Veterinary Microbiology and Immunobiology Commons^™

Development Of An Indirect Elisa, Blocking Elisa, Fluorescent Microsphere Immunoassay And Fluorescent Focus Neutralization Assay For Serologic Evaluation Of Exposure To North American Strains Of Porcine Epidemic Diarrhea Virus, Faten Okda, Xiaodong Liu, Aaron Singrey, Travis Clement, Julie Nelson, Jane Christopher-Hennings, Eric A. Nelson, Steven Lawson

Veterinary and Biomedical Sciences Faculty Publications

Recent, severe outbreaks of porcine epidemic diarrhea virus (PEDV) in Asia and North America highlight the need for well-validated diagnostic tests for the identification of PEDV infected animals and evaluation of their immune status to this virus. PEDV was first detected in the U.S. in May 2013 and spread rapidly across the country. Some serological assays for PEDV have been previously described, but few were readily available in the U.S. Several U.S. laboratories quickly developed indirect fluorescent antibody (IFA) assays for the detection of antibodies to PEDV in swine serum, indicating prior exposure. However, the IFA has several disadvantages, including …

An Evaluation Of Porcine Epidemic Diarrhea Virus Survival In Individual Feed Ingredients In The Presence Or Absence Of A Liquid Antimicrobial, Scott Dee, Casey Neill, Travis Clement, Aaron Singrey, Jane Christopher-Hennings, Eric A. Nelson

Veterinary and Biomedical Sciences Faculty Publications

Background: Contaminated complete feed and porcine plasma are risk factors for PEDV introduction to farms and a liquid antimicrobial has been proven useful for reducing risk. This study provides information on the survivability of PEDV across common swine feed ingredients in the presence or absence of the liquid antimicrobial.
Results: Eighteen ingredients commonly included in commercial swine diets were selected, including 3 grain sources (corn, soybean meal (SBM), dried distillers grains with solubles (DDGS)), 5 porcine by-products (spray-dried plasma, purified plasma, intestinal mucosa, meat and bone meal and red blood cells (RBCs)), 3 vitamin/trace mineral (VTM) mixes (sow, nursery, finishing), …

An Evaluation Of A Liquid Antimicrobial (Sal Curb®) For Reducing The Risk Of Porcine Epidemic Diarrhea Virus Infection Of Naïve Pigs During Consumption Of Contaminated Feed, Scott Dee, Casey Neill, Travis Clement, Jane Christopher-Hennings, Eric A. Nelson

Veterinary and Biomedical Sciences Faculty Publications

Background: Since its initial detection in May 2013, porcine epidemic diarrhea virus (PEDV) has spread rapidly throughout the US swine industry. Recently, contaminated feed was confirmed as a vehicle for PEDV infection of naïve piglets. This research provides in vivo data supporting the ability of a liquid antimicrobial product to reduce this risk.
Results: Sal CURB® (Kemin Industries, Des Moines, IA, USA) is a FDA-approved liquid antimicrobial used to control Salmonella contamination in poultry and swine diets. To test its effect against PEDV, Sal CURB®-treated feed was spiked with a stock isolate of PEDV (Ct = 25.22), which PEDV-naïve piglets …

An Evaluation Of Contaminated Complete Feed As A Vehicle For Porcine Epidemic Diarrhea Virus Infection Of Naïve Pigs Following Consumption Via Natural Feeding Behavior: Proof Of Concept, Scott Dee, Travis Clement, Adam Schelkopf, Joel Nerem, David Knudsen, Jane Christopher-Hennings, Eric A. Nelson

Veterinary and Biomedical Sciences Faculty Publications

Background: Since its initial detection in May 2013, porcine epidemic diarrhea virus (PEDV) has spread rapidly throughout the US swine industry. Initially, contaminated feed was proposed as a risk factor for PEDV; however, data were not available to support this theory. Here we provide proof of concept of this risk by describing a novel means for recovering PEDV-contaminated complete feed material from commercial swine sites and conducting an in vivo experiment to prove its infectivity.

Results: For on-farm detection of PEDV RNA in feed, paint rollers were used to collect material from at-risk feed bins from 3 clinically affected breeding …

Characterization Of A Novel Influenza Virus In Cattle And Swine: Proposal For A New Genus In The Orthomyxoviridae Family, Ben M. Hause, Emily A. Collin, Runxia Liu, Bing Huang, Zizhang Sheng, Wuxun Lu, Dan Wang, Eric A. Nelson, Feng Li

Veterinary and Biomedical Sciences Faculty Publications

We have recently reported the isolation of a novel virus, provisionally designated C/swine/Oklahoma/1334/2011 (C/OK), with 50% overall homology to human influenza C viruses (ICV), from a pig in Oklahoma. Deep RNA sequencing of C/OK virus found a matrix 1 (M1) protein expression strategy that differed from that of ICV. The novelty of C/OK virus prompted us to investigate whether C/OK virus could exist in a nonswine species. Significantly, we found that C/OK virus was widespread in U.S. bovine herds, as demonstrated by reverse transcription (RT)-PCR and serological assays. Genome sequencing of three bovine viruses isolated from two herds in different …

The Presence Of Alpha Interferon At The Time Of Infection Alters The Innate And Adaptive Immune Responses To Porcine Reproductive And Respiratory Syndrome Virus, Susan L. Brockman, Crystal A. Loving, Eric A. Nelson, Laura C. Miller, Tracy L. Nicholson, Karen B. Register, Marvin J. Grubman, Douglas E. Brough, Marcus E. Kehrli Jr

Veterinary and Biomedical Sciences Faculty Publications

Porcine reproductive and respiratory syndrome (PRRS) is one of the most devastating and costly diseases to the swine industry worldwide. Overall, the adaptive immune response to PRRS virus (PRRSV) is weak, which results in delayed elimination of virus from the host and inferior vaccine protection. PRRSV has been shown to induce a meager alpha interferon (IFN-α) response, and we hypothesized that elevated IFN-α levels early in infection would shorten the induction time and increase elements of the adaptive immune response. To test this, we measured both antibody and cell-mediated immunity in pigs after the administration of a nonreplicating human adenovirus …

Development Of A Fluorescent Microsphere Immunoassay For Detection Of Antibodies Against Porcine Reproductive And Respiratory Syndrome Virus Using Oral Fluid Samples As An Alternative To Serum-Based Assays, Robert J. Langenhorst, Steven Lawson, Apisit Kittawornrat, Jeffery J. Zimmerman, Zhi Sun, Yanhua Li, Jane Christopher-Hennings, Eric A. Nelson, Ying Fang

Veterinary and Biomedical Sciences Faculty Publications

For effective disease surveillance, rapid and sensitive assays are needed to detect antibodies developed in response to porcine reproductive and respiratory syndrome virus (PRRSV) infection. In this study, we developed a multiplexed fluorescent microsphere immunoassay (FMIA) for detection of PRRSV-specific antibodies in oral fluid and serum samples. Recombinant nucleocapsid protein (N) and nonstructural protein 7 (nsp7) from both PRRSV genotypes (type I and type II) were used as antigens and covalently coupled to Luminex fluorescent microspheres. Based on an evaluation of 488 oral fluid samples with known serostatus, the oral fluid-based FMIAs achieved >92% sensitivity and 91% specificity. For serum …

The Lack Of An Inherent Membrane Targeting Signal Is Responsible For The Failure Of The Matrix (M1) Protein Of Influenza A Virus To Bud Into Virus-Like Particles, Dan Wang, Aaron Harmon, Jing Jin, David H. Francis, Jane Christopher-Hennings, Eric A. Nelson, Ronald C. Montelaro, Feng Li

Veterinary and Biomedical Sciences Faculty Publications

The matrix protein (M1) of influenza A virus is generally viewed as a key orchestrator in the release of influenza virions from the plasma membrane during infection. In contrast to this model, recent studies have indicated that influenza virus requires expression of the envelope proteins for budding of intracellular M1 into virus particles. Here we explored the mechanisms that control M1 budding. Similarly to previous studies, we found that M1 by itself fails to form virus-like-particles (VLPs). We further demonstrated that M1, in the absence of other viral proteins, was preferentially targeted to the nucleus/perinuclear region rather than to the …

Antibiotic-Mediated Inhibition Of Porcine Reproductive And Respiratory Syndrome Virus (Prrsv) Infection: A Novel Quinolone Function Which Potentiates The Antiviral Cytokine Response In Marc-145 Cells And Pig Macrophages, William A. Cafruny, Richard G. Duman, Raymond R. Rowland, Eric A. Nelson, Grace H. Wong

Veterinary and Biomedical Sciences Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically significant agent for which there currently are no effective treatments. Development of antiviral agents for PRRSV as well as many other viruses has been limited by toxicity of known antiviral compounds. In contrast, antibiotics for non-virus microbial infections have been widely useful, in part because of their acceptable toxicity in animals. We report here the discovery that the quinolone containing compound Plasmocin™, as well as the quinolones nalidixic acid and ciprofl oxacin, have potent anti-PRRSV activity in vitro. PRRSV replication was inhibited by these antibiotics in both cultured MARC-145 cells …