Replication of Bovine Parainfluenza-3 Virus in Bovine Alveolar Macrophages : Effects on Phagocytosis and Phagosome-Lysosome Fusion

Bovine parainfluenza-3 virus was found to replicate in alveolar macrophages in vitro. Cytopathic changes include spindle cell and giant cell formation, cellular detachment, and diffuse cell lysis progressing to total destruction of the monolayer. Direct immunofluorescent microscopy demonstrated viral antigens in greater than 90% of the cells three days after virus inoculation. Virus titers in culture supernatants increased by 6 a factor of 1.6 X 10 TCID50 by six days post inoculation. Phagocytosis assays showed no statistical differences of glass adherent cells in virus infected and control macrophages. When the number of glass adherent cells available for assay are taken into account (normalization) differences in phagocytic values are significant at 5 and 7 days post inoculation. Phagosomelysosome fusion assays demonstrated marked reduction of fusion activity of virus infected macrophages compared to control macrophages. Fusion values of infected cells were 51% and 53% that of control cells at days 4 and 6, respectively Normalization of these values reduced the fusion rate to 37% of control macrophages. Relatively little is known about the interactions of BPI-3 virus and cultured bovine alveolar macrophages (BAJ1). Rossi et al demonstrated that monocytes derived macrophage cultures exhibited cytopathic effect (CPE) after BPI-3 inoculation. However, it is not known if this virus will undergo productive replication in BAM or what effect it will have upon BAM functions. This study examines the interactions of BPI-3 and cultured BAM with regard to CPE, quantitation of progeny virus, and the quantitation of macrophage processes of phagocytosis and phagosome-lysosome fusion

Bovine Rhinitis Viruses Are Common in US Cattle with Bovine Respiratory Disease

Citation: Hause, B. M., Collin, E. A., Anderson, J., Hesse, R. A., & Anderson, G. (2015). Bovine Rhinitis Viruses Are Common in US Cattle with Bovine Respiratory Disease. Plos One, 10(3), 12. doi:10.1371/journal.pone.0121998Bovine rhinitis viruses (BRV) are established etiological agents of bovine respiratory disease complex however little research into their epidemiology and ecology has been published for several decades. In the U.S., only bovine rhinitis A virus 1 (BRAV1) has been identified while bovine rhinitis A virus 2 (BRAV2) and bovine rhinitis B virus (BRBV) were previously only identified in England and Japan, respectively. Metagenomic sequencing of a nasal swab from a bovine respiratory disease (BRD) diagnostic submission from Kansas identified contigs with approximately 90% nucleotide similarity to BRAV2 and BRBV. A combination of de novo and templated assemblies using reference genomes yielded near complete BRAV2 and BRBV genomes. The near complete genome of bovine rhinitis A virus 1 (BRAV1) was also determined from a historical isolate to enable further molecular epidemiological studies. A 5'-nuclease reverse transcription PCR assay targeting the 3D polymerase gene was designed and used to screen 204 archived BRD clinical specimens. Thirteen (6.4%) were positive. Metagenomic sequencing of six positive samples identified mixed BRAV1/BRAV2, BRAV1/BRBV and BRAV2/BRBV infections for five samples. One sample showed infection only with BRAV1. Seroprevalence studies using a cell culture adapted BRBV found immunofluorescence assay-reactive antibodies were common in the herds analyzed. Altogether, these results demonstrate that BRV infections are common in cattle with respiratory disease and that BRAV1, BRAV2 and BRBV co-circulate in U.S. cattle and have high similarity to viruses isolated more than 30 years ago from diverse locations

Proceedings of Abstracts, School of Physics, Engineering and Computer Science Research Conference 2022

© 2022 The Author(s). This is an open-access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For further details please see https://creativecommons.org/licenses/by/4.0/. Plenary by Prof. Timothy Foat, ‘Indoor dispersion at Dstl and its recent application to COVID-19 transmission’ is © Crown copyright (2022), Dstl. This material is licensed under the terms of the Open Government Licence except where otherwise stated. To view this licence, visit http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: [email protected] present proceedings record the abstracts submitted and accepted for presentation at SPECS 2022, the second edition of the School of Physics, Engineering and Computer Science Research Conference that took place online, the 12th April 2022

Onset and duration of transient infections among antibody-diverse beef calves exposed to a bovine viral diarrhea virus persistently infected calf

Persistently infected (PI) cattle are the reservoir of bovine viral diarrhea virus (BVDV), yet data describing BVDV transient infections (TI) among non-PI populations are minimal. Study objectives consisted of: 1. Estimating the onset and duration of TI based on serum VI and rRT-PCR, and 2. Determination of the potential of TI cattle to shed BVDV. Two 21-day studies were performed where one PI calf was commingled with a confirmed non-PI cattle population with heterogeneous BVDV antibody status (n=12 and n=15, respectively). After PI exposure, virus isolation on serum and nasal swabs failed to detect BVDV among non-PI cattle. Despite minimal disease (n=1), BVDV transmission occurred as 78% (n=21) of non-PI calves displayed a four-fold rise in BVDV antibody titers, 81.5% (n=22) displayed a transient positive serum BVDV rRT-PCR outcome, and 74.1% (n=20) displayed a transient positive rRT-PCR result on nasal swabs. Median days of positive serum rRT-PCR onset and duration were 10.0 (range: 6-21) and 3.0 (range: 1-9) days, respectively. These data suggest that non-PI cattle can become TI with minimal clinical disease while possessing the potential to transmit BVDV. The speed with which exposed cattle become transiently infected and their potential ability to shed the virus may impact design and implementation of BVDV control programs