Previous studies have demonstrated the safety and efficacy of a live-attenuated glycoprotein G (gG) deletion mutant vaccine strain of ILTV (∆gG-ILTV). In the current study, transcriptional profiles of chicken tracheal organ cultures (TOCs), 24 h post inoculation with ∆gG-ILTV or the gG-expressing parent wild-type strain, CSW-1 ILTV were explored and compared with the mock-infected TOCs using RNA-seq analysis. Transcriptomes of the vaccine and wild-type ILTV were also compared with each other.
View Article and Find Full Text PDFInfectious bronchitis virus (IBV), an avian coronavirus, can be isolated and cultured in tracheal organ cultures (TOCs), embryonated eggs and cell cultures, the first two of which are commonly used for viral isolation. Previous studies have suggested that foetal bovine serum (FBS) can inhibit coronavirus replication in cell cultures. In this study, the replication of IBV in chicken embryo kidney (CEK) cell cultures and the Leghorn hepatocellular carcinoma (LMH) cell line was assessed using two different cell culture media containing FBS or yeast extract (YE) and two different IBV strains.
View Article and Find Full Text PDFAntimicrobial resistance (AMR) is an urgent and growing global health concern, and a clear understanding of existing capacities to address AMR, particularly in low-income and middle-income countries (LMICs), is needed to inform national priorities, investment targets and development activities. Across LMICs, there are limited data regarding existing mechanisms to address AMR, including national AMR policies, current infection prevention and antimicrobial prescribing practices, antimicrobial use in animals, and microbiological testing capacity for AMR. Despite the development of numerous individual tools designed to inform policy formulation and implementation or surveillance interventions to address AMR, there is an unmet need for easy-to-use instruments that together provide a detailed overview of AMR policy, practice and capacity.
View Article and Find Full Text PDFMycoplasma synoviae is a pathogen of poultry that causes upper respiratory tract disease. MS-H is a live attenuated temperature-sensitive vaccine that effectively control M. synoviae infection in chickens.
View Article and Find Full Text PDFAntimicrobial resistance (AMR) has been identified as a leading threat to global public health. One Health approaches that integrate sectors across human health, animal health, food production and the environment are essential to both addressing the growing threat of AMR and achieving the Sustainable Development Goals.
View Article and Find Full Text PDFData on the use of antimicrobials in humans and livestock may provide evidence to guide policy changes to mitigate the risk of antimicrobial resistance (AMR). However, there is limited information available about antimicrobial use in livestock in low- and middle-income countries, even though these nations are most vulnerable to the impact of AMR. This study aimed to assess the consumption of veterinary antimicrobials in Bhutan and identify areas for improvement to reduce the use of antimicrobials in livestock.
View Article and Find Full Text PDFTracheitis associated with the chronic respiratory disease in chickens caused by Mycoplasma gallisepticum is marked by infiltration of leukocytes into the mucosa. Although cytokines/chemokines are known to play a key role in the recruitment, differentiation, and proliferation of leukocytes, those that are produced and secreted into the trachea during the chronic stages of infection with M. gallisepticum have not been described previously.
View Article and Find Full Text PDFInfectious laryngotracheitis virus (ILTV, Gallid alphaherpesvirus 1) causes severe respiratory disease in chickens and has a major impact on the poultry industry worldwide. Live attenuated vaccines are widely available and are administered early in the life of commercial birds, often followed by one or more rounds of revaccination, generating conditions that can favour recombination between vaccines. Better understanding of the factors that contribute to the generation of recombinant ILTVs will inform the safer use of live attenuated herpesvirus vaccines.
View Article and Find Full Text PDFAvian Pathol
August 2020
Latency is an important feature of infectious laryngotracheitis virus (ILTV) yet is poorly understood. This study aimed to compare latency characteristics of vaccine (SA2) and field (CL9) strains of ILTV, establish an reactivation system and examine ILTV infection in peripheral blood mononuclear cells (PBMC) in specific pathogen-free chickens. Birds were inoculated with SA2 or CL9 ILTV and then bled and culled at 21 or 35 days post-inoculation (dpi).
View Article and Find Full Text PDFInfectious laryngotracheitis virus (ILTV) is an economically significant respiratory pathogen of poultry. Novel recombinant strains of ILTV have emerged in Australia during the last decade and currently class 9 (CL9) and class 10 (CL10) ILTV are the most prevalent circulating strains. This study conducted a comprehensive investigation of the pathogenesis of these two viral strains.
View Article and Find Full Text PDFIncreasing access to next-generation sequencing (NGS) technologies is revolutionizing the life sciences. In disease ecology, NGS-based methods have the potential to provide higher-resolution data on communities of parasites found in individual hosts as well as host populations.Here, we demonstrate how a novel analytical method, utilizing high-throughput sequencing of PCR amplicons, can be used to explore variation in blood-borne parasite (-Apicomplexa: Piroplasmida) communities of African buffalo at higher resolutions than has been obtained with conventional molecular tools.
View Article and Find Full Text PDFInfectious laryngotracheitis virus (ILTV) causes severe respiratory disease in chickens. ILTV can establish latency and reactivate later in life, but there have been few investigations of ILTV latency. This study aimed to contribute to the methodologies available to detect latent ILTV.
View Article and Find Full Text PDFInfectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that infects chickens, causing upper respiratory tract illness and substantial economic losses to the commercial poultry industry worldwide. Due to its geographical isolation, Australia has had a unique population of ILTV genotypes, and this has provided the researchers with an excellent opportunity to examine the evolution of herpesviruses. Recent studies on the evolution of ILTV have reported the emergence of recombinant ILTVs in Australian poultry flocks.
View Article and Find Full Text PDFInfectious laryngotracheitis (ILT) is a respiratory disease that affects chickens. It is caused by the alphaherpesvirus, infectious laryngotracheitis virus (ILTV). This virus undergoes lytic replication in the epithelial cells of the trachea and upper respiratory tract (URT) and establishes latent infection in the trigeminal ganglia (TG) and trachea.
View Article and Find Full Text PDFInfectious laryngotracheitis (ILT) is an upper respiratory tract disease of chickens that is caused by infectious laryngotracheitis virus (ILTV), an alphaherpesvirus. This disease causes significant economic loses in poultry industries worldwide. Despite widespread use of commercial live attenuated vaccines, many poultry industries continue to experience outbreaks of disease caused by ILTV.
View Article and Find Full Text PDFInfectious laryngotracheitis (ILTV; ) causes mild to severe respiratory disease in poultry worldwide. Recombination in this virus under natural (field) conditions was first described in 2012 and more recently has been studied under laboratory conditions. Previous studies have revealed that natural recombination is widespread in ILTV and have also demonstrated that recombination between two attenuated ILTV vaccine strains generated highly virulent viruses that produced widespread disease within poultry flocks in Australia.
View Article and Find Full Text PDFRecombination is closely linked with virus replication and is an important mechanism that contributes to genome diversification and evolution in alphaherpesviruses. Infectious laryngotracheitis (ILTV; Gallid alphaherpesvirus 1) is an alphaherpesvirus that causes respiratory disease in poultry. In the past, natural (field) recombination events between different strains of ILTV generated virulent recombinant viruses that have caused severe disease and economic loss in poultry industries.
View Article and Find Full Text PDFInfectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that infects chickens, causing upper respiratory tract disease and significant losses to poultry industries worldwide. Glycoprotein G (gG) is a broad-range viral chemokine-binding protein conserved among most alphaherpesviruses, including ILTV. A number of studies comparing the immunological parameters between infection with gG-expressing and gG-deficient ILTV strains have demonstrated that expression of gG is associated with increased virulence, modification of the amount and the composition of the inflammatory response, and modulation of the immune responses toward antibody production and away from cell-mediated immune responses.
View Article and Find Full Text PDFRecombination is a feature of many alphaherpesviruses that infect people and animals. Infectious laryngotracheitis virus (ILTV; ) causes respiratory disease in chickens, resulting in significant production losses in poultry industries worldwide. Natural (field) ILTV recombination is widespread, particularly recombination between attenuated ILTV vaccine strains to create virulent viruses.
View Article and Find Full Text PDFIndonesia has implemented multiple strategies to control Highly Pathogenic Avian Influenza H5N1 (HPAI/H5N1), including the licensure and use of multiple vaccine formulations. The continuous drift of Indonesian HPAI/H5N1 viruses and emergence of a new clade in 2012 that became dominant in 2016, demands the assessment of commercial vaccine formulations against Indonesian field viruses. Seven databases were explored to identify relevant literature reporting performance of commercial vaccines against Indonesian HPAI/H5N1 viruses.
View Article and Find Full Text PDFTo date, recombination between different strains of the avian alphaherpesvirus infectious laryngotracheitis virus (ILTV) has only been detected in field samples using full genome sequencing and sequence analysis. These previous studies have revealed that natural recombination is widespread in ILTV and have demonstrated that recombination between two attenuated ILTV vaccine strains generated highly virulent viruses that produced widespread disease within poultry flocks in Australia. In order to better understand ILTV recombination, this study developed a TaqMan single nucleotide polymorphism (SNP) genotyping assay to detect recombination between two field strains of ILTV (CSW-1 and V1-99 ILTV) under experimental conditions.
View Article and Find Full Text PDFRecombination in alphaherpesviruses was first described more than sixty years ago. Since then, different techniques have been used to detect recombination in natural (field) and experimental settings. Over the last ten years, next-generation sequencing (NGS) technologies and bioinformatic analyses have greatly increased the accuracy of recombination detection, particularly in field settings, thus contributing greatly to the study of natural alphaherpesvirus recombination in both human and veterinary medicine.
View Article and Find Full Text PDFVet Microbiol
December 2016
Australian strains of infectious bronchitis virus (IBV) have been evolving independently for many years, with control achieved by vaccination with local attenuated strains. Previous studies have documented the emergence of recombinants over the last 20 years, with the most recent one, Ck/Aus/N1/08, detected in 2008. These recombinants did not appear to be controlled by the vaccines currently in use.
View Article and Find Full Text PDFSpillover of viruses from farmed poultry into wild birds is a relatively new area of study at the livestock-wildlife interface. These transmission events can threaten the health of wild birds. There is growing evidence of transmission of vaccine viruses from poultry to wild birds, including attenuated vaccine strains of Newcastle disease virus and infectious bronchitis virus, and also spread of virulent viruses that may have evolved under the pressure of vaccine use, such as Marek's disease virus.
View Article and Find Full Text PDF