Development and application of a WebGIS-based prediction system for multi-criteria decision analysis of porcine pasteurellosis.

Porcine pasteurellosis is an infectious disease caused by Pasteurella multocida (P. multocida), which seriously endangers the healthy development of pig breeding industry. Early detection of disease transmission in animals is a crucial early warning for humans. Therefore, predicting risk areas for disease is essential for public health authorities to adopt preventive measures and control strategies against diseases. In this study, we developed a predictive model based on multi-criteria decision analysis (MCDA) and assessed risk areas for porcine pasteurellosis in the Chinese mainland. By using principal component analysis, the weights of seven spatial risk factors were determined. Fuzzy membership function was used to standardize all risk factors, and weight linear combination was used to create a risk map. The sensitivity of the risk map was analyzed by calculating the mean of absolute change rates of risk factors, as well as calculating an uncertainty map. The results showed that risk areas for porcine pasteurellosis were predicted to be locate in the south-central of the Chinese mainland, including Sichuan, Chongqing, Guangdong, and Guangxi. The maximum standard deviation of the uncertain map was less than 0.01and the ROC results showed that the prediction model has moderate predictive performance with the area under the curve (AUC) value of 0.80 (95% CI 0.75-0.84). Based on the above process, MCDA was combined with WebGIS technology to construct a system for predicting risk areas of porcine pasteurellosis. Risk factor data was directly linked to the developed model, providing decision support for disease prevention and control through monthly updates.

Control of swine dysentery at national level in Sweden.

BACKGROUND: Swine dysentery, caused by Brachyspira hyodysenteriae, is a severe pig disease. Resistance to tylosins is common and resistance to tiamulin has been reported since the 1990s. Still, dysentery is not notifiable to authorities. The disease therefore escapes control from an overall population perspective. In Sweden, a program that aimed to control dysentery at national level was initiated in 2020, mainly due to the unexpected diagnosis of tiamulin resistant Brachyspira hyodysenteriae in 2016. RESULTS: Through joint efforts of a network including farmers, government, animal health organisations and abattoirs it was concluded that outbreaks of dysentery had taken place in 25 herds between 2016 and 2019. By 1 January 2020, nine of these herds were still not declared free from the disease. From that date, the network decided that Brachyspira hyodysenteriae was to be cultured whenever dysentery could be suspected. Thus, 148, 157 and 124 herds were scrutinised for Brachyspira hyodysenteriae in 2020, 2021 and 2022, respectively, whereof five, three and two new herds were confirmed positive. By 31 December 2022, four herds were judged as impossible to sanitise. However, they posed no problem since they were identified by the network, pigs to and from these enterprises could be transported without jeopardising other herds. When Brachyspira hyodysenteriae was diagnosed in fattening herds purchasing growers, Brachyspira hyodysenteriae could not be detected in the delivering herds. That result, together with other observations, indicated that Brachyspira hyodysenteriae ought to be regarded as ubiquitous, although at a low level in healthy pigs. CONCLUSIONS: Eradication of dysentery contributed to substantial welfare and financial improvements in affected herds. Dysentery was controlled successfully at national level through the united efforts from competing stake holders, such as different abattoirs and animal health organisations. However, as Brachyspira hyodysenteriae was assumed to be ubiquitous, although at a low level in healthy pigs, the duration of the successful control of dysentery was concluded to only be transient. Without permanent monitoring for Brachyspira hyodysenteriae, the knowledge of the national status will rapidly decline to the level prior to the initiation of the control program.

The genetic resistance of sows to Escherichia coli F4 adhesion reduces their response to a vaccine containing F4 fimbriae but does not affect the preweaning performance of their susceptible piglets.

INTRODUCTION: Pigs without intestinal receptors for F4 fimbriae are congenitally resistant to F4 fimbriae-bearing enterotoxigenic Escherichia coli (ETEC F4). In general, 50 % and 100 % of piglets born to resistant (RR) sows crossed with hetero- or homozygous susceptible (SR, SS) boars, respectively, are susceptible but do not receive colostral antibodies against F4 fimbriae unless the sows have been vaccinated. The question arises as to whether resistant sows produce protective amounts of F4 antifimbrial antibodies after vaccination. The serum and colostrum antibody titres of 12 resistant and 12 susceptible vaccinated gilts were compared. The effect of the receptor status of the dam and sire on the preweaning performance of 5027 piglets was evaluated using Agroscope's recordings. The sows of the experimental herd, where ETEC F4 was circulating, were vaccinated against ETEC twice during the first pregnancy and once during each following pregnancy. The log2 transformed F4 antibody titres in the serum obtained after the second vaccine injection as well as in the colostrum of the 12 resistant animals were lower than the titres of the susceptible animals (serum: F4ab 11,19 ± 1,44 vs. 12,18 ± 1,33, P = 0,096; F4ac 10,03 ± 1,58 vs. 11,59 ± 1,43, P = 0,019; colostrum: F4ab 12,20 ± 2,41 vs. 14,02 ± 1,31, P = 0,033; F4ac 10,93 ± 2,46 vs. 13,03 ± 5,21, P = 0,006). The heat labile enterotoxin (LT) antibody titres after vaccination did not differ between susceptible and resistant animals (p > 0,10). Preweaning mortality in the offspring of RR sows × SS boars was slightly lower than in the offspring of SS sows × RR boars (P = 0,04), suggesting that the disease risk of susceptible piglets born to vaccinated resistant sows was not increased, even though they received colostrum with a slightly reduced content of antibody against F4 fimbriae.

INTRODUCTION: Les porcs dépourvus de récepteurs intestinaux pour les fimbriae F4 sont congénitalement résistants aux Escherichia coli entérotoxinogènes porteurs de fimbriae F4 (ETEC F4). En général, 50 % et 100 % des porcelets nés de truies résistantes (RR) croisées avec des verrats hétéro- ou homozygotes sensibles (SR, SS), respectivement, sont sensibles mais ne reçoivent pas d'anticorps colostraux contre les fimbriae F4, à moins que les truies n'aient été vaccinées. La question se pose de savoir si les truies résistantes produisent des quantités protectrices d'anticorps antifimbriae F4 après la vaccination. Les titres d'anticorps dans le sérum et le colostrum de 12 truies reproductrices vaccinées résistantes et de 12 truies reproductrices vaccinées sensibles ont été comparés et l'effet du statut récepteur de la mère et du père sur les performances avant sevrage de 5027 porcelets a été évalué. Les truies du troupeau expérimental, où circulait ETEC F4, ont été vaccinées deux fois au cours de la première gestation et une fois au cours de chaque gestation suivante contre ETEC. Les titres d'anticorps F4 transformés en log2 dans le sérum obtenu après la deuxième injection de vaccin ainsi que dans le colostrum des 12 animaux résistants étaient inférieurs aux titres des animaux sensibles (sérum : F4ab 11,19 ± 1,44 vs. 12,18 ± 1,33, P = 0,096 ; F4ac 10,03 ± 1,58 vs. 11,59 ± 1,43, P = 0,019 ; colostrum : F4ab 12,20 ± 2,41 vs. 14,02 ± 1,31, P = 0,033 ; F4ac 10,93 ± 2,46 vs. 13,03 ± 5,21, P = 0,006). Les titres d'anticorps contre l'entérotoxine thermolabile (LT) après la vaccination ne différaient pas entre les animaux sensibles et résistants (p > 0,10). La mortalité avant sevrage dans la progéniture des truies RR × verrats SS était légèrement inférieure à celle de la progéniture des truies SS × verrats RR (P = 0,04), ce qui suggère que le risque de maladie des porcelets sensibles nés de truies résistantes vaccinées n'a pas été augmenté, même s'ils ont reçu du colostrum avec une teneur légèrement réduite en anticorps contre les fimbriae F4.

Assessment of Brazil's vesicular syndrome surveillance system: Profile of notifications and performance of the official veterinary service.

Foot-and-mouth disease (FMD) is an ailment that causes serious damage to the productive chain, and its control through vaccination is of utmost importance for its eradication. Brazil initiated the National Foot-and-Mouth Disease Surveillance Program (PNEFA) with the aim of making the country FMD-free by 2026. As part of the program, notifications of vesicular lesions became mandatory for the Official Veterinary Service (OVS), which is responsible for verifying them. Due to its size, border areas with countries that do not have FMD-free status pose a risk to Brazil and require greater attention. This study described the profile of notifications of suspected outbreaks of vesicular syndrome in Brazil and analyzed the performance of the surveillance system. The results showed 7134 registered notifications of suspected vesicular syndrome outbreaks from 2018 to 2022, with 2022 having the highest number (n = 2343 or 32.85 %). The species that generated the most notifications were swine (90.99 %), cattle and buffaloes (7.54 %), goats and sheep (1.44 %), and others (0.03 %). The sources of notification were "Veterinary medicine professionals" (61.82 %), "Owners or employees" (13.66 %), "Third parties" (8.90 %), "OVS" (7.20 %), and "others" (2.66 %). 41.69 % of notifications originated from non-border municipalities, and 58.32 % from border areas. Only the state of Paraná account for 51.73 % of the total notifications. This state also accounted for 66.70 % of the 32.47 % of notifications with a final diagnosis of "absence of clinically compatible signs or susceptible animals", indicating a certain lack of knowledge in the area, leading to unnecessary notifications and system overload. The performance of the OVS was evaluated based on the service response time from notification registration trough Logistic and Negative binomial regressions. A total of 27.83 % of notifications did not meet the Brazilian legally specified time, and the zone related to the state of Parana needs improvements in performance. The presence and peaks of Senecavirus A cases may have influenced an increased number of swine notifications and led to a decrease in OVS response time. The results demonstrate better performance of surveillance in border areas. Given the vast territory of Brazil, it is not expected that 100 % of responses occur within the legal timeframe, however, the performance of the surveillance system proved to be adequate, with 86 % complied to the legislation. The performance indicators could be used as a monitoring tool, along with indicators to demonstrate system overload. Continued education actions are crucial for strengthening PNEFA.

Analysis of the swine movement network in Mexico: A perspective for disease prevention and control.

Pig farming in Mexico is critical to the economy and food supply. Mexico has achieved advancements in swine health and established an electronic database that records swine movements (Sistema Nacional de Avisos de Movilización, SNAM). In this study, we characterized swine movement patterns in México between 2017 and 2019 to identify specific areas and periods that require concentrated efforts for effective epidemiological surveillance and disease control. We employed a Social Network Analysis (SNA) methodology to comprehensively describe and analyze the intricate patterns of pig movement. In addition, we sought to integrate swine population density into the analysis. We used metrics to characterize the network structure and identify the most critical nodes in the movement network. Cohesion metrics were used to identify commercial communities characterized by a high level of interconnectivity in swine movements between groups of nodes. Of a cumulative count of 662,255 pig shipments, 95.9% were attributed to slaughterhouse shipments. We observed that 54% of all Mexican municipalities were part of the network; however, the density of the movement network was less than 0.14%. We identified four Swine Production Centers in Mexico with high interconnectivity in the movement network. We detected moderate positive correlations (ρ ≥0.4 and <0.6, p < 0.001) between node metrics and swine population indicators, whereas the number of commercial swine facilities showed weak correlations with the node metrics. We identified six large, geographically clustered commercial communities that aligned with the Swine Production Centers. This study provides a comprehensive overview of swine movement patterns in Mexico and their close association with swine production centers, which play a dual role as producers and traders within the swine industry of Mexico. Our research offers valuable insights for policymakers in developing disease prevention and control strategies.

A field evaluation of a new porcine circovirus type 2d and Mycoplasma hyopneumoniae bivalent vaccine in herds suffering from subclinical PCV2d infection and enzootic pneumonia.

BACKGROUND: This field efficacy study was designed to determine the efficacy of a new bivalent vaccine containing porcine circovirus type 2d (PCV2d) and Mycoplasma hyopneumoniae at three independent pig farms. METHODS: Three pig farms were selected based on their history of subclinical PCV2 infection and enzootic pneumonia. Each farm housed a total of 40, 18-day-old pigs that were randomly allocated to 1 of 2 treatment groups. Pigs were administered a 2.0 mL dose of the bivalent vaccine intramuscularly at 21 days of age in accordance with the manufacturer's recommendations, whereas unvaccinated pigs were administered a single dose of phosphate-buffered saline at the same age. RESULTS: Clinically, the average daily weight gain of vaccinated groups was significantly higher (p < 0.05) than those of unvaccinated animals during the growing (70-112 days of age), finishing (112-175 days of age) and overall (3-175 days of age) stages of production. Vaccinated animals elicited neutralizing anti-PCV2 antibodies and PCV2d-specific interferon-γ secreting cells (IFN-γ-SC), which reduced the amount of PCV2d genomic copies in blood and reduced lymphoid lesions severity when compared with unvaccinated animals. Similarly, vaccinated animals elicited M. hyopneumoniae-specific IFN-γ-SC, which reduced the amount of M. hyopneumoniae in the larynx and reduced lung lesions severity. CONCLUSIONS: The result of the field trial demonstrated that the bivalent vaccine was efficacious in the protection of swine herds suffering from subclinical PCV2d infection and enzootic pneumonia.

Could a ring treatment approach be proposed to control Taenia solium transmission in a post elimination setting? A pilot study in Zambia.

BACKGROUND: Geographically targeted Taenia solium ring approaches consisting of treating individuals within a radius of 100-meter of a cysticercosis positive pig have been trialled in Peru. This study explored if a similar approach could be proposed to control T. solium transmission in a post elimination setting in Zambia, focussing on community members' willingness to be sampled and treated. METHODOLOGY AND PRINCIPAL FINDINGS: The study was conducted in a community where elimination of active T. solium transmission was achieved. All eligible pigs and people were sampled, at 4- to 6-monthly intervals, followed by implementation of the ring treatment approach. This implied that whenever a pig was seropositive for cysticercosis during sampling, every human and pig residing in a radius of 50-meters of the seropositive pig would be treated. The results of the positive human stool samples were used to create the rings, whenever no pigs were positive. From June 2018 to October 2019, four samplings, followed by ring treatments were conducted. Between 84% and 91% of the willing people provided a stool sample, covering 46% to 59% of the total population living in the study area. Between 78% and 100% of the eligible pigs got sampled. Three ring treatments were based on porcine seropositivity and one on taeniosis results. Two to four rings were opened per sampling. During the ring treatments, between 89% and 100% of the eligible human and pig population living within a ring was treated. CONCLUSIONS: Participants were willing to participate and get treatment, once the rings were opened. However, the utility of ring treatment approaches in a post elimination setting needs further evaluation, given the lack of highly accurate diagnostic tools for porcine cysticercosis and the challenges in obtaining stool samples. The ring treatment approach adopted should be further improved before recommendations to public health authorities can be given.

Epitopes screening and vaccine molecular design of PEDV S protein based on immunoinformatics.

Porcine epidemic diarrhea virus (PEDV) is a serious disease that poses a significant threat to the pig industry. This study focused on analyzing the Spike protein of PEDV, which harbors crucial antigenic determinants, in identifying dominant epitopes. Immunoinformatics tools were used to screen for B-cell, CD4+ and CD8+ predominance epitopes. These epitopes were then connected to the N-terminal of ferritin to form a self-assembled nanoparticle vaccine. Various physical and chemical properties of the candidate vaccine were analyzed, including secondary structure prediction, tertiary structure modeling, molecular docking, immune response simulation and computer cloning. The results demonstrated that the candidate vaccine was antigenic, soluble, stable, non-allergic, and formed a stable complex with the target receptor TLR-3. Immune simulation analysis showed that the candidate vaccine effectively stimulated both cellular and humoral reactions, leading to increased related cytokines production. Furthermore, efficient and stable expression of the candidate vaccine was achieved through reverse translation in the Escherichia coli K12 expression system following codon optimization and in silico cloning. The developed nanoparticle candidate vaccine in this study holds promise as an effective PEDV vaccine candidate, offering a new approach for the research, development and improvement of vaccines targeting porcine enteric diarrhea coronavirus.

Lipid nanoparticle-encapsulated DNA vaccine confers protection against swine and human-origin H1N1 influenza viruses.

In 2009, a novel swine-origin H1N1 virus emerged, causing a pandemic. The virus, known as H1N1pdm09, quickly displaced the circulating H1 lineage and became the dominant seasonal influenza A virus subtype infecting humans. Human-to-swine spillovers of the H1N1pdm09 have occurred frequently, and each occurrence has led to sustained transmission of the human-origin H1N1pdm09 within swine populations. In the present study, we developed a lipid nanoparticle-based DNA vaccine (LNP-DNA) containing the hemagglutinin gene of a swine-origin H1N1pdm09. In pigs, this LNP-DNA vaccine induced a robust antibody response after a single intramuscular immunization and protected the pigs against challenge infection with the homologous swine-origin H1N1pdm09 virus. In a mouse model, the LNP-DNA vaccine induced antibody and T-cell responses and protected mice against lethal challenge with a mouse-adapted human-origin H1N1pdm09 virus. These findings demonstrate the potential of the LNP-DNA vaccine to protect against both swine- and human-origin H1N1pdm09 viruses. IMPORTANCE: Swine influenza A virus (IAV) is widespread and causes significant economic losses to the swine industry. Moreover, bidirectional transmission of IAV between swine and humans commonly occurs. Once introduced into the swine population, human-origin IAV often reassorts with endemic swine IAV, resulting in reassortant viruses. Thus, it is imperative to develop a vaccine that is not only effective against IAV strains endemic in swine but also capable of preventing the spillover of human-origin IAV. In this study, we developed a lipid nanoparticle-encapsulated DNA plasmid vaccine (LNP-DNA) that demonstrates efficacy against both swine- and human-origin H1N1 viruses. The LNP-DNA vaccines are non-infectious and non-viable, meeting the criteria to serve as a vaccine platform for rapidly updating vaccines. Collectively, this LNP-DNA vaccine approach holds great potential for alleviating the impact of IAV on the swine industry and preventing the emergence of reassortant IAV strains.

Baicalin and probenecid protect against Glaesserella parasuis challenge in a piglet model.

Glaesserella parasuis (G. parasuis) induces vascular damage and systemic inflammation. However, the mechanism by which it causes vascular damage is currently unclear. Baicalin has important anti-inflammatory, antibacterial and immunomodulatory functions. In this study, we explored the ability of baicalin and probenecid to protect against G. parasuis challenge in a piglet model. Sixty piglets were randomly divided into a control group; an infection group; a probenecid group; and 25 mg/kg, 50 mg/kg and 100 mg/kg baicalin groups. The probenecid group and the 25 mg/kg, 50 mg/kg and 100 mg/kg baicalin groups were injected intramuscularly with 20 mg/kg body weight (BW) probenecid and 25 mg/kg BW, 50 mg/kg BW and 100 mg/kg BW baicalin, respectively. All piglets except those from the control group were injected intraperitoneally with 1 × 108 CFU of G. parasuis. The control group was injected intraperitoneally with TSB. The results showed baicalin and probenecid protected piglets against G. parasuis challenge, improved body weight and decreased temperature changes in piglets. Baicalin and probenecid attenuated IL-1ß, IL-10, IL-18, TNF-α and IFN-γ mRNA levels in the blood for 48 h, inhibited the production of the nucleosides ATP, ADP, AMP and UMP from 24 to 72 h, reduced Panx-1/P2Y6/P2X7 expression, weakened NF-kB, AP-1, NLRP3/Caspase-1 and ROCK/MLCK/MLC signalling activation, and upregulated VE-cadherin expression in the blood vessels of piglets challenged with G. parasuis. Baicalin and probenecid alleviated pathological tissue damage in piglets induced by G. parasuis. Our results might provide a promising strategy to control and treat G. parasuis infection in the clinical setting.

Monovalent, bivalent and biparatopic nanobodies targeting S1 protein of porcine epidemic diarrhea virus efficiently neutralized the virus infectivity.

BACKGROUND: Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that causes severe diarrhea and death in neonatal piglets, which has brought huge economic losses to the pork industry worldwide since its first discovery in the early 1970s in Europe. Passive immunization with neutralizing antibodies against PEDV is an effective prevention measure. To date, there are no effective therapeutic drugs to treat the PEDV infection. RESULTS: We conducted a screening of specific nanobodies against the S1 protein from a phage display library obtained from immunized alpacas. Through competitive binding to antigenic epitopes, we selected instead of chose nanobodies with high affinity and constructed a multivalent tandem. These nanobodies were shown to inhibit PEDV infectivity by the neutralization assay. The antiviral capacity of nanobody was found to display a dose-dependent pattern, as demonstrated by IFA, TCID50, and qRT-PCR analyses. Notably, biparatopic nanobody SF-B exhibited superior antiviral activity. Nanobodies exhibited low cytotoxicity and high stability even under harsh temperature and pH conditions, demonstrating their potential practical applicability to animals. CONCLUSIONS: Nanobodies exhibit remarkable biological properties and antiviral effects, rendering them a promising candidate for the development of anti-PEDV drugs.

[Fusion expression and immunogenicity of receptor-binding domains of porcine deltacoronavirus and porcine epidemic diarrhea virus].

This study aims to develop an effective bivalent subunit vaccine that is promising to prevent both porcine deltacoronavirus (PDCoV) and porcine epidemic diarrhea virus (PEDV). The receptor-binding domains (RBDs) of PDCoV and PEDV were fused and cloned into the eukaryotic expression vector pCDNA3.1(+). The fusion protein PDCoV-RBD-PEDV-RBD (pdRBD-peRBD) was expressed by the ExpiCHOTM expression system and purified. Mice were immunized with the fusion protein at three different doses (10, 20, and 30 µg). The humoral immune response and cellular immune response induced by the fusion protein were evaluated by ELISA and flow cytometry. The neutralization titers of the serum of immunized mice against PDCoV and PEDV were determined by the microneutralization test. The results showed that high levels of IgG antibodies were induced in the three different dose groups after booster immunization, and there was no significant difference in the antibody level between different dose groups, indicating that the immunization dose of 10 µg could achieve the fine immune effect. The results of flow cytometry showed that the immunization groups demonstrated increased proportion of CD3+CD4+ T cells and decreased proportion of CD3+CD8+ T cells, which was consistent with the expectation about the humoral immune response induced by the subunit vaccine. At the same time, the levels of interleukin (IL)-2, IL-4, and interferon (IFN)-γ in the serum were determined. The results showed that the fusion protein induced both humoral immune effect and cellular immune response. The results of the neutralization test showed that the antibody induced by 10 µg fusion protein neutralized both PDCoV and PEDV in vitro, with the titers of 1:179.25 and 1:141.21, respectively. The above results suggested that the pdRBD-peRBD could induce a high level of humoral immune response at a dose of 10 µg, and the induced antibody could neutralize both PDCoV and PEDV. Therefore, the fusion protein pdRBD-peRBD is expected to be an effective subunit vaccine that can simultaneously prevent PDCoV and PEDV.

A nanoparticle vaccine based on the VP121-26 and VP2 structural proteins of Senecavirus A induces robust protective immune responses.

Senecavirus A (SVA) is a causative agent that can cause vesicular disease in swine, which causes a great threat to the swine husbandry in the world. Therefore, it is necessary to develop a vaccine that can effectively prevent the spread of SVA. In this study, we developed a 24-polymeric nano-scaffold using ß-annulus peptide from tomato bushy effect virus (TBSV) by coupling this antigen to SVA B cell epitope VP121-26 and VP2 proteins via linkers, respectively. The SVA-based nanoparticle protein of the VP1(B)-ß-VP2 was expressed and purified by low-cost prokaryotic system to prepare a SVA nanoparticle vaccine. The immunological protective effect of SVA nanoparticle vaccine was evaluated in mouse and swine models, respectively. The results suggested that both mice and swine could induce high levels SVA neutralizing antibodies and IgG antibodies after two doses immunization. In addition, the swine challenge protection experiment showed that the protection rate of immune SVA nanoparticle vaccine and SVA inactivated vaccine both were 80 %, while the negative control had no protection effect. It demonstrated that SVA nanoparticle vaccine effectively prevented SVA infection in swine. In summary, the preparation of SVA vaccine by using ß-annulus peptide is a promising candidate vaccine for prevent SVA transmission, and provides a new idea for the development of novel SVA vaccines.

Design of multi-epitope vaccine against porcine rotavirus using computational biology and molecular dynamics simulation approaches.

Porcine Rotavirus (PoRV) is a significant pathogen affecting swine-rearing regions globally, presenting a substantial threat to the economic development of the livestock sector. At present, no specific pharmaceuticals are available for this disease, and treatment options remain exceedingly limited. This study seeks to design a multi-epitope peptide vaccine for PoRV employing bioinformatics approaches to robustly activate T-cell and B-cell immune responses. Two antigenic proteins, VP7 and VP8*, were selected from PoRV, and potential immunogenic T-cell and B-cell epitopes were predicted using immunoinformatic tools. These epitopes were further screened according to non-toxicity, antigenicity, non-allergenicity, and immunogenicity criteria. The selected epitopes were linked with linkers to form a novel multi-epitope vaccine construct, with the PADRE sequence (AKFVAAWTLKAAA) and RS09 peptide attached at the N-terminus of the designed peptide chain to enhance the vaccine's antigenicity. Protein-protein docking of the vaccine constructs with toll-like receptors (TLR3 and TLR4) was conducted using computational methods, with the lowest energy docking results selected as the optimal predictive model. Subsequently, molecular dynamics (MD) simulation methods were employed to assess the stability of the protein vaccine constructs and TLR3 and TLR4 receptors. The results indicated that the vaccine-TLR3 and vaccine-TLR4 docking models remained stable throughout the simulation period. Additionally, the C-IMMSIM tool was utilized to determine the immunogenic triggering capability of the vaccine protein, demonstrating that the constructed vaccine protein could induce both cell-mediated and humoral immune responses, thereby playing a role in eliciting host immune responses. In conclusion, this study successfully constructed a multi-epitope vaccine against PoRV and validated the stability and efficacy of the vaccine through computational analysis. However, as the study is purely computational, experimental evaluation is required to validate the safety and immunogenicity of the newly constructed vaccine protein.

Analyzing the intrastate and interstate swine movement network in the United States.

Identifying and restricting animal movements is a common approach used to mitigate the spread of diseases between premises in livestock systems. Therefore, it is essential to uncover between-premises movement dynamics, including shipment distances and network-based control strategies. Here, we analyzed three years of between-premises pig movements, which include 197,022 unique animal shipments, 3973 premises, and 391,625,374 pigs shipped across 20 U.S. states. We constructed unweighted, directed, temporal networks at 180-day intervals to calculate premises-to-premises movement distances, the size of connected components, network loyalty, and degree distributions, and, based on the out-going contact chains, identified network-based control actions. Our results show that the median distance between premises pig movements was 74.37 km, with median intrastate and interstate movements of 52.71 km and 328.76 km, respectively. On average, 2842 premises were connected via 6705 edges, resulting in a weak giant connected component that included 91 % of the premises. The premises-level network exhibited loyalty, with a median of 0.65 (IQR: 0.45 - 0.77). Results highlight the effectiveness of node targeting to reduce the risk of disease spread; we demonstrated that targeting 25 % of farms with the highest degree or betweenness limited spread to 1.23 % and 1.7 % of premises, respectively. While there is no complete shipment data for the entire U.S., our multi-state movement analysis demonstrated the value and the needs of such data for enhancing the design and implementation of proactive- disease control tactics.

AhR ligands from LGG metabolites promote piglet intestinal ILC3 activation and IL-22 secretion to inhibit PEDV infection.

In maintaining organismal homeostasis, gut immunity plays a crucial role. The coordination between the microbiota and the immune system through bidirectional interactions regulates the impact of microorganisms on the host. Our research focused on understanding the relationships between substantial changes in jejunal intestinal flora and metabolites and intestinal immunity during porcine epidemic diarrhea virus (PEDV) infection in piglets. We discovered that Lactobacillus rhamnosus GG (LGG) could effectively prevent PEDV infection in piglets. Further investigation revealed that LGG metabolites interact with type 3 innate lymphoid cells (ILC3s) in the jejunum of piglets through the aryl hydrocarbon receptor (AhR). This interaction promotes the activation of ILC3s and the production of interleukin-22 (IL-22). Subsequently, IL-22 facilitates the proliferation of IPEC-J2 cells and activates the STAT3 signaling pathway, thereby preventing PEDV infection. Moreover, the AhR receptor influences various cell types within organoids, including intestinal stem cells (ISCs), Paneth cells, and enterocytes, to promote their growth and development, suggesting that AhR has a broad impact on intestinal health. In conclusion, our study demonstrated the ability of LGG to modulate intestinal immunity and effectively prevent PEDV infection in piglets. These findings highlight the potential application of LGG as a preventive measure against viral infections in livestock.IMPORTANCEWe observed high expression of the AhR receptor on pig and human ILC3s, although its expression was negligible in mouse ILC3s. ILC3s are closely related to the gut microbiota, particularly the secretion of IL-22 stimulated by microbial signals, which plays a crucial regulatory role in intestinal immunity. In our study, we found that metabolites produced by beneficial gut bacteria interact with ILC3s through AhR, thereby maintaining intestinal immune homeostasis in pigs. Moreover, LGG feeding can enhance the activation of ILC3s and promote IL-22 secretion in the intestines of piglets, ultimately preventing PEDV infection.

Luteolin, a natural flavonoid, exhibits a protective effect on intestinal injury induced by soybean meal in early-weaned piglets.

Soybean meal is known to be able to cause intestinal damage and dysfunction in early-weaned piglets. However, research on natural compounds that can alleviate these effects is scarce. In this study, the effect of luteolin, a natural flavonoid, on intestinal health of piglets fed on a soybean meal-based diet was explored. A total of eighteen 21-d-old piglets were selected and randomly divided into 3 groups: a negative control group fed with an animal protein-based diet, a positive control group fed with a soybean meal-based diet, and a luteolin group that was fed with the positive control diet supplemented with luteolin. The results suggested that luteolin supplementation significantly increased the average daily gain and average daily feed intake of early-weaned piglets, while effectively reducing the diarrhea incidence. Additionally, luteolin supplementation lowered the levels of soybean antigen-specific immunoglobulin G and immunoglobulin E anitbodies, increased the superoxide dismutase activity in both sera and small intestine mucosa, and enhanced the total antioxidant capacity in sera. Further research found that luteolin supplementation increased the intestinal villi height and decreased the crypt depth, resulting in an increased ratio of villi to crypts. At the same time, it reduced the concentration of serum diamine oxidase, improving intestinal barrier function. Moreover, luteolin significantly decreased the gene expression of Bax and Caspase-3, reducing cell apoptosis in the intestinal mucosa. Luteolin supplementation also increased the abundance of Actinobacteria at the phylum level, reduced the abundance of Prevotella and increased the abundance of Olsenella at the genus level. In conclusion, the supplementation of luteolin to the soybean meal diet was capable of effectively reducing allergic response, enhancing the antioxidant capacity of early-weaned piglets, protecting their intestinal barrier function, inhibiting intestinal mucosal cell apoptosis, and altering the intestinal microbiota structure, therefore promoting intestinal health and improving production performance in early-weaned piglets.

Soybean meal can cause intestinal injury in early-weaned piglets. We wanted to know if luteolin has a protective effect against the intestinal injury caused by soybean meal in piglets. We found that luteolin was capable to alleviate intestinal injury and dysfunction caused by soybean meal in early-weaned piglets, promote their intestinal health, and improve production performance.

Surface display of the COE antigen of porcine epidemic diarrhoea virus on Bacillus subtilis spores.

Porcine epidemic diarrhoea virus (PEDV) infects pigs of all ages by invading small intestine, causing acute diarrhoea, vomiting, and dehydration with high morbidity and mortality among newborn piglets. However, current PEDV vaccines are not effective to protect the pigs from field epidemic strains because of poor mucosal immune response and strain variation. Therefore, it is indispensable to develop a novel oral vaccine based on epidemic strains. Bacillus subtilis spores are attractive delivery vehicles for oral vaccination on account of the safety, high stability, and low cost. In this study, a chimeric gene CotC-Linker-COE (CLE), comprising of the B. subtilis spore coat gene cotC fused to the core neutralizing epitope CO-26 K equivalent (COE) of the epidemic strain PEDV-AJ1102 spike protein gene, was constructed. Then recombinant B. subtilis displaying the CLE on the spore surface was developed by homologous recombination. Mice were immunized by oral route with B. subtilis 168-CLE, B. subtilis 168, or phosphate-buffered saline (PBS) as control. Results showed that the IgG antibodies and cytokine (IL-4, IFN-γ) levels in the B. subtilis 168-CLE group were significantly higher than the control groups. This study demonstrates that B. subtilis 168-CLE can generate specific systemic immune and mucosal immune responses and is a potential vaccine candidate against PEDV infection.

Lactiplantibacillus argentoratensis AGMB00912 alleviates salmonellosis and modulates gut microbiota in weaned piglets: a pilot study.

This study aimed to evaluate the efficacy of Lactiplantibacillus argentoratensis AGMB00912 (LA) in reducing Salmonella Typhimurium infection in weaned piglets. The investigation focused on the influence of LA on the gut microbiota composition, growth performance, and Salmonella fecal shedding. The results indicated that LA supplementation significantly improved average daily gain and reduced the prevalence and severity of diarrhea. Fecal analysis revealed reduced Salmonella shedding in the LA-supplemented group. Furthermore, LA notably altered the composition of the gut microbiota, increasing the levels of beneficial Bacillus and decreasing those of harmful Proteobacteria and Spirochaetes. Histopathological examination showed less intestinal damage in LA-treated piglets than in the controls. The study also observed that LA affected metabolic functions related to carbohydrate, amino acid, and fatty acid metabolism, thereby enhancing gut health and resilience against infection. Short-chain fatty acid concentrations in the feces were higher in the LA group, suggesting improved gut microbial activity. LA supplementation enriched the population of beneficial bacteria, including Streptococcus, Clostridium, and Bifidobacterium, while reducing the number of harmful bacteria, such as Escherichia and Campylobacter. These findings indicate the potential of LA as a probiotic alternative for swine nutrition, offering protective effects to the gut microbiota against Salmonella infection.