Investigation of Senecavirus A pathogenesis in finishing pigs

Dr. Fabio Vannucci, a University of Minnesota swine pathologist and his graduate student Dr. Talita Resende collaborated with a team from South Dakota State University to study the pathogenesis of Senecavirus A in finishing pigs. The results of their experiments were published online a few weeks ago in the Journal of General Virology and the printed version should be following shortly.

The importance of Senecavirus A in swine production resides in a striking resemblance in clinical signs with Food and Mouth Disease. Indeed, Senecavirus A causes vesicular lesions around the mouth and on the feet of pigs.

The collaborative work showed that Senecavirus A viremia occurred between 3 to 10 days post-inoculation (dpi), and that the neutralizing antibody response started 5 dpi. Clinical signs first observed 4dpi, lasted up to 10 days.
This study advances our understanding of Senecavirus A pathogenesis to hopefully be able to better manage it in the future.

vannucci-senecavirusa

Abstract: Senecavirus A (SVA) is an emerging picornavirus that has been recently associated with vesicular disease and neonatal mortality in swine. Many aspects of SVA infection biology and pathogenesis, however, remain unknown. Here the pathogenesis of SVA was investigated in finishing pigs. Animals were inoculated via the oronasal route with a contemporary SVA strain SD15-26 and monitored for clinical signs and lesions associated with SVA infection. Viremia was assessed in serum and virus shedding monitored in oral and nasal secretions and feces by real-time reverse transcriptase PCR (RT-qPCR) and/or virus isolation. Additionally, viral load and tissue distribution were assessed during acute infection and following convalescence from disease. Clinical signs characterized by lethargy and lameness were first observed on day 4 pi and persisted for ~2-10 days. Vesicular lesions were observed on the snout and feet, affecting the coronary bands, dewclaws, interdigital space and heel/sole of SVA-infected animals. A short-term viremia was detected between days 3-10 post-inoculation (pi), whereas virus shedding was detected between days 1-28 pi in oral and nasal secretions and feces. Notably, RT-qPCR and in situ hybridization (ISH) performed on tissues collected on day 38 pi revealed the presence of SVA RNA in the tonsil of all SVA infected animals. Serological responses to SVA were characterized by early neutralizing antibody responses (5 days pi), which coincided with a progressive decrease in the levels of viremia, virus shedding and viral load in tissues. This study provides significant insights on the pathogenesis and infectious dynamics of SVA in swine.

Link to the full article

Infectious Disease Research Laboratories, Food Centric Corridor

The University of Minnesota, College of Veterinary Medicine announces the grand opening of the newly remodeled and expanded state of the art infectious disease research laboratories.

The remodeled research space has over 3,500 sq ft of open access laboratories and shared equipment and will host highly collaborative research teams. The laboratories are equipped with state of the art equipment for sample processing, cell culture, virus isolation, serology, molecular diagnostics and bacteriology and will foster collaborative research related to infectious disease including the study of endemic and emerging diseases, food safety, antimicrobial resistance and the microbiome.

The laboratories are part of the Food Centric Corridor which goal is to enhance food security by promoting food animal health and productivity. The Food Centric Corridor brings interdisciplinary teams together equipped with integrated modern analytical capabilities related to infectious diseases, animal health and nutrition to address challenges of food security thus supporting the University’s mission to produce a safe, secure and sustainable food supply.

The newly remodeled space and the state of the art equipment was made possible by funds from the College of Veterinary Medicine and the Office of the Vice-President of Research.

This slideshow requires JavaScript.

Thank you for a great 2016 Leman conference!

Tuesday marked the end of the 2016 Allen D. Leman conference held in St. Paul, MN. The conference gathered more than 850 professionals and veterinarians from the swine industry for 4 days of conferences and exchanges on the latest science-driven solutions.

Among the highlights from this conference, we would like to congratulate Dr. Deb Murray from New Fashion Pork for receiving the Science in Practice Award. The Pijoan lecture was given by Dr. Peter Davies from the University of Minnesota whereas Dr. Paul Ruen from Fairmont Veterinary Clinic presented the Hanson lecture. Dr. Joe Connor was recognized as the Breakfast Conversation Honoree this year. Lastly, our Distinguished Lecturer, Dr. Alison Van Eenennaam challenged the audience on Genetically Modified Organisms (GMOs).

If you attended the conference, you may have received an email with a link to a survey. Please, consider taking a few minutes to answer it as we very much value your input and feedback.

Thank you and see you next year, September 16−19, for another amazing edition of the Allen D. Leman conference!

This slideshow requires JavaScript.

Airborne transmission of highly pathogenic avian influenza during the 2015 outbreak in the Midwest

In 2015, the Midwestern part of the United States was the theater of an outbreak of a highly pathogenic strain of avian influenza. Drs. Torremorell, Alonso and Davies from the University of Minnesota were involved during the epidemic and just published in Avian Diseases and their findings concerning the airborne transmission of the virus were just published in Avian Diseases.

The study showed that the air exhausted from an infected poultry facility was a source of contamination for the environment but also a risk of transmission for Highly Pathogenic Avian Influenza (HPAI) that needs to be seriously taken into consideration. Indeed, live and infectious virus was found at a distance up to 70m (76.5 yards) from the farm facilities.

airborne-high-path-avian-flu

Abstract: We investigated the plausibility of aerosol transmission of H5N2 highly pathogenic avian influenza (HPAI) virus during the 2015 spring outbreaks that occurred in the U.S. midwest. Air samples were collected inside and outside of infected turkey and layer facilities. Samples were tested to assess HPAI virus concentration (RNA copies/m3 of air), virus viability, and virus distribution by particle size. HPAI virus RNA was detected inside and up to 1000 m from infected facilities. HPAI virus was isolated from air samples collected inside, immediately outside, up to 70 m from infected facilities, and in aerosol particles larger than 2.1 lm. Direct exposure to exhausted aerosols proved to be a significant source of environmental contamination. These findings demonstrate HPAI virus aerosolization from infected flocks, and that both the transport of infectious aerosolized particles and the deposition of particles on surfaces around infected premises represent a potential risk for the spread of HPAI.

Link to the full text

Miracle of Birth center: success at the 2016 Minnesota State Fair!

The Minnesota State Fair closed its doors a week ago and once again the Miracle of Birth Center has been a huge success. This attraction, one of the visitors favorite displays cows, sows, does, goats, and hens giving birth and caring for their offspring. Animals are selected based on their estimated delivery date so that at least one birthing happens every day during the Fair.

Drs. Matt Sturos, Jerry Torrison, Alex Bianco, Bob Morrison, Fabio Vannucci, Maria Pieters, and Perle Boyer, faculty members from the swine group at the College of Veterinary Medicine, University of Minnesota as well as Drs. Megan Thompson, Nathan Winkelman, Abigail Redalen and Michael Strobel, professionals from the pork industry volunteered their time and shared their knowledge and expertise with the Minnesotans in order to increase awareness on what is actually happening on an American farm nowadays. Let’s also not forget the great participation of our graduate students, Drs. Talita Resende, Catalina Picasso, Luiza Roos, Jorge Garrido, Michael Rahe, and Fernando Leite.

Among the thousands of visitors admiring new-born calves and piglets, the Miracle of Birth Center had the honor of receiving the visit of the President of the University of Minnesota.

img_9949
President Kaler visiting the Miracle of Birth Center at the 2016 Minnesota State Fair.

The Miracle of Birth Center has the very noble mission to educate people about modern farm production and we wish it many more successful years!

Ionophore intoxication in swine

In this month column of the National Hog Farmer, Dr. Albert Rovira from the University of Minnesota is reviewing the cases of intoxication due to ionophores, these antibiotics given through the feed to control bacterial and coccidial infections in swine.Clinical signs are non-specific. Indeed, pigs become weak and stop eating but do not have a fever. In more severe cases, neurological signs can be noted. However, histological lesions are striking with a dramatic change of the muscle structure as is shown in Figure 1 below.

ionophore-intoxication

There are three main causes of ionophore intoxication in swine:

  1. Dosage error in the diet: the optimal concentration is very small, between 15 and 30 parts per milliom.
  2. Mixing ionophore and tiamulin: Tiamulin prevents the ionophore from being excreted by the body, leading to toxic blood levels.
  3. Inclusion of ionophores designed for another species. Usually, the levels are incorporated at a concentration higher than the toxic level.

In conclusion although cases of ionophore intoxication are rare in swine, it may become more prevalent starting in 2017, with the approval of the only swine ionophore as a growth promotant.

Link to the full article

Effect of electrostatic particle ionization technology on swine airborne pathogens

Dr. Alonso who just graduated from her PhD at the University of Minnesota, published in collaboration with Drs. Davies, Morrison and Torremorell an article evaluating the electrostatic particle ionization (EPI) technology as a technique to reduce  particle load in the air. The results showed that EPI was the most efficient when the system was close to the particle source and when the particle size was between 3.3 and 9 μm no matter what swine pathogen was evaluated. This technique could be promising in decreasing the risk of disease transmission between swine facilities.

Alonso ionization technology 2016

Abstract Influenza A virus (IAV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV) and Staphylococcus aureus are important swine pathogens capable of being transmitted via aerosols. The electrostatic particle ionization system (EPI) consists of a conductive line that emits negative ions that charge particles electrically resulting in the settling of airborne particles onto surface s and potentially decreasing the risk of pathogen dissemination. The objectives of this study were to determine the effect of the EPI system on the quantity and viability of IAV, PRRSV, PEDV and S. aureus in experimentally generated aerosols and in aerosols generated by infected animals. Efficiency at removing airborne particles was evaluated as a function of particle size (ranging from 0.4 to 10 μm), distance from the source of ions (1, 2 and 3 m) and relative air humidity (RH 30 vs. 70 %). Aerosols were sampled with the EPI system ‘‘off’ and ‘on.’ Removal efficiency was significantly greater for all pathogens when the EPI line was the closest to the source of aerosols. There was a greater reduction for larger particles ranging between 3.3 and 9 μm, which varied by pathogen. Overall airborne pathogen reduction ranged between 0.5 and 1.9 logs. Viable pathogens were detected with the EPI system ‘‘on,’ but there was a trend to reducing the quantity of viable PRRSV and IAV. There was not a significant effect on the pathogens removal efficiency based on the RH conditions tested. In summary, distance to the source of ions, type of pathogen and particle size influenced the removal efficiency of the EPI system. The reduction in inf ectious agents in the air by the EPI technology could potentially decrease the microbial exposure for pigs and people in confinement livestock facilities.

Link to the full article