniques (e.g., syringe method, batch culture, RUSITEC), in vivo techniques (e.g., respiration chambers, Greenfeed, laser CH₄ detectors), and statistical modeling approaches. The advantages and limitations of each method are critically analyzed in terms of accuracy, cost, feasibility, and applicability to different farming systems. We then examine a wide range of mitigation strategies, organized into four core pillars: (1) animal and feed management (e.g., genetic selection, pasture quality improvement), (2) diet formulation (e.g., feed additives such as oils, tannins, saponins, and seaweed), (3) rumen manipulation (e.g., probiotics, ionophores, defaunation, vaccination), and (4) manure management practices and policy-level interventions. These strategies are evaluated not only for their environmental impact but also for their economic and practical viability in diverse livestock systems. By integrating technological innovations with sustainable agricultural practices, this review highlights pathways to reduce CH₄ emissions while maintaining animal productivity. It aims to support decision-makers, researchers, and livestock producers in the global effort to transition toward climate-smart, low-emission livestock farming. Full article

A novel bivalent oral vaccine candidate against H5N1 and H9N2 avian influenza virus (AIV) was developed using Lactobacillus surface display technology without genetic modification. The hemagglutinin subunit 1 (HA1) antigens from both subtypes were fused to the surface layer-binding domain of Lactobacillus crispatus K313, expressed in Escherichia coli, and purified. Wild-type Lactobacillus johnsonii H31, isolated from chicken intestine, served as a delivery vehicle by adsorbing and stably displaying the HA1 proteins on its surface. This approach eliminates the need for bacterial engineering while utilizing lactobacilli’s natural capacity to protect surface-displayed antigens, as evidenced by HA1’s protease resistance. Mouse immunization studies demonstrated induction of strong systemic IgG and mucosal IgA responses against both H5N1 and H9N2 HA1. The system offers several advantages, including safety through non-GMO probiotics, potential for multivalent vaccine expansion, and intrinsic antigen protection by lactobacilli. These findings suggest this platform could enable development of cost-effective, multivalent AIV vaccines. Full article

The growth of aquaculture production in recent years has revealed multiple challenges, including the rise of antimicrobial resistance (AMR) in aquatic animal production, which is currently attracting significant attention from multiple one-health stakeholders. While antibiotics have played a major role in the treatment of bacterial infections for almost a century, a major consequence of their use is the increase in AMR, including the emergence of AMR in aquaculture. The AMR phenomenon creates a situation where antibiotic use in one system (e.g., aquaculture) may impact another system (e.g., terrestrial–human). Non-prudent use of antibiotics in aquaculture and animal farming increases the risk of AMR emergence, since bacteria harboring antibiotic resistance genes can cross between compartments such as wastewater or other effluents to aquatic environments, including intensive aquaculture. Transferable antimicrobial resistance gene (AMG) elements (plasmids, transposons, integrons, etc.) have already been detected in varying degrees from pathogenic bacteria that are often causing infections in farmed fish (Aeromonas, Vibrio, Streptococcus, Pseudomonas, Edwardsiella, etc.). This review of current veterinary approaches for the prevention and control of AMR emergence in aquaculture focuses on the feasibility of alternatives to antimicrobials and supplemental treatment applications during on-farm bacterial disease control and prevention. The use of vaccines, bacteriophages, biosurfactants, probiotics, bacteriocins, and antimicrobial peptides is discussed. Full article

Background/Objectives: Research efforts and substantial funding have been dedicated to finding cost-effective and sustainable alternatives to antibiotics. Probiotics have been proposed as promising substitutes for antibiotics in human nutrition and livestock production; however, their functional mechanisms remain incompletely understood, limiting their sustainable applications as food supplements, feed additives and for therapeutic and cosmetic purposes. Methods: In this study, the probiotic potential of two bacterial genomes, Ligilactobacillus saerimneri and Ligilactobacillus salivarius, were explored. Their protein-coding hypothetical proteins were analyzed for their potential to induce interleukin-5 (IL-5) and interleukin-13 (IL-13). Results: The IL-5- and IL-13-inducing peptides were identified as immunogens against bacterial and tumor peptides. Conclusions: These findings provide insights into the probiotic bacteria’s immune functionality pathways, sustainability and potential as therapeutic feed additives, food supplements and candidates for vaccine development. Full article

Salmonella Heidelberg (SH) is a major serotype of foodborne Salmonella associated with turkeys. Understanding the effect of antibiotic alternatives (AAs) on the cecal microbiome of turkeys challenged with Salmonella could inform the development of microbiome-based strategies on farms. This study examined the effects of multiple AAs, such as probiotics, Lactobacillus and Propionibacterium, and a Salmonella Typhimurium vaccine, on the turkey cecal microbiome exposed to multidrug-resistant (MDR) SH. Microbial DNA was extracted from the cecal contents of 12-week-old commercial turkeys grown in five treatments for shotgun metagenomic sequencing and analysis: NC—Negative Control; PC—Salmonella Control; LAB—Lactobacillus treatment; PF—P. freudenreichii treatment; and VAC—vaccine treatment. Except for the NC, turkeys were challenged with MDR SH (10⁸ CFU/turkey) on the 11th week. Differential abundance tests at the species level found that all AA treatments resulted in an increased abundance of multiple lactic acid-producing bacteria in the cecum compared to PC. In addition, multiple metabolic pathways were differentially abundant in AA treatments compared to PC. This study highlights the importance of AA strategies producing an increased abundance of lactic acid bacteria and critical metabolic pathways, indicating the potential of AAs to improve the gut health of turkeys during the Salmonella challenge. Full article

Coccidiosis, caused by Eimeria spp., remains a major challenge in poultry production, significantly affecting poultry health and performance, leading to substantial economic losses. While its impact on gut health is well documented, the interplay of Eimeria spp. challenge and/or vaccination with the intestinal microbiota remain insufficiently understood. Therefore, the aim of this study was to investigate the effects of Eimeria spp. (E. acervulina, E. maxima, and E. tenella) challenge, alone or in combination with a commercially available vaccine, on broiler performance, intestinal gross lesions, and cecal microbiota structure and function in experimentally challenged broiler chicks. A total of 216 Ross 308^® broilers were randomly divided into three groups, with six replicates per group, according to the following experimental design: (A) negative control, (B) Eimeria spp.-challenged birds on day 16, and (C) Eimeria spp.-vaccinated and -challenged birds. Performance parameters were recorded on a weekly basis, coccidiosis gross lesions in the intestine were evaluated on days 23 and 29, and microbiota samples were collected on day 23. Broilers in the challenged group exhibited significantly (p ≤ 0.05) increased coccidiosis gross lesions in the intestine at both sampling periods (7 and 19 days post-infection, dpi), whereas vaccination significantly (p ≤ 0.05) minimized the severity of lesions at both time points. The challenged-only group showed significantly (p ≤ 0.05) lower average daily weight gain (ADWG) during the finisher phase and the overall experimental period compared to the vaccinated group. Additionally, average daily feed intake (ADFI) during the post-challenge period (22–29 dpi) was significantly (p ≤ 0.05) reduced in both challenged groups. Alpha diversity decreased in the challenged (p = 0.016) and vaccinated–challenged (p = 0.016) groups compared to control, Accordingly, beta diversity was reduced in groups B and C compared to the control group. This reduction was accompanied by an increased relative abundance of Proteobacteria (18, 71% in Group B and 10, 87% in Group C) and potentially pathogenic genera (Escherichia spp. and Shigella spp. p < 0.05), along with a decline in short-chain fatty acid (SCFA)-producing bacteria (Oscillibacter spp. and Eisenbergiella spp.) in groups B and C, respectively, compared to the control. Predictive functional metagenomics indicated disruptions in amino acid metabolism, nucleotide degradation, and lipid metabolism, potentially affecting gut integrity and nutrient absorption. Additionally, in the vaccinated group, gross lesions in the intestine were reduced in severity and microbial diversity was partially preserved, resulting in a microbiota composition more similar to that of the control group. Overall, these findings support that Eimeria spp. infection alters gut microbiota and function in broiler chicks, underscoring the need for further research into alternative strategies, such as probiotics and phytobiotics, to support gut health and disease resilience in poultry. Full article