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Bearings usually play numerous important functionalities such as deformation regulation, load transfer, and seismic isolation in bridges. A better mastery of their service performance is increasingly desired for bridge owners. In the present study, a novel sparse Bayesian temperature-displacement relationship (TDR) model is proposed to characterize and predict the bearing displacement responses induced by temperature actions in a probabilistic manner, based on the use of long-term structural health monitoring (SHM) data. Compared with the traditional deterministic TDR model, the newly proposed model can deal with two critical problems: (1) most of temperature difference terms barely have effects on bearing displacement responses, leading to the sparsity of model parameters; and (2) uncertainties will inevitably arise from factors such as measurement noise and inherent randomness, resulting in the uncertainty of model parameters. Therefore, it enables to account for the uncertainty associated with the predictions of temperature-induced bearing displacement responses. By combining the probabilistic prediction results with the reliability and anomaly analysis principles, a reliability index is adopted to assess the service performance of bearings subjected to extreme temperature actions. In addition, an anomaly index is defined to determine whether there are performance degradations and then trigger early warnings for the degraded bearings. The long-term SHM data from an in-service long-span railway bridge is employed for effectiveness verifications. The results show that the sparse Bayesian TDR model can achieve effective probabilistic predictions for temperature-induced bearing displacement responses and the reliability and anomaly indices are favorable for bearing performance assessment and early warning. [ABSTRACT FROM AUTHOR]

Deep learning techniques have gradually attracted considerable research interest in numerous application scenarios because of their capacity to simplify and accelerate calculations. Several researchers have adopted deep learning models, primarily end-to-end long short-term memory networks, to predict structural seismic responses in a data-driven manner and have achieved remarkable improvements. However, further research is required to reduce the training cost and complexity while maintaining the prediction accuracy of end-to-end models. In this study, a pre-training strategy was developed to meet these requirements. In brief, a generic base model was pre-trained by embedding the knowledge of calculating the response of single-degree-of-freedom systems, which was used as the basis for building tailored top models for the online prediction of seismic responses of different structures. This strategy modularized and simplified deep-learning-based seismic response prediction for training while maintaining the advantages of the end-to-end method. Proposed method was verified by using both simulation and actual datasets. The results demonstrated that a significantly lower training cost and complexity were required to achieve a prediction accuracy similar to that of the classic end-to-end method. Specifically, there was a reduction in FLOPs ranging from 20% to 80%, and a decrease in training time ranging from 44% to 82%. Moreover, the performance of deep learning with limited actual data was discussed. [ABSTRACT FROM AUTHOR]

Chicken coccidiosis is a protozoan parasitic disease that leads to considerable economic losses in the poultry industry. In this study, we used invasive Lactobacillus plantarum (L.P) expressing the FnBPA protein as a novel bacterial carrier for DNA delivery into epithelial cells to develop a live oral DNA vaccine. A fusion DNA vaccine co-expressing EtMIC2 and chicken IL-18 (chIL-18) was constructed and then delivered to the host by invasive L.P. Its efficacy against Eimeria tenella challenge was evaluated in chickens by examining the relative weight gain rate; caecal lesion score; OPG; anti-coccidial index (ACI); levels of EtMIC2 antibody, FnBPA, IL-4, IL-18, IFN-γ and SIgA; and proliferation ability and percentages of CD4+ and CD8+ splenocytes. The experimental results showed that chickens immunized with invasive L.P carrying the eukaryotic expression vector pValac-EtMIC2 (pValac-EtMIC2/pSIP409-FnBPA) had markedly improved immune protection against challenge compared with that of chickens immunized with non-invasive L.P (pValac-EtMIC2/pSIP409). However, invasive L.P co-expressing EtMIC2 with the chIL-18 vector exhibited the highest protection efficiency against E. tenella. These results indicate that invasive Lactobacillus-expressing FnBPA improved humoural and cellular immunity and enhanced resistance to E. tenella. The DNA vaccine delivered by invasive Lactobacillus provides a new concept and method for the prevention of E. tenella. [ABSTRACT FROM AUTHOR]

Coccidiosis is a parasitic disease in the intestine caused by the genus Eimeria that poses a substantial economic threat to the broiler breeding industry. The misuse of chemoprophylaxis and live oocyst vaccines has a negative impact on chicken reproductivity. Therefore, there is a pressing need to develop safe, convenient, and effective vaccines. Lactic acid bacteria can be used as a means to deliver mucosal vaccines against intestinal pathogens, which is a promising strategy. In this study, a recombinant Lactobacillus plantarum ( L. plantarum ) with surface-expressed antigens constructed from the fusion of Eimeria tenella ( E. tenella ) antigen profilin and the Salmonella enterica serovar Typhimurium flagellin protein FliC was created. After oral immunization with the recombinant L. plantarum , T-cell differentiation was analyzed by flow cytometry, and specific antibody levels were determined via indirect ELISA. Oocyst shedding, body weight, and cecum lesions were assessed as measures of protective immunity after challenge with E. tenella. The results of this study demonstrate the effectiveness of recombinant L. plantarum as an immunization agent for chickens. Specific IgA titers in the intestine and specific IgG antibody titers in the serum were significantly higher in chickens immunized with recombinant L. plantarum (P < 0.001). Additionally, the levels of IL-2 (P < 0.05) and IFN-γ (P < 0.01) in the serum were markedly increased. Recombinant L. plantarum induced T-cell differentiation, resulting in a higher proportion of CD4+ and CD8+ T cells in splenocytes (P < 0.001). Fecal oocyst shedding in the immunized group was significantly reduced (P < 0.001). Additionally, recombinant L. plantarum significantly relieved pathological damage in the cecum, as evidenced by lesion scores (P < 0.01) and histopathological cecum sections. In conclusion, the present study provides evidence to support the possibility of using L. plantarum as a promising carrier for the delivery of protective antigens to effectively protect chickens against coccidiosis. [ABSTRACT FROM AUTHOR]

• A subdomain PCA method is proposed for damage detection of structures. • GMM and LRT are adopted to divide nonlinear frequency data into linear subdmains. • Weighted averages of normalized distance measures are defined as damage indicators. • LRT-based subdomain PCA is more robust/immune to changing environments. Modal frequencies that capture structural dynamics are the most commonly used damage-sensitive features in vibration-based structural health monitoring. However, environmental changes usually lead to nonlinear frequency variabilities, which further mask the damage effects on modal frequencies. In this paper, a subdomain principal component analysis (Sub-PCA) method is proposed for damage detection of structures with robustness/immunity to environmental interference. Considering in mind the linear nature of PCA, it is performed in each of the disjoint linear subdomains of nonlinear frequency data. Two statistical analysis techniques including the Gaussian mixture model and the likelihood ratio test are adopted for subdomain division. Then damage indicators, i.e., the Mahalanobis and Euclidean distances, and their thresholds are calculated according to each Sub-PCA model. After that, weighted averages of the threshold-normalized indicators are defined to detect damages. Two case studies involving an experimental wooden bridge and an actual concrete bridge are employed to verify the effectiveness of the Sub-PCA method. The analysis results demonstrate that the Sub-PCA models, especially those constructed from the likelihood ratio test, are particularly robust/immune to changing environments in terms of damage detection. [ABSTRACT FROM AUTHOR]

Sensor faults, which occur when sensor outputs display unacceptable deviations from the true values of measured variable, will cause false alarms and missed detections in structural health monitoring (SHM) systems. The study about sensor validation is a relatively new research direction in the SHM field and it is meaningful to guarantee the accuracy and reliability of health-condition evaluations for monitored structures. This paper provides a comprehensive review of current research and development activities in sensor validation methodology for SHM. At first, seven typical sensor fault types are described and a detailed methodology categorization is provided. Following that, the progresses on sensor validation, which mainly focusses on the detection, isolation and reconstruction of sensor faults, are reviewed based on the categorization. Finally, concluding remarks and promising research efforts about sensor validation are summarized in detail. [ABSTRACT FROM AUTHOR]

It is essential to diagnose, i.e., detect and isolate, potential sensor faults for structural health monitoring to guarantee reliable condition evaluations. This paper proposes an innovative method called weighted principal-component analysis for sensor-fault detection and isolation. It is first illustrated that the fault sensitivity of each principal direction of traditional principal-component analysis is different from others for the same fault occurring in a certain sensor. Then, a fault-sensitive factor is theoretically derived to quantify the fault sensitivities. Based on that, a weighted fault-detection statistic determined according to the difference in fault sensitivities is developed and shown to have enhanced fault-detection ability. Bayesian inference is used to integrate all the weighted statistics corresponding to all the sensors to quickly judge whether a sensor fault occurred. Meanwhile, contribution analysis is used to establish a fault isolation index to identify the specific faulty sensor. Case studies using numerical simulation and a benchmark model demonstrate that the new proposed method is excellent and superior to the traditional approach. [ABSTRACT FROM AUTHOR]

• FRP-to-concrete bond strength models are developed for EBROG joints. • An experimental database containing 304 test samples is collected. • Bayesian inference is adopted for probabilistic model calibration. • Analytical expressions are derived for probabilistic model prediction. • Traditional models are compared to illustrate the superior of proposed ones. Recent years have witnessed the superiorities of a grooving technique, i.e., the externally-bonded reinforcement on grooves (EBROG), over the traditional technique, i.e., externally-bonded reinforcement (EBR), in terms of strengthening reinforced-concrete members by fiber-reinforced polymer (FRP) composites. Similar to EBR, the prediction of interfacial bond strength is critical for the EBROG type of FRP-to-concrete joints. There have been a series of experiments conducted to study the bond strength of EBROG joints, however, the corresponding prediction models (especially those capable of uncertainty quantification) are rarely available. Therefore, this paper aims to develop probabilistic models able to both predict the bond strength of EBROG joints and quantify the associated uncertainties. Firstly, an experimental database containing 304 bond strength tests for EBROG joints with longitudinal grooves is collected. Secondly, two widely-accepted deterministic bond strength models are selected as candidates to be calibrated by including a model correction factor. Thirdly, the factor is expressed by power and exponential functions of the influencing variables, meanwhile the deterministic model parameters are replaced with probabilistic ones. Finally, the probabilistic models are determined by means of Bayesian inference and Markov chain Monte Carlo. Moreover, an approximate analytical expressions are derived to achieve the probabilistic bond strength prediction. The experimental database is used to investigate the model performances, and the results show that: 1) the developed models can predict the FRP-to-concrete bond strength of EBROG joints with sufficient predictive accuracies and reasonable uncertainty quantifications; 2) the groove geometry has significant influence on the model correction factor; and 3) the developed probabilistic models is only applicable to EBROG joints with longitudinal grooves, but not to ones with transverse/diagonal grooves. [ABSTRACT FROM AUTHOR]

Eimeria tenella ( E. tenella ) is the most pathogenic genus in Eimeria and can lead to a huge number of deaths of chickens, causing significant economic losses in the poultry industry worldwide. As a natural alkaloid, sanguinarine has many medicinal effects; to a certain extent, it can replace antibiotics and has good application prospects in veterinary medicine. To evaluate the effect of sanguinarine on sporozoites of E.tenella , we used flow cytometry and immunofluorescence staining to detect reactive oxygen species (ROS), mitochondrial membrane potential (MMP), calcium ion (Ca2+), and caspase-3 activation in E.tenella sporozoites treated with different concentrations of sanguinarine. The results of flow cytometry showed that sanguinarine could inhibit the invasion of sporozoites of E.tenella in vitro (P < 0.05) and increase the reactive oxygen species and calcium ions in the sporozoites (P < 0.05). The results of immunofluorescence staining showed that sanguinarine could decrease the mitochondrial membrane potential of sporozoites. Our analysis suggests that sanguinarine can induce apoptosis of E. tenella sporozoites through reactive oxygen species-mediated reduction of the mitochondrial membrane potential and an increase in calcium ion concentration. It follows that sanguinarine is likely to be a novel type of anticoccidiosis drug with good research and clinical application prospects. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates an approach for multi-criterion decision making (MCDM) problems with interval-valued intuitionistic fuzzy preference relations (IVIFPRs). Based on the novel interval score function, some extended concepts associated with IVIFPRs are defined, including the score matrix, the approximate optimal transfer matrix and the possibility degree matrix. By using these new matrixes, a prioritization method for IVIFPRs is proposed. Then, we investigate an interval-valued intuitionistic fuzzy AHP method for multi-criteria decision making (MCDM) problems. In the end, a numerical example is provided to illustrate the application of the proposed approach. [Copyright &y& Elsevier]

• Bayesian inference is adopted to develop probabilistic bond strength models. • A large database containing 1,288 experimental samples is constructed. • Model uncertainties are quantified by the MCMC sampling algorithm. • Traditional models are compared to illustrate the superior of probabilistic ones. Nowadays, externally bonded (EB) fiber-reinforced polymer (FRP) sheets/plates have been recognized as a major strengthening approach for aged concrete structures. In order to evaluate the capacities of strengthened structures, a model capable of predicting the bond strength accurately and quantifying the corresponding uncertainty reasonably is necessary for EB FRP-to-concrete joints. In this study, a probabilistic approach is proposed to calibrate existing deterministic bond strength models to improve the accuracies and quantify the uncertainties of model predictions. A large and extensive experimental database containing 1,228 single-/double-lap shear test samples is firstly collected. Three widely-accepted deterministic bond strength models presented by design codes are then selected as candidates of which the predictive performances are evaluated through the database. After that, the potential influencing variables are added to the candidate bond strength models and the deterministic model parameters are replaced with the probabilistic ones. The probabilistic model calibration is proposed to be accomplished based on Bayesian inference which can yield probability distributions associated with the model parameters and predictions by means of the Markov chain Monte Carlo algorithm. Furthermore, the Kolmogorov-Smirnov test is adopted to study the probabilistic distributions of parameters and predictions of the calibrated models, as well as several statistical evaluation metrics are used to verify the performance of the probabilistic models. The proposed probabilistic models are capable of predicting the bond strength of EB FRP-to-concrete joints with improved predictive accuracies and reasonable uncertainty quantifications. [ABSTRACT FROM AUTHOR]

Abstract: Case-based reasoning (CBR) was firstly introduced into the area of business failure prediction (BFP) in 1996. The conclusion drawn out in its first application in this area is that CBR is not more applicable than multiple discriminant analysis (MDA) and Logit. On the contrary, there are some arguments which claim that CBR with k-nearest neighbor (k-NN) as its heart is not surely outranked by those machine learning techniques. In this research, we attempt to investigate whether or not CBR is sensitive to the so-called optimal feature subsets in BFP, since feature subset is an important factor that accounts for CBR’s performance. When CBR is used to solve such classification problem, the retrieval process of its life-cycle is mainly used. We use the classical Euclidean metric technique to calculate case similarity. Empirical data two years prior to failure are collected from Shanghai Stock Exchange and Shenzhen Stock Exchange in China. Four filters, i.e. MDA stepwise method, Logit stepwise method, One-way ANOVA, independent-samples t-test, and the wrapper approach of genetic algorithm are employed to generate five optimal feature subsets after data normalization. Thirty-times hold-out method is used as assessment of predictive performances by combining leave-one-out cross-validation and hold-out method. The two statistical baseline models, i.e. MDA and Logit, and the new model of support vector machine are employed as comparative models. Empirical results indicate that CBR is truly sensitive to optimal feature subsets with data for medium-term BFP. The stepwise method of MDA, a filter approach, is the first choice for CBR to select optimal feature subsets, followed by the stepwise method of Logit and the wrapper. The two filter approaches of ANOVA and t-test are the fourth choice. If MDA stepwise method is employed to select optimal feature subset for the CBR system, there are no significant difference on predictive performance of medium-term BFP between CBR and the other three models, i.e. MDA, Logit, SVM. On the contrary, CBR is outperformed by the three models at the significant level of 1%, if ANOVA or t-test is used as feature selection method for CBR. [Copyright &y& Elsevier]

The condition of the bearings is crucial for the operational functionality of the bridge. However, detecting damage in elastomeric bearings, which are often deeply positioned in bridges and surrounded by complex structures, remains a challenging task when using computer vision. To address this issue, a comprehensive dataset of bearing images relevant to engineering was first established. Subsequently, a lightweight network that incorporates a multi-level information fusion attention mechanism called LSK-YOLOv8n was introduced. The optimal embedding location for Large Selective Kernel Attention was determined to improve the lightweight nature of the LSK-YOLOv8n model, ensuring optimal performance in detecting bearing damage. Furthermore, the Focal-EIoU loss function was utilized to address the issue of positive and negative sample inhomogeneity more effectively. Experimental results demonstrate that LSK-YOLOv8n outperforms the benchmark model by 5.7% in recognizing bearing diseases, as measured by mAP 0.5 %. Moreover, LSK-YOLOv8n surpassed several state-of-the-art networks in both the number of integrated parameters and mAP 0.5 %, demonstrating its effectiveness and robustness. • Deep learning models for bridge elastomeric bearing inspection are proposed. • Utilizing Attention Mechanisms to Improve Model Performance. • Comparative studies validate the superior performance of the proposed models. • The proposal provides a cost-effective method for bridge bearing inspection. [ABSTRACT FROM AUTHOR]

• T.spiralis infection could induce the production of Bregs in mice. • Bregs are an important source of spleen and MLN IL-10 in mice infected with T.spiralis. • IL-10 was mainly secreted by the CD19+CD1dhigh CD5+ B cell subset. • The Bregs phenotype is similar toT2-MZP cells after T.spiralis infection in mice. Regulatory B cells (Bregs), a subset of B lymphocytes discovered in the past few decades, have the capacity to suppress the immune response and dampen inflammation by secreting cytokines (IL-10 and TGF-β). Whether Bregs are involved in Trichinella spiralis infection and the phenotypic characteristics of these cells after infection are still unknown. We investigated the phenotype of and dynamic changes in IL-10-producing Bregs in Trichinella spiralis infection in BALB/c mice. We used multicolour fluorescence immunostaining of microwave-treated paraffin sections to investigate the number of Bregs in T. spiralis infection. Flow cytometry (FCM) was used to determine the frequency of Bregs and related subgroups and cytokines in the spleen and mesenteric lymph nodes (MLNs). High levels of IL-10 were detected in the spleen and MLNs of mice after infection with T. spiralis. Furthermore, the frequencies of IL-10-producing CD19+CD1dhighCD5+ regulatory B cells and CD19+ cells were increased during T. spiralis infection. We also showed that the induced phenotype was similar to that of transitional type 2 marginal zone precursor B cells (T-MZP) cells after T. spiralis infection in mice. This study is the first demonstration of the expansion of Bregs following T. spiralis infection. [ABSTRACT FROM AUTHOR]

The near-infrared responsivity of a silicon photodetector employing the impurity photovoltaic (IPV) effect is investigated with a numerical method. The improvement of the responsivity can reach 0.358 A/W at a wavelength of about 1200 nm, and its corresponding quantum efficiency is 41.1%. The origin of the enhanced responsivity is attributed to the absorption of sub-bandgap photons, which results in the carrier transition from the impurity energy level to the conduction band. The results indicate that the IPV effect may provide a general approach to enhancing the responsivity of photodetectors. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a well-characterized bone toxic agent and can induce bone damage via inhibiting osteogenic differentiation. Bone morphogenetic protein (BMP)/SMAD signaling pathway can mediate osteogenic differentiation, but the association between Cd and BMP/SMAD signaling pathway is yet to be illuminated. To understand what elements of BMPs and SMADs are affected by Cd to influence osteogenic differentiation and if BMPs can be the biomarkers of which Cd-induced osteoporosis, human bone marrow mesenchymal stem cells (hBMSCs) were treated with cadmium chloride (CdCl2) in vitro to detect the expression of BMPs and SMADs, and 134 subjects were enrolled to explore if the BMPs can be potential biomarkers of Cd-associated bone damage. Our results showed that Cd exposure significantly promoted the adipogenic differentiation of hBMSCs and inhibited its osteogenic differentiation by inhibiting the expression of BMP-2/4, SMAD4, and p-SMAD1/5/9 complex. And mediation analyses yielded that BMP-4 mediated 39.32% (95% confidence interval 7.47, 85.00) of the total association between the Cd and the risk of Cd-associated bone damage. Moreover, during differentiation, BMP-4 had the potential to enhance mineralization compared with CdCl2 only group. These results reveal that BMP-4 can be a diagnostic biomarker and therapeutic target for Cd-associated bone damage. [ABSTRACT FROM AUTHOR]

Avian influenza virus (AIV) subtype H9N2 has significantly threatened the poultry business in recent years by having become the predominant subtype in flocks of chickens, ducks, and pigeons. In addition, the public health aspects of H9N2 AIV pose a significant threat to humans. Early and rapid diagnosis of H9N2 AIV is therefore of great importance. In this study, a new method for the detection of H9N2 AIV based on fluorescence intensity was successfully established using CRISPR/Cas13a technology. The Cas13a protein was first expressed in a prokaryotic system and purified using nickel ion affinity chromatography, resulting in a high-purity Cas13a protein. The best RPA (recombinase polymerase amplification) primer pairs and crRNA were designed and screened, successfully constructing the detection of H9N2 AIV based on CRISPR/Cas13a technology. Optimal concentration of Cas13a and crRNA was determined to optimize the constructed assay. The sensitivity of the optimized detection system is excellent, with a minimum detection limit of 10° copies/μL and didn't react with other avian susceptible viruses, with excellent specificity. The detection method provides the basis for the field detection of the H9N2 AIV. [ABSTRACT FROM AUTHOR]

Cementitious material is used to make conductive coatings for structural health monitoring of concrete structures with the advantages of low cost, good durability, similar properties to concrete, and easy replacement. In this paper, the feasibility of using cementitious capillary crystalline conductive coating to monitor surface strains and cracks in concrete structures is verified through a series of experiments and simulations. At first, the conductive coating was fabricated and its resistivity was measured. The relationship between the resistivity of the coating and the proportion of conductive particles was investigated through experiments. The experimental results showed that all types of coatings exhibit significant percolation phenomena and the resistivity stabilizes after 72 hours of curing of the coating. Then, an aggregate placement generation program suitable for the coating was developed, and numerical simulations were performed based on the microscopic cells of the coating generated by the program. The effect of conductive particles on the conductive properties of the coating was analyzed by simulating the resulting cross-section images of current density. The formation of conductive pathways is therefore explained on a microscopic level. And finally, based on the experimental and simulation results, a loading experiment was designed to measure the changes in electrical resistivity of surface coatings on concrete specimens during the loading process. The experimental results proved that this type of coating has a good sensing ability for strains and cracks of concrete surfaces. • Conductive coatings exhibit significant percolation and coating with flake graphite can have better conductivity. • An aggregate placement generation program is developed for different types of particles. • Formation of conductive pathways within coatings analyzed by COMSOL Multiphysics. • Sensing small cracks successfully through resistivity changes. [ABSTRACT FROM AUTHOR]

• T. spiralis disrupts gut homeostasis and impairs the development of the intestinal ecosystem. • Ascending mucosal type II immunity is associated with increased gut microbiota diversity. • Beneficial genera such as the Lachnospiraceae NK4A136 group, Ruminococcus 1 and Lactococcus decreased in abundance and proinflammatory bacteria Parabacteroides increased in abundance after T. spiralis infection. Understanding the interaction between the gut microbiota and Trichinella spiralis is of interest for the early diagnosis and development of therapeutics for trichinellosis and to reveal the potential role of microbiota in the mechanism of immunomodulation of this tissue-dwelling helminth. In this study, we utilized 16S rRNA gene sequencing to monitor the dynamics of the microbes in BALB/c mice challenged with T. spiralis. Flow cytometry and ELISA were used to analyze cytokines at the same time. Histopathological analysis of the duodenum was also conducted. We found that microbial perturbations occurred during infection. The abundance of the Lachnospiraceae NK4A136 group, Ruminococcus 1 and Lactococcus decreased. However, the abundance of proinflammatory Parabacteroides increased over time after infection. T. spiralis infection also tended to inhibit IFN-γ production, and promote IL-4 and IL-10 levels. In total, T. spiralis disrupts gut homeostasis and impairs the development of the intestinal ecosystem. Defining the bacterial populations affected by T. spiralis infection might help identify microbial markers for diagnosis of the disease, and the populations could also be further exploited as a novel option to treat T. spiralis infection. [ABSTRACT FROM AUTHOR]

African classical swine fever virus (ASFV) has spread seriously around the world and has dealt with a heavy blow to the pig breeding industry due to the lack of vaccines. In this study, we produced recombinant Lactobacillus plantarum (L. plantarum) expressing an ASFV p54 and porcine IL-21 (pIL-21) fusion protein and evaluated the immune effect of NC8-pSIP409-pgsA'-p54-pIL-21 in a mouse model. First, we verified that the ASFV p54 protein and p54-pIL-21 fusion protein were anchored on the surface of L. plantarum NC8 by flow cytometry, immunofluorescence and Western blotting. Then, the results were verified by flow cytometry, ELISA and MTT assays. Mouse-specific humoral immunity and mucosal and T cell-mediated immune responses were induced by recombinant L. plantarum. The results of feeding mice recombinant L. plantarum showed that the levels of serum IgG and mucosal secreted IgA (SIgA), the number of CD4 and CD8 T cells, and the expression of IFN-γ in CD4 and CD8 T cells increased significantly, and lymphocyte proliferation occurred under stimulation with the ASFV p54 protein. Our data lay a foundation for the development of oral vaccines against ASFV in the future. [ABSTRACT FROM AUTHOR]

African classical swine fever virus (ASFV) has spread seriously around the world and has dealt with a heavy blow to the pig breeding industry due to the lack of vaccines. In this study, we produced recombinant Lactobacillus plantarum (L. plantarum) expressing an ASFV p54 and porcine IL-21 (pIL-21) fusion protein and evaluated the immune effect of NC8-pSIP409-pgsA'-p54-pIL-21 in a mouse model. First, we verified that the ASFV p54 protein and p54-pIL-21 fusion protein were anchored on the surface of L. plantarum NC8 by flow cytometry, immunofluorescence and Western blotting. Then, the results were verified by flow cytometry, ELISA and MTT assays. Mouse-specific humoral immunity and mucosal and T cell-mediated immune responses were induced by recombinant L. plantarum. The results of feeding mice recombinant L. plantarum showed that the levels of serum IgG and mucosal secreted IgA (SIgA), the number of CD4 and CD8 T cells, and the expression of IFN-γ in CD4 and CD8 T cells increased significantly, and lymphocyte proliferation occurred under stimulation with the ASFV p54 protein. Our data lay a foundation for the development of oral vaccines against ASFV in the future. [ABSTRACT FROM AUTHOR]

• Invasive Lactobacillus plantarum expressing TsCPF1-IL-4 was constructed. • Invasive L. plantarum induced mucosal immunity and humoral immune responses. • Oral vaccination with invasive L. plantarum could reduce worm burden. • Histopathological damage was reduced after infected with Trichinella spiralis. Trichinellosis is a very important food-borne parasitic disease, that seriously endangers animal husbandry and food safety. Therefore, it is necessary to develop a safe and effective vaccine against Trichinella spiralis infection. In this experiment, invasive Lactobacillus plantarum carrying the FnBPA gene served as a live bacterial vector to deliver nucleic acids to the host to produce a novel oral nucleic acid vaccine. Coexpression of the T. spiralis cathepsin F-like protease 1 gene (TsCPF1) and murine IL-4 (mIL-4) by the nucleic acid vaccine was constructed and subsequently delivered to intestinal epithelial cells via invasive L. plantarum. Thirty-seven days after the first immunization, the experimental mice were challenged with 350 T. spiralis infective larvae by oral gavage. The results showed that mice orally immune-stimulated with invasive L. plantarum pValac-TsCPF1/pSIP409-FnBPA not only produce anti-TsCPF1-specific IgG antibodies, sIgA, Th1/Th2 cytokine distinctly increased but also intestinal damage and worm burden relieved compare to non-invasive TsCPF1 group (pValac-TsCPF1/pSIP409). Most notably, experimental mice immunized with invasive L. plantarum coexpressing TsCPF1 and mIL-4 (pValac-TsCPF1-IL-4/pSIP409-FnBPA) exhibited the highest protection efficiency against T. spiralis infection. The above results reveal that invasive L. plantarum -expressing the FnBPA protein improved mucosal and cellular immunity and enhanced resistance to T. spiralis. The nucleic acid vaccine delivered by invasive L. plantarum described in this study offers a novel idea for the prevention of T. spiralis. [ABSTRACT FROM AUTHOR]

• A recombinant adenovirus rAd-NP-M2e-GFP expressing multiple copies of influenza virus conserved antigens NP and M2e was constructed. • rAd-NP-M2e-GFP promoted the activation of dendritic cell in vitro and in vivo. • The mucosal and systemic immune responses were significantly elicited by rAd-NP-M2e-GFP. • rAd-NP-M2e-GFP provided protection against H1N1 AIV. Influenza virus is a kind of virus that poses several hazards of animal and human health. Therefore, it is important to develop an effective vaccine to prevent influenza. To this end we successfully packaged recombinant adenovirus rAd-NP-M2e-GFP expressing multiple copies of influenza virus conserved antigens NP and M2e and packaged empty vector adenovirus rAd-GFP. The effect of rAd-NP-M2e-GFP on the activation of dendritic cell (DC) in vitro and in vivo was detected by intranasal immunization. The results showed that rAd-NP-M2e-GFP promoted the activation of DC in vitro and in vivo. After the primary immunization and booster immunization of mice through the nasal immune way, the results showed that rAd-NP-M2e-GFP induced enhanced local mucosal-specific T cell responses, increased the content of SIgA in broncho alveolar lavage fluids (BALF) and triggered the differentiation of B cells in the germinal center. It is proved that rAd-NP-M2e-GFP can significantly elicit mucosal immunity and systemic immune response. In addition, rAd-NP-M2e-GFP could effectively protect mice after H1N1 influenza virus challenge. To lay the foundation and provide reference for further development of influenza virus mucosal vaccine in the future. [ABSTRACT FROM AUTHOR]

Background: Eimeria spp. are responsible for chicken coccidiosis which is the most important enteric protozoan disease resulting in tremendous economic losses in the poultry industry. Understanding the interaction between the avian cecal microbiota and coccidia is of interest in the development of alternative treatments that do not rely on chemotherapeutics and do not lead to drug resistance. Methods: We utilized 16S rRNA gene sequencing to detect the dynamics of the cecal microbial community in AA broilers challenged with Eimeria tenella. Histopathological analysis of the cecum was also conducted. Results: We found that microbial shifts occur during the infection. Lactobacillus, Faecalibacterium, Ruminococcaceae UCG-013, Romboutsia and Shuttleworthia decreased in abundance. However, the opportunistic pathogens Enterococcus and Streptococcus increased in abundance over time in response to the infection. Conclusions: Eimeria tenella disrupts the integrity of the cecal microbiota and could promote the establishment and growth of potentially pathogenic bacteria. Defining bacterial populations affected by coccidial infection might help identify bacterial markers for intestinal disease as well as populations or species that could be beneficial in maintaining and restoring gut homeostasis during and after infection with E. tenella. [ABSTRACT FROM AUTHOR]

• Constructed recombinant Lactobacillus plantarum NC8-pSIP409- pgsA -mIL-4. • Up-regulated Th2 immune response. • Improved antibody level against Trichinella spiralis. • Mice immunized with recombinant NC8-pSIP409- pgsA -mIL-4 showed reduces parasite loads in intestinal phase and muscular phase. Interleukin-4 (IL-4), an immunomodulatory cytokine derived from activated T lymphocytes were shown to regulate Th2-type immune responses. It plays an important role in anti-parasitic infections. In this study, a recombinant plasmid was designed using murine IL-4 co-expressed with pgsA anchor system of Lactobacillus plantarum NC8 and was delivered by live Lactobacillus plantarum NC8, which exhibited an enhanced immunogenicity in protection of BALB/c mice from infection with Trichinella spiralis. The results showed that the levels of serum IgG1 and mucosal secretory IgA (sIgA) were both increased significantly in mice orally inoculated with NC8-pSIP409- pgsA -mIL-4, and the Th2 phenotype immune response was up-regulated. A 29.9 % reduction in adult worm burden at 7 days post-infection (dpi) and 83.3 % reduction in muscle larvae burden at 28 dpi were observed in immune-stimulated mice with NC8-pSIP409- pgsA -mIL-4. Moreover, weight loss and pathological changes were also improved in mice of NC8-pSIP409- pgsA -mIL-4 group. Taken together, it suggests that NC8-pSIP409- pgsA -mIL-4 could improve the intestinal mucosal immunity and promoted the elimination of the adult worm in Trichinella -infected mice. This study laid the foundation for the development of a novel vaccines against Trichinellosis. [ABSTRACT FROM AUTHOR]

Abstract To evaluate the efficiency of preventing pathogenic avian influenza by vaccination with recombinant Lactobacillus plantarum (L. plantarum) that expresses conserved antigens, the mucosal and systemic immune responses in animals vaccinated with recombinant L. plantarum NC8-409-1 (NC8-pSIP409-pgsA'-HA2) and NC8-409-2 (NC8-pSIP409-pgsA'-3M2e-HA2) were evaluated. Our results showed that recombinant L. plantarum NC8-409-1 and NC8-409-2 could substantially stimulate the specific IgA titer in the intestine and the specific IgG antibody titer in the serum. We also found that recombinant L. plantarum induced increases in the number of B220+ IgA+ cells in Peyer's patches (PPs), in lymphocyte proliferation and in the number of IFN-γ+ producing CD8+ T cells after immunization in mice. Most importantly, the mice that were vaccinated with recombinant L. plantarum NC8-409-2 and NC8-409-1 were to some extent protected against infection challenge with the H9N2 and H1N1 viruses. In particular, NC8-409-2 provided up to 80% protection against the H9N2 virus, and NC8-409-1 provided up to 60% protection. Lung tissue pathology was also reduced. Therefore, recombinant L. plantarum NC8-409-2 and NC8-409-1 may be candidate oral vaccines against bird flu. [ABSTRACT FROM AUTHOR]

Transmissible gastroenteritis coronavirus (TGEV) is one of the most severe threats to the swine industry. In this study, we constructed a suite of recombinant Lactobacillus plantarum with surface displaying the spike (S) protein coming from TGEV and fused with DC cells targeting peptides (DCpep) to develop an effective, safe, and convenient vaccine against transmissible gastroenteritis. Our research results found that the recombinant Lactobacillus plantarum (NC8-pSIP409-pgsA-S-DCpep) group expressing S fused with DCpep could not only significantly increase the percentages of MHC-II+CD80+ B cells and CD3+CD4+ T cells but also the number of IgA+ B cells and CD3+CD4+ T cells of ileum lamina propria, which elevated the specific secretory immunoglobulin A (SIgA) titers in feces and IgG titers in serum. Taken together, these results suggest that NC8-pSIP409-pgsA-S-DCpep expressing the S of TGEV fused with DCpep could effectively induce immune responses and provide a feasible original strategy and approach for the design of TGEV vaccines. [ABSTRACT FROM AUTHOR]

The highly infectious porcine transmissible gastroenteritis virus (TGEV), which belongs to the coronaviruses (CoVs), causes diarrhea and high mortality rates in piglets, resulting in severe economic losses in the pork industry worldwide. In this study, we used Lactobacillus plantarum (L. plantarum) to anchor the expression of TGEV antigen (S) to dendritic cells (DCs) via dendritic cell-targeting peptides (DCpep). The results show that S antigen could be detected on the surface of L. plantarum by different detection methods. Furthermore, flow cytometry and ELISA techniques were used to measure the cellular, mucosal, and humoral immune responses of the different orally gavaged mouse groups. The obtained results demonstrated the significant effect of the constructed L. plantarum expressing S-DCpep fusion proteins in inducing high expression levels of B7 molecules on DCs, as well as high levels of IgG, secretory IgA, and IFN-γ and IL-4 cytokines compared with the other groups. Accordingly, surface expression of DC-targeted antigens successfully induced cellular, mucosal, and humoral immunity in mice and could be used as a vaccine. [ABSTRACT FROM AUTHOR]

Avian influenza virus (AIV) can infect poultry, mammals, and other hosts and causes enormous economic losses to the global poultry industry. In this study, to develop a novel and potent oral vaccine based on Lactobacillus plantarum (L. plantarum) for controlling the spread of AIV in the poultry industry, we constructed a recombinant L. plantarum strain displaying the 3M2e-HA2 protein of the influenza virus and determined the effect of N/pgsA′-3M2e-HA2 against AIV in chicks. We first confirmed that the 3M2e-HA2 fusion protein was expressed on the surface of L. plantarum via flow cytometry and immunofluorescence experiments. Our experimental results demonstrated that chicks immunized with N/pgsA′-3M2e-HA2 could induce specific humoral, mucosal, and T cell-mediated immune responses, eliciting the host body to protect itself against AIV. Additionally, compared to oral administration, the intranasal immunization of chicks with N/pgsA′-3M2e-HA2 provided a stronger immune response, resulting in a potent protective effect that hindered the loss of body weight, decreasing pulmonary virus titers and reducing lung and throat pathological damages. Thus, our results indicate that our novel approach is an effective method of vaccine design to promote mucosal immunity. [ABSTRACT FROM AUTHOR]

Porcine epidemic diarrhea virus (PEDV) is one of the most important causative pathogens of swine diarrhea, which is widely prevalent throughout the world and is responsible for significant economic losses in the commercial pig industry, both domestic and abroad. The spike (S) protein in the PEDV capsid structure can carry the major B lymphocyte epitope, which induces production of neutralizing antibodies and provides immunoprotective effects. Moreover, the conserved region encoded by the S gene can be considered a target for establishing a new diagnostic method and is a new candidate for vaccine design. In this study, use of anchorin pgsA' allowed the fusion protein of S-DCpep to express on the surface of recombinant Lactobacillus plantarum (NC8-pSIP409-pgsA'-S-DCpep) NC8 strain. Mice were immunized by lavage administration of the recombinant NC8-pSIP409-pgsA'-S-DCpep, which was observed to induce DC activation and high production of sIgA and IgG antibodies in experimental animals, while also eliciting production of significantly more IgA + B220 + B cells. More importantly, secretion of cytokines IFN-γ, IL-4 and IL-17 in mice that were vaccinated with NC8-pSIP409-pgsA'-S-DCpep was remarkably increased. The results of our study suggest that NC8-pSIP409-pgsA'-S-DCpep potently triggers cellular and humoral immune responses. The obtained experimental results can provide a theoretical basis that lays the foundation for production of a novel oral vaccine against PED. [ABSTRACT FROM AUTHOR]

Low pathogenic H9N2 subtype avian influenza virus (AIV) can lead to moderate respiratory symptoms and low egg production rates in poultry. Due to its immunologic suppression, other various infectious pathogens give rise to the co-infection of hosts, causing heavy economic losses in the commercial poultry industry in both China and worldwide. Therefore, it is time to explore a novel, safe, and effective vaccine. We have already made use of the surface of Lactobacillus plantarum to display AIV HA2 (NC8-pSIP409-pgsA′-HA2), which demonstrated that it has a good immunogenicity. In this study, by evaluating the immune protection effect of NC8-pSIP409-pgsA′-HA2 on chickens, we found that the hemagglutination inhibition (HI) antibodies, specificity IgG antibody in chickens, the sIgA titer in broncho alveolar lavage fluids (BALF), and the T cell response were increased notably after oral vaccination with NC8-pSIP409-pgsA′-HA2. In addition, weight loss, lung titers, and lung pathologies were improved when chickens were orally vaccinated with NC8-pSIP409-pgsA′-HA2 after challenge with H9N2 AIV. This strategy lays the foundation for the development of recombinant L. plantarum oral vaccines in the prevention of AIV. [ABSTRACT FROM AUTHOR]

Recombination activating gene 2 (RAG2) is necessary for immature B cell differentiation. Antibodies to human and rabbit RAG2 are currently commercially available, but antibodies to swine RAG remain unavailable to date. In this study, the swineRAG2 genes sequence was synthesized and then cloned into a pET-28a vector. The recombinant fusion protein was successfully expressed inE. coli,purified through nickel column chromatography, and further digested with Tobacco Etch Virus protease. The cleaved protein was purified by molecular-exclusion chromatography and named pRAG2. We used pRAG2 to immunize rabbits, collected the serum and purified rabbit anti-pRAG2 polyclonal antibodies. The rabbit anti-pRAG2 polyclonal antibodies were tested via immunofluorescence on eukaryotic cells overexpressing pRAG2 and also able to recognize pig natural RAG2 and human RAG2 protein in western blotting. These results indicated that the prepared rabbit anti-pRAG2 polyclonal antibodies may serve as a tool to detect immature B cell differentiation of swine. [ABSTRACT FROM PUBLISHER]

Avian influenza virus (AIV) is spreading worldwide and is a serious threat to the health of poultry and humans. In many countries, low pathogenic AIVs, such as H9N2, have become an enormous economic burden on the commercial poultry industry because they cause mild respiratory disease and decrease egg production. A recombinant Lactobacillus plantarum NC8 strain expressing NP-M1-DCpep from H9N2 AIV has been studied in a mouse model. However, it remains unknown whether this L. plantarum strain can induce an immune response and provide protection against H9N2 AIV in chickens. In this study, chickens that were orally vaccinated with NC8-pSIP409-NP-M1-DCpep exhibited significantly increased T cell-mediated immune responses and mucosal sIgA and IgG levels, which provided protection against H9N2 AIV challenge. More importantly, compared with oral administration of NC8-pSIP409-NP-M1-DCpep, intranasal administration induced stronger immune responses and provided effective protection against challenge with the H9N2 virus by reducing body weight loss, lung virus titers, and throat pathology. Taken together, these findings suggest that L. plantarum expressing NP-M1-DCpep has potential as a vaccine to combat H9N2 AIV infection. [ABSTRACT FROM AUTHOR]

The influenza A (H1N1) virus is a highly contagious acute respiratory disease affecting pigs and humans. This disease causes severe economic loss in many countries, and developing mucosal vaccines is an efficient strategy to control the influenza virus. The neonatal Fc receptor (FcRn) plays an important role in transferring IgG across polarized epithelial cells. In the present study, an oral vaccine was developed using Lactobacillus plantarum to deliver the internal influenza viral protein M2e fused to an IgG Fc fragment. Oral vaccination with recombinant L. plantarum expressing 3M2e-Fc elicited Peyer's patch (PP) DC activation, improved the number of gamma interferon (IFN-γ)-producing T cells and increased the frequency of CD8 + IFN-γ + cells in the mesenteric lymph nodes (MLNs). In addition, the recombinant L . plantarum can induce PP B220 + IgA + expression and enhance specific sIgA secretion and the shaping of growth centers (GCs) in PPs. Furthermore, the data demonstrated that immunization with recombinant L. plantarum expressing 3M2e-Fc markedly reduced the viral load in the lung and protected against H1N1 influenza virus and mouse-adapted H9N2 avian influenza virus (AIV) challenge in BALB/c mice. Collectively, the data also showed that this vaccine strategy provided effective protective immunity against infection with homologous and heterologous influenza viruses in a mouse model and may be useful for future influenza vaccine development. [ABSTRACT FROM AUTHOR]

The zoonotic pathogen avian influenza A H5N8 causes enormous economic losses in the poultry industry and poses a serious threat to the public health. Here, we report the first systematic review and meta-analysis of the worldwide prevalence of birds. We filtered 45 eligible articles from seven databases. A random-effects model was used to analyze the prevalence of H5N8 in birds. The pooled prevalence of H5N8 in birds was 1.6%. In the regions, Africa has the highest prevalence (8.0%). Based on the source, village (8.3%) was the highest. In the sample type, the highest prevalence was organs (79.7%). In seasons, the highest prevalence was autumn (28.1%). The largest prevalence in the sampling time was during 2019 or later (7.0%). Furthermore, geographical factors also were associated with the prevalence. Therefore, we recommend site-specific prevention and control tools for this strain in birds and enhance the surveillance to reduce the spread of H5N8. • Potential risk factors of global transmission of H5N8 in birds were assessed. • Africa was the region with the highest prevalence of H5N8 in birds. • The incidence of H5N8 in birds was also impacted by different geographical and climatic conditions. [ABSTRACT FROM AUTHOR]

Piglet diarrhea caused by the porcine epidemic diarrhea virus (PEDV) is a common problem on pig farms in China associated with high morbidity and mortality rates. In this study, three PEDV isolates were successfully detected after the fourth blind passage in Vero cells. The samples were obtained from infected piglet farms in Jilin (Changchun), and Shandong (Qingdao) Provinces of China and were designated as CH/CC-1/2018 , CH/CC-2/2018, and CH/QD/2018. According to the analysis of the complete S protein gene sequence, the CH/CC-1/2018 and CH/CC-2/2018 were allocated to the G2b branch, while CH/QD/2018 was located in the G1a interval and was closer to the vaccine strain CV777. Successful detection and identification of the isolated strains were carried out using electron microscopy and indirect immunofluorescence. Meanwhile, animal challenge experiments and viral RNA copies determination were used to compare the pathogenicity. The results showed that CH/CC-1/2018 in Changchun was more pathogenic than CH/QD/2018 in Qingdao. In conclusion, the discovery of these new strains is conducive to the development of vaccines to prevent the pandemic of PEDV, especially that the CH/CC-1/2018, and CH/CC-2/2018 were not related to the classical vaccine strain CV777. • Three PEDV strains were isolated and identified in China. • The genetic evolution relationship of PEDV virus was analyzed. • The pathogenicity of PEDV virus was compared by animal experiments. [ABSTRACT FROM AUTHOR]

Trichinellosis is a food-borne zoonotic parasitic disease that causes serious harm to human health and the pig breeding industry. However, there are reports that Trichinella spiralis (T. spiralis) infection can treat autoimmune diseases, including enteritis and experimental autoimmune encephalitis (EAE). However, research on the mechanism of T. spiralis infection in infectious enteritis has not been fully elucidated. Therefore, this experiment used Citrobacter rodentium (C. rodentium) to induce colitis in mouse models and explored its underlying mechanisms. In this experiment, a total of 72 C57BL/6 mice were randomly divided into four groups. Experimental mice in the TS and TS + CR groups were orally inoculated with individual T. spiralis larvae. At 21 days postinfection (dpi) with T. spiralis , experimental animals in the CR and TS + CR groups were inoculated by orogastric gavage with C. rodentium. The control group received PBS only. The results indicated that the weight loss and macroscopic and microscopic colon damage of mice in the TS + CR group were significantly decreased compared with those observed in the CR group. The results of flow cytometry showed that the expression levels of IL-4, IL-10 and CD4+CD25+Foxp3+ Tregs were increased (P < 0.05), while the expression levels of IFN-γ, IL-12 and IL-17 were decreased in the spleens and MLNs of the TS + CR experimental mice compared with the colitis model mice. ELISA results revealed that the TS + CR group not only elicited a strong IgG1 response (P < 0.01) but also a low level of IgG2a response (P < 0.05) relative to the CR group. The above results demonstrated that prior exposure of mice to T. spiralis infection ameliorated the severity of C. rodentium -induced infectious colitis. [Display omitted] • C. rodentium -induced colitis model in mice was successfully established. • Prior exposure of mice to T. spiralis infection reduce weight loss and colon damage. • The population of Th2 and iTregs were increased in mice of T. spiralis infection. • T. spiralis infection ameliorates the severity of C. rodentium -induced colitis. [ABSTRACT FROM AUTHOR]

The H9N2 avian influenza virus (AIV) has become increasingly concerning due to its role in severe economic losses in the poultry industry. Transmission of AIV to mammals, including pigs and humans, has accelerated efforts to devise preventive strategies. To develop an effective oral vaccine against H9N2 AIV, a recombinant Lactobacillus plantarum NC8 strain expressing the hemagglutinin (HA) gene of H9N2 AIV was constructed in this study. Mice were orally immunized with the recombinant NC8-pSIP409-HA strain, and sIgA, IgG and HI antibodies were produced by the NC8-pSIP409-HA strain, which also induced CD8 + T cell immune responses. Most importantly, oral administration produced complete protection against challenge with mouse-adapted H9N2 virus. These results indicate that the recombinant NC8-pSIP409-HA was more effective at inducing the mucosal, humoral and cellular immune responses. Therefore, L. plantarum NC8-pSIP409-HA could become a promising oral vaccine candidate against H9N2 AIV. [ABSTRACT FROM AUTHOR]

• Invasive recombinant L. plantarum expressing SS1-IL-4 was constructed. • Invasive L. plantarum induced mucosal immunity and humoral immune responses. • Oral vaccination with invasive L. plantarum could reduce AW and ML burden. • Masseter muscle and intestinal damage were reduced after infected with T. spiralis. Trichinellosis is a foodborne zoonosis caused by Trichinella spiralis (T. spiralis) that not only causes considerable economic losses for the global pig breeding and food industries, but also seriously threats the health of human. Therefore, it is very necessary to develop an effective vaccine to prevent trichinellosis. In this study, the invasive Lactobacillus plantarum (L. plantarum) expressing fibronectin-binding protein A (FnBPA) was served as a live bacterial vector to deliver DNA to the host to produce a novel oral DNA vaccine. Co-expressing T. spiralis SS1 and murine interleukin-4 (mIL-4) of DNA vaccine were constructed and subsequently delivered to intestinal epithelial cells via invasive L. plantarum. At 10 days after the third immunization, the experimental mice were challenged with 350 T. spiralis infective larvae. The results found that the mice orally vaccinated with invasive L. plantarum harboring pValac-SS1/pSIP409-FnBPA not only stimulated the production of anti-SS1-specific IgG, Th1/Th2 cell cytokines, and secreted(s) IgA but also decreased worm burden and intestinal damage. However, the mice inoculated with invasive L. plantarum co-expressing SS1 and mIL-4 (pValac-SS1-IL-4/pSIP409-FnBPA) induced the highest protective immune response against T. spiralis infection. The DNA vaccine delivered by invasive L. plantarum provides a novel idea for the prevention of T. spiralis infection. [ABSTRACT FROM AUTHOR]

H9N2 subtype, a low pathogenic avian influenza virus, is emerging as a major causative agent circulating poultry workplaces across China and other Asian countries. Increasing case number of interspecies transmissions to mammals reported recently provoked a great concern about its risks inducing global pandemics. In an attempt to understand the underlying mechanism of how the H9N2 virus disrupts the interspecies segregation to transmit to mammals. A mutant H9N2 strain was obtained by passaging the wildtype H9N2 A/chicken/Hong Kong/G9/1997 eight times from lung to lung in BALB/c mice. Our finding revealed that mice manifested severe clinical symptoms including losses of body weight, pathological damages in pulmonary sites and all died within two weeks after infected with the mutated H9N2, whereas all mice survived upon infected with wildtype strain in comparison, which suggested increased pathogenicity of the mutant strain. In addition, mice showed enhanced levels of proinflammatory cytokines in sera, including IL-6, TNF-α and IL-1β compared to those subjected to wildtype viral infections. Sequence analysis showed that five amino acid substitutions occurred at PB2 627 , HA 87, HA 234 , NP 387 and M 156 , and a deletion mutation happened in the M gene (M 157). Of these mutations, PB2 E627K played key roles in modulating lethality in mice. Taken together, the mutant H9N2 strain obtained by serial passaging of its wildtype in mice significantly increased its virulence leading to death of mice, which might be associated the accumulated mutations occurred on its genome. • H9N2 subtype avian influenza virus acquired high virulence via serial 8 passages. • Five amino acid substitutions occurred in mouse-adapted H9N2 virus. • Secretion of proinflammatory cytokines enhanced by the mouse-adapted H9N2 virus. [ABSTRACT FROM AUTHOR]

• Development a vaccine that oral vaccination with Ts 43 delivered by attenuated Salmonella in murine model. • The vaccine elicited local and systemic concurrent Th1/Th2/Th17 immune responses. • The vaccine induced a strong intestinal mucosal sIgA and serum IgG antibody responses. • The immunization animals exhibited partial protection against T. spiralis infection. A vaccine against Trichinella spiralis infection is urgently needed to interrupt its transmission from domestic animals to humans. However, no vaccine against T. spiralis is currently available. Our previous study demonstrated that the use of the 43-kDa glycoprotein present in excretory-secretory (ES) proteins of muscle larvae (ML) as an intramuscular DNA vaccine led to a 52.1% protection rate against T. spiralis infection. Attenuated Salmonella strains have the advantage of eliciting mucosal immunity, which is important for controlling T. spiralis infections at the intestinal stage and can be provided as vaccines via oral or intranasal routes. Therefore, in this study, complete 43-kDa glycoprotein (Ts 43) sequences of T. spiralis were cloned into the vector pYA3681, and the recombinant plasmid pYA3681- Ts 43 was transformed into the attenuated Salmonella typhimurium strain χ11802. The results showed that oral vaccination of mice with attenuated Salmonella carrying the recombinant plasmid pYA3681- Ts 43 induced an evident elevation of the local intestinal mucosal sIgA and serum IgG antibody responses. The flow cytometry results showed that the percentages of CD4+ T cells and secreted IFN-γ, IL-4, and IL-17A in CD4+ T cells were significantly increased in the spleen and mesenteric lymph node (MLN) lymphocytes of the vaccinated groups. In addition, increased levels of the IFN-γ, IL-4, and IL-17A cytokines were also observed in the serum of the immunized groups. The above immune response results in the immunized groups demonstrated that protective immunity was elicited in this study. Finally, vaccinated mice demonstrated a significant 45.9% reduction in ML burden after infection with T. spiralis. This study demonstrated that oral vaccination with Ts 43 delivered by attenuated Salmonella elicited local and systemic concurrent Th1/Th2/Th17 immune responses and provided partial protection against T. spiralis infection in BALB/c mice. This is a prospective strategy for the prevention and control of trichinellosis. [ABSTRACT FROM AUTHOR]

• Constructed recombinant Lactobacillus plantaru m NC8-pLp-TsNd-S-pgsA′-gp43. • Elicited high levels of specific serum IgG and mucosal sIgA. • Mice immunized with recombinant strain exhibited a significant larval reduction. • Protection was associated with a Th2-dominated immune response. Trichinellosis is a significant food-borne zoonotic parasitic disease caused by parasite Trichinella. Given the side effects of anti- Trichinella drugs (e.g., Mebendazole) aroused in the course of treatments, an effective vaccine against the parasite is called for. The therapies available to date are in most instances targeting a single stage of Trichinella , resulting in an incomplete protective immunity against the parasite in terms of the complexity of its developmental stages. In this study, a recombinant dual-expression double anchor vector NC8-pLp-TsNd-S-pgsA′-gp43 was constructed carrying two antigen genes from Trichinella spiralis (T. spiralis), encoding the gp43 and T. spiralis Nudix hydrolase (TsNd) proteins which were mainly expressed in muscle larva (ML) and intestinal infective larva stages of the parasite respectively. These two proteins were to be expressed by Lactobacillus plantarum NC8 (L. plantarum NC8) which was designed to express the two anchored peptides, a truncated poly-γ-glutamic acid synthetase A (pgsA′) and the surface layer protein of Lactobacillus acidophilus (SlpA), on its surface for attaching expressed foreign proteins. Oral immunization with the above recombinant vaccine induced higher levels of specific serum IgG and mucosal secretory IgA (SIgA) in BALB/c mice. In addition, cytokines, interferon-γ (IFN- γ), interleukin-4 (IL-4) and IL-17 released by lymphocytes, and CD4+ levels displayed on the surfaces of splenic and mesenteric lymph cells were significantly enhanced by the vaccination. Moreover, after larval challenges, a 75.67 % reduction of adult worms (AW) at 7 days post-infection (dpi) and 57.14 % reduction of ML at 42 dpi were observed in mice immunized with the recombinant vaccine. Furthermore, this oral vaccination reduced the counts of encysted larvae presented in tongue and masseter muscles after infected with T. spiralis in mice. The overall results demonstrated that the recombinant vaccine developed in this study could induce specific humoral, mucosal, and cellular immune responses, and provides protections against different stages (adult worms and muscle larva) of T. spiralis infections in BALB/c mice, which could make it a promising oral vaccine candidate against trichinellosis. [Display omitted] [ABSTRACT FROM AUTHOR]

Salmonellosis is a worldwide zoonotic disease that poses a serious threat to the reproduction of livestock and poultry and the health of young animals. Probiotics including Bacillus species, have received increasing attention as a substitute for antibiotics. In this study, chicks infected with Salmonella were fed feed supplemented with the BSH to observe the pathological changes in the liver, detect the number of viable bacteria in the liver and spleen, and record the death of the chicks. The results showed that BSH could reduce the pathological changes in the liver and the invasion of Salmonella into the liver and spleen of chicks. In addition, the survival rate of chicks in the BSH experimental group was 60%, while that in the infected control group was 26%, indicating that BSH had a protective effect on chicks infected with Salmonella. Finally, the fecal microflora of 9-day-old chicks was analyzed by 16S rRNA high-throughput sequencing. The results showed that Salmonella infection could cause intestinal flora changes, while BSH could alleviate this change. In addition, BSH also promoted the proliferation of Lactobacillus salivarius in the cecum of chick. This study emphasized that BSH has anti- Salmonella infection effects in chickens and can be used as a candidate microecological preparation strain. • BSH had a protective effect on chicks infected with Salmonella. • BSH could reduce the pathological changes in the liver and the invasion of Salmonella into the liver and spleen of chicks. • Salmonella infection could cause intestinal flora changes, while BSH could alleviate this change. • BSH can be used as a candidate microecological preparation strain. [ABSTRACT FROM AUTHOR]

• A recombinant L. plantarum expressing the conserved gene of AIV with FliC flagellin was constructed. • Recombinant L. plantarum induced strong T cell immune response in the spleen in chickens. • IgG and sIgA antibodies were elicited by the recombinant L. plantarum in chickens. • Recombinant L. plantarum provided protection against H9N2 AIV. The H9N2 avian influenza virus (AIV) causes serious economic losses to the poultry industry every year. Vaccines that induce a mucosal immune response may be successful against influenza virus infection because its transmission occurs primarily in the mucosa. To develop novel and potent oral vaccines based on Lactobacillus plantarum (L. plantarum) to control the spread of AIV in poultry industry, in the present study, we constructed and expressed fusions of the influenza antigens NP and M2 with the Salmonella Typhimurium flagellinprotein FliC on the surface of L. plantarum. Oral immunization of chicks was performed, and serum antibodies, mucosal antibodies, and specific cellular immunity were detected. Immunizing chicks with avian influenza virus was evaluated. The results showed high levels of IgG in addition to high levels of secretory immunoglobulin A (sIgA) in chickens orally administered recombinant L. plantarum. In addition, the fusion may significantly increase the levels of NP- and M2-specific T cell-mediated immunity in the case of mucosal administration of NC8-pSIP409-pgsA'-NP-M2-FliC. Recombinant NC8-pSIP409-pgsA'-NP-M2-FliC mediated effectively protected chickens against influenza virus and reduced virus titers in the lung. Our study outcomes indicate that the expression of influenza NP-M2 and a mucosal adjuvant (FliC), by L. plantarum could generate a mucosal vaccine candidate for animals in the future to defend against AIVs. [ABSTRACT FROM AUTHOR]

• Recombinant invasive Lactobacillus plantarum expressing TA4-AMA1 was constructed. • T cell differentiation was induced in peripheral blood. • Antibody levels were improved in serum. • Recombinant Lactobacillus plantarum could increase the body weight of chickens. • Oocyst shedding and intestinal lesions were reduced after challenge with oocysts. Coccidiosis is an intestinal parasitic disease that is caused by Eimeria tenella and other species, and it seriously restricts the economic development of the broiler breeding industry. In this study, a recombinant Lactobacillus plantarum with an invasive effect was constructed, and it expressed the TA4-AMA1 protein of E. tenella. After oral immunization with recombinant L. plantarum , specific humoral and mucosal immune levels were measured by indirect ELISA, and the differentiation of T cells was analysed by flow cytometry. After challenge with sporulated oocysts, the body weight, oocyst shedding and cecum lesions of the chicken were evaluated. The results indicated that chickens immunized with recombinant invasive L. plantarum produced higher levels of specific antibodies in the serum than did the non-immunized controls, and the secretory IgA (sIgA) levels were increased in the intestinal washes compared to those of the controls (P < 0.05). Flow cytometry showed that recombinant invasive L. plantarum significantly stimulated T cell differentiation compared to the PBS group (P < 0.01, P < 0.001), and a higher proportion of CD4+ and CD8+ T cells were detected in peripheral blood. Moreover, the lesion scores and histopathological caecum sections showed that immunizing chickens with recombinant invasive L. plantarum can significantly relieve pathological damage in the cecum (P < 0.01), and the relative body weight gain was 89.64 %, which was higher than the 79.83 % gain in the chickens immunized with non-invasive L. plantarum. After the challenge, faeces from ten chickens in each group were collected between 4 and 7 days, and the oocysts per gram (OPG) was determined by the McMaster technique. The data indicated that oocysts in the faeces of chickens immunized with the recombinant invasive L. plantarum were significantly lower than those of the controls (P < 0.01). The results suggest that recombinant invasive L. plantarum effectively activated immune responses against E. tenella infection and can be used as a candidate vaccine against E. tenella infection. [ABSTRACT FROM AUTHOR]