Search Results (160)

Neonatal puppies and kittens face a critical period after birth, during which their health depends heavily on the microorganisms they acquire from their mothers and environment. These microorganisms, known as the gut microbiota, help newborns develop their immune systems, digest nutrients, and protect against disease. This review explores how these microorganisms are transferred from the mother to her offspring before, during, and after birth, including the process of delivery, nursing, and maternal care. It also examines how factors such as birth type, hygiene, feeding, and maternal health can influence the development of these microbial communities. When this process is disrupted, it may lead to health problems such as infections, diarrhea, and immune disorders. Understanding how and when these microbes are passed to newborns, and how to support this process, is essential to improving survival rates and long-term health in puppies and kittens. Full article

Porcine epidemic diarrhea virus (PEDV) causes lethal enteritis in neonatal piglets, yet the mechanisms underlying rapid intestinal injury remain unclear. In particular, it is unknown whether different regulated cell death pathways act separately or cooperatively to worsen mucosal damage. To address this question, we performed multi-omics analyses of infected intestinal tissues and found concurrent activation of pyroptosis and ferroptosis during PEDV infection. PEDV infection activated the Caspa-se-1/GSDMD pathway in the duodenum and jejunum, as shown by generation of the Caspase-1 p20 fragment and cleavage of GSDMD into its active N-terminal form, indicating pyroptosis. At the same time, infected tissues displayed key features of ferroptosis, including weakened antioxidant defenses, increased lipid peroxidation, iron accumulation, lipid remodeling, and dysregulated ACSL4 and GPX4 expression. These two processes were closely linked and together contributed to tight junction disruption and barrier instability. Molecular docking further suggested that PEDV NSP1 and S proteins may interact with Caspase-1, providing a possible explanation for pyroptosis induction. Correlation analysis also showed strong associations between pyroptosis-related genes and ferroptosis-associated metabolites. Overall, our findings indicate that pyroptosis and ferroptosis cooperate to drive PEDV-induced intestinal inflammation and barrier damage, highlighting their joint inhibition as a potential strategy to reduce PEDV pathogenicity. Full article

Bovine rotavirus (BRV) poses a major threat to the global cattle industry, driving significant morbidity and mortality in young calves. In Yunnan Province, China, BRV is the primary cause of neonatal calf diarrhea (NCD), yet the molecular epidemiology of circulating strains remains poorly understood. This study aimed to investigate the molecular characteristics of bovine rotavirus strains associated with a severe outbreak of the NCD on a local farm. Fecal samples were collected from 396 calves and screened for BRV by RT-PCR targeting the VP6 gene. Positive samples were subjected to virus isolation in MA104 cells, followed by whole-genome sequencing, phylogenetic analysis, and pathogenicity assessment in suckling mice. Of 396 samples, 85 tested positive for BRV, corresponding to an animal-level prevalence of 21.5% (95% CI: 17.5–25.8%), with four fatalities recorded. A strain designated as BRV-YN1-2021 was successfully isolated, exhibiting characteristic cytopathic effects, specific immunofluorescence, and typical rotavirus morphology by electron microscopy. Genomic analysis revealed the constellation G8-P[1]-I2-R2-C2-M2-A3-N2-T6-E2-H3, identified as genotype G8P[1]. BLAST analysis showed that four genomic segments shared the highest identity with deer rotavirus strains, five with human rotavirus strains, and two with bovine rotavirus strains. Phylogenetic analysis demonstrated close relationships with US deer strains, Japanese bovine strains, and human strains circulating in China. Experimental infection in suckling mice induced diarrhea and significant intestinal histopathology, degeneration of villous epithelial cells, goblet cell hyperplasia, and inflammatory infiltration. This study reports the first isolation of a G8P[1] bovine rotavirus from a diarrhea outbreak in Chinese cattle. The multi-host genetic composition provides evidence of interspecies reassortment events, highlighting the zoonotic potential of BRV and emphasizing the need for continuous molecular surveillance to inform effective control strategies. Full article

Bacillus subtilis is aerobic or facultatively anaerobic. After entering the gastrointestinal tract, its spores germinate and colonize the gut, inhibiting the growth of harmful aerobic bacteria (Escherichia coli, Streptococcus, Staphylococcus aureus). However, it remains unclear whether B. subtilis can inhibit Clostridium perfringens type A infection. In this study, B. subtilis PB6 was added to the diets of pregnant sows infected with Clostridium perfringens type A, which significantly improved the reproductive performance and reduced the incidence of bloat in sows and diarrhea in neonatal piglets. The treatment significantly increased the abundance of intestinal probiotics (B. subtilis, Lactobacillus, Limosilactobacillus reuteri, Lactobacillus johnsonii, Muribaculaceae, Lactobacillus amylovorus, and Lactobacillus reuteri) in sows and decreased the relative abundance of Clostridium perfringens type A after feeding B. subtilis administration. These probiotics can repair the intestinal tissue and improve intestinal histomorphology, and enhance the expression of MUC2 and sIgA in sows, thereby further strengthening the mucosal immune function. B. subtilis can also reduce the levels of inflammatory factors (CRP, IL-1β, and IFN-γ) and attenuate the inflammatory response in sows and neonatal piglets. Taken together, our results suggest that dietary supplementation with B. subtilis PB6 could reduce bloat in sows and diarrhea in piglets while improving intestinal barrier function and microbial balance in sows. Full article

Bovine rotavirus (BRV) is one of the leading causes of neonatal diarrhea in calves and remains a major concern in veterinary medicine due to its high morbidity and economic impact. Rapid, sensitive, and cost-effective diagnostic approaches are therefore required for early detection and disease control. In this study, electrochemical immunosensors were developed for the detection of BRV with the aim of improving existing multiplex diagnostic strategies. Screen-printed carbon electrodes (SPEs) were employed as the sensing platform and modified with molybdenum disulfide nanoparticles (MoS₂ NPs) to enhance electrochemical performance. Mouse monoclonal antibodies against the BRV VP6 protein were immobilized onto the electrode surface, followed by blocking with bovine serum albumin. BRV detection was carried out using differential pulse voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy. To further improve sensitivity, a sandwich immunoassay format was constructed using gold nanoparticle-labeled secondary antibodies. The MoS₂-modified sandwich immunosensor exhibited superior analytical performance, achieving a limit of detection of 1.11 ng/mL, a limit of quantification of 3.72 ng/mL, a relative standard deviation of 1.89% (n = 5), and a linear response with R² = 0.99. The developed immunosensors demonstrated reliable performance in real sample analysis, with a selectivity rate of 100 ± 2.95%. These findings suggest that MoS₂-based electrochemical immunosensors offer a promising platform for rapid and sensitive BRV detection and have potential applications in veterinary diagnostics. Full article

The family Caliciviridae encompasses a diverse group of non-enveloped, positive-sense RNA viruses that are significant pathogens in veterinary medicine. This narrative review summarizes the current state of knowledge regarding the clinical, molecular, and epidemiological features of the three calicivirus genera identified in bovine hosts: Norovirus, Nebovirus, and Vesivirus. Bovine noroviruses and neboviruses are neglected enteric pathogens, frequently detected in association with neonatal calf diarrhea and often present in co-infections with other enteric agents. Clinical presentations for these enteric viruses range from severe, watery diarrhea to asymptomatic shedding, with distinct pathogenic profiles observed between norovirus genotypes GIII.1 and GIII.2. In contrast, the genus Vesivirus exhibits a broad host range, and bovine vesivirus strains are phylogenetically linked to vesiviruses identified in pigs and marine animals. Bovine vesivirus infections are associated with a broader spectrum of clinical manifestations, including respiratory disease, vesicular lesions, and abortion. Serological and virological surveys indicate that exposure to these viruses is ubiquitous in cattle populations globally. While direct evidence of human infection by bovine noroviruses and neboviruses remains limited, vesiviruses possess a confirmed capacity for cross-species transmission to humans. Significant knowledge gaps remain, particularly regarding in vitro culture systems, necessitating further research to facilitate vaccine development and clarify transmission dynamics. Full article

Porcine epidemic diarrhea virus (PEDV), a coronavirus responsible for severe watery diarrhea in neonatal piglets, leads to significant economic losses globally. Effective prevention and treatment of PEDV infection is critical to the swine industry. Currently, there are no available therapeutic drugs for PEDV. Porcine interferons (poIFNs) have been identified as promising molecules against a series of swine viruses due to their broad-spectrum antiviral and immunomodulatory properties. In this study, we demonstrated that type I interferon-α (IFN-α) offered both prophylactic and therapeutic benefits against PEDV infection. Recombinant poIFN-α produced by a prokaryotic expression system was purified through affinity chromatography, and its prophylactic and therapeutic effects against PEDV infection were evaluated in vitro and in vivo through RT-qPCR, clinical symptom monitoring, and pathological examination. In vitro studies revealed a strong antiviral activity of poIFN-α against PEDV in Vero E6 cells, with a more pronounced prophylactic effect compared to therapeutic outcomes. In vivo studies showed that poIFN-α significantly alleviated clinical diarrhea in PEDV-infected piglets and reduced intestinal viral loads. These findings suggest that poIFN-α holds considerable promise as an antiviral agent for PEDV and provides a foundation for the development of therapeutic strategies targeting this virus. Full article

Gilts have a lower capacity for voluntary feed intake and body reserves than multiparous sows, which limits their ability to cope with the needs of gestation and lactation. In this study, a nutritional supplement was formulated to support gilts during the peripartum period. Both control (C, n = 64) and treatment (T, n = 63) groups received standard commercial diets. Group T received 300gr of supplement per gilt and day for the last 35 days of gestation until the fifth day of lactation. This supplement contained calcium (Ca; 4.1%), sodium (Na; 4.0%), lysine (Lys; 1.96%), methionine (Met; 1.32%), vitamin B₁₂ (0.3 mg/kg), choline chloride (600 mg/kg), betaine (475 mg/kg), and L-carnitine (500 mg/kg). Supplementation significantly reduced (p < 0.050) stillbirth rate, neonatal diarrhea, postpartum hypophagia, and both β-hydroxybutyrate (BHBA) and creatinine (CREA) concentrations (effect sizes: 0.240–0.993). Also, supplementation significantly increased (p < 0.050) piglet weight at birth and at 15 days of lactation and maternal backfat thickness at 26 days of lactation (effect sizes: 0.491–0.719). The concentrations of BHBA and CREA showed significant and negative associations with several productive parameters (p < 0.05); the strength of the associations was low–medium. Targeted peripartum supplementation represents a feasible nutritional strategy for commercial herds characterized by large litter sizes and limited voluntary feed intake capacity. Full article

Background/Objectives: Porcine epidemic diarrhea (PED) is a highly contagious enteric disease caused by porcine epidemic diarrhea virus (PEDV) and is associated with severe clinical signs and high mortality in neonatal piglets. Vaccination is an important strategy for PED control through the induction of humoral immunity. This study aimed to compare immune responses induced by inactivated and live-attenuated PEDV vaccines and to evaluate a heterologous prime-boost vaccination strategy in PEDV-naïve replacement gilts. Methods: Twenty-four PEDV-naïve replacement gilts were randomly assigned to four groups: unvaccinated control, inactivated vaccine administered twice (K/K), live-attenuated vaccine administered twice (L/L), and live-attenuated priming followed by an inactivated booster (L/K). Pigs received two intramuscular vaccinations at 16 weeks of age and two weeks later. Serum samples collected up to 42 days post-vaccination were analyzed for PEDV-specific IgG and IgA antibodies by ELISA, and serum-neutralizing antibody titers were determined using a serum neutralization test. Results: The L/K regimen induced the highest PEDV-specific IgG responses, with peak levels at day 28 post-vaccination that were significantly higher than those in the K/K and control groups. Serum-neutralizing antibody titers were significantly higher in the L/K and L/L groups than in the K/K and control groups. Serum IgA responses were low and transient across all vaccination groups. Conclusions: A heterologous prime-boost vaccination strategy using a live-attenuated PEDV vaccine followed by an inactivated booster induces strong systemic humoral immune responses in replacement gilts and represents a promising approach for PEDV vaccination programs. Full article

Senecavirus A (SVA) is a picornavirus that causes vesicular disease in swine and has been associated with increased neonatal mortality. Although SVA had only been detected sporadically in the United States since the 1980s, there was a sharp increase in cases in the United States and around the world starting in 2015. The cause of this shift in SVA epidemiology remains unknown; however, changes in the virus that have resulted in enhanced infectivity may have contributed. The aim of this research was to establish the infectious dose of a post-2015 SVA isolate in neonatal pigs and compare its infectivity to previous work with a 2011 SVA isolate. A 2018 SVA isolate (SVA/KS/2018) was serially 10-fold diluted to generate six inoculums. Animals were individually housed with four pigs inoculated with 2 mL orally per dilution. Detection of SVA RNA in serum and swabs, as well as the presence of neutralizing antibodies, were used to classify the infection status of animals. The minimum infectious dose for SVA/KS/2018 in neonates was 10^2.5 TCID₅₀/mL (2 × 10^2.5 or 632 TCID₅₀/pig). This value is similar to the infectious dose determined for SVA/CAN/2011, thus providing evidence that the increase in SVA detections was not due to increases in infectivity of contemporary isolates. Neonatal mortality has not been experimentally reproduced; however, pigs inoculated with higher doses of SVA/KS/2018 developed diarrhea and mortality, suggesting increased virulence, which should be investigated further. Full article

Diarrhea in kids is a significant health and economic concern for small-scale ruminant farms. This study aims to investigate the properties of Lactobacillus amylovorus as a treatment for kids with diarrhea and its effect on the composition of the gut microbiota. A total of 20 neonatal goats (approximately 2 months old) were divided into three groups: healthy control (HC, n = 4), diarrhea (D, n = 8), and diarrhea treated with probiotic (DT, n = 8). We tracked gut microbial profiles, fecal consistency, short-chain fatty acids (SCFAs), and clinical symptoms. Probiotic-treated kids recovered fully from diarrhea within two weeks, while their untreated counterparts showed signs of clinical deterioration and gradual emaciation. Kids with diarrhea had lower microbial richness, according to alpha diversity analysis, and this was only partially restored after probiotic treatment. The kids with diarrhea had the lowest Shannon, ACE, Simpson, Dominance, Pielou-e, and Chao1 indices compared to the HC group, while the administration of Lactobacillus amylovorus significantly (p < 0.05) restored their normal enrichment in the DT group compared to the D group. The healthy group had a higher abundance of Verrucomicrobiota, while Firmicutes and Bacteroidota predominated in all groups. Bacteroides and Akkermansia predominated in the healthy and treated groups. At the genus level, analysis showed elevated levels of Escherichia-Shigella and UCG-005 in kids with diarrhea. In addition, the concentration of each SCFA in the D group was significantly (p < 0.05) lower than in the HC group. This study provides novel evidence that Lactobacillus amylovorus administration not only alleviates diarrhea but also uniquely restores the production of key SCFAs—including butyrate, acetate, and propionate—in neonatal goats, a finding not previously reported in this species. The concurrent recovery of microbial diversity and SCFA profiles highlights the dual mechanistic potential of Lactobacillus amylovorus as a gut microbiota modulator and metabolic therapeutic in young ruminants. These results lend credence to its potential as a probiotic treatment for small ruminant enteric diseases. Full article

Porcine epidemic diarrhea virus (PEDV) is a major pathogen responsible for severe diarrhea, dehydration, and high mortality in neonatal piglets, continually threatening global swine production. Rapid differentiation of its major genotypes (classical G1, variant G2, and recombinant S-INDEL) is vital for molecular epidemiology and effective disease control, yet existing approaches rely mainly on time-consuming sequencing and phylogenetic analysis of the S gene. To overcome this limitation, we developed a novel triplex TaqMan-based real-time PCR assay for rapid detection and differentiation of the three PEDV genotypes. The assay demonstrated high sensitivity, with the lowest detection limit of 10² copies/μL, and strong specificity, showing no cross-reactivity with six other common swine pathogens (TGEV, PDCoV, PoRV, PRRSV, CSFV, and PRV). It also exhibited excellent reproducibility, with both intra- and inter-assay coefficients of variation maintained below 1.5%. In clinical validation, the assay showed 100% concordance with results obtained from S gene sequencing and phylogenetic analysis. Furthermore, testing of 160 clinical samples revealed cases of co-infection involving G2 and S-INDEL strains. In conclusion, this rapid, specific, and reproducible assay provides a reliable tool for routine molecular diagnosis, facilitating large-scale epidemiological surveillance and enabling genotype-informed control strategies against PEDV. Full article

Background/Objectives: Porcine epidemic diarrhea virus (PEDV), particularly the emerging GII genotype, poses a severe threat to the swine industry in affected regions, primarily in Asia. Current vaccines based on classical strains often provide limited cross-protection against these heterogeneous variants, though it should be noted that these vaccines are primarily designed to induce maternal immunity in sows. The objective of this study was to develop a novel inactivated vaccine using an emerging PEDV GIIc variant and evaluate its immunogenicity and cross-protective efficacy against heterologous strains. Methods: A novel PEDV strain, designated PEDV-HeN2024, was isolated from clinical samples and identified through cell culture, immunofluorescence assay (IFA), genetic sequencing, and phylogenetic analysis. An inactivated vaccine was prepared by emulsifying the purified virus with ISA 201 VG adjuvant (1:1, v/v). Immunogenicity was assessed in piglets by measuring virus-neutralizing antibody titers and PEDV-specific IgG levels. Cross-protective efficacy was evaluated through in vitro neutralization assays and in vivo challenge studies with homologous GIIc and heterologous GIIa and GIIb strains. Results: The isolated PEDV-HeN2024 strain demonstrated pathogenicity, causing severe diarrhea and 100% mortality in PEDV-naïve neonatal piglets. Sera from vaccinated animals showed potent cross-neutralizing activity against homologous GIIc, as well as heterologous GIIa and GIIb strains. In challenge studies, vaccinated piglets were significantly protected against clinical disease, showing no diarrhea or viral shedding, and maintained normal intestinal architecture. Conclusions: The inactivated vaccine developed from the emerging PEDV GIIc variant elicits robust humoral immunity and provides cross-protection against prevalent heterologous GII strains. These findings highlight its potential as a promising spectrum vaccine candidate for controlling PEDV outbreaks. This study underscores the importance of using recently circulating strains for vaccine development to overcome the limitations of current vaccines. Full article

Porcine epidemic diarrhea virus (PEDV) is a highly infectious virus that leads to severe diarrhea and high death rates in neonatal piglets. Because PEDV primarily infects the intestinal mucosa, the induction of effective mucosal immunity through oral vaccination represents a promising strategy for disease prevention. In this study, a recombinant Lactobacillus paracasei (L. paracasei) strain expressing a multicomponent fusion antigen composed of the PEDV S1 protein, M cell- and dendritic cell-targeting peptides, and the mucosal adjuvant LTB was constructed as a candidate oral vaccine. Pregnant mice orally immunized with the recombinant strain exhibited significantly increased levels of PEDV-specific serum IgG as well as secretory IgA (SIgA) in intestinal mucus and feces, both of which showed in vitro neutralizing activity. In addition, oral immunization markedly enhanced cellular immune responses, as indicated by elevated serum levels of IFN-γ, IL-2, IL-4, and IL-10. Notably, newborn mice delivered by immunized dams displayed significantly higher levels of PEDV-specific SIgA, demonstrating effective maternal antibody transfer. These results indicate that the recombinant L. paracasei strain can robustly induce humoral, cellular, and mucosal immune responses and confer maternal immune protection. This study emphasizes the possibility of oral vaccinations based on L. paracasei as a viable approach to the prevention and management of epidemic diarrhea in piglets. Full article

Swine enteric coronaviruses (SECoVs), including transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea syndrome coronavirus (SADS-CoV), are major enteric pathogens causing severe diarrhea, dehydration, high neonatal mortality, and substantial global economic losses. Rapid viral evolution and recombination continually generate antigenically diverse variants that limit cross-protection and undermine vaccine efficacy, particularly for PEDV genogroup II strains that now dominate worldwide circulation. This review synthesizes current knowledge on epidemiology, diagnostic innovations, and emerging vaccine platforms, with emphasis on advances since 2022. Recent progress includes molecular surveillance tools, rapid point-of-care diagnostics, and next-generation vaccine technologies such as mRNA-based and virus-like particle platforms. However, significant knowledge gaps persist regarding viral evolution dynamics, co-infection synergies, and zoonotic spillover potential, particularly following documented human infections with PDCoV. Effective long-term control requires integrated genomic surveillance, strengthened farm-level biosecurity, rationally designed multivalent vaccines targeting conserved epitopes, and harmonized international surveillance systems to reduce outbreak risk and enhance pandemic preparedness at the human–animal interface. Full article