African Swine Fever Research Articles

Ancestry and genome-wide association study of domestic pigs that survive African swine fever in Uganda

African swine fever (ASF) is endemic to Uganda and causes annual outbreaks. Some pigs survive these outbreaks and remain asymptomatic but are African swine fever virus (ASFV) positive. The potential heritability and genetic disparities in disease susceptibility among Ugandan pigs are not fully understood. In a 12-year study, whole blood and tissue samples were collected from 212 pigs across 19 districts in Uganda. Polymerase chain reaction (PCR) assays were used to determine ASFV infection status and genotyping was completed using a commercial porcine array. The point prevalence of ASF was calculated for each district, and breed composition origins were quantified for the sampled pigs by implementing established ancestry analyses. Genome-wide associated studies (GWAS) were conducted using all available domestic swine samples (full study population; n = 206) as well as a reduced dataset (farm-level study population; n = 129). This study revealed a greater number of ASFV-positive pigs in border districts than in non-border districts, a high level of admixture among domestic pigs sampled from Ugandan smallholder farms, and 48 loci that were associated with ASFV infection status. The discovery of 48 significant SNPs and 28 putative candidate genes may imply the possibility of heritability for resistance to ASFV. However, additional investigations in ASFV-endemic regions are required to fully elucidate the heritability of ASFV susceptibility among surviving pigs in Uganda.

EVIT-YOLOv8: Construction and research on African Swine Fever facial expression recognition

The threats of infectious diseases such as African Swine Fever, Swine Erysipelas, and Blue Ear Disease to the pig farming industry have been increasing year by year. Producers often face difficulties in diagnosis, leading to the misuse of measures and the spread of epidemics. Addressing this, the proposed EVIT-YOLOv8 model integrates the EViT module to surpass ViT limitations and incorporates the CBAM module for enhanced image feature representation. Employing the GIOU loss function ensures better precision in capturing facial expression features, yielding an impressive Mean Average Precision (mAP) of 86.6% in differentiation tasks. Specifically, in African Swine Fever facial expression recognition, the model achieves a remarkable Precision of 85.2%, outperforming YOLOv5, YOLOv7, and YOLOv8 models by 6%, 23.5%, and 7.3%, respectively. This provides pig producers with a precise diagnostic tool, mitigating the risk of epidemic spread due to misdiagnosis and facilitating effective prevention and control of infectious diseases.

Identification and characterization of linear B-cell epitopes on African swine fever virus H171R protein.

African swine fever virus (ASFV) poses a severe threat to the global swine industry. This study characterizes linear B-cell epitopes on the crucial ASFV H171R protein, facilitating the development of improved diagnostics and subunit vaccines. Four immunogenic epitopes were identified, offering valuable information for designing sensitive diagnostic assays and potential subunit vaccine candidates. By advancing the understanding of H171R's antigenic landscape, this research contributes to controlling ASFV's devastating impacts, safeguarding the swine industry, and ensuring food security.

Enhanced Recovery and Detection of Highly Infectious Animal Disease Viruses by Virus Capture Using Nanotrap® Microbiome A Particles

This study reports the use of Nanotrap® Microbiome A Particles (NMAPs) to capture and concentrate viruses from diluted suspensions to improve their recovery and sensitivity to detection by real-time PCR/RT-PCR (qPCR/RT-qPCR). Five highly infectious animal disease viruses including goatpox virus (GTPV), sheeppox virus (SPPV), lumpy skin disease virus (LSDV), peste des petits ruminants virus (PPRV), and African swine fever virus (ASFV) were used in this study. After capture, the viruses remained viable and recoverable by virus isolation (VI) using susceptible cell lines. To assess efficacy of recovery, the viruses were serially diluted in phosphate-buffered saline (PBS) or Eagle’s Minimum Essential Medium (EMEM) and then subjected to virus capture using NMAPs. The NMAPs and the captured viruses were clarified on a magnetic stand, reconstituted in PBS or EMEM, and analyzed separately by VI and virusspecific qPCR/RT-qPCR. The PCR results showed up to a 100-fold increase in the sensitivity of detection of the viruses following virus capture compared to the untreated viruses from the same dilutions. Experimental and clinical samples were subjected to virus capture using NMAPs and analyzed by PCR to determine diagnostic sensitivity (DSe) that was comparable (100%) to that determined using untreated (-NMAPs) samples. NMAPs were also used to capture spiked viruses from EDTA whole blood (EWB). Virus capture from EWB was partially blocked, most likely by hemoglobin (HMB), which also binds NMAPs and outcompetes the viruses. The effect of HMB could be removed by either dilution (in PBS) or using HemogloBind™ (Biotech Support Group; Monmouth Junction, NJ), which specifically binds and precipitates HMB. Enhanced recovery and detection of viruses using NMAPs can be applicable to other highly pathogenic animal viruses of agricultural importance.

Development and optimization of a double antigen sandwich ELISA detecting for Senecavirus A antibodies based on VP2 protein.

Senecavirus A (SVA) is an emerging viral pathogen that threatens the global swine industry significantly. The major clinical symptoms of SVA-infected animals are vesicular lesions, but various diseases can cause the same symptoms, which makes it difficult to distinguish SVA from other vesicular diseases clinically. The absence of an effective and safe vaccine necessitates the development of a simple, specific, and sensitive serological detection method for SVA antibodies. The VP2 protein of SVA, characterized by high immunogenicity and sequence conservatism, is an essential target for serological diagnosis. In this study, a double-antigen sandwich enzyme-linked immunosorbent assay [ELISA (DAgS-ELISA)] based on VP2 protein expressed by Escherichia coli was established for SVA antibody detection. With a cutoff value of 0.237, this assay demonstrated outstanding performance, showing high sensitivity and sharp specificity, which is manifested in the absence of cross-reaction with classical swine fever virus (CSFV), African swine fever virus (ASFV), pseudorabies virus (PRV), and porcine reproductive and respiratory syndrome virus (PRRSV), and foot-and-mouth disease virus (FMDV) serotype A and O. Additionally, the repeatability of the method is remarkable, as shown by the coefficients variation (CV) of both the intra- and inter-assay below 10%. By detecting 166 clinical sera, it was found that the kappa value of the DAgS-ELISA was 0.78 compared with that of the virus neutralization test (VNT), indicating a high level of consistency. In general, this method has high sensitivity, sharp specificity, remarkable repeatability, sound consistency, and low cost, making it a reliable and effective tool for detecting SVA antibodies.IMPORTANCESVA has rapidly become prevalent in many countries, and its outbreaks have threatened the global swine industry significantly. The major clinical symptoms of SVA-infected animals are vesicular lesions that are similar to other vesicular diseases, making it difficult to distinguish SVA. Currently, no commercial vaccines are available for SVA; therefore, effective diagnosis of SVA infection is vital for its prevention and control. In this study, VP2 protein of SVA was expressed by E. coli, and a double-antigen sandwich enzyme-linked immunosorbent assay [ELISA (DAgS-ELISA)] for SVA antibodies detection was successfully established based on the VP2 protein. The DAgS-ELISA has a high sensitivity, sharp specificity, remarkable repeatability, sound consistency, and low cost for detecting SVA antibodies. Therefore, the DAgS-ELISA established in this study may be a reliable and effective tool for detecting SVA antibodies and may be used to strengthen the monitoring and prevention of SVA epidemic in the long run.

Recombinant Lactiplantibacilllus plantarum modulate gut microbial diversity and function

BackgroundGut microbes are important regulators of host health and can also function as disease indicators. Lactiplantibacilllus plantarum(L. plantarum)used as express and delivery vaccines for mucosal immunity have been shown to activate specific immune responses in numerous studies.ResultsThe interaction between recombinant L. plantarum and the gut microbiota was investigated in this study. The results indicated a change in the amount of gut OTU by recombinant L. plantarum. Recombinant L. plantarum dramatically boosted the species diversity of gut bacteria based on the Shannon-Wiener index. Beta diversity analysis showed that microbial structure was changed by recombinant L. plantarum. Furthermore, recombinant NC8 L. plantarum expressing a fusion between the P14.5 protein of the African swine fever virus and IL-33 enhanced the functions of gut bacteria in metabolism and immune regulation. Increased levels of IgG and IgG1 in serum and sIgA in feces, as well as enrichment of CD4+ T cells and IgA+ B cells, indicated that the gut microbiota exerted an immunomodulatory role when mediated by recombinant L. plantarum.ConclusionsThese results revealed that recombinant L. plantarum exerted its potential role in the gut microbiota and gut immunity.These fndings contribute to a broader understanding and utilization of L. plantarum bacteria in various therapeutic applications.

Reply to Graille, "InsPection of electron density maps supports wrongly modeled hexakisphosphate (InsP6) bound to African swine fever mRNA-decapping enzyme g5Rp".

Reply to Graille, "InsPection of electron density maps supports wrongly modeled hexakisphosphate (InsP6) bound to African swine fever mRNA-decapping enzyme g5Rp".

Exploring the Effect of Active Components in Oil Tree Peony Seed Meal on Swine Disease Resistance and its Potential Mechanisms Based on Network Pharmacology and Molecular Docking.

This study aims to explore the feasibility of using network pharmacology and molecular docking technology to predict the effects of active components from oil tree peony seed meal (PSM) on swine diseases. Ten active components of PSM were screened Screening through literature search and network pharmacology standards, including Betulinic acid, Quercetin, Kaempferol, Luteolin, Isorhamnetin, Hydroxygenkwanin, Hederagenin, Benzoyl Paeoniflorin, Albiflorin, Paeoniflorin. Ten types of swine diseases were selected, including African Swine Fever, Aftosa, Swine Vesicular Disease, Transmissible Gastroenteritis, Swine Streptococcal Infection, Blue Aural Disease, Swine Infectious Atrophic Rhinitis, Swine Influenza, Swine Erysipelas, Swine Epidemic Encephalitis. The results showed that the average number of cross genes between the potential target genes of PSM active components and each swine disease target gene accounted for 7.64 % of the total number of swine disease target genes. The GO enrichment analyses showed that putative targets exist in endosomes, lysosomes, cell membranes, nerves, growth factor activity, receptor tyrosine kinase binding, enzyme binding, growth factor binding, transcription coactivator binding, oxidoreductase activity, prostaglandin E receptor activity and insulin receptor substrate binding. The KEGG enrichment analysis results showed that these putative genes were involved in various cancer progression pathways, signaling pathways, and hormone regulatory pathways. A total of 8 core targets were obtained through protein-protein interaction networks analysis, including Protein Kinase CAMP-Activated Catalytic Subunit Alpha (PRKACA), Non-Receptor Tyrosine Kinase (SRC), Mitogen-Activated Protein Kinase 1 (MAPK1), E1A Binding Protein P300 (EP300), Hypoxia Inducible Factor 1 Subunit Alpha (HIF1A), Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Beta (PIK3CB), C-X-C chemokine receptor type 4 (CXCR4) and Estrogen Receptor 2 (ESR2). The HIF-1 signaling pathway was found to be associated with all 10 selected swine diseases. The PD-L1 expression, and PD-1 checkpoint pathway in cancer, and thyroid hormone signaling pathway were not only enriches the core target with a quantity of 7, but also associated with 9 Swine diseases. In addition, the molecular docking results indicate that the core ingredients have strong affinity with hub genes. The research suggests that the active components of PSM may intervene in swine diseases through multiple components, targets, and pathways.

Assessment of Nine Real-Time PCR Kits for African Swine Fever Virus Approved in Republic of Korea.

The African swine fever virus (ASFV) causes severe disease in wild and domestic pigs, with high mortality rates, extensive spread, and significant economic losses globally. Despite ongoing efforts, an effective vaccine remains elusive. Therefore, effective diagnostic methods are needed to rapidly detect and prevent the further spread of ASF. This study assessed nine commercial kits based on real-time polymerase chain reaction (PCR) approved in the Republic of Korea using the synthesized ASFV plasmid, 20 food waste samples, and artificially spiked samples (ASSs). The kits were evaluated for their diagnostic sensitivity, specificity, cost per reaction, and reaction running time. In addition, the results were compared with those of the World Organization for Animal Health (WOAH) standard methods. Three commercial kits (VDx® ASFV qPCR Kit, Palm PCR™ ASFV Fast PCR Kit, and PowerChek™ ASFV Real-time PCR Detection Kit Ver.1.0) demonstrated the highest sensitivity (100 ag/μL), cost-effectiveness (less than KRW 10,000), and shortest running time (less than 70 min). These kits are suitable for the monitoring, early diagnosis, and prevention of the spread of ASF. This is the first report on the performance comparison of ASFV diagnostic kits approved in the Republic of Korea, providing valuable information for selecting kits for testing with food waste samples.

A plant-based oligomeric CD2v extracellular domain antigen exhibits equivalent immunogenicity to the live attenuated vaccine ASFV-G-∆I177L.

African swine fever (ASF), caused by the African swine fever virus (ASFV), is a deadly, highly contagious disease in both domestic pigs and wild boar. With mortality up to 100%, the disease has been making a serious impact on the swine industry worldwide. Because no effective antiviral treatment has been observed, proactive prevention such as vaccination remains the key to controlling the outbreak. In the pursuit of expediting vaccine development, our current work has made the first report for heterologous production of the viral outer envelope glycoprotein CD2v extracellular domain (CD2v ED), a proposed promising vaccine antigen candidate in the "green" synthetic host Nicotiana benthamiana. Protein oligomerization strategies were implemented to increase the immunogenicity of the target antigen. Herein, the protein was expressed in oligomeric forms based on the C-terminally fused GCN4pII trimerization motif and GCN4pII_TP oligomerization motif. Quantitative western blot analysis showed significantly higher expression of trimeric CD2v ED_GCN4pII with a yield of about 12mg/100g of fresh weight, in comparison to oligomeric CD2v ED_GCN4pII_TP, revealing the former is the better choice for further studies. The results of purification and size determination by size exclusion chromatography (SEC) illustrated that CD2v ED_GCN4pII was successfully produced in stable oligomeric forms throughout the extraction, purification, and analysis process. Most importantly, purified CD2v ED_GCN4pII was demonstrated to induce both humoral and cellular immunity responses in mice to extents equivalent to those of the live attenuated vaccine ASFV-G-∆I177L, suggesting it as the potential subunit vaccine candidate for preventing ASFV.

Antiviral Activity of Plant-Based Additives Against African Swine Fever Virus (ASFV) in Feed Ingredients.

African swine fever (ASF) is one of the deadliest swine diseases with haemorrhagic symptoms and a high mortality rate. Plant-derived additives are potential antiviral agents against viruses due to their environmental and user-friendly properties. This study aims to evaluate the efficacy of plant-based additives (Phyto.A04 and Phyto.B) compared to an organic acid blend (OAB) in inactivating ASF virus (ASFV) in cell culture and feed. ASFV-spiked feed was treated with individual or combined additives such as OAB, Phyto.A04 and Phyto.B. The viability of ASFV after treatment of ASFV-spiked feed with additives was then confirmed by both methods, real-time PCR and cell culture. The results of the in vitro test with cell cultures showed that all three additives (OAB, Phyto.A04 and Phyto.B) exerted a strong virucidal effect on ASFV in porcine alveolar macrophage cells. OAB at a concentration of 0.3% reduced the virus concentration from 4.48 log10 HAD50/mL after 1 day of treatment (day 1) to 3.29 log10 HAD50/mL after 3 days of treatment (day 3) and remained undetected after 7 days of treatment (day 7). In Phyto.A04 with 1%, the virus was only detectable on day 1 (3.53 log10 HAD50/mL). Phyto.B with 0.01% and 0.05% both showed good efficacy in completely inhibiting virus presence on days 3 and 7. All additives, OAB, Phyto.A04 and Phyto.B, were able to inactivate ASFV in a dose-dependent manner, as confirmed by cell culture and PCR methods. The combination of additives at different concentrations consistently improved the virucidal results.

PK205R targets the proximal element of IFN-I signaling pathway to assist African swine fever virus to escape host innate immunity at the early stage of infection.

African swine fever virus (ASFV) is a nuclear cytoplasmic large DNA virus (NCLDV) that causes devastating hemorrhagic diseases in domestic pigs and wild boars, seriously threatening the development of the global pig industry. IFN-I plays an important role in the body's antiviral response. Similar to other DNA viruses, ASFV has evolved a variety of immune escape strategies to antagonize IFN-I signaling and maintain its proliferation. In this study, we showed that the ASFV early protein pK205R strongly inhibited interferon-stimulated genes (ISGs) as well as the promoter activity of IFN-stimulated regulatory elements (ISREs). Mechanistically, pK205R interacted with the intracellular domains of IFNAR1 and IFNAR2, thereby inhibiting the interaction of IFNAR1/2 with JAK1 and TYK2 and hindering the phosphorylation and nuclear translocation of STATs. Subsequently, we generated a recombinant strain of the ASFV-pK205R point mutation, ASFV-pK205R7PM. Notably, we detected higher levels of ISGs in porcine alveolar macrophages (PAMs) than in the parental strain during the early stages of ASFV-pK205R7PM infection. Moreover, ASFV-pK205R7PM attenuated the inhibitory effect on IFN-I signaling. In conclusion, we identified a new ASFV immunosuppressive protein that increases our understanding of ASFV immune escape mechanisms.

Replication Characteristics of African Swine Fever Virus (ASFV) Genotype I E70 and ASFV Genotype II Belgium 2018/1 in Perivenous Macrophages Using Established Vein Explant Model.

African Swine Fever Virus (ASFV), resulting in strain-dependent vascular pathology, leading to hemorrhagic fever, is an important pathogen in swine. The pathogenesis of ASFV is determined by the array and spatial distribution of susceptible cells within the host. In this study, the replication characteristics of ASFV genotype I E70 (G1-E70) and ASFV genotype II Belgium 2018/1 (G2-B18) in the environment of small veins were investigated in an established vein explant model. Immunofluorescence staining analysis revealed that perivenous macrophages (CD163+ cells) were widely distributed in the explant, with most of them (approximately 2-10 cells/0.03 mm2) being present close to the vein (within a radius of 0-348 µm). Upon inoculation with G1-E70 and G2-B18, we observed an increase in the quantity of cells testing positive for viral antigens over time. G1-E70 replicated more efficiently than G2-B18 in the vein explants (7.6-fold for the ear explant at 72 hpi). The majority of ASFV+ cells were CD163+, indicating that macrophages are the primary target cells. Additional identification of cells infected with ASFV revealed the presence of vimentin+, CD14+, and VWF+ cells, demonstrating the cellular diversity and complexity associated with ASFV infection. By the use of this new vein explant model, the susceptibility of vascular and perivascular cells to an ASFV infection was identified. With this model, it will be possible now to conduct more functional analyses to get better insights into the pathogenesis of ASFV-induced hemorrhages.

Isolation and characterization of a subtype G2c variant of porcine epidemic diarrhea virus that adapts well to cell culture.

Porcine epidemic diarrhea virus (PEDV) causes the third most important disease in the pig industry, after African swine fever and porcine reproductive and respiratory syndrome, and leads to illness or death of the entire litter, causing significant economic losses. In this study, three PEDV strains (HN-1, HN-2, and SC2023) were isolated from swine farms with suspected PEDV infections in Sichuan and Henan provinces. Phylogenetic analysis based on complete S gene sequences showed that all three strains belonged to the G2c subgroup. HN-1 adapted readily to cell culture, grew to a viral titer as high as 2 × 108 TCID50/mL in Vero cells, and caused the formation of large syncytia. We analyzed the amino acid sequence of the HN-1 isolate and found that its S1 subunit contained a three-amino-acid insertion (355KRL358). A seven-amino-acid-deletion (1377FEKVHVQ1383) in the S2 subunit resulted in the partial deletion of the endocytosis signal YxxΦ and the complete deletion of the endoplasmic reticulum retrieval signal (ERRS) KVHVQ in the cytoplasmic tail of the S protein. Consequently, HN-1 is predicted to be less pathogenic than its parent strain, an attribute that facilitates rapid cell-to-cell spread by enhancing syncytium formation. In addition, strain HN-1 was found to have the mutation 884-885SG→RR, which may favor adaptation to cell culture by providing new trypsin cleavage sites. These results suggest that HN-1 is a G2c subtype variant that adapts well to cell culture and can be used to study the adaptive mechanisms of PEDV and develop attenuated vaccines.

Attenuated African swine fever viruses and the live vaccine candidates: a comprehensive review.

The African swine fever virus (ASFV) is spreading worldwide and causing huge economic losses to the global pig industry. The ASFV genome is 170-193 kb in length, contains approximately 150 open reading frames, and encodes more than 200 proteins, most of which have unknown functions. Owing to the unique viral structure, replication strategy, large number of genes of unknown function, and complicated pathogenesis, vaccine development research is challenging. Several naturally attenuated ASFV isolates have been extensively investigated and many genetically manipulated, gene-deleted, and cell-adapted ASFVs have been reported. Currently, live attenuated viruses prepared from weakly virulent strains are an efficient method to provide effective protection in vaccinated pigs; however, these have seldom been widely approved for vaccine use, except in Vietnam. Herein, we summarize the attenuated isolates or vaccine candidates for live vaccines derived from different sources, including naturally mutated, attenuated, cell-adapted, and genetically modified recombinant ASFVs. This will help to understand the gene function and immunogenicity of attenuated live ASFV, as well as the shortcomings of these viruses as vaccine candidates, and provide clues to prepare live, efficient, and safe vaccines for African swine fever.IMPORTANCEOutbreaks of African swine fever (ASF) have caused devastating losses to the global pig industry. Pigs immunized with ASFV attenuated virus can resist the lethal challenge of a strongly virulent virus. Here, we summarize the virulence of naturally mutated, cell-adapted, and genetically recombinant ASFV for pigs, and the protective effect after facing an attack challenge. We also analyze the advantages and disadvantages of ASFV attenuated viruses as vaccine candidates to provide clues for the preparation of efficient and safe live African swine fever vaccines.

Modulation of Autophagy-Lysosome Axis by African Swine Fever Virus and Its Encoded Protein pEP153R.

The autophagy-lysosome axis is an evolutionarily conserved intracellular degradation pathway which constitutes an important component of host innate immunity against microbial infections. Here, we show that African swine fever virus (ASFV), one of most devastating pathogens to the worldwide swine industry, can reshape the autophagy-lysosome axis by recruiting the critical lysosome membrane proteins (LAMP1 and LAMP2) to viral factories while inhibiting autophagic induction in macrophages. The screening of viral membrane proteins led to the identification of several ASFV membrane proteins, exemplified by viral protein pEP153R, that could significantly alter the subcellular localization of LAMP1/2 when expressed alone in transfected cells. Further analysis showed that pEP153R was also a component of viral factories and could induce endoplasmic reticulum (ER) retention of LAMP1/2, leading to the inhibition of the fusion of autophagosomes with lysosomes. Interestingly, the ASFV mutant lacking EP153R could still actively recruit LAMP into viral factories (VFs) and inhibit autophagic flux, indicating the existence of a functional redundancy of other viral proteins in the absence of pEP153R and highlighting the complexity of ASFV replication biology. Taken together, our results reveal novel information about the interplay of ASFV with the autophagy-lysosome axis and a previously unrecognized function of ASFV protein pEP153R in regulating the cellular autophagic process.

Strategic nucleic acid detection approaches for diagnosing African swine fever (ASF): navigating disease dynamics.

African swine fever (ASF) is a devastating disease caused by African swine fever virus (ASFV) and leads to significant economic losses in the pig farming industry. Given the absence of an effective vaccine or treatment, the mortality rate of ASF is alarmingly close to 100%. Consequently, the ability to rapidly and accurately detect ASFV on site and promptly identify infected pigs is critical for controlling the spread of this pandemic. The dynamics of the ASF virus load and antibody response necessitate the adoption of various detection strategies at different stages of infection, a topic that has received limited attention to date. This review offers detailed guidance for choosing appropriate ASF diagnostic techniques tailored to the clinical manifestations observed from the acute to chronic phases, including asymptomatic cases. We comprehensively summarize and evaluate the latest advancements in ASFV detection methods, such as CRISPR-based diagnostics, biosensors, and microfluidics. Additionally, we address the challenges of false negatives or positives due to ASF variants or the use of injected live attenuated vaccines. This review provides an exhaustive list of diagnostic tests suitable for detecting each stage of symptoms and potential target genes for developing new detection methods. In conclusion, we highlight the current challenges and future directions in ASFV detection, underscoring the need for continued research and innovation in this field.

Development of a Formula for Calculating the Probability of the Spread of African Swine Fever

Robust epidemiological knowledge and predictive modelling tools are needed to address challenging objectives forecasting epidemics. Often, multiple modelling approaches can be used during an epidemic to support effective decision making in a timely manner. A formula has been developed for calculating the probability of spreading african swine fever from infected animals of a threatened pig farm to other farms. The formula allows you to calculate the probability of an outbreak of infection for pigs of each of the pig farms located in the analyzed area. This takes into account the possible ways of spreading the pathogen in the presence of mechanisms and factors of transmission of african swine fever in real time.

Development of a fully automated chemiluminescent immunoassay for the quantitative and qualitative detection of antibodies against African swine fever virus p72.

African swine fever (ASF), caused by ASF virus (ASFV), is a highly infectious and severe hemorrhagic disease of pigs that causes major economic losses. Currently, no commercial vaccine is available and prevention and control of ASF relies mainly on early diagnosis. Here, a novel automated double antigen sandwich chemiluminescent immunoassay (DAgS-aCLIA) was developed to detect antibodies against ASFV p72 (p72-Ab). For this purpose, recombinant p72 trimer was produced, coupled to magnetic particles as carriers and labeled with acridinium ester as a signal trace. Finally, p72-Ab can be sensitively and rapidly measured on an automated chemiluminescent instrument. For quantitative analysis, a calibration curve was established with a laudable linearity range of 0.21 to 212.0 ng/mL (R2 = 0.9910) and a lower detection limit of 0.15 ng/mL. For qualitative analysis, a cut-off value was set at 1.50 ng/mL with a diagnostic sensitivity of 100.00% and specificity of 98.33%. Furthermore, antibody response to an ASF gene-deleted vaccine candidate can be accurately quantified using this DAgS-aCLIA, as evidenced by early seroconversion as early as 7 days post-immunization and high antibody levels. Compared with available enzyme-linked immunosorbent assays, this DAgS-aCLIA demonstrated a wider linearity range of 4 to 16-fold, and excellent analytical sensitivity and agreement of over 95.60%. In conclusion, our proposed DAgS-aCLIA would be an effective tool to support ASF epidemiological surveillance.IMPORTANCEAfrican swine fever virus (ASFV) is highly contagious in wild boar and domestic pigs. There is currently no vaccine available for ASF, so serological testing is an important diagnostic tool. Traditional enzyme-linked immunosorbent assays provide only qualitative results and are time and resource consuming. This study will develop an automated chemiluminescent immunoassay (CLIA) that can quantitatively and qualitatively detect antibodies to ASFV p72, greatly reducing detection time and labour-intensive operation, and improving detection sensitivity and linearity range. This novel CLIA would serve as a reliable and convenient tool for ASF pandemic surveillance and vaccine development.

An intelligent and portable fiber optic real-time fluorescence detection system for pathogenic microorganisms detection

The detection of pathogenic microorganisms poses an increasingly serious challenge to food safety. This paper proposes an intelligent fiber optic fluorescence sensing system for detection of pathogenic microorganisms. The system integrates light-emitting diodes and fiber optic sensing arrays. Compact and multi-channel detection is achieved by this kind of design. Environmental parameters such as temperature, humidity, and location are intelligently analyzed together with sampled fluorescence signal, which successfully achieved a high accuracy detection result without affected or interfered by environmental parameters. A Radial Basis Function Neural Network (RBFNN) algorithm is utilized for intelligent analysis and prediction of pathogenic microorganisms’ concentration with environmental parameters. Under different environmental parameters, the system has successfully detected African swine fever virus or salmonella in real-time with high accuracy and sensitivity. Since location of the sensing system can be determined by GPS module integrated in the system, the change of pathogenic microorganisms with different locations can be determined even during transportation. This innovative solution provides a convenient and accurate method for high accurate on-site real time sensing of pathogenic microorganisms.