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Papers by Christopher Chase

Veterinary Pathology, Mar 1, 2017

This issue of Veterinary Pathology contains the report "Natural Outbreak of BVDV-1d-Induced Mucos... more This issue of Veterinary Pathology contains the report "Natural Outbreak of BVDV-1d-Induced Mucosal Disease Lacking Intestinal Lesions" by Bianchi et al. 1 This report continues a recent trend seen among pestiviruses worldwide, with atypical being the watch word. At the recent Seventh BVDV Symposium, Evolution of Ecology of BVDV: Implications for Health and Control, held December 6-7, 2016, in Chicago, Illinois, reports were given on continued emergence of Hobi-like viruses in ruminants and 3 emerging pestiviruses in swine: atypical porcine pestivirus, Bungowannah virus, and reducedvirulence classical swine fever virus. Atypical porcine pestivirus was identified in 2015 and detected in newborn pigs with congenital tremor. Bungowannah virus was first described nearly a decade ago as the putative agent of a porcine myocarditis syndrome. Reduced-virulence classical swine fever virus poses the greatest risk due to misdiagnosis based on clinical signs. With this article by Bianchi et al, 1 BVDV type 1d joins the list of pestiviruses that exhibit atypical clinical signs and lesions. The animals exhibited clinical signs and gross lesions consistent with vesicular disease with little evidence of the expected clinical signs or lesions of BVDV infection. They had no mucosal erosions or ulcers of the Peyer's patches that have characterized classic mucosal disease associated with persistent infection with BVDV. The lack of mucosal ulcers has also been reported in 6 calves that were necropsied from a group of 23 persistently infected with BVDV2a. 2 All 23 of these calves died without any clinical signs of mucosal disease. 2 This article 1 provides a further reminder that a full diagnostic workup needs to be done to ensure that new atypical syndromes of well-characterized viruses like BVDV are identified and the etiologic agents documented.

One of the most threatening endemic diseases facing the cattle industry today is bovine viral dia... more One of the most threatening endemic diseases facing the cattle industry today is bovine viral diarrhea virus (BVDV). Economic losses caused by high-virulent strains are as high as $57 million per million calvings (Houe, H. 1999. Epidemiological features and economical importance of bovine virus diarrhoea (BVDV) infections. Vet. Microbiol. 64(2-3): 89-107). Within the host, the virus affects many different cell types, the most significant of which are immune cells. Our lab has shown previously that different strains of the virus inhibit the phagocytic capabilities of bovine macrophages. We believe that this is due to the ability of the virus to interfere with the restructuring of actin filaments within the cell. Monocyte derived macrophages were infected with different strains of BVDV. At 48 hours post-infection, the cells were fixed and stained using rhodamine phalloidin. The strains were found to vary in the extent to which they affected actin structure within the cell. Our current...

Animal Health Research Reviews, 2020

Every five years the Multi-State Bovine Respiratory Disease (BRD) Committee of the United States ... more Every five years the Multi-State Bovine Respiratory Disease (BRD) Committee of the United States Department of Agriculture (USDA) takes the opportunity to host the Bovine Respiratory Disease Symposium. The 2019 meeting theme was 'Challenges and Opportunities for Reducing the Incidence of Bovine Respiratory Disease' and was held in Denver, Colorado, USA on 7 and 8 August 2019. The aim of this symposium was to provide the latest information and opportunities for discussion on current concepts and approaches to improve understanding of BRD risk factors, economic impacts, animal genomics and BRD, the microbiome and BRD, novel diagnostic approaches, and antimicrobial stewardship. This special issue of Animal Health Research Reviews includes most of the papers from the 2019 BRD Symposium. We hope these articles will provide additional insight and food for thought on the best practices to implement for management of animals, people and microbes to lessen the impact of BRD.

Veterinaria italiana, Jan 31, 2015

Recent Orbivirus occurrences in the Americas have been investigated using whole genome amplificat... more Recent Orbivirus occurrences in the Americas have been investigated using whole genome amplification and sequencing followed by phylogenetic analysis. The bluetongue virus (BTV) and epizootic haemorrhagic disease virus (EHDV) whole genomes were amplified without prior sequence knowledge and deep sequenced. This technology was applied to evaluate BTV‑3 isolates spanning 4 decades from Florida, Arkansas, Mississippi, South Dakota, Central America, and the Caribbean basin. The results of the dataset analysis are consistent with the hypothesis that these viruses were introduced into the United States from Central America and the Caribbean basin. A similar analysis has been performed on a recent BTV‑2 isolate from California. It indicates that the BTV‑2 strain was likely introduced into Florida and then moved South to the Caribbean and West to California. A historical (1955‑2012) molecular characterisation of EHDV strains was also completed, and subsequently used as reference sequence fo...

Abstract Text: Crossbred steer calves (n = 2,870) were received at a commercial feedlot in Southe... more Abstract Text: Crossbred steer calves (n = 2,870) were received at a commercial feedlot in Southeastern Colorado. Upon arrival, weight (REC), ultrasound back fat (UBF), rib eye area (UREA) and intramuscular fat (UIMF) measures were collected. Animals treated for BRD received a treatment code (TRT) of 1 while animals not treated received a 0. Univariate sire model heritability estimates were calculated for TRT, REC, UBF, UREA and UIMF. Genetic correlations were calculated using bivariate sire models. Heritability estimates for TRT were (0.17 ± 0.08), REC (0.48 ± 0.08), UREA (0.49 ± 0.08), UBF (0.15 ± 0.05) and UIMF (0.33 ± 0.07). Genetic correlations varied between TRT and REC (0.62 ± 0.20), UREA (0.11 ± 0.22), UBF (-0.31 ± 0.31) and UIMF (0.06 ± 0.24). Results suggest that BRD resistance is heritable and related to initial feedlot body weight and back fat thickness. Keywords: beef cattle, bovine respiratory disease, immunity

American Journal of Veterinary Research, 2002

Objective—To study the antiviral activity of genistein, a soya isoflavone, on in vitro replicatio... more Objective—To study the antiviral activity of genistein, a soya isoflavone, on in vitro replication of bovine herpesvirus type 1 (BHV-1). Sample Population—Madin-Darby bovine kidney (MDBK) cells. Procedure—Effects of genistein on the magnitude and kinetics of inhibition of BHV-1 phosphorylation of glycoprotein E (gE) and in vitro replication of BHV-1 in MDBK cells were evaluated. Antiviral activity of genistein was compared with 2 compounds, estradiol-17β (EST) and tamoxifen (TAM), that have estrogenic and antiestrogenic activity, respectively. High-performance liquid chromatography (HPLC) was used to determine the concentration of genistein in medium from infected and uninfected MDBK cultures. Results—Genistein reduced BHV-1, but not gE-deleted BHV-1 (BHV-1gEΔ3.1), replication by 90% at 18 hours after inoculation. This inhibition was not sustained through 24 hours after inoculation. The genistein concentration in media from MDBK cells was decreased by 40% during BHV-1 infection, com...

Journal of General Virology, 1989

Pathogens

Bovine viral diarrhea virus (BVDV) induces immune dysfunction that often results in a secondary b... more Bovine viral diarrhea virus (BVDV) induces immune dysfunction that often results in a secondary bacterial infection in the infected animals. The underlying mechanism of BVDV-induced immune dysfunction is not well understood. The role of BVDV-infected macrophage-secreted factors was investigated. BVDV-infected monocyte-derived macrophage (MDM) supernatants down-regulated the expression of neutrophil L-selectin and CD18. Regardless of the biotype, phagocytic activity and oxidative burst were downregulated by BVDV-infected MDM supernatants. However, only supernatants from cytopathic (cp) BVDV down-regulated nitric oxide production and neutrophil extracellular traps (NET) induction. Our data suggested that BVDV-induced macrophage-secreted factors caused immune dysfunction in neutrophils. Unlike lymphocyte depletion, the negative impact on neutrophils seems to be specific to cp BVDV biotype. Interestingly the majority of modified live BVDV vaccines are based on cp strain of BVDV.

American Association of Bovine Practitioners Conference Proceedings

Yearly vaccination of cow herds for reproductive diseases is the norm in US cattle industry. Ther... more Yearly vaccination of cow herds for reproductive diseases is the norm in US cattle industry. There has been controversy throughout veterinary medicine about vaccination of animals. Theoretically, a single dose of modified live vaccine has been claimed to give life-long immunity. Because there have not been multiple year duration studies in cattle, the long-term efficacy of cow vaccinations has been difficult to assess. In this study we divided a 1000-cow herd into three groups: 1) vaccination every year, 2) vaccination every other year, and 3) vaccination every third year. The herd production records and serology of the herd were subsequently evaluated.

American Association of Bovine Practitioners Conference Proceedings

Bovine herpesvirus type 1 (BHV-1, IBR), an alphaherpesvirus, and bovine viral diarrhea virus (BVD... more Bovine herpesvirus type 1 (BHV-1, IBR), an alphaherpesvirus, and bovine viral diarrhea virus (BVDV), a pestivirus, are important cattle pathogens. Genistein, a naturally occurring flavonoid in soybeans, inhibits in vitro replication of herpes simplex virus 1, another alphaherpesvirus. Genistein has also been used to protect against a wide range of animal and human conditions including cancer, cardiovascular disease, loss of brain function, osteoporosis and menopausal symptoms. This makes genistein an excellent candidate for use as an anti-viral drug. Genistein was tested for its ability to inhibit the replication of BHV-1 and BVDV.

American Association of Bovine Practitioners Conference Proceedings

Vaccinology involves the preparation and testing of vaccines, the animal's immune response to... more Vaccinology involves the preparation and testing of vaccines, the animal's immune response to the vaccine and the outcome against a challenge. This area of veterinary medicine, which offers great promise, is misused, abused and often expected to cure the impossible. Unfortunately, there is no "magic bullet" and the myths of vaccinology outweigh the reality. Our understanding of the immune response has been greatly expanded in the last 10 years. Terms such as "danger signals" and "dendritic cells" were unknown in vaccinology until the last 5-6 years. In this vaccinology review, I will emphasize the primary immune response and its importance for setting up the long-term memory and duration of immunity.

American Association of Bovine Practitioners Conference Proceedings

The interaction of the gastrointestinal tract (GIT) and the microbiome (all the microbes in the l... more The interaction of the gastrointestinal tract (GIT) and the microbiome (all the microbes in the lumen of the GIT) has become an increasing area of interest in terms of the effect on the immune system and overall health of cattle. Feed changes (including feed restriction) and dehydration (including water restriction), let alone the use antimicrobials, plus the normal stressors (weather, density, weaning, etc.) all effect both the mucosal epithelial (ME) cells of the GIT and the microbiome. The ME maintain a kill zone barrier to keep out pathogens in concert with the commensal microorganisms (microbiome) and other cells of the immune system. The microbiome functions best when it is in a stable condition resulting in immune homeostasis. Immunoregulation by the ME and microbiome results in the establishment of a mucosal firewall. Disruptions in the microbiome result in dysbiosis, which decreases the kill zone, allows leaky gut, and increases inflammation. This increased inflammation is ...

American Association of Bovine Practitioners Conference Proceedings

Bovine viral diarrhea virus (BVDV) is a positive single-stranded RNA virus belonging to the Pesti... more Bovine viral diarrhea virus (BVDV) is a positive single-stranded RNA virus belonging to the Pestivirus genus of the Flaviviridae family. BVDV has a wide host range that includes most ruminants. Noncytopathic (ncp) BVDV may establish lifelong persistent infections in calves following infection of the fetus between 40 and 120 days of gestation. Cytopathic (cp) BVDV strains arise from ncp strains via mutations. The most common cp mutations are insertions of RNA derived from either host or a duplication of viral sequences into the region of the genome coding for the NS2/3 protein. Superinfection of a persistently infected animal with a cp virus can give rise to mucosal disease (MD), a condition that is invariably fatal.

Veterinary Clinics of North America: Food Animal Practice, 2019

The largest organ of the immune system is the mucosa making the management of it essential for pr... more The largest organ of the immune system is the mucosa making the management of it essential for productivity and health. The mucosal barrier consists of mucous, antimicrobial peptides, and IgA and is a "kill zone" to prevent microbial invasion of the epithelium. The mucosal epithelial cells are key cells that maintain the "kill zone" and "mucosal firewall" and respond to metabolites and microbial components from the lumen and signals from immune cells to maintain tight junctions and prevent leaky gut. The mucosal immune system has a unique circulatory system where immune cells that have activated in mucosal region recirculate to mucosal regions, a system termed the common mucosal system.

Translational Animal Science, 2019

A blend of essential oils (EO) and a prebiotic were combined (EOC) to formulate a colostrum-based... more A blend of essential oils (EO) and a prebiotic were combined (EOC) to formulate a colostrum-based liquid birth supplement and a separate feeding supplement (Start Strong and Stay Strong, Ralco Inc., Marshall, MN). These products were designed to promote immunity and stimulate appetite to diminish health challenges and stresses experienced by newborn calves. The hypothesis was that calves supplemented with an oral dose of liquid EOC at birth (10-mL aliquot at birth and 10 mL at 12 h of age) when fed the EOC feeding supplement would result in improved growth performance, health, and immunity. The objective was to determine if an additional feeding of liquid EOC at birth in combination with EOC in the milk replacer (MR) would allow calves to demonstrate improved growth, health, and immunity compare with calves only offered EO in MR. Sixty-one Holstein calves (18 males and 43 females) from a commercial dairy operation were blocked by birth date and randomly assigned to 1 of 3 treatments...

Journal of Animal Science, 2017

for the assistance in viral neutralization and consolidation of data.

Microbial Pathogenesis, 2018

The innate immune response is a vital part of the body's antiviral defense system. The innate imm... more The innate immune response is a vital part of the body's antiviral defense system. The innate immune response is initiated by various receptor interactions, including danger associated molecular patterns (DAMPs). The S100A9 is a member of the DAMPs protein family and, is released by activated phagocytic cells such as neutrophils, monocytes, macrophages or endothelial cells, and S100A9 induces its effect through TLR4/MyD88 pathway. Bovine viral diarrhea virus (BVDV) is one of the major devastating disease in the cattle industry worldwide. It shows its effect through immunosuppression and develops persistent infection in calves born from infected cows. The current study revealed that BVDV potentially induced immunosuppression by the interaction of BVDV Npro protein with cellular S100A9 protein. The Inhibition of S100A9 protein expression by small interfering RNA (siRNA) enhanced the virus replication in infected cells. Overexpression of bovine S100A9 enhanced the ncpBVDV2a 1373 mediated Type-I interferon production. A co-immunoprecipitation experiment demonstrated a strong interaction between ncp BVDV2a 1373 Npro protein and cellular S100A9 protein. This suggested that BVDV Npro reduced the S100A9 protein availability/activity in infected cells, resulting in reduced Type-I interferon production. A further study of S100A9-BVDV interaction will be need for better understanding of BVDV pathophysiology.

Pathogens (Basel, Switzerland), Jan 6, 2018

Non-cytopathic bovine viral diarrhea virus (ncp BVDV) can cause persistent infection (PI) in anim... more Non-cytopathic bovine viral diarrhea virus (ncp BVDV) can cause persistent infection (PI) in animals infected in utero during early gestation. PI animals shed the virus for life and are the major source of the virus in herds. The mechanism responsible for BVDV immune tolerance in the PI fetus is unknown. We assessed the impact of BVDV infection on the fetal liver. Dams were inoculated with ncp BVDV at gestational day 75. Fetal liver samples were collected at necropsy, 7 and 14 days post-maternal-BVDV inoculation. BVDV antigen was not detected in the liver at gestational day 82 (7 days post-maternal inoculation). However, at 14 days post-maternal inoculation, BVDV was detected by immunohistochemistry in fetal Kupffer cells. Flow cytometry analysis showed a higher percentage of hepatic immune cells expressed MHC I and MHC II in BVDV-infected fetal liver (as compared to uninfected controls). Immunofluorescence was used to identify Kupffer cells, which were positive for BVDV antigen, ne...

Vaccine, Jan 24, 2016

This study investigated viruses in bovine respiratory disease (BRD) cases in feedlots, including ... more This study investigated viruses in bovine respiratory disease (BRD) cases in feedlots, including bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine coronaviruses (BoCV) and parainfluenza-3 virus (PI3V). Nasal swabs were collected from 114 cattle on initial BRD treatment. Processing included modified live virus (MLV) vaccination. Seven BRD necropsy cases were included for 121 total cases. Mean number of days on feed before first sample was 14.9 days. Swabs and tissue homogenates were tested by gel based PCR (G-PCR), quantitative-PCR (qPCR) and quantitative real time reverse transcriptase PCR (qRT-PCR) and viral culture. There were 87/114 (76.3%) swabs positive for at least one virus by at least one test. All necropsy cases were positive for at least one virus. Of 121 cases, positives included 18/121 (14.9%) BoHV-1; 19/121 (15.7%) BVDV; 76/121 (62.8%) BoCV; 11/121 (9.1%) BRSV; and 10/121 (8.3%) PI3V. For nasal swabs, G-...

Veterinary Pathology, Mar 1, 2017

This issue of Veterinary Pathology contains the report "Natural Outbreak of BVDV-1d-Induced Mucos... more This issue of Veterinary Pathology contains the report "Natural Outbreak of BVDV-1d-Induced Mucosal Disease Lacking Intestinal Lesions" by Bianchi et al. 1 This report continues a recent trend seen among pestiviruses worldwide, with atypical being the watch word. At the recent Seventh BVDV Symposium, Evolution of Ecology of BVDV: Implications for Health and Control, held December 6-7, 2016, in Chicago, Illinois, reports were given on continued emergence of Hobi-like viruses in ruminants and 3 emerging pestiviruses in swine: atypical porcine pestivirus, Bungowannah virus, and reducedvirulence classical swine fever virus. Atypical porcine pestivirus was identified in 2015 and detected in newborn pigs with congenital tremor. Bungowannah virus was first described nearly a decade ago as the putative agent of a porcine myocarditis syndrome. Reduced-virulence classical swine fever virus poses the greatest risk due to misdiagnosis based on clinical signs. With this article by Bianchi et al, 1 BVDV type 1d joins the list of pestiviruses that exhibit atypical clinical signs and lesions. The animals exhibited clinical signs and gross lesions consistent with vesicular disease with little evidence of the expected clinical signs or lesions of BVDV infection. They had no mucosal erosions or ulcers of the Peyer's patches that have characterized classic mucosal disease associated with persistent infection with BVDV. The lack of mucosal ulcers has also been reported in 6 calves that were necropsied from a group of 23 persistently infected with BVDV2a. 2 All 23 of these calves died without any clinical signs of mucosal disease. 2 This article 1 provides a further reminder that a full diagnostic workup needs to be done to ensure that new atypical syndromes of well-characterized viruses like BVDV are identified and the etiologic agents documented.

One of the most threatening endemic diseases facing the cattle industry today is bovine viral dia... more One of the most threatening endemic diseases facing the cattle industry today is bovine viral diarrhea virus (BVDV). Economic losses caused by high-virulent strains are as high as $57 million per million calvings (Houe, H. 1999. Epidemiological features and economical importance of bovine virus diarrhoea (BVDV) infections. Vet. Microbiol. 64(2-3): 89-107). Within the host, the virus affects many different cell types, the most significant of which are immune cells. Our lab has shown previously that different strains of the virus inhibit the phagocytic capabilities of bovine macrophages. We believe that this is due to the ability of the virus to interfere with the restructuring of actin filaments within the cell. Monocyte derived macrophages were infected with different strains of BVDV. At 48 hours post-infection, the cells were fixed and stained using rhodamine phalloidin. The strains were found to vary in the extent to which they affected actin structure within the cell. Our current...

Animal Health Research Reviews, 2020

Every five years the Multi-State Bovine Respiratory Disease (BRD) Committee of the United States ... more Every five years the Multi-State Bovine Respiratory Disease (BRD) Committee of the United States Department of Agriculture (USDA) takes the opportunity to host the Bovine Respiratory Disease Symposium. The 2019 meeting theme was 'Challenges and Opportunities for Reducing the Incidence of Bovine Respiratory Disease' and was held in Denver, Colorado, USA on 7 and 8 August 2019. The aim of this symposium was to provide the latest information and opportunities for discussion on current concepts and approaches to improve understanding of BRD risk factors, economic impacts, animal genomics and BRD, the microbiome and BRD, novel diagnostic approaches, and antimicrobial stewardship. This special issue of Animal Health Research Reviews includes most of the papers from the 2019 BRD Symposium. We hope these articles will provide additional insight and food for thought on the best practices to implement for management of animals, people and microbes to lessen the impact of BRD.

Veterinaria italiana, Jan 31, 2015

Recent Orbivirus occurrences in the Americas have been investigated using whole genome amplificat... more Recent Orbivirus occurrences in the Americas have been investigated using whole genome amplification and sequencing followed by phylogenetic analysis. The bluetongue virus (BTV) and epizootic haemorrhagic disease virus (EHDV) whole genomes were amplified without prior sequence knowledge and deep sequenced. This technology was applied to evaluate BTV‑3 isolates spanning 4 decades from Florida, Arkansas, Mississippi, South Dakota, Central America, and the Caribbean basin. The results of the dataset analysis are consistent with the hypothesis that these viruses were introduced into the United States from Central America and the Caribbean basin. A similar analysis has been performed on a recent BTV‑2 isolate from California. It indicates that the BTV‑2 strain was likely introduced into Florida and then moved South to the Caribbean and West to California. A historical (1955‑2012) molecular characterisation of EHDV strains was also completed, and subsequently used as reference sequence fo...

Abstract Text: Crossbred steer calves (n = 2,870) were received at a commercial feedlot in Southe... more Abstract Text: Crossbred steer calves (n = 2,870) were received at a commercial feedlot in Southeastern Colorado. Upon arrival, weight (REC), ultrasound back fat (UBF), rib eye area (UREA) and intramuscular fat (UIMF) measures were collected. Animals treated for BRD received a treatment code (TRT) of 1 while animals not treated received a 0. Univariate sire model heritability estimates were calculated for TRT, REC, UBF, UREA and UIMF. Genetic correlations were calculated using bivariate sire models. Heritability estimates for TRT were (0.17 ± 0.08), REC (0.48 ± 0.08), UREA (0.49 ± 0.08), UBF (0.15 ± 0.05) and UIMF (0.33 ± 0.07). Genetic correlations varied between TRT and REC (0.62 ± 0.20), UREA (0.11 ± 0.22), UBF (-0.31 ± 0.31) and UIMF (0.06 ± 0.24). Results suggest that BRD resistance is heritable and related to initial feedlot body weight and back fat thickness. Keywords: beef cattle, bovine respiratory disease, immunity

American Journal of Veterinary Research, 2002

Objective—To study the antiviral activity of genistein, a soya isoflavone, on in vitro replicatio... more Objective—To study the antiviral activity of genistein, a soya isoflavone, on in vitro replication of bovine herpesvirus type 1 (BHV-1). Sample Population—Madin-Darby bovine kidney (MDBK) cells. Procedure—Effects of genistein on the magnitude and kinetics of inhibition of BHV-1 phosphorylation of glycoprotein E (gE) and in vitro replication of BHV-1 in MDBK cells were evaluated. Antiviral activity of genistein was compared with 2 compounds, estradiol-17β (EST) and tamoxifen (TAM), that have estrogenic and antiestrogenic activity, respectively. High-performance liquid chromatography (HPLC) was used to determine the concentration of genistein in medium from infected and uninfected MDBK cultures. Results—Genistein reduced BHV-1, but not gE-deleted BHV-1 (BHV-1gEΔ3.1), replication by 90% at 18 hours after inoculation. This inhibition was not sustained through 24 hours after inoculation. The genistein concentration in media from MDBK cells was decreased by 40% during BHV-1 infection, com...

Journal of General Virology, 1989

Pathogens

Bovine viral diarrhea virus (BVDV) induces immune dysfunction that often results in a secondary b... more Bovine viral diarrhea virus (BVDV) induces immune dysfunction that often results in a secondary bacterial infection in the infected animals. The underlying mechanism of BVDV-induced immune dysfunction is not well understood. The role of BVDV-infected macrophage-secreted factors was investigated. BVDV-infected monocyte-derived macrophage (MDM) supernatants down-regulated the expression of neutrophil L-selectin and CD18. Regardless of the biotype, phagocytic activity and oxidative burst were downregulated by BVDV-infected MDM supernatants. However, only supernatants from cytopathic (cp) BVDV down-regulated nitric oxide production and neutrophil extracellular traps (NET) induction. Our data suggested that BVDV-induced macrophage-secreted factors caused immune dysfunction in neutrophils. Unlike lymphocyte depletion, the negative impact on neutrophils seems to be specific to cp BVDV biotype. Interestingly the majority of modified live BVDV vaccines are based on cp strain of BVDV.

American Association of Bovine Practitioners Conference Proceedings

Yearly vaccination of cow herds for reproductive diseases is the norm in US cattle industry. Ther... more Yearly vaccination of cow herds for reproductive diseases is the norm in US cattle industry. There has been controversy throughout veterinary medicine about vaccination of animals. Theoretically, a single dose of modified live vaccine has been claimed to give life-long immunity. Because there have not been multiple year duration studies in cattle, the long-term efficacy of cow vaccinations has been difficult to assess. In this study we divided a 1000-cow herd into three groups: 1) vaccination every year, 2) vaccination every other year, and 3) vaccination every third year. The herd production records and serology of the herd were subsequently evaluated.

American Association of Bovine Practitioners Conference Proceedings

Bovine herpesvirus type 1 (BHV-1, IBR), an alphaherpesvirus, and bovine viral diarrhea virus (BVD... more Bovine herpesvirus type 1 (BHV-1, IBR), an alphaherpesvirus, and bovine viral diarrhea virus (BVDV), a pestivirus, are important cattle pathogens. Genistein, a naturally occurring flavonoid in soybeans, inhibits in vitro replication of herpes simplex virus 1, another alphaherpesvirus. Genistein has also been used to protect against a wide range of animal and human conditions including cancer, cardiovascular disease, loss of brain function, osteoporosis and menopausal symptoms. This makes genistein an excellent candidate for use as an anti-viral drug. Genistein was tested for its ability to inhibit the replication of BHV-1 and BVDV.

American Association of Bovine Practitioners Conference Proceedings

Vaccinology involves the preparation and testing of vaccines, the animal's immune response to... more Vaccinology involves the preparation and testing of vaccines, the animal's immune response to the vaccine and the outcome against a challenge. This area of veterinary medicine, which offers great promise, is misused, abused and often expected to cure the impossible. Unfortunately, there is no "magic bullet" and the myths of vaccinology outweigh the reality. Our understanding of the immune response has been greatly expanded in the last 10 years. Terms such as "danger signals" and "dendritic cells" were unknown in vaccinology until the last 5-6 years. In this vaccinology review, I will emphasize the primary immune response and its importance for setting up the long-term memory and duration of immunity.

American Association of Bovine Practitioners Conference Proceedings

The interaction of the gastrointestinal tract (GIT) and the microbiome (all the microbes in the l... more The interaction of the gastrointestinal tract (GIT) and the microbiome (all the microbes in the lumen of the GIT) has become an increasing area of interest in terms of the effect on the immune system and overall health of cattle. Feed changes (including feed restriction) and dehydration (including water restriction), let alone the use antimicrobials, plus the normal stressors (weather, density, weaning, etc.) all effect both the mucosal epithelial (ME) cells of the GIT and the microbiome. The ME maintain a kill zone barrier to keep out pathogens in concert with the commensal microorganisms (microbiome) and other cells of the immune system. The microbiome functions best when it is in a stable condition resulting in immune homeostasis. Immunoregulation by the ME and microbiome results in the establishment of a mucosal firewall. Disruptions in the microbiome result in dysbiosis, which decreases the kill zone, allows leaky gut, and increases inflammation. This increased inflammation is ...

American Association of Bovine Practitioners Conference Proceedings

Bovine viral diarrhea virus (BVDV) is a positive single-stranded RNA virus belonging to the Pesti... more Bovine viral diarrhea virus (BVDV) is a positive single-stranded RNA virus belonging to the Pestivirus genus of the Flaviviridae family. BVDV has a wide host range that includes most ruminants. Noncytopathic (ncp) BVDV may establish lifelong persistent infections in calves following infection of the fetus between 40 and 120 days of gestation. Cytopathic (cp) BVDV strains arise from ncp strains via mutations. The most common cp mutations are insertions of RNA derived from either host or a duplication of viral sequences into the region of the genome coding for the NS2/3 protein. Superinfection of a persistently infected animal with a cp virus can give rise to mucosal disease (MD), a condition that is invariably fatal.

Veterinary Clinics of North America: Food Animal Practice, 2019

The largest organ of the immune system is the mucosa making the management of it essential for pr... more The largest organ of the immune system is the mucosa making the management of it essential for productivity and health. The mucosal barrier consists of mucous, antimicrobial peptides, and IgA and is a "kill zone" to prevent microbial invasion of the epithelium. The mucosal epithelial cells are key cells that maintain the "kill zone" and "mucosal firewall" and respond to metabolites and microbial components from the lumen and signals from immune cells to maintain tight junctions and prevent leaky gut. The mucosal immune system has a unique circulatory system where immune cells that have activated in mucosal region recirculate to mucosal regions, a system termed the common mucosal system.

Translational Animal Science, 2019

A blend of essential oils (EO) and a prebiotic were combined (EOC) to formulate a colostrum-based... more A blend of essential oils (EO) and a prebiotic were combined (EOC) to formulate a colostrum-based liquid birth supplement and a separate feeding supplement (Start Strong and Stay Strong, Ralco Inc., Marshall, MN). These products were designed to promote immunity and stimulate appetite to diminish health challenges and stresses experienced by newborn calves. The hypothesis was that calves supplemented with an oral dose of liquid EOC at birth (10-mL aliquot at birth and 10 mL at 12 h of age) when fed the EOC feeding supplement would result in improved growth performance, health, and immunity. The objective was to determine if an additional feeding of liquid EOC at birth in combination with EOC in the milk replacer (MR) would allow calves to demonstrate improved growth, health, and immunity compare with calves only offered EO in MR. Sixty-one Holstein calves (18 males and 43 females) from a commercial dairy operation were blocked by birth date and randomly assigned to 1 of 3 treatments...

Journal of Animal Science, 2017

for the assistance in viral neutralization and consolidation of data.

Microbial Pathogenesis, 2018

The innate immune response is a vital part of the body's antiviral defense system. The innate imm... more The innate immune response is a vital part of the body's antiviral defense system. The innate immune response is initiated by various receptor interactions, including danger associated molecular patterns (DAMPs). The S100A9 is a member of the DAMPs protein family and, is released by activated phagocytic cells such as neutrophils, monocytes, macrophages or endothelial cells, and S100A9 induces its effect through TLR4/MyD88 pathway. Bovine viral diarrhea virus (BVDV) is one of the major devastating disease in the cattle industry worldwide. It shows its effect through immunosuppression and develops persistent infection in calves born from infected cows. The current study revealed that BVDV potentially induced immunosuppression by the interaction of BVDV Npro protein with cellular S100A9 protein. The Inhibition of S100A9 protein expression by small interfering RNA (siRNA) enhanced the virus replication in infected cells. Overexpression of bovine S100A9 enhanced the ncpBVDV2a 1373 mediated Type-I interferon production. A co-immunoprecipitation experiment demonstrated a strong interaction between ncp BVDV2a 1373 Npro protein and cellular S100A9 protein. This suggested that BVDV Npro reduced the S100A9 protein availability/activity in infected cells, resulting in reduced Type-I interferon production. A further study of S100A9-BVDV interaction will be need for better understanding of BVDV pathophysiology.

Pathogens (Basel, Switzerland), Jan 6, 2018

Non-cytopathic bovine viral diarrhea virus (ncp BVDV) can cause persistent infection (PI) in anim... more Non-cytopathic bovine viral diarrhea virus (ncp BVDV) can cause persistent infection (PI) in animals infected in utero during early gestation. PI animals shed the virus for life and are the major source of the virus in herds. The mechanism responsible for BVDV immune tolerance in the PI fetus is unknown. We assessed the impact of BVDV infection on the fetal liver. Dams were inoculated with ncp BVDV at gestational day 75. Fetal liver samples were collected at necropsy, 7 and 14 days post-maternal-BVDV inoculation. BVDV antigen was not detected in the liver at gestational day 82 (7 days post-maternal inoculation). However, at 14 days post-maternal inoculation, BVDV was detected by immunohistochemistry in fetal Kupffer cells. Flow cytometry analysis showed a higher percentage of hepatic immune cells expressed MHC I and MHC II in BVDV-infected fetal liver (as compared to uninfected controls). Immunofluorescence was used to identify Kupffer cells, which were positive for BVDV antigen, ne...

Vaccine, Jan 24, 2016

This study investigated viruses in bovine respiratory disease (BRD) cases in feedlots, including ... more This study investigated viruses in bovine respiratory disease (BRD) cases in feedlots, including bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine coronaviruses (BoCV) and parainfluenza-3 virus (PI3V). Nasal swabs were collected from 114 cattle on initial BRD treatment. Processing included modified live virus (MLV) vaccination. Seven BRD necropsy cases were included for 121 total cases. Mean number of days on feed before first sample was 14.9 days. Swabs and tissue homogenates were tested by gel based PCR (G-PCR), quantitative-PCR (qPCR) and quantitative real time reverse transcriptase PCR (qRT-PCR) and viral culture. There were 87/114 (76.3%) swabs positive for at least one virus by at least one test. All necropsy cases were positive for at least one virus. Of 121 cases, positives included 18/121 (14.9%) BoHV-1; 19/121 (15.7%) BVDV; 76/121 (62.8%) BoCV; 11/121 (9.1%) BRSV; and 10/121 (8.3%) PI3V. For nasal swabs, G-...