Geographic variation in the PRNP gene and its promoter, and their relationship to chronic wasting disease in North American deer

PRNP genotypes, number of octarepeats (PHGGGWGQ) and indels in the PRNP promoter can influence the progression of prion disease in mammals. We found no relationship between presence of promoter indels in white-tailed deer and mule deer from Nebraska and CWD presence. White-tailed deer with the 95 H allele and G20D mule deer were more likely to be CWD- free, but unlike other studies white-tailed deer with the 96S allele(s) were equally likely to be CWD-free. We provide the first information on PRNP genotypes and indels in the promoter for Key deer (all homozygous 96SS) and Coues deer (lacked 95 H and 96S alleles, but possessed a uniquely high frequency of 103 T). All deer surveyed were homozygous for three tandem octarepeats

Haemorrhagic Colitis Associated with Enterohaemorrhagic \u3ci\u3eEscherichia coli\u3c/i\u3e O165:H25 Infection in a Yearling Feedlot Heifer

Introduction: Enterohaemorrhagic Escherichia coli (EHEC) cause haemorrhagic colitis and haemolytic uraemic syndrome in humans. Although EHEC infection typically results in haemorrhagic colitis in all ages of human patients, in cattle it is usually limited to 1- to 5-week-old nursing calves. Case Presentation: A 1-year-old feedlot beef heifer was moribund with neurological signs and bloody diarrhoea. At necropsy, the colonic mucosa contained multiple grossly visible haemorrhagic erosions, each measuring \u3c1 mm in diameter. Histologically, foci corresponding to the gross erosions had E. coli O165 antigen-positive bacterial rods adherent to the apical surfaces of degenerate and necrotic colonic mucosal epithelial cells in association with attaching and effacing lesions, and also within cytoplasmic vacuoles in some of these cells. An E. coli O165:H25 strain was isolated from the colonic mucosal tissue, and by microarray analysis was found to contain virulence genes corresponding to type III secretion system (T3SS) structure and regulation (cesD, cesT, escD, escF, escN/escV, escR, escT, ler, sepL, sepQ), T3SS effectors (espA, espB, espC, espD, espD, espF, espH, espJ, nleB, nleC, nleD, nleH, tir), serine proteases (eatA, espC, espP), Shiga toxin (stx2), EHEC-haemolysin (ehxA), and adhesins [intimin-ε (eae-ε), type 1 fimbria (fimA, fimB, fimH), type IV pili (pilA, pilB, pilC, pilM, pilP, pilQ) and non-fimbrial adhesin (efa1/lifA)]. Conclusion: To the best of our knowledge, this is the first report of disease in cattle associated with EHEC O165:H25 infection, the oldest bovine EHEC disease case with isolation of the pathogen and the first bovine case to demonstrate grossly evident, haemorrhagic, colonic mucosal erosions associated with EHEC infection

Haemorrhagic Colitis Associated with Enterohaemorrhagic \u3ci\u3eEscherichia coli\u3c/i\u3e O165:H25 Infection in a Yearling Feedlot Heifer

Introduction: Enterohaemorrhagic Escherichia coli (EHEC) cause haemorrhagic colitis and haemolytic uraemic syndrome in humans. Although EHEC infection typically results in haemorrhagic colitis in all ages of human patients, in cattle it is usually limited to 1- to 5-week-old nursing calves. Case Presentation: A 1-year-old feedlot beef heifer was moribund with neurological signs and bloody diarrhoea. At necropsy, the colonic mucosa contained multiple grossly visible haemorrhagic erosions, each measuring \u3c1 mm in diameter. Histologically, foci corresponding to the gross erosions had E. coli O165 antigen-positive bacterial rods adherent to the apical surfaces of degenerate and necrotic colonic mucosal epithelial cells in association with attaching and effacing lesions, and also within cytoplasmic vacuoles in some of these cells. An E. coli O165:H25 strain was isolated from the colonic mucosal tissue, and by microarray analysis was found to contain virulence genes corresponding to type III secretion system (T3SS) structure and regulation (cesD, cesT, escD, escF, escN/escV, escR, escT, ler, sepL, sepQ), T3SS effectors (espA, espB, espC, espD, espD, espF, espH, espJ, nleB, nleC, nleD, nleH, tir), serine proteases (eatA, espC, espP), Shiga toxin (stx2), EHEC-haemolysin (ehxA), and adhesins [intimin-ε (eae-ε), type 1 fimbria (fimA, fimB, fimH), type IV pili (pilA, pilB, pilC, pilM, pilP, pilQ) and non-fimbrial adhesin (efa1/lifA)]. Conclusion: To the best of our knowledge, this is the first report of disease in cattle associated with EHEC O165:H25 infection, the oldest bovine EHEC disease case with isolation of the pathogen and the first bovine case to demonstrate grossly evident, haemorrhagic, colonic mucosal erosions associated with EHEC infection

Evaluation of an Algal Biomass as an Ingredient in Cattle Feed

A study was conducted evaluating the effects of feeding condensed algal residue solubles (CARS; available in 2019 in Blair, NE area) to finishing cattle for 100 days. Four levels of CARS were evaluated with 5 steers and 5 heifers individually fed per level of inclusion. The diets consisted of 70% dry rolled corn with CARS displacing corn at 0, 2.5, 5, and 7.5% of dry matter. Increasing CARS inclusion resulted in a linear decrease in intake, a quadratic increase in daily gain, and a linear decrease in feed:gain. Calculations showed a linear increase in dietary net energy as CARS increased in the diet. Minimal differences in organ weights, blood chemistry, hematology, and urine were observed. Daily observations and histology results suggest no differences in cattle health due to dietary treatment. Including CARS at 5% of diet dry matter increased gain 4.2% and feed:gain 10.1% relative to a corn based finishing diet

Time and temperature stability of Tritrichomonas foetus in phosphate-buffered saline as evaluated by a reverse transcription real-time PCR assay and field analysis

Tritrichomonas foetus (TF) is a significant reproductive pathogen of cattle, and sample collection, handling, transport, and testing are significant hurdles to surveillance programs. Recent methods have been developed that allow for the direct detection of TF using a reverse transcription real-time PCR (direct RT-qPCR) approach. To evaluate these methods, a comparative analysis was conducted to assess the technical performance of this assay with a commercially available real-time PCR (qPCR) assay. In addition, the evaluation of two types of collection media (PBS and TF transport tube) was conducted that evaluated sample stability from 0 to 3 days when stored at 4°C or 25°C. Extended incubation times for PBS media were also evaluated (5, 7, and 14 days) at both refrigeration and frozen temperatures to evaluate the effect of extended transport time on samples. Limits of detection (LODs), dynamic range, and RNA stability were assessed using lab-cultured TF spiked into samples of normal bovine smegma collected in PBS or TF transport media, and performance was assessed on field samples collected in parallel. 100% agreement was found between direct RT-qPCR and qPCR at 10 parasites/extraction and a LOD of 1 parasite/extraction. Differences in detection were not observed in either collection media when incubated at either temperatures for up to 3 days of incubation. In addition, the extended incubation experiments indicate that samples containing 10 parasites/extraction can be detected at 4°C for 5 days with a mean Cq 26.34 (95% CI: 23.11–29.58) and detected at −20°C for 7 or 14 days, with a mean Cq 29.55 (95% CI: 27.73–31.37). A significant decrease in detectable RNA was observed in samples containing <10 parasites/extraction at −20°C for 14 days, which should be considered for long-term storage. In summary, direct RT-qPCR was found to be equivalent or superior to qPCR and PBS was not significantly different from TF transport media. The findings of the current study allows for more flexibility during sample collection and transport and ultimately enhancement of TF surveillance programs

Experimental infection of conventional nursing pigs and their dams with \u3ci\u3ePorcine deltacoronavirus\u3c/i\u3e

Porcine deltacoronavirus (PDCoV) is a newly identified virus that has been detected in swine herds of North America associated with enteric disease. The aim of this study was to demonstrate the pathogenicity, course of infection, virus kinetics, and aerosol transmission of PDCoV using 87 conventional piglets and their 9 dams, including aerosol and contact controls to emulate field conditions. Piglets 2–4 days of age and their dams were administered an oronasal PDCoV inoculum with a quantitative real-time reverse transcription (qRT)-PCR quantification cycle (Cq) value of 22 that was generated from a field sample having 100% nucleotide identity to USA/Illinois121/2014 determined by metagenomic sequencing and testing negative for other enteric disease agents using standard assays. Serial samples of blood, serum, oral fluids, nasal and fecal swabs, and tissues from sequential autopsy, conducted daily on days 1–8 and regular intervals thereafter, were collected throughout the 42-day study for qRT-PCR, histopathology, and immunohistochemistry. Diarrhea developed in all inoculated and contact control pigs, including dams, by 2 days post-inoculation (dpi) and in aerosol control pigs and dams by 3–4 dpi, with resolution occurring by 12 dpi. Mild to severe atrophic enteritis with PDCoV antigen staining was observed in the small intestine of affected piglets from 2 to 8 dpi. Mesenteric lymph node and small intestine were the primary sites of antigen detection by immunohistochemistry, and virus RNA was detected in these tissues to the end of the study. Virus RNA was detectable in piglet fecal swabs to 21 dpi, and dams to 14–35 dpi

Key Points From the 48th Annual George A. Young Swine Health and Management Conference, August 16, 2007

The conference focused on biosecurity with particular attention to porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2). Speakers included faculty from the University of Minnesota, Iowa State University, and Kansas State University and veterinary practitioners from Iowa and Minnesota. Many of the topics focused on details relating to on-farm and off-farm biosecurity measures. Economic impacts of PRRSV and PCV2 infections were discussed in terms of specific case reports

\u3ci\u3eMoraxella\u3c/i\u3e Spp. Isolated from Field Outbreaks of Infectious Bovine Keratoconjunctivitis: A Retrospective Study of Case Submissions from 2010 to 2013

Infectious bovine keratoconjunctivitis (IBK), also known as pinkeye, is the most costly eye disease of cattle. The principal etiologic agent of IBK is the Gram-negative bacterium Moraxella bovis. However, there have been reports of IBK outbreaks associated with Moraxella bovoculi. A retrospective study of IBK diagnostic cases submitted from July 1, 2010, through October 31, 2013, was conducted. Included in the study were 1,042 Moraxella isolates from 1,538 swabs of lacrimal secretions collected from 282 herds from 30 U.S. states. Moraxella isolates were identified to the species level and were composed of M. bovoculi (701 isolates), M. bovis (295 isolates), Moraxella ovis (5 isolates), and other Moraxella spp. (41). Minimum inhibitory concentrations required for 90% growth inhibition (MIC90) was calculated for representative isolates. The MIC90 values for both M. bovis and M. bovoculi were as follows: ampicillin and ceftiofur: ≤ 0.25 μg/ml; clindamycin: 2 μg/ml; danofloxacin and enrofloxacin: ≤ 0.12 μg/ml; florfenicol: 0.5 μg/ml; gentamicin: 1 μg/ml; neomycin: 4 μg/ml; tulathromycin: 2 μg/ml; and tylosin: 8 μg/ml. The MIC90 values for M. bovoculi included the following: chlortetracycline: ≤ 0.5 μg/ml; oxytetracycline: 4 μg/ml; penicillin: 0.25 μg/ml; spectinomycin: 32 μg/ml; sulfadimethoxine: \u3e 256 μg/ml; tiamulin: 1 μg/ml; and trimethoprim-sulfamethoxazole: 4 μg/ml. For M. bovis, MIC90 values included the following: chlortetracycline and oxytetracycline: 1 μg/ml; penicillin: ≤ 0.12 μg/ml; spectinomycin: 16 μg/ml; sulfadimethoxine: ≤ 256 μg/ml; tiamulin: ≤ 0.5 μg/ml; and trimethoprim-sulfamethoxazole: ≤ 2 μg/ml. The current work describes the frequency of isolation and differences in antimicrobial sensitivity observed among Moraxella isolates from case submissions

Geographic variation in the PRNP gene and its promoter, and their relationship to chronic wasting disease in North American deer

PRNP genotypes, number of octarepeats (PHGGGWGQ) and indels in the PRNP promoter can influence the progression of prion disease in mammals. We found no relationship between presence of promoter indels in white-tailed deer and mule deer from Nebraska and CWD presence. White-tailed deer with the 95 H allele and G20D mule deer were more likely to be CWD- free, but unlike other studies white-tailed deer with the 96S allele(s) were equally likely to be CWD-free. We provide the first information on PRNP genotypes and indels in the promoter for Key deer (all homozygous 96SS) and Coues deer (lacked 95 H and 96S alleles, but possessed a uniquely high frequency of 103 T). All deer surveyed were homozygous for three tandem octarepeats