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1.
Transbound Emerg Dis ; 69(2): 396-412, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1774900

ABSTRACT

A limited understanding of the transmission dynamics of swine disease is a significant obstacle to prevent and control disease spread. Therefore, understanding between-farm transmission dynamics is crucial to developing disease forecasting systems to predict outbreaks that would allow the swine industry to tailor control strategies. Our objective was to forecast weekly porcine epidemic diarrhoea virus (PEDV) outbreaks by generating maps to identify current and future PEDV high-risk areas, and simulating the impact of control measures. Three epidemiological transmission models were developed and compared: a novel epidemiological modelling framework was developed specifically to model disease spread in swine populations, PigSpread, and two models built on previously developed ecosystems, SimInf (a stochastic disease spread simulations) and PoPS (Pest or Pathogen Spread). The models were calibrated on true weekly PEDV outbreaks from three spatially related swine production companies. Prediction accuracy across models was compared using the receiver operating characteristic area under the curve (AUC). Model outputs had a general agreement with observed outbreaks throughout the study period. PoPS had an AUC of 0.80, followed by PigSpread with 0.71, and SimInf had the lowest at 0.59. Our analysis estimates that the combined strategies of herd closure, controlled exposure of gilts to live viruses (feedback) and on-farm biosecurity reinforcement reduced the number of outbreaks. On average, 76% to 89% reduction was seen in sow farms, while in gilt development units (GDU) was between 33% to 61% when deployed to sow and GDU farms located in probabilistic high-risk areas. Our multi-model forecasting approach can be used to prioritize surveillance and intervention strategies for PEDV and other diseases potentially leading to more resilient and healthier pig production systems.


Subject(s)
Coronavirus Infections , Porcine epidemic diarrhea virus , Swine Diseases , Animals , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Disease Outbreaks/prevention & control , Disease Outbreaks/veterinary , Ecosystem , Farms , Female , Swine , Swine Diseases/epidemiology , Swine Diseases/prevention & control
2.
Transbound Emerg Dis ; 68(6): 3349-3359, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1526423

ABSTRACT

The influenza D virus (IDV) was first identified and characterized in 2011. Considering the virus' zoonotic potential, its genome nature (segmented RNA virus), its worldwide circulation in livestock and its role in bovine respiratory disease, an increased interest is given to IDV. However, few data are available on drivers of emergence of IDV. We first listed fifty possible drivers of emergence of IDV in ruminants and swine. As recently carried out for COVID-19 in pets (Transboundary and Emerging Diseases, 2020), a scoring system was developed per driver and scientific experts (N = 28) were elicited to (a) allocate a score to each driver, (b) weight the drivers' scores within each domain and (c) weight the different domains among themselves. An overall weighted score was calculated per driver, and drivers were ranked in decreasing order. Drivers with comparable likelihoods to play a role in the emergence of IDV in ruminants and swine in Europe were grouped using a regression tree analysis. Finally, the robustness of the expert elicitation was verified. Eight drivers were ranked with the highest probability to play a key role in the emergence of IDV: current species specificity of the causing agent of the disease; influence of (il)legal movements of live animals (ruminants, swine) from neighbouring/European Union member states and from third countries for the disease to (re-)emerge in a given country; detection of emergence; current knowledge of the pathogen; vaccine availability; animal density; and transport vehicles of live animals. As there is still limited scientific knowledge on the topic, expert elicitation of knowledge and multi-criteria decision analysis, in addition to clustering and sensitivity analyses, are very important to prioritize future studies, starting from the top eight drivers. The present methodology could be applied to other emerging animal diseases.


Subject(s)
COVID-19 , Influenza, Human , Orthomyxoviridae Infections , Swine Diseases , Animals , COVID-19/veterinary , Cattle , Europe/epidemiology , Humans , Orthomyxoviridae Infections/epidemiology , Orthomyxoviridae Infections/prevention & control , Orthomyxoviridae Infections/veterinary , SARS-CoV-2 , Swine , Swine Diseases/epidemiology , Swine Diseases/prevention & control
3.
Transbound Emerg Dis ; 68(5): 2676-2686, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1411003

ABSTRACT

As of 21 April 2020, 176 ASF outbreaks have occurred in China. For each outbreak, an investigation was conducted, including historical data retrieval and traceability of potential contacts. The purpose of this study is to conduct a preliminary analysis of the data obtained from the outbreak investigations, including an investigation of the possible contributing factors of the spread of ASF in China. Based on the epidemic situation and the policies issued, the entire epidemic can be divided into three phases. 71 outbreaks were reported between 3 August 2018 and 17 November 2018; 44 outbreaks between 19 November 2018 and 30 March 2019; and 61 outbreaks between 4 April 2019 and 12 April 2020. Based on the reported outbreaks, the proportional rate of outbreaks in small farms (livestock ≤ 500, 127/168) is significantly higher than that of medium (501 ≤ livestock < 2,000, 14/168; 2001 ≤ livestock ≤ 5,000, 9/168) and large farms (livestock ≥ 5,001, 18/168). The odds of infection related to swill feeding (OR = 2.5, 95% CI, 1.5-4.3) and the mechanical dissemination of vehicles and personnel (OR = 2.7, 95% CI, 1.6-4.5) are significantly higher than those of pigs and pig production transportation. Swill feeding is the major contributing factor for small farms while mechanical dissemination of vehicles and personnel is the major contributing factor for large farms. The average duration from the beginning of the infection to the official outbreak report is gradually decreasing, which means that response speed of industry entities and the animal husbandry and veterinary departments from the beginning of the infection to the outbreak report is gradually increasing. Based on the analysis for ASF outbreaks, some policies and suggestions were put forward, such as improving the biosecurity level of the farms, as well as strengthening the supervision of breeding, transportation and slaughter.


Subject(s)
African Swine Fever Virus , African Swine Fever , Epidemics , Swine Diseases , African Swine Fever/epidemiology , African Swine Fever/prevention & control , Animal Husbandry , Animals , China/epidemiology , Disease Outbreaks/prevention & control , Disease Outbreaks/veterinary , Risk Factors , Swine , Swine Diseases/epidemiology , Swine Diseases/prevention & control
4.
J Am Vet Med Assoc ; 259(4): 415-424, 2021 08 15.
Article in English | MEDLINE | ID: covidwho-1337606

ABSTRACT

CASE DESCRIPTION: In February 2020, a swine farm operating in multiple states throughout the Midwest began to evaluate emergency plans to respond to potential impacts of the COVID-19 pandemic. CLINICAL FINDINGS: From February through April, extensive mitigation strategies were implemented in anticipation of market disruption. The farm consulted the AVMA Guidelines for the Depopulation of Animals to identify preferred methods for depopulation of swine; however, none of these methods were feasible. When the first US packing plant closed in April 2020 because of human COVID-19 infection, the farm began to evaluate whether ventilation shutdown plus (VSD+) could be used for depopulation. TREATMENT AND OUTCOME: Through proof-of-concept trials, a method for ventilation shutdown with the addition of supplemental temperature and humidity was developed. A single location with 4 barns that could be retrofitted for the process was selected, and between April and June 2020, 243,016 pigs were depopulated (59,478 nursery and 183,538 finishing pigs). Mean ± SD time to silent (the time when no sounds could be heard and no motion seen) was 55.4 ± 14.5 minutes for the nursery pigs and 65.0 ± 18.1 minutes for the finishing pigs. Only 728 (0.300%) pigs required manual euthanasia at the end of the depopulation process. CLINICAL RELEVANCE: Efficacy exceeded AVMA recommendations for the use of VSD+ (> 95% mortality rate in < 1 hour). Findings could potentially guide the use of this method for mass depopulation in the event of a foreign animal disease outbreak or severe market disruption in the future.


Subject(s)
COVID-19 , Swine Diseases , Animal Husbandry , Animals , COVID-19/veterinary , Humans , Humidity , Pandemics , SARS-CoV-2 , Swine , Swine Diseases/prevention & control , Temperature
5.
J Virol ; 95(4)2021 01 28.
Article in English | MEDLINE | ID: covidwho-1075935

ABSTRACT

Swine influenza A virus (swIAV) infection causes substantial economic loss and disease burden in humans and animals. The 2009 pandemic H1N1 (pH1N1) influenza A virus is now endemic in both populations. In this study, we evaluated the efficacy of different vaccines in reducing nasal shedding in pigs following pH1N1 virus challenge. We also assessed transmission from immunized and challenged pigs to naive, directly in-contact pigs. Pigs were immunized with either adjuvanted, whole inactivated virus (WIV) vaccines or virus-vectored (ChAdOx1 and MVA) vaccines expressing either the homologous or heterologous influenza A virus hemagglutinin (HA) glycoprotein, as well as an influenza virus pseudotype (S-FLU) vaccine expressing heterologous HA. Only two vaccines containing homologous HA, which also induced high hemagglutination inhibitory antibody titers, significantly reduced virus shedding in challenged animals. Nevertheless, virus transmission from challenged to naive, in-contact animals occurred in all groups, although it was delayed in groups of vaccinated animals with reduced virus shedding.IMPORTANCE This study was designed to determine whether vaccination of pigs with conventional WIV or virus-vectored vaccines reduces pH1N1 swine influenza A virus shedding following challenge and can prevent transmission to naive in-contact animals. Even when viral shedding was significantly reduced following challenge, infection was transmissible to susceptible cohoused recipients. This knowledge is important to inform disease surveillance and control strategies and to determine the vaccine coverage required in a population, thereby defining disease moderation or herd protection. WIV or virus-vectored vaccines homologous to the challenge strain significantly reduced virus shedding from directly infected pigs, but vaccination did not completely prevent transmission to cohoused naive pigs.


Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza Vaccines/administration & dosage , Orthomyxoviridae Infections/transmission , Swine Diseases/transmission , Virus Shedding , Adjuvants, Immunologic/administration & dosage , Animals , Female , Influenza A Virus, H1N1 Subtype/immunology , Influenza A Virus, H1N1 Subtype/isolation & purification , Orthomyxoviridae Infections/prevention & control , Swine , Swine Diseases/prevention & control , Vaccination , Vaccines, Attenuated/administration & dosage , Vaccines, Inactivated/administration & dosage
6.
Front Immunol ; 11: 596964, 2020.
Article in English | MEDLINE | ID: covidwho-1067653

ABSTRACT

We designed the killed swine influenza A virus (SwIAV) H1N2 antigen (KAg) with polyriboinosinic:polyribocytidylic acid [(Poly(I:C)] adsorbed corn-derived Nano-11 particle based nanovaccine called Nano-11-KAg+Poly(I:C), and evaluated its immune correlates in maternally derived antibody (MDA)-positive pigs against a heterologous H1N1 SwIAV infection. Immunologically, in tracheobronchial lymph nodes (TBLN) detected enhanced H1N2-specific cytotoxic T-lymphocytes (CTLs) in Nano-11-KAg+Poly(I:C) vaccinates, and in commercial vaccinates detected CTLs with mainly IL-17A+ and early effector phenotypes specific to both H1N2 and H1N1 SwAIV. In commercial vaccinates, activated H1N2- and H1N1-specific IFNγ+&TNFα+, IL-17A+ and central memory T-helper/Memory cells, and in Nano-11-KAg+Poly(I:C) vaccinates H1N2-specific central memory, IFNγ+ and IFNγ+&TNFα+, and H1N1-specific IL-17A+ T-helper/Memory cells were observed. Systemically, Nano-11-KAg+Poly(I:C) vaccine augmented H1N2-specific IFNγ+ CTLs and H1N1-specific IFNγ+ T-helper/Memory cells, and commercial vaccine boosted H1N2- specific early effector CTLs and H1N1-specific IFNγ+&TNFα+ CTLs, as well as H1N2- and H1N1-specific T-helper/Memory cells with central memory, IFNγ+&TNFα+, and IL-17A+ phenotypes. Remarkably, commercial vaccine induced an increase in H1N1-specific T-helper cells in TBLN and naive T-helper cells in both TBLN and peripheral blood mononuclear cells (PBMCs), while H1N1- and H1N2-specific only T-helper cells were augmented in Nano-11-KAg+Poly(I:C) vaccinates in both TBLN and PBMCs. Furthermore, the Nano-11-KAg+Poly(I:C) vaccine stimulated robust cross-reactive IgG and secretory IgA (SIgA) responses in lungs, while the commercial vaccine elicited high levels of serum and lung IgG and serum hemagglutination inhibition (HI) titers. In conclusion, despite vast genetic difference (77% in HA gene identity) between the vaccine H1N2 and H1N1 challenge viruses in Nano-11-KAg+Poly(I:C) vaccinates, compared to over 95% identity between H1N1 of commercial vaccine and challenge viruses, the virus load and macroscopic lesions in the lungs of both types of vaccinates were comparable, but the Nano-11-KAg+Poly(I:C) vaccine cleared the virus from the nasal passage better. These data suggested the important role played by Nano-11 and Poly(I:C) in the induction of polyfunctional, cross-protective cell-mediated immunity against SwIAV in MDA-positive pigs.


Subject(s)
Influenza A virus/immunology , Influenza Vaccines/administration & dosage , Influenza Vaccines/immunology , Nanoparticles , Orthomyxoviridae Infections/veterinary , Poly I-C , Swine Diseases/prevention & control , Vaccines, Inactivated , Animals , Antibodies, Viral/immunology , Antigens, Viral/immunology , Cross Reactions , Cytokines/metabolism , Immunity, Cellular , Immunologic Memory , Influenza Vaccines/chemistry , Nanoparticles/chemistry , Poly I-C/chemistry , Swine , Swine Diseases/immunology , Swine Diseases/virology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Cytotoxic/metabolism , T-Lymphocytes, Helper-Inducer/immunology , T-Lymphocytes, Helper-Inducer/metabolism , Viral Load
7.
Vaccine ; 38(33): 5212-5218, 2020 07 14.
Article in English | MEDLINE | ID: covidwho-828034

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) has had a negative economic impact on the global swine industry for decades since its first emergence in the 1970s in Europe. In 2013, PEDV emerged for the first time in the United States, causing immense economic losses to the swine industry. Efforts to protect U.S. swine herds from PEDV infection and limit PEDV transmission through vaccination had only limited success so far. Following the previous success in our virus-like particle (VLP) based vaccine in mouse model, in this study we determined the immunogenicity and protective efficacy of a VLP-based vaccine containing B-cell epitope 748YSNIGVCK755 from the spike protein of PEDV incorporated into the hepatitis B virus core capsid (HBcAg), in a comprehensive pregnant gilt vaccination and piglet challenge model. The results showed that the vaccine was able to induce significantly higher virus neutralization response in gilt milk, and provide alleviation of clinical signs for piglets experimentally infected with PEDV. Piglets from pregnant gilt that was vaccinated with the VLP vaccine had faster recovery from the clinical disease, less small intestinal lesions, and higher survival rate at 10 days post-challenge (DPC).


Subject(s)
Coronavirus Infections , Porcine epidemic diarrhea virus , Swine Diseases , Vaccines, Virus-Like Particle , Viral Vaccines , Animals , Antibodies, Viral , Capsid , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Epitopes, B-Lymphocyte , Europe , Female , Hepatitis B virus , Mice , Pregnancy , Swine , Swine Diseases/prevention & control , United States
8.
Transbound Emerg Dis ; 67(1): 417-430, 2020 Jan.
Article in English | MEDLINE | ID: covidwho-826322

ABSTRACT

New variants of porcine epidemic diarrhoea virus (PEDV) causing a highly contagious intestinal disease, porcine epidemic diarrhoea virus (PED), have resulted in high mortality in suckling pigs across several countries since 2013. After 2015, the prevalence of the genogroup 2b (G2b) PEDVs decreased in a cyclical pattern with endemic seasonal outbreaks occasionally seen. To better understand the genetic diversity of PEDVs recently circulating in Taiwan, full-length spike (S) genes of 31 PEDV strains from 28 pig farms collected during 2016-2018 were sequenced. While the majority of S gene sequences (from 27/28 farms) were closely related to the previous G2b PEDV strains, increased genetic diversities leading to several nonsynonymous mutations scattering in the neutralizing epitopes of the S gene were detected in PEDVs recently circulating in Taiwan. Furthermore, novel recombinant variants, the PEDV TW/Yunlin550/2018 strains exhibiting recombinant events between a previously isolated Taiwan PEDV G2b strain and a wild-type PEDV G1a strain, were identified and further classified into a new genogroup, G1c. These results provide updated information about the genetic diversity of currently circulating PEDVs in the field and could help to develop more suitable strategies for controlling this disease.


Subject(s)
Coronavirus Infections/veterinary , Disease Outbreaks/veterinary , Genetic Variation , Porcine epidemic diarrhea virus/genetics , Spike Glycoprotein, Coronavirus/genetics , Swine Diseases/virology , Animals , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Farms , Female , Genotype , Phylogeny , Porcine epidemic diarrhea virus/isolation & purification , Swine , Swine Diseases/epidemiology , Swine Diseases/prevention & control , Taiwan/epidemiology
9.
J Anim Sci ; 98(1)2020 Jan 01.
Article in English | MEDLINE | ID: covidwho-825369

ABSTRACT

An experiment was conducted to evaluate the effect of dietary medium-chain fatty acid (MCFA) addition on nursery pig growth performance, fecal microbial composition, and mitigation of porcine epidemic diarrhea virus (PEDV) following storage. A total of 360 pigs (DNA 400 × 200, Columbus, NE; initially 6.7 ± 0.07 kg) were randomized to pens (5 pigs per pen) on the day of weaning (approximately 20 d of age), allowed a 6-d acclimation, blocked by BW, and randomized to dietary treatment (9 pens per treatment). All MCFA (Sigma-Aldrich, St. Louis, MO) were guaranteed ≥98% purity, including hexanoic (C6:0), octanoic (C8:0), and decanoic (C10:0) acids. Treatment diets were formulated in 2 phases (7 to 11 and 11 to 23 kg BW) and formulated to meet or exceed NRC requirement estimates. Treatments (n = 8) were a dose response including 0%, 0.25%, 0.5%, 1.0%, and 1.5% added MCFA blend (1:1:1 ratio C6:0, C8:0, and C10:0), as well as treatments with individual additions of 0.5% C6:0, C8:0, or C10:0. Fecal samples were collected from pigs fed control and 1.5% MCFA blend diets on days 0 and 14 and analyzed using 16s rDNA sequencing. Following feed manufacture, feed was stored in bags at barn temperature and humidity for 40 d before laboratory inoculation with PEDV. Subsamples of retained feed were inoculated with PEDV to achieve a titer of 104 TCID50/g and separate sample bottles were analyzed on 0 and 3 d post-inoculation (dpi). Overall, ADG and ADFI were increased (linear, P ≤ 0.010) and feed efficiency (G:F) improved (linear, P = 0.004) with increasing MCFA blend. Pigs fed 0.5% C8:0 had greater (P = 0.038) ADG compared with pigs fed the control diet, and G:F was improved (P ≤ 0.024) when pigs were fed 0.5% C6:0, 0.5% C8:0, or 0.5% C10:0 compared with control. An inclusion level × day interaction was observed (quadratic, P = 0.023), where PEDV Ct values increased (quadratic, P = 0.001) on 0 dpi with increasing levels of MCFA blend inclusion and also increased on 3 dpi (linear, P < 0.001). Fecal microbial diversity and composition were similar between control and 1.5% MCFA blend. In summary, the use of MCFA in nursery pig diets improves growth performance, provides residual mitigation activity against PEDV, and does not significantly alter fecal microbial composition.


Subject(s)
Animal Feed/analysis , Coronavirus Infections/veterinary , Fatty Acids/pharmacology , Gastrointestinal Microbiome/drug effects , Porcine epidemic diarrhea virus/drug effects , Swine Diseases/prevention & control , Animals , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Diet/veterinary , Feces/microbiology , Female , Male , Swine , Swine Diseases/virology , Weaning
10.
Arch Virol ; 165(3): 609-618, 2020 Mar.
Article in English | MEDLINE | ID: covidwho-824459

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) targets the intestinal mucosa in pigs. To protect against PEDV invasion, a mucosal vaccine is utilized effectively. In this study, we generated a recombinant adenovirus vaccine encoding the heat-labile enterotoxin B (LTB) and the core neutralizing epitope (COE) of PEDV (rAd-LTB-COE). The fusion protein LTB-COE was successfully expressed by the recombinant adenovirus in HEK293 cells, and the immunogenicity of the vaccine candidate was assessed in BALB/c mice and piglets. Three intramuscular or oral vaccinations with rAd-LTB-COE at two-week intervals induced robust humoral and mucosal immune responses. Moreover, a cell-mediated immune response was promoted in immunized mice, and the neutralizing antibody inhibited both the vaccine strain and the emerging PEDV isolate. Immunization experiments in piglets revealed that rAd-LTB-COE was immunogenic and induced good immune responses in piglets. Further studies are required to evaluate the efficacy of rAd-LTB-COE against a highly virulent PEDV challenge.


Subject(s)
Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Porcine epidemic diarrhea virus/immunology , Swine Diseases/prevention & control , Viral Vaccines/immunology , Adenoviridae/genetics , Adenoviridae/immunology , Animals , Cell Line , Coronavirus Infections/immunology , Enterotoxins/genetics , Enterotoxins/immunology , Epitopes/genetics , Epitopes/immunology , Escherichia coli/immunology , Escherichia coli/pathogenicity , Female , HEK293 Cells , Humans , Mice , Mice, Inbred BALB C , Porcine epidemic diarrhea virus/genetics , Recombinant Fusion Proteins/immunology , Swine , Swine Diseases/immunology , Swine Diseases/virology , Viral Vaccines/administration & dosage , Viral Vaccines/therapeutic use
11.
Microb Pathog ; 149: 104553, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-808667

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) causes an emerging and re-emerging coronavirus disease characterized by vomiting, acute diarrhea, dehydration, and up to 100% mortality in neonatal suckling piglets, leading to huge economic losses in the global swine industry. Vaccination remains the most promising and effective way to prevent and control PEDV. However, effective vaccines for PEDV are still under development. Understanding the genomic structure and function of PEDV and the influence of the viral components on innate immunity is essential for developing effective vaccines. In the current review, we systematically describe the recent developments in vaccine against PEDV and the roles of structural proteins, non-structural proteins and accessory proteins of PEDV in affecting viral virulence and regulating innate immunity, which will provide insight into the rational design of effective and safe vaccines for PEDV or other coronaviruses.


Subject(s)
Coronavirus Infections/veterinary , Porcine epidemic diarrhea virus/genetics , Porcine epidemic diarrhea virus/immunology , Swine Diseases/immunology , Swine Diseases/virology , Viral Vaccines/immunology , Animals , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Immunity, Innate , Porcine epidemic diarrhea virus/pathogenicity , Swine , Swine Diseases/prevention & control , Vaccination/veterinary , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/immunology , Viral Proteins/genetics , Viral Vaccines/administration & dosage , Virulence
12.
J Anim Sci ; 98(6)2020 Jun 01.
Article in English | MEDLINE | ID: covidwho-478332

ABSTRACT

Feed has been shown to be a vector for viral transmission. Four experiments were conducted to: 1) determine if medium chain fatty acids (MCFA) are effective mitigants when applied to feed both pre- and post-porcine epidemic diarrhea virus (PEDV) inoculation measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR), 2) evaluate varying levels and combinations of MCFA measured by qRT-PCR, and 3) evaluate selected treatments in bioassay to determine infectivity. In exp. 1, treatments were arranged in a 2 × 2 + 1 factorial with main effects of treatment (0.3% commercial formaldehyde [CF] product, Sal CURB [Kemin Industries, Inc.; Des Moines, IA], or 1% MCFA blend (Blend) of 1:1:1 C6:C8:C10 [PMI, Arden Hills, MN]) and timing of application (pre- or post-inoculation with PEDV) plus a positive control (PC; feed inoculated with PEDV and no treatment). All combinations of treatment and timing decreased detectable PEDV compared with the PC (P < 0.05). Pre-inoculation treatment elicited decreased magnitude of PEDV detection (cycle threshold value) compared with post-inoculation (P = 0.009). Magnitude of PEDV detection was decreased for CF compared with Blend (P < 0.0001). In exp. 2, pre-inoculation treatments consisted of: 1) PC, 2) 0.3% CF, 3 to 5) 0.125% to 0.33% C6:0, 6 to 8) 0.125% to 0.33% C8:0, 9 to 11) 0.125% to 0.33% C10:0, and 12 to 15) 0.125% to 0.66% C5:0. Treating feed with 0.33% C8:0 resulted in decreased (P < 0.05) PEDV detection compared with all other treatments. Increasing concentration of each individual MCFA decreased PEDV detectability (P < 0.042). In exp. 3, pre-inoculation treatments consisted of: 1) PC, 2) 0.3% CF, 3 to 7) 0.25% to 1% Blend, 8 to 10) 0.125% to 0.33% C6:0 + C8:0, 11 to 13) 0.125% to 0.33% C6:0 + C10:0, and 14 to 16) 0.125% to 0.33% C8:0 + C10:0. Treating feed with CF, 0.5% Blend, 0.75% Blend, 1% Blend, all levels of C6:0+C8:0, 0.25% C6:0 + 0.25% C10:0, 0.33% C6:0 + 0.33% C10:0, 0.25% C8:0 + 0.25% C10:0, or 0.33% C8:0 + 0.33% C10:0 elicited decreased detection of PEDV compared with PC (P < 0.05). Increasing concentration of each MCFA combination decreased PEDV detectability (linear, P < 0.012). In exp. 4, feed was treated pre-inoculation with: 1) no treatment (PC), 2) 0.3% CF, 3) 0.5% Blend, or 4) 0.3% C8:0 and analyzed via qRT-PCR and bioassay. Adding 0.5% Blend or 0.3% C8:0 resulted in decreased PEDV compared with PC and only PC resulted in a positive bioassay. Therefore, MCFA can decrease detection of PEDV in feed. Further, inclusion of lower levels of MCFA than previously evaluated are effective against PEDV.


Subject(s)
Animal Feed/virology , Coronavirus Infections/veterinary , Fatty Acids/analysis , Fatty Acids/pharmacology , Porcine epidemic diarrhea virus/drug effects , Swine Diseases/prevention & control , Animal Feed/analysis , Animals , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Food Contamination/analysis , Swine , Swine Diseases/virology
13.
J Microbiol Biotechnol ; 30(4): 515-525, 2020 04 28.
Article in English | MEDLINE | ID: covidwho-325674

ABSTRACT

Interferon (IFN)-λ plays an essential role in mucosal cells which exhibit strong antiviral activity. Lactobacillus plantarum (L. plantarum) has substantial application potential in the food and medical industries because of its probiotic properties. Alphacoronaviruses, especially porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), cause high morbidity and mortality in piglets resulting in economic loss. Co-infection by these two viruses is becoming increasingly frequent. Therefore, it is particularly important to develop a new drug to prevent diarrhea infected with mixed viruses in piglets. In this study, we first constructed an anchored expression vector with CWA (C-terminal cell wall anchor) on L. plantarum. Second, we constructed two recombinant L. plantarum strains that anchored IFN-λ3 via pgsA (N-terminal transmembrane anchor) and CWA. Third, we demonstrated that both recombinant strains possess strong antiviral effects against coronavirus infection in the intestinal porcine epithelial cell line J2 (IPEC-J2). However, recombinant L. plantarum with the CWA anchor exhibited a more powerful antiviral effect than recombinant L. plantarum with pgsA. Consistent with this finding, Lb.plantarum-pSIP-409-IFN-λ3-CWA enhanced the expression levels of IFN-stimulated genes (ISGs) (ISG15, OASL, and Mx1) in IPEC-J2 cells more than did recombinant Lb.plantarum-pSIP-409-pgsA'-IFN-λ3. Our study verifies that recombinant L. plantarum inhibits PEDV and TGEV infection in IPEC-J2 cells, which may offer great potential for use as a novel oral antiviral agent in therapeutic applications for combating porcine epidemic diarrhea and transmissible gastroenteritis. This study is the first to show that recombinant L. plantarum suppresses PEDV and TGEV infection of IPEC-J2 cells.


Subject(s)
Coronavirus Infections/veterinary , Gastroenteritis, Transmissible, of Swine/prevention & control , Interferons/administration & dosage , Lactobacillus plantarum/genetics , Swine Diseases/prevention & control , Animals , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Epithelial Cells/immunology , Epithelial Cells/virology , Female , Gastroenteritis, Transmissible, of Swine/genetics , Gastroenteritis, Transmissible, of Swine/immunology , Gastroenteritis, Transmissible, of Swine/virology , Gene Expression , Interferons/genetics , Interferons/immunology , Lactobacillus plantarum/metabolism , Male , Porcine epidemic diarrhea virus/physiology , Swine , Swine Diseases/genetics , Swine Diseases/immunology , Swine Diseases/virology , Transmissible gastroenteritis virus/physiology
14.
Vet Microbiol ; 242: 108604, 2020 Mar.
Article in English | MEDLINE | ID: covidwho-2324

ABSTRACT

Here, we examined the efficacy of are combinant subunit antigen-based oral vaccine for preventing porcine epidemic diarrhea virus (PEDV). First, we generated a soluble recombinant partial spike S1 protein (aP2) from PEDV in E. coli and then evaluated the utility of aP2 subunit vaccine-loaded hydroxypropyl methylcellulose phthalate microspheres (HPMCP) and RANKL-secreting L. lactis (LLRANKL) as a candidate oral vaccine in pregnant sows. Pregnant sows were vaccinated twice (with a 2 week interval between doses) at 4 weeks before farrowing. Titers of virus-specific IgA antibodies in colostrum, and neutralizing antibodies in serum, of sows vaccinated with HPMCP (aP2) plus LL RANKL increased significantly at 4 weeks post-first vaccination. Furthermore, the survival rate of newborn suckling piglets delivered by sows vaccinated with HPMCP (aP2) plus LL RANKL was similar to that of piglets delivered by sows vaccinated with a commercial killed porcine epidemic diarrhea virus (PED) vaccine. The South Korean government promotes a PED vaccine program (live-killed-killed) to increase the titers of IgA and IgG antibodies in pregnant sows and prevent PEDV. The oral vaccine strategy described herein, which is based on a safe and efficient recombinant subunit antigen, is an alternative PED vaccination strategy that could replace the traditional strategy, which relies on attenuated live oral vaccines or artificial infection with virulent PEDV.


Subject(s)
Coronavirus Infections/veterinary , Lactobacillus/immunology , Methylcellulose/analogs & derivatives , RANK Ligand/immunology , Swine Diseases/prevention & control , Viral Vaccines/immunology , Administration, Oral , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Colostrum/immunology , Coronavirus Infections/prevention & control , Female , Methylcellulose/administration & dosage , Microspheres , Porcine epidemic diarrhea virus , Pregnancy , RANK Ligand/administration & dosage , Swine , Swine Diseases/virology , Vaccines, Subunit/administration & dosage , Vaccines, Subunit/immunology , Viral Proteins/genetics , Viral Proteins/immunology , Viral Vaccines/administration & dosage
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