Tulathromycin metaphylaxis increases nasopharyngeal isolation of multidrug resistant Mannheimia haemolytica in stocker heifers.

Bovine respiratory disease (BRD) is a leading cause of disease in feedlot and stocker calves with Mannheimia haemolytica (MH) as one of the most common etiologies. One of the most effective means of controlling BRD is through metaphylaxis, which involves administering antimicrobials to all animals at high risk of developing BRD. However, increasing prevalence of multidrug resistant (MDR) MH may reduce efficacy of metaphylaxis due to decreased susceptibility to drugs used for metaphylaxis. Primarily, this study aimed to determine the effect of tulathromycin metaphylaxis and subsequent BRD treatment on antimicrobial resistance (AMR) in MH isolated from stocker calves. Secondary objectives included evaluating the effect of metaphylaxis and treatment for BRD on animal health and comparing the genetic relationship of MH isolated. Crossbred beef heifers (n = 331, mean weight = 232, SD = 17.8 kg) at high risk for BRD were randomly assigned to receive tulathromycin metaphylaxis (META, n = 167) or not (NO META, n = 164). Nasopharyngeal swabs were collected for MH isolation, antimicrobial susceptibility testing and whole genome sequencing at arrival and 3 (WK3) and 10 (WK10) weeks later. Mixed-effects logistic regression was used to identify risk factors for isolation of MH and MDR MH (resistant to ≥3 antimicrobial drug classes) at 3 and 10 weeks, BRD morbidity, and crude mortality. Animals in the META group had higher odds of isolation of MDR MH at 3 weeks [OR (95% CI) = 13.08 (5-30.9), p < 0.0001] and 10 weeks [OR (95% CI) = 5.92 (1.34-26.14), p = 0.019] after arrival. There was no difference in risk of isolation of any MH (resistant or susceptible) between META and NO META groups at all timepoints. Animals in the NO META group had 3 times higher odds of being treated for BRD [WK3: OR (95% CI) = 3.07 (1.70-5.52), p = 0.0002; WK10: OR (95% CI) = 2.76 (1.59-4.80), p = 0.0002]. Antimicrobial resistance genes found within isolates were associated with integrative conjugative element (ICE) genes. Tulathromycin metaphylaxis increased risk of isolation of MDR MH and in this population, the increase in MDR MH appeared to be associated with ICE containing antimicrobial resistance genes for multiple antimicrobial classes. This may have important implications for future efficacy of antimicrobials for control and treatment of BRD.

The Sialyl Lewis X Glycan Receptor Facilitates Infection of Subtype H7 Avian Influenza A Viruses.

Subtype H7 avian influenza A viruses (IAVs) are enzootic in wild aquatic birds and have caused sporadic spillovers into domestic poultry and humans. Here, we determined the distribution of fucosylated α2,3 sialoglycan (i.e., sialyl Lewis X [SLeX]) in chickens and five common dabbling duck species and the association between SLeX and cell/tissue/host tropisms of H7 IAVs. Receptor binding analyses showed that H7 IAVs bind to both α2,3-linked (SA2,3Gal) and α2,6-linked sialic acids (SA2,6Gal), but with a higher preference for SLeX; H7 IAVs replicated more efficiently in SLeX-overexpressed than SLeX-deficient MDCK cells. While chickens and all tested dabbling ducks expressed abundant SA2,3Gal and SA2,6Gal, SLeX was detected in both respiratory and gastrointestinal tissues of chickens and mallard ducks and in only the respiratory tissues of gadwall, green-wing teal, and northern shoveler but not in wood ducks. Viral-tissue binding assays showed that H7 IAVs bind to chicken colon crypt cells that express SLeX but fewer bind to mallard colon crypt cells, which do not express SLeX; H7 IAVs bind efficiently to epithelial cells of all tissues expressing SA2,3Gal. High viral replication was identified in both chickens and mallards infected with an H7 virus, regardless of SLeX expression, and viruses were detected in all cells to the same degree as viruses detected in the viral-tissue binding assays. In summary, this study suggests that SLeX facilitates infection of H7 viruses, but other types of SA2,3Gal glycan receptors shape the tissue/host tropisms of H7 IAVs. IMPORTANCE In addition to causing outbreaks in domestic poultry, subtype H7 IAVs can cause sporadic spillover infections in lower mammals and humans. In this study, we showed that SLeX expression varies among wild dabbling ducks. Although it facilitated virus binding and affected infection of H7 IAV in cells, SLeX expression is not the only determinant of viral replication at either the tissue or host level. This study suggested that access to heterologous SA2,3Gal glycan receptors, including fucosylated α2,3-linked sialoglycans, shape tissue and host tropism of H7 IAVs in aquatic wild birds.

Assessment of Diversity of Antimicrobial Resistance Phenotypes and Genotypes of Mannheimia haemolytica Isolates From Bovine Nasopharyngeal Swabs.

The threat of bovine respiratory disease (BRD) for cattle operations is exacerbated by increasing prevalence of antimicrobial resistance (AMR) in Mannheimia haemolytica, a leading cause of BRD. Characterization of AMR in M. haemolytica by culture and susceptibility testing is complicated by uncertainty regarding the number of colonies that must be selected to accurately characterize AMR phenotypes (antibiograms) and genotypes in a culture. The study objective was to assess phenotypic and genotypic diversity of M. haemolytica isolates on nasopharyngeal swabs (NPS) from 28 cattle at risk for BRD or with BRD. NPS were swabbed onto five consecutive blood agar plates; after incubation up to 20 M. haemolytica colonies were selected per plate (up to 100 colonies per NPS). Phenotype was determined by measuring minimum inhibitory concentrations (MIC) for 11 antimicrobials and classifying isolates as resistant or not. Genotype was indirectly determined by matrix-assisted laser desorption/ionization time of flight mass spectroscopy (MALDI-TOF MS). NPS from 11 of 28 cattle yielded at least one M. haemolytica isolate; median (range) of isolates per NPS was 48 (1-94). NPS from seven cattle yielded one phenotype, 3 NPS yielded two, and 1 NPS yielded three; however, within a sample all phenotypic differences were due to only one MIC dilution. On each NPS all M. haemolytica isolated were the same genotype; genotype 1 was isolated from three NPS and genotype two was isolated from eight. Diversity of M. haemolytica on bovine NPS was limited, suggesting that selection of few colonies might adequately identify relevant phenotypes and genotypes.

Time-Dependent Proinflammatory Responses Shape Virus Interference during Coinfections of Influenza A Virus and Influenza D Virus.

Both influenza A virus (IAV) and influenza D virus (IDV) are enzootic in pigs. IAV causes approximately 100% morbidity with low mortality, whereas IDV leads to only mild respiratory diseases in pigs. In this study, we performed a series of coinfection experiments in vitro and in vivo to understand how IAV and IDV interact and cause pathogenesis during coinfection. The results showed that IAV inhibited IDV replication when infecting swine tracheal epithelial cells (STECs) with IAV 24 or 48 h prior to IDV inoculation and that IDV suppressed IAV replication when IDV preceded IAV inoculation by 48 h. Virus interference was not identified during simultaneous IAV/IDV infections or with 6 h between the two viral infections, regardless of their order. The interference pattern at 24 and 48 h correlated with proinflammatory responses induced by the first infection, which, for IDV, was slower than for IAV by about 24 h. The viruses did not interfere with each other if both infected the cells before proinflammatory responses were induced. Coinfection in pigs further demonstrated that IAV interfered with both viral shedding and virus replication of IDV, especially in the upper respiratory tract. Clinically, coinfection of IDV and IAV did not show significant enhancement of disease pathogenesis, compared with the pigs infected with IAV alone. In summary, this study suggests that interference during coinfection of IAV and IDV is primarily due to the proinflammatory response; therefore, it is dependent on the time between infections and the order of infection. This study facilitates our understanding of virus epidemiology and pathogenesis associated with IAV and IDV coinfection.

Multipopulational transcriptome analysis of post-weaned beef cattle at arrival further validates candidate biomarkers for predicting clinical bovine respiratory disease.

Bovine respiratory disease (BRD) remains the leading infectious disease in post-weaned beef cattle. The objective of this investigation was to contrast the at-arrival blood transcriptomes from cattle derived from two distinct populations that developed BRD in the 28 days following arrival versus cattle that did not. Forty-eight blood samples from two populations were selected for mRNA sequencing based on even distribution of development (n = 24) or lack of (n = 24) clinical BRD within 28 days following arrival; cattle which developed BRD were further stratified into BRD severity cohorts based on frequency of antimicrobial treatment: treated once (treated_1) or treated twice or more and/or died (treated_2+). Sequenced reads (~ 50 M/sample, 150 bp paired-end) were aligned to the ARS-UCD1.2 bovine genome assembly. One hundred and thirty-two unique differentially expressed genes (DEGs) were identified between groups stratified by disease severity (healthy, n = 24; treated_1, n = 13; treated_2+, n = 11) with edgeR (FDR ≤ 0.05). Differentially expressed genes in treated_1 relative to both healthy and treated_2+ were predicted to increase neutrophil activation, cellular cornification/keratinization, and antimicrobial peptide production. Differentially expressed genes in treated_2+ relative to both healthy and treated_1 were predicted to increase alternative complement activation, decrease leukocyte activity, and increase nitric oxide production. Receiver operating characteristic (ROC) curves generated from expression data for six DEGs identified in our current and previous studies (MARCO, CFB, MCF2L, ALOX15, LOC100335828 (aka CD200R1), and SLC18A2) demonstrated good-to-excellent (AUC: 0.800-0.899; ≥ 0.900) predictability for classifying disease occurrence and severity. This investigation identifies candidate biomarkers and functional mechanisms in at arrival blood that predicted development and severity of BRD.

Comprehensive at-arrival transcriptomic analysis of post-weaned beef cattle uncovers type I interferon and antiviral mechanisms associated with bovine respiratory disease mortality.

BACKGROUND: Despite decades of extensive research, bovine respiratory disease (BRD) remains the most devastating disease in beef cattle production. Establishing a clinical diagnosis often relies upon visual detection of non-specific signs, leading to low diagnostic accuracy. Thus, post-weaned beef cattle are often metaphylactically administered antimicrobials at facility arrival, which poses concerns regarding antimicrobial stewardship and resistance. Additionally, there is a lack of high-quality research that addresses the gene-by-environment interactions that underlie why some cattle that develop BRD die while others survive. Therefore, it is necessary to decipher the underlying host genomic factors associated with BRD mortality versus survival to help determine BRD risk and severity. Using transcriptomic analysis of at-arrival whole blood samples from cattle that died of BRD, as compared to those that developed signs of BRD but lived (n = 3 DEAD, n = 3 ALIVE), we identified differentially expressed genes (DEGs) and associated pathways in cattle that died of BRD. Additionally, we evaluated unmapped reads, which are often overlooked within transcriptomic experiments. RESULTS: 69 DEGs (FDR<0.10) were identified between ALIVE and DEAD cohorts. Several DEGs possess immunological and proinflammatory function and associations with TLR4 and IL6. Biological processes, pathways, and disease phenotype associations related to type-I interferon production and antiviral defense were enriched in DEAD cattle at arrival. Unmapped reads aligned primarily to various ungulate assemblies, but failed to align to viral assemblies. CONCLUSION: This study further revealed increased proinflammatory immunological mechanisms in cattle that develop BRD. DEGs upregulated in DEAD cattle were predominantly involved in innate immune pathways typically associated with antiviral defense, although no viral genes were identified within unmapped reads. Our findings provide genomic targets for further analysis in cattle at highest risk of BRD, suggesting that mechanisms related to type I interferons and antiviral defense may be indicative of viral respiratory disease at arrival and contribute to eventual BRD mortality.

Limited Cross-Protection Provided by Prior Infection Contributes to High Prevalence of Influenza D Viruses in Cattle.

Since its detection in swine, influenza D virus (IDV) has been shown to be present in multiple animal hosts, and bovines have been identified as its natural reservoir. However, it remains unclear how IDVs emerge, evolve, spread, and maintain in bovine populations. Through multiple years of virological and serological surveillance in a single order-buyer cattle facility in Mississippi, we showed consistently high seroprevalence of IDVs in cattle and recovered a total of 32 IDV isolates from both healthy and sick animals, including those with antibodies against IDV. Genomic analyses of these isolates along with those isolated from other areas showed that active genetic reassortment occurred in IDV and that five reassortants were identified in the Mississippian facility. Two antigenic groups were identified through antigenic cartography analyses for these 32 isolates and representative IDVs from other areas. Remarkably, existing antibodies could not protect cattle from experimental reinfection with IDV. Additional phenotypic analyses demonstrated variations in growth dynamics and pathogenesis in mice between viruses independent of genomic constellation. In summary, this study suggests that, in addition to epidemiological factors, the ineffectiveness of preexisting immunity and cocirculation of a diverse viral genetic pool could facilitate its high prevalence in animal populations.IMPORTANCE Influenza D viruses (IDVs) are panzootic in multiple animal hosts, but the underlying mechanism is unclear. Through multiple years of surveillance in the same order-buyer cattle facility, 32 IDV isolates were recovered from both healthy and sick animals, including those with evident antibodies against IDV. Active reassortment occurred in the cattle within this facility and in those across other areas, and multiple reassortants cocirculated in animals. These isolates are shown with a large extent of phenotypic diversity in replication efficiency and pathogenesis but little in antigenic properties. Animal experiments demonstrated that existing antibodies could not protect cattle from experimental reinfection with IDV. This study suggests that, in addition to epidemiological factors, limited protection from preexisting immunity against IDVs in cattle herds and cocirculation of a diverse viral genetic pool likely facilitate the high prevalence of IDVs in animal populations.

Whole blood transcriptomic analysis of beef cattle at arrival identifies potential predictive molecules and mechanisms that indicate animals that naturally resist bovine respiratory disease.

Bovine respiratory disease (BRD) is a multifactorial disease complex and the leading infectious disease in post-weaned beef cattle. Clinical manifestations of BRD are recognized in beef calves within a high-risk setting, commonly associated with weaning, shipping, and novel feeding and housing environments. However, the understanding of complex host immune interactions and genomic mechanisms involved in BRD susceptibility remain elusive. Utilizing high-throughput RNA-sequencing, we contrasted the at-arrival blood transcriptomes of 6 beef cattle that ultimately developed BRD against 5 beef cattle that remained healthy within the same herd, differentiating BRD diagnosis from production metadata and treatment records. We identified 135 differentially expressed genes (DEGs) using the differential gene expression tools edgeR and DESeq2. Thirty-six of the DEGs shared between these two analysis platforms were prioritized for investigation of their relevance to infectious disease resistance using WebGestalt, STRING, and Reactome. Biological processes related to inflammatory response, immunological defense, lipoxin metabolism, and macrophage function were identified. Production of specialized pro-resolvin mediators (SPMs) and endogenous metabolism of angiotensinogen were increased in animals that resisted BRD. Protein-protein interaction modeling of gene products with significantly higher expression in cattle that naturally acquire BRD identified molecular processes involving microbial killing. Accordingly, identification of DEGs in whole blood at arrival revealed a clear distinction between calves that went on to develop BRD and those that resisted BRD. These results provide novel insight into host immune factors that are present at the time of arrival that confer protection from BRD.

Pathogenesis of co-infections of influenza D virus and Mannheimia haemolytica in cattle.

Bovine respiratory disease (BRD) is economically significant, and influenza D virus (IDV) is commonly identified in cattle with BRD. Mannheimia haemolytica (MHA) is an opportunistic bacterial contributor to BRD; surveillance data suggest that MHA and IDV co-infection occurs in cattle. The objective of this study was to evaluate the synergistic pathogenesis in cattle co-infected with IDV and MHA. Sixteen dairy calves were randomly assigned to four groups of four calves. The IDV + MHA + group received D/bovine/C00046 N/Mississippi/2014 (D/46 N) intranasally at 0 days post-inoculation (DPI) and Mannheimia haemolytica D153 (MHA D153) intratracheally at 5 DPI. The IDV + MHA- group received only D/46 N at 0 DPI; the IDV-MHA + group received only MHA D153 at 5 DPI; and the IDV-MHA- group received neither agent. Clinical scores were calculated twice daily. At 10 DPI, IDV + MHA+, IDV-MHA+, and IDV-MHA- calves were euthanized and evaluated for pathologic lesions. The IDV + groups seroconverted to IDV by 10 DPI. Clinical scores were higher in IDV + groups than IDV- groups on 2-5 DPI (p = 0.001). After MHA challenge on 5 DPI, clinical scores (6-10 DPI) were slightly lower in IDV+MHA+ group than IDV-MHA+ group (p < 0.05) but not significantly different between MHA+ groups and MHA- groups. The average gross pathology score was higher for IDV-MHA+ group than groups IDV-MHA- and IDV+MHA+; however, no significant differences were identified among groups. Under the conditions of this study, infection with IDV before MHA enhance neither clinical disease nor lung pathology, relative to calves infected with MHA alone.

Multidrug resistant Mannheimia haemolytica isolated from high-risk beef stocker cattle after antimicrobial metaphylaxis and treatment for bovine respiratory disease.

Antimicrobial resistance (AMR) in bacterial respiratory pathogens in high-risk stocker cattle has been poorly characterized. The objective of this study was to describe the prevalence of multidrug resistant (MDR; resistance to > 3 antimicrobial classes) respiratory pathogens in 50 conventionally managed stocker cattle over 21 days after arrival. Cattle received tildipirosin metaphylaxis on day 0 and were eligible to receive up to 3 additional antimicrobials for bovine respiratory disease (BRD): florfenicol, ceftiofur and enrofloxacin. Nasopharyngeal swabs were collected on days 0, 7, 14, and 21 for bacterial culture and antimicrobial susceptibility testing using disc diffusion and broth microdilution. Mannheimia haemolytica was isolated from 5 of 48, 27 of 50, 44 of 50, and 40 of 50 cattle on days 0, 7, 14, and 21, respectively. One of 5, 27 of 27, 43 of 44, and 40 of 40 M. haemolytica were MDR on days 0, 7, 14, and 21, respectively. Pasteurella multocida was isolated from 6 of 48 cattle on day 0 and none were MDR; no other pathogens were isolated. Twenty-four cattle required at least one BRD treatment; M. haemolytica was isolated before treatment from 13 of 24 cattle; all were MDR. One hundred-eighteen M. haemolytica isolates were subjected to pulsed-field gel electrophoresis (PFGE); multiple genotypes were identified. Whole genome sequencing of 33 isolates revealed 14 known AMR genes. Multidrug resistant M. haemolytica can be highly prevalent and genetically diverse in stocker cattle; additional research is necessary to determine factors that influence prevalence and the impact on cattle health.

Influenza D Virus Infection in Feral Swine Populations, United States.

Influenza D virus (IDV) has been identified in domestic cattle, swine, camelid, and small ruminant populations across North America, Europe, Asia, South America, and Africa. Our study investigated seroprevalence and transmissibility of IDV in feral swine. During 2012-2013, we evaluated feral swine populations in 4 US states; of 256 swine tested, 57 (19.1%) were IDV seropositive. Among 96 archived influenza A virus-seropositive feral swine samples collected from 16 US states during 2010-2013, 41 (42.7%) were IDV seropositive. Infection studies demonstrated that IDV-inoculated feral swine shed virus 3-5 days postinoculation and seroconverted at 21 days postinoculation; 50% of in-contact naive feral swine shed virus, seroconverted, or both. Immunohistochemical staining showed viral antigen within epithelial cells of the respiratory tract, including trachea, soft palate, and lungs. Our findings suggest that feral swine might serve an important role in the ecology of IDV.

A randomized controlled trial to test the effect of on-arrival vaccination and deworming on stocker cattle health and growth performance.

Our objective was to determine the effect of vaccination and deworming at arrival (d 0) on bovine respiratory disease (BRD) incidence, mortality, and growth of stocker calves. Calves (n=80) were stratified by d -3 weight and fecal egg count (FEC) into 20 pens of 4 calves. Pens were randomly assigned to treatments in a 2×2 factorial design, testing d 0 vaccination (modified-live respiratory virus and clostridial vaccine, or not) and deworming (oral fenbendazole and levamisole, or not). Body weights were measured on days 0, 14, 28, 42, 56, 70, and 85, and FEC were measured on days -3, 28, 56, and 85. Incidence of BRD was greater for d 0 vaccination (RR=3.2), high fever (≥104°F, ≥40°C) at d 0 (RR=6), and higher d -3 FEC (RR=1.2 per 100 epg). Mortality was greater for d 0 vaccination (OR=8.3) and high fever (OR=41.6). Growth was 10.3 lb (4.7 kg) lower for d 0 vaccination, 24 lb (11 kg) and 16 lb (7.3 kg) lower for moderate (103°F to 103.9°F; 39.4°C to 39.9°C) and high fever, respectively, and 17.6 lb (8 kg) lower for each additional BRD treatment a calf received. Deworming was neither beneficial nor detrimental to any health or performance factors. Health and growth performance of stocker calves may be adversely affected by vaccination at arrival, higher arrival FEC, and fever at arrival.

Notre objectif était de déterminer l'effet de la vaccination et de la vermifugation à l'arrivée (j0) sur l'incidence du complexe respiratoire bovin (CRB), la mortalité et la croissance des veaux d'élevage. Les veaux (n=80) ont été stratifiés selon le poids et le compte d'œufs fécaux (COF) à j-3 et placés dans 20 enclos avec chacun quatre veaux. Les enclos étaient assignés aléatoirement aux traitements selon un plan factoriel 2×2 avec la vaccination à j0 (avec ou sans vaccin anti-clostridial avec virus respiratoires vivants modifiés) et la vermifugation (avec ou sans injection orale de fenbendazole et de lévamisole) comme facteurs. Le poids corporel a été mesuré aux jours 0, 14, 28, 42, 56, 70 et 85 et le COF a été fait aux jours −3, 28, 56 et 85. L'incidence du CRB était plus élevée suivant la vaccination à j0 (RR=3.2), lorsque la fièvre était élevée à j0 (≥104°F, ≥40°C) (RR=6) et lorsque le COF était plus élevé à j-3 (RR=1.2 par 100 oeufs par gramme). La mortalité était plus élevée suivant la vaccination à j0 (RC=8.3) et lorsque la fièvre était élevée (RC=41.6). Il y a eu une perte de croissance de 10.3 lb (4.6 kg) suivant la vaccination à j0, une perte de 24.1 lb (11 kg) lorsque la fièvre était modérée (103­103.9°F), une perte de 16 lb (7.3 kg) lorsque la fièvre était élevée et une perte de 17.5 lb (8 kg) pour chaque traitement additionnel contre le CRB reçu par un veau. La vermifugation n'a pas eu d'effet bénéfique ou néfaste sur tous les facteurs reliés à la santé ou à la performance. La santé et la croissance des veaux d'élevage peuvent être affectées négativement par la vaccination à l'arrivée, par un COF initialement élevé et par la fièvre à l'arrivée.

Serological evidence for high prevalence of Influenza D Viruses in Cattle, Nebraska, United States, 2003-2004.

Influenza D virus (IDV), a new member of the influenza virus family, was first reported in 2011 in swine in Oklahoma, USA, and then soon found in cattle across North America and Eurasia. Earlier studies suggested cattle serve as natural reservoir for IDV. The goal of this study is to perform a retrospective study looking at sera collected from Nebraska beef herds in 2003-2004 and 2014 for evidence of IDV antibodies. Results showed that all 40 randomly selected farms (2003-2004) we tested contained IDV seropositive adult animals and that approximately 98% of newborn calves (2014) had high levels of maternal antibodies against IDV. This study suggested that IDV exposures were present in Nebraska beef cattle since at least 2003.

Use of focused ultrasonication in activity-based profiling of deubiquitinating enzymes in tissue.

To develop a reproducible tissue lysis method that retains enzyme function for activity-based protein profiling, we compared four different methods to obtain protein extracts from bovine lung tissue: focused ultrasonication, standard sonication, mortar & pestle method, and homogenization combined with standard sonication. Focused ultrasonication and mortar & pestle methods were sufficiently effective for activity-based profiling of deubiquitinases in tissue, and focused ultrasonication also had the fastest processing time. We used focused-ultrasonicator for subsequent activity-based proteomic analysis of deubiquitinases to test the compatibility of this method in sample preparation for activity-based chemical proteomics.

Provider Burnout and Patient Engagement: The Quadruple and Quintuple Aims.

The Triple Aim has become the guiding light and benchmark by which healthcare organizations plan their future efforts. It has been adopted into healthcare policies with little regard for including the skill sets of compassion and emotional intelligence. The multiple increasing demands on providers of healthcare are unsustainable and will cripple the system, resulting in outcomes that are counter to the Triple Aim goals. Patient engagement with shared decision-making should become the primary focus of care delivery. New delivery models and care plans are unaffordable to far too many patients and payers, despite the efforts of futurists who seek to advance quality and lower costs. Clinical care delivery and patient engagement efforts must be drastically redirected to innovative and sustainable value-based delivery models that support the goals of the Triple Aim.

Pathogenesis of Influenza D Virus in Cattle.

UNLABELLED: Cattle have been proposed as the natural reservoir of a novel member of the virus family Orthomyxoviridae, which has been tentatively classified as influenza D virus (IDV). Although isolated from sick animals, it is unclear whether IDV causes any clinical disease in cattle. To address this aspect of Koch's postulates, three dairy calves (treatment animals) held in individual pens were inoculated intranasally with IDV strain D/bovine/Mississippi/C00046N/2014. At 1 day postinoculation, a seronegative calf (contact animal) was added to each of the treatment animal pens. The cattle in both treatment and contact groups seroconverted, and virus was detected in their respiratory tracts. Histologically, there was a significant increase in neutrophil tracking in tracheal epithelia of the treatment calves compared to control animals. While infected and contact animals demonstrated various symptoms of respiratory tract infection, they were mild, and the calves in the treatment group did not differ from the controls in terms of heart rate, respiratory rate, or rectal temperature. To mimic zoonotic transmission, two ferrets were exposed to a plastic toy fomite soaked with infected nasal discharge from the treatment calves. These ferrets did not shed the virus or seroconvert. In summary, this study demonstrates that IDV causes a mild respiratory disease upon experimental infection of cattle and can be transmitted effectively among cattle by in-pen contact, but not from cattle to ferrets through fomite exposure. These findings support the hypothesis that cattle are a natural reservoir for the virus. IMPORTANCE: A novel influenza virus, tentatively classified as influenza D virus (IDV), was identified in swine, cattle, sheep, and goats. Among these hosts, cattle have been proposed as the natural reservoir. In this study, we show that cattle experimentally infected with IDV can shed virus and transmit it to other cattle through direct contact, but not to ferrets through fomite routes. IDV caused minor clinical signs in the infected cattle, fulfilling another of Koch's postulates for this novel agent, although other objective clinical endpoints were not different from those of control animals. Although the disease observed was mild, IDV induced neutrophil tracking and epithelial attenuation in cattle trachea, which could facilitate coinfection with other pathogens, and in doing so, predispose animals to bovine respiratory disease.

Application of Functional Genomics for Bovine Respiratory Disease Diagnostics.

Bovine respiratory disease (BRD) is the most common economically important disease affecting cattle. For developing accurate diagnostics that can predict disease susceptibility/resistance and stratification, it is necessary to identify the molecular mechanisms that underlie BRD. To study the complex interactions among the bovine host and the multitude of viral and bacterial pathogens, as well as the environmental factors associated with BRD etiology, genome-scale high-throughput functional genomics methods such as microarrays, RNA-seq, and proteomics are helpful. In this review, we summarize the progress made in our understanding of BRD using functional genomics approaches. We also discuss some of the available bioinformatics resources for analyzing high-throughput data, in the context of biological pathways and molecular interactions. Although resources for studying host response to infection are avail-able, the corresponding information is lacking for majority of BRD pathogens, impeding progress in identifying diagnostic signatures for BRD using functional genomics approaches.

Influenza D virus infection in Mississippi beef cattle.

A new member of the Orthomyxoviridae family, influenza D virus (IDV), was first reported in swine in the Midwest region of the United States. This study aims to extend our knowledge on the IDV epidemiology and to determine the impact of bovine production systems on virus spread. A total of 15 isolates were recovered from surveillance of bovine herds in Mississippi, and two genetic clades of viruses co-circulated in the same herd. Serologic assessment from neonatal beef cattle showed 94% seropositive, and presumed maternal antibody levels were substantially lower in animals over six months of age. Active IDV transmission was shown to occur at locations where young, weaned, and comingled calves were maintained. Serological characterization of archived sera suggested that IDV has been circulating in the Mississippi cattle populations since at least 2004. Continuous surveillance is needed to monitor the evolution and epidemiology of IDV in the bovine population.

Factors influencing diagnostic sample submission by food animal veterinarians in Mississippi.

A focus group was organised to gather information and opinions from food animal veterinarians in Mississippi regarding sample submission to diagnostic laboratories. The research found that a range of factors influence the veterinarian's decision regarding whether samples will be submitted to a diagnostic laboratory, with the cost of diagnostics as the key influence. The veterinarians believed that the relationship they had with diagnostic laboratories was important in the protection of public health, but they thought that their role in disease surveillance was under-utilised. More attention needs to be directed towards strengthening veterinary surveillance at ground level to ensure that emergent diseases are detected effectively by a partnership approach between veterinary practitioners in the field and diagnosticians in diagnostic laboratories. This partnership is a vital component of the 'One Health' concept for the protection of both animal and human health. This study demonstrates that qualitative social science methodologies, such as focus groups, can usefully be applied to topics of relevance to veterinary public health.