PAKET INFORMASI PERPUSTAKAAN BBLITVET NO.3, 2018

CLOSTRIDIUM:

  1. Brightwell, G., & Horváth, K. M. (2018). Molecular discrimination of New Zealand sourced meat spoilage associated psychrotolerant Clostridium species by ARDRA and its comparison with 16s RNA gene sequencing. Meat Science, 138(August 2017), 23–27. https://doi.org/10.1016/j.meatsci.2017.12.007

ABSTRACT

ARDRA analysis was carried out on 90 New Zealand psychrotolerant Clostridium isolates derived from three meat production animal types and their environments. The isolates included species associated with spoilage: C. gasigenes, C. algidicarnis, C. tagluense, C. frigidicarnis and C. estertheticum. The isolates fell into 14 distinct ARDRA Groups, with 13 previously characterised meat spoilage-associated isolates shared between 6 of the 14 groups. The accuracy of ARDRA profiling analysis was supported by sequencing the 16s rRNA gene from isolates, including the representative spoilage associated Clostridium species and was consistent with previous phylogenetic relationships and classical cultural characterisation. The ARDRA methodology described in this study successfully discriminated between the different spoilage-associated species of clostridia as well as other pyschrotolerant Clostridium species associated with meat production. This discriminatory molecular screen will aid future source attribution studies as well as enable meat processors to identify and validate control measures for clostridia contamination, thus gaining greater efficacy in controlling meat spoilage caused by psychrotolerant clostridia.

CLASSICAL SWINE FEVER:

 

  1. Lin, J., Wang, C., Liang, W., Zhang, J., Zhang, L., Lv, H., … Zhang, Y. (2018). Rab1A is required for assembly of classical swine fever virus particle. Virology, 514(October 2017), 18–29. https://doi.org/10.1016/j.virol.2017.11.002

 

ABSTRACT

Rab1A belongs to the small Rab GTPase family and is involved in the lifecycle of numerous viruses. Here, knockdown of Rab1A inhibited CSFV growth. Further study revealed that Rab1A depletion decreased intracellular and extracellular CSFV titers, but did not affect intracellular virus genome copies and E2 protein expression within a virus lifecycle, which suggested that Rab1A is required for CSFV particle assembly rather than for genome replication or virion release. This was proofed by blocking the spread of virus using neutralizing antibodies, through which the negative effects of Rab1A knockdown on multi-cycle replication of CSFV were eliminated. Moreover, co-immunoprecipitation and confocal microscopy assays showed that Rab1A bound to CSFV NS5A protein, indicating that Rab1A and viral NS5A proteins may work cooperatively during CSFV particle assembly. In conclusion, this study demonstrated for the first time that Rab1A is required for CSFV particle assembly and binds to viral particle assembly-related NS5A protein.

 

  1. Otter, V., Näther, M., & Theuvsen, L. (2018). Culling vs. emergency vaccination: A comparative economic evaluation of strategies for controlling classical swine fever in the EU. Livestock Science, 207(October 2017), 133–146. https://doi.org/10.1016/j.livsci.2017.11.014

 

ABSTRACT

Outbreaks of epidemic animal diseases, especially classical swine fever (CSF), are associated with high costs for livestock-producing regions like the European Union (EU). Alternative and complimentary measures exist for dealing with epidemics of animal diseases such as CSF: culling, quarantine, emergency vaccination, preventive vaccination and disease monitoring. In the EU culling in combination with quarantine has remained the only strategy to handle CSF outbreaks. Due to member states’ concerns about the tradability of vaccinated pigs and products from vaccinated animals, recent EU decisions have not considered emergency vaccination an appro- priate alternative measure although modern DIVA vaccines allow the distinction between infected and vacci- nated animals. Concurrently, the potential contribution of DIVA vaccines to the reduction of economic damages of CSF outbreaks has not been thoroughly addressed so far. This research gap motivates to compare the costs of culling and emergency vaccination for the latest outbreak of CSF in the EU exemplarily by applying a self- developed comprehensive simulation tool (TEUS) on the 2006 CSF epidemic in Germany. The results reveal that emergency vaccination involves lower direct costs but higher indirect costs than culling. Especially political interventions by the European Commission, the governments of its member states and the governments of non- EU member states are considered to make an emergency vaccination in case of an CSF outbreak economically unattractive under current conditions. This outcome implies the request for more emergency vaccination friendly EU regulations and OIE requirements.1.

 

  1. Liu, X., Wang, X., Wang, Q., Luo, M., Guo, H., Gong, W., … Sun, J. (2018). The eukaryotic translation initiation factor 3 subunit E binds to classical swine fever virus NS5A and facilitates viral replication. Virology, 515(July 2017), 11–20. https://doi.org/10.1016/j.virol.2017.11.019

 

ABSTRACT

Classical swine fever virus (CSFV) NS5A protein is a multifunctional protein, playing critical roles in viral RNA replication, translation and assembly. To further explore its functions in viral replication, interaction of NS5A with host factors was assayed using a his-tag “pull down” assay coupled with shotgun LC-MS/MS. Host protein translation initiation factor 3 subunit E was identified as a binding partner of NS5A, and confirmed by co-immunoprecipitation and co-localization analysis. Overexpression of eIF3E markedly enhanced CSFV genomic replication, viral protein expression and production of progeny virus, and downregulation of eIF3E by siRNA significantly decreased viral proliferation in PK-15 cells. Luciferase reporter assay showed an enhancement of translational activity of the internal ribosome entry site of CSFV by eIF3E and a decrease in cellular translation by NS5A. These data indicate that eIF3E plays an important role in CSFV replication, thereby identifying it as a potential target for inhibition of the virus.

 

  1. Muñoz-González, S., Sordo, Y., Pérez-Simó, M., Suarez, M., Canturri, A., Rodriguez, M. P., … Ganges, L. (2018). Corrigendum to “Efficacy of E2 glycoprotein fused to porcine CD154 as a novel chimeric subunit vaccine to prevent classical swine fever virus vertical transmission in pregnant sows” (Veterinary Microbiology (2017) 211 (74–83) (S0378113517305096) (10.1016/j.vetmic.2017.10.001)). Veterinary Microbiology, 213(xxxx), 143–149. https://doi.org/10.1016/j.vetmic.2017.10.014

 

ABSTRACT

Here we evaluated the effect of double vaccination with a novel subunit marker vaccine candidate based in the CSFV E2 glycoprotein fused to the porcine CD154 to prevent CSFV vertical transmission. A lentivirus-based gene delivery system was used to obtain a stable recombinant HEK 293 cell line for the expression of E2 fused to porcine CD154 molecule. Six pregnant sows were distributed in two groups and at 64 days of gestation animals numbered 1–4 (group 1) were vaccinated via intramuscular inoculation with 50 μg of E2-CD154 subunit vaccine. Animals from group 2 (numbered 5 and 6, control animals) were injected with PBS. Seventeen days later sows from group 1 were boosted with the same vaccine dose. Twenty-seven days after the first immunization, the sows were challenged with a virulent CSFV Margarita strain and clinical signs were registered. Samples were collected during the experiment and at necropsy to evaluate immune response and virological protection. Between 14 and 18 days after challenge, the sows were euthanized, the foetuses were obtained and samples of sera and tissues were collected. E2-CD154 vaccinated animals remained clinically healthy until the end of the study; also, no adverse reaction was shown after vaccination. An effective boost effect in the neutralizing antibody response after the second immunization and viral challenge was observed and supports the virological protection detected in these animals after vaccination. Protection against CSFV vertical transmission was found in the 100% of serums samples from foetus of vaccinated sows. Only two out of 208 samples (0.96%) were positive with Ct value about 36 corresponding to one tonsil and one thymus, which may be non-infective viral particles. Besides, its DIVA potential and protection from vertical transmission, the novel CSFV E2 bound to CD154 subunit vaccine, is a promising alternative to the live-attenuated vaccine for developing countries.

 

  1. Su, Y., Liu, Y., Chen, Y., Xing, G., Hao, H., Wei, Q., … Zhang, G. (2017). A novel duplex TaqMan probe-based real-time RT-qPCR for detecting and differentiating classical and variant porcine epidemic diarrhea viruses. Molecular and Cellular Probes, (October), 0–1. https://doi.org/10.1016/j.mcp.2017.10.003

 

ABSTRACT

Two different genotypes of porcine epidemic diarrhea virus (PEDV), the classical and variant strains, are classified by multiple insertions and deletions in their S genes. It is critical to detect and differentiate two genotypes in the pork industry to prevent PEDV outbreaks. In the present study, a novel duplex TaqMan RT-PCR was developed for detecting and differentiating PEDV strains in China. There was no cross-amplification between the two probes when using standard recombinant plasmids, and the specificity was further confirmed by using other seven non-PEDV swine pathogens. The minimum copies required for the detection of both classical and variant PEDV were 4.8 × 102DNA copies/reaction. The repeatability of TaqMan RT-PCR was evaluated using standard recombinant plasmids and gave coefficients of variation 0.19-4.93. In recent 5 years, 79 clinical samples were collected from piglets with severe diarrhea in the Central China. Among these clinical samples, 51 were confirmed as PEDV positive by conventional RT-PCR, whereas 63 variant PEDV, 3 co-infections and 1 classical PEDV were confirmed by this duplex TaqMan RT-PCR, with viral loads of 102-108, 102-103, and 104copies/reaction, respectively. Therefore, the duplex TaqMan RT-PCR could be a useful method for detecting and differentiating variant and classical PEDV strains. The results showed that variant PEDV was prevalent in clinical samples in central China. Moreover, in this study, co-infection by PEDV strains was detected for the first time and might help explain the emergence of the novel recombinant PEDV in recent years.

 

  1. Li, X. Q., Li, X. N., Liang, J. J., Cai, X. Bin, Tao, Q., Li, Y. X., … Luo, T. R. (2018). IRF1 up-regulates isg15 gene expression in dsRNA stimulation or CSFV infection by targeting nucleotides −487 to −325 in the 5′ flanking region. Molecular Immunology, 94(100), 153–165. https://doi.org/10.1016/j.molimm.2017.12.025

 

ABSTRACT

Interferon (IFN)-stimulated gene 15 (ISG15) encodes a ubiquitin-like protein that is heavily involved in immune response elicitation. As an important member of interferon regulatory factor (IRF) family, IRF1 can activate the expression of multiple genes, including the human optineurin gene (Sudhakar et al., 2013). In this study, a sequence in the promoter region of the optineurin gene was compared to the 5′ flanking region of the porcine isg15 gene. Porcine IRF1 also possesses antiviral activity against several swine viruses (Li et al., 2015), but the mechanism is not well understood. Herein, we report that porcine IRF1 and ISG15 were up-regulated in porcine kidney (PK-15) cells following stimulation with double-stranded RNA (dsRNA) or classical swine fever virus (CSFV) infection. We also found that siRNA-mediated knockdown of IRF1 expression resulted in lower ISG15 expression in response to polyinosinic:polycytidylic acid [poly(I:C)] or CSFV infection. The overexpression of IRF1 resulted in ISG15 up-regulation. IRF1 was shown to translocate to the nucleus in response to dsRNA stimulation. To further identify the functional domain of the isg15 gene that promotes IRF1 transcriptional activity, firefly luciferase and ISG15 reporter systems were constructed. The results of the firefly luciferase and ISG15 reporter assay suggested that IRF1 mediates the up-regulation of ISG15. Nucleotides −487 to −325, located in the 5′ flanking region of the isg15 gene, constituted the promoter region of IRF1. ChIP assay indicated that IRF1 protein was able to interact with the DNA in the 5′fr of isg15 gene in cells. As an innate immune response protein with broad-spectrum antiviral activity, the up-regulation of ISG15 mediated by IRF1 in porcine cells is reported for the first time. These results warrant further investigation into the antiviral activity of porcine IRF1 against reported swine viruses.

 

 

  1. Wang, J., Zhang, R., Wang, J., Han, Q., Liu, L., Li, Y., & Yuan, W. (2018). Real-time reverse transcription recombinase polymerase amplification assay for rapid detection of porcine epidemic diarrhea virus. Journal of Virological Methods, 253(38), 49–52. https://doi.org/10.1016/j.jviromet.2018.01.001

 

ABSTRACT

Evidence from animal models indicates that lowering temperature by a few degrees can produce substantial neuroprotection. In humans, hypothermia has been found to be neuroprotective with a significant impact on mortality and long-term functional outcome only in cardiac arrest and neonatal hypoxic–ischemic encephalopathy. Clinical trials have explored the potential role of maintaining normothermia and treating fever in critically ill brain injured patients. This review concentrates on basic concepts to understand the physiologic interactions of thermoregulation, effects of thermal modulation in critically ill patients, proposed mechanisms of action of temperature modulation, and practical aspects of targeted temperature management

 

  1. Sun, Y. F., Zhou, L., Bian, T., Tian, X. X., Ren, W. K., Lu, C., … Yu, H. (2018). Efficacy evaluation of two commercial modified-live virus vaccines against a novel recombinant type 2 porcine reproductive and respiratory syndrome virus. Veterinary Microbiology, 216(518), 176–182. https://doi.org/10.1016/j.vetmic.2018.02.016

 

ABSTRACT

NADC30-like porcine reproductive and respiratory syndrome virus (PRRSV) causing clinical disease outbreaks has been recently reported in China. The recombination occurring among PRRSV strains could lead to the emergence of novel and more virulent viruses. In our previous study, a novel recombinant type 2 PRRSV (TJnh1501) between NADC30-like and modified-live virus (MLV)-like derived from the Chinese highly pathogenic PRRSV was shown to have higher pathogenicity than NADC30-like PRRSV. It remains unknown whether the emergence of the novel recombinant PRRSV strain can lead to variable protection efficacy of the MLV vaccines. In this paper, two typical commercial MLV vaccines were used to evaluate their efficacy to block TJnh1501 infection and onset of clinical symptoms. Our results showed that both MLV vaccines could shorten the period of fever and reduce viral loads in sera, but were not able to reduce the clinical signs and lung lesions indicating that the two commercial MLV vaccines provide limited cross-protection efficacy against the novel recombinant type 2 PRRSV infection. This study gives valuable suggestions for the use of MLV vaccines to control PRRSV infection in the field.

 

  1. Jesudoss Chelladurai, J., Derscheid, R., & Brewer, M. T. (2018). Respiratory disease associated with migrating Ascaris larvae in a beef calf. Veterinary Parasitology: Regional Studies and Reports, 12(December 2017), 9–12. https://doi.org/10.1016/j.vprsr.2017.12.005

 

ABSTRACT

A group of 4-month-old beef calves were examined for clinical respiratory disease with labored breathing, coughing, and fevers of over 104 °F. Necropsy of one of the calves revealed lungs that were not collapsed but had red mottled appearance on cut surface. Assessment of lung tissue by bacterial culture and PCR did not reveal bovine bacterial or viral respiratory pathogens. Histopathology of affected tissues and lymph nodes revealed larval ascarid nematodes. In combination with phylogenetic analysis, amplification and sequencing of ITS1 was used to identify the larvae as Ascaris.

 

  1. Wang, J., Liu, L., Wang, J., Pang, X., & Yuan, W. (2018). Real-time RPA assay for rapid detection and differentiation of wild-type pseudorabies and gE-deleted vaccine viruses. Analytical Biochemistry, 543(38), 122–127. https://doi.org/10.1016/j.ab.2017.12.012

 

ABSTRACT

The objective of this study was to develop a dual real-time recombinase polymerase amplification (RPA) assay using exo probes for the detection and differentiation of pseudorabies virus (PRV). Specific RPA primers and probes were designed for gB and gE genes of PRV within the conserved region of viral genome. The reaction process can be completed in 20 min at 39 °C. The dual real-time RPA assay performed in the single tube was capable of specific detecting and differentiating of the wild-type PRV and gE-deleted vaccine strains, without cross-reactions with other non-targeted pig viruses. The analytical sensitivity of the assay was 102copies for gB and gE genes. The dual real-time RPA demonstrated a 100% diagnostic agreement with the real-time PCR on 4 PRV strains and 37 clinical samples. Through the linear regression analysis, the R2value of the real-time RPA and the real-time PCR for gB and gE was 0.983 and 0.992, respectively. The dual real-time RPA assay provides an alternative useful tool for rapid, simple, and reliable detection and differentiation of PRV, especially in remote and rural areas.

 

 

INFECTIOUS BURSAL DISEASES:

 

  1. Ganguly, B., & Rastogi, S. K. (2018). Structural and functional modeling of viral protein 5 of Infectious Bursal Disease Virus. Virus Research, 247(January), 55–60. https://doi.org/10.1016/j.virusres.2018.01.017

 

ABSTRACT

Infectious Bursal Disease (IBD) is an acute, highly contagious and immunosuppressive disease of young chicken. The causative virus (IBDV) is a bi-segmented, double-stranded RNA virus. The virus encodes five major proteins, viral protein (VP) 1–5. VPs 1–3 have been characterized crystallographically. Albeit a rise in the number of studies reporting successful heterologous expression of VP5 in recent times, challenging the notion that rapid death of host cells overexpressing VP5 disallows obtaining sufficiently pure preparations of the protein for crystallographic studies, the structure of VP5 remains unknown and its function controversial. Our study describes the first 3D model of IBD VP5 obtained through an elaborate computational workflow. Based on the results of the study, IBD VP5 can be predicted to be a structural analog of the leucine-rich repeat (LRR) family of proteins. Functional implications arising from structural similarity of VP5 with host Toll-like receptor (Tlr) 3 also satisfy the previously reported opposing roles of the protein in first abolishing and later inducing host-cell apoptosis.

 

  1. Abed, M., Soubies, S., Courtillon, C., Briand, X., Allee, C., Amelot, M., … Temim, S. (2018). Infectious bursal disease virus in Algeria: Detection of a novel lineage of highly pathogenic reassortant viruses. Infection, Genetics and Evolution, 60(2017), 48–57. https://doi.org/10.1016/j.meegid.2018.01.029

 

ABSTRACT

Infectious bursal disease (IBD) is an immunosuppressive viral disease, present worldwide, which causes mor- tality and immunosuppression in young chickens. The causative agent, the Avibirnavirus IBDV, is a non-envel- oped virus whose genome consists of two segments (A and B) of double-stranded RNA. Different pathotypes of IBDV exist, ranging from attenuated vaccine strains to very virulent viruses (vvIBDV). In Algeria, despite the prophylactic measures implemented, cases of IBD are still often diagnosed clinically and the current molecular epidemiology of IBDV remains unknown. The presence of the virus and especially of strains genetically close to vvIBDV was confirmed in 2000 by an unpublished OIE report. In this study, nineteen IBDV isolates were col- lected in Algeria between September 2014 and September 2015 during clinical outbreaks. These isolates were analyzed at the genetic, antigenic and pathogenic levels. Our results reveal a broad genetic and phenotypic diversity of pathogenic IBDV strains in Algeria, with, i) the circulation of viruses with both genome segments related to European vvIBDV, which proved as pathogenic for specific pathogen-free chickens as vvIBDV re- ference strain, ii) the circulation of viruses closely related – yet with a specific segment B – to European vvIBDV, their pathogenicity being lower than reference vvIBDV, iii) the detection of reassortant viruses whose segment A was related to vvIBDV whereas their segment B did not appear closely related to any reference sequence. Interestingly, the pathogenicity of these potentially reassortant strains was comparable to that of reference vvIBDV. All strains characterized in this study exhibited an antigenicity similar to the cognate reference IBDV strains. These data reveal the continuous genetic evolution of IBDV strains in Algerian poultry through re- assortment and acquisition of genetic material of unidentified origin. Continuous surveillance of the situation as well as good vaccination practice associated with appropriate biosecurity measures are necessary for disease control.Abbreviations:

 

  1. He, Z., Chen, X., Fu, M., Tang, J., Li, X., Cao, H., … Zheng, S. J. (2017). Infectious bursal disease virus protein VP4 suppresses type I interferon expression via inhibiting K48-linked ubiquitylation of glucocorticoid-induced leucine zipper (GILZ). Immunobiology, (October), 0–1. https://doi.org/10.1016/j.imbio.2017.10.048

ABSTRACT

Viruses have developed a variety of methods to evade host immune response. Our previous study showed that infectious bursal disease virus (IBDV) inhibited type I interferon production via interaction of VP4 with cellular glucocorticoid-induced leucine zipper (GILZ) protein. However, the exact underlying molecular mechanism is still unclear. In this study, we found that IBDV VP4 suppressed GILZ degradation by inhibiting K48-linked ubiquitylation of GILZ. Furthermore, mutation of VP4 (R41G) abolished the inhibitory effect of VP4 on IFN-β expression and GILZ ubiquitylation, indicating that the amino acid 41R of VP4 was required for the suppression of IFN-β expression and GILZ ubiquitylation. Moreover, IBDV infection or VP4 expression markedly inhibited endogenous GILZ ubiquitylation. Thus, IBDV VP4 suppresses type I interferon expression by inhibiting K48-linked ubiquitylation of GILZ, revealing a new mechanism employed by IBDV to suppress host response.

 

  1. Brown Jordan, A., Sookhoo, J., Blake, L., Crooks, P., Mohammed, Z., Molawatti-Bisnath, J., … Oura, C. A. L. (2018). Serological evidence for eight globally important poultry viruses in Trinidad & Tobago. Preventive Veterinary Medicine, 149(September 2017), 75–81. https://doi.org/10.1016/j.prevetmed.2017.11.006

ABSTRACT

Viruses affecting poultry cause significant levels of disease leading to severe economic losses among poultry farmers worldwide. The Americas region continues to be vulnerable to the spread of poultry viruses across the continents and Caribbean island chains. In Trinidad and Tobago (T&T) there is limited information on the viruses circulating in poultry. Many flock are vulnerable to infection and there are occasional outbreaks of disease resulting in high levels of morbidity and mortality. This study aims to identify important viruses of poultry circulating in T&T through a broad-based surveillance approach. Serum samples from 29 layer farms in Trinidad and 14 layer farms in Tobago were collected from the eldest laying hens. Samples were tested from unvaccinated birds for antibodies by enzyme-linked immunosorbent assay (ELISA) against Avian influenza virus (AIV), Infectious bronchitis virus (IBV), Newcastle disease virus (NDV), Infectious laryngotracheitis virus (ILTV), Avian pneumovirus (APV), Infectious bursal disease virus (IBDV), Fowl adenovirus Gp1 (FADV) and Egg drop syndrome virus (EDSV). In Trinidad, the estimated true seroprevalence levels of antibodies were 0% (CI 95%: 0–0%) for AIV, 100% (CI 95%: 97–100%) for IBV, 79.8% (CI 95%: 70.6–86.9%) for NDV, 1% (CI 95%: 0–2.6%) for ILTV, 67.55% (CI 95%: 62.3–72.4%) for APV, 94.93% (CI 95%: 88.0–98.6%) for IBDV, 100% (CI 95%: 99.7–100%) for FADV and 67.8% (CI 95%: 62.4–72.8%) for EDSV. In Tobago, seroprevalence levels were 0% (CI 95%: 0–0%) for AIV, 100% (CI 95%: 95.6–100%) for IBV, 80.5% (CI 95%: 70.1–88.5%) for NDV, 29.9% (CI 95%: 20.8–40.6%) for ILTV, 100% (CI 95%: 97.7–100%) for APV, 97.1% (CI95%: 89.9–100%) for IBDV, 100% (CI 95%: 97.5–100%) for FADV and 100% (CI 95%: 99–100%) for EDSV. The results reveal strong evidence for the circulation of IBV, NDV, APV, IBDV, FADV and EDSV in layer poultry on both islands, as well as ILTV in Tobago.

 

  1. Ingrao, F., Rauw, F., Steensels, M., van den Berg, T., & Lambrecht, B. (2017). Early immune responses and profiling of cell-mediated immunity-associated gene expression in response to rHVT-IBD vaccination. Vaccine. https://doi.org/10.1016/j.vaccine.2017.12.059

ABSTRACT

Infectious bursal disease (IBD) remains a major threat to the poultry industry. Recombinant herpesvirus of turkey (rHVT)-IBD vaccines have been successfully used to induce a protective immune response against IBD. However, the capacity for rHVT-IBD vaccines to induce early protection without detectable antibodies, and the underlying mechanisms mediating specific cell-mediated responses in the early stages following vaccination, have been poorly investigated. Therefore, in this study, specific pathogen- free (SPF) chickens were vaccinated with rHVT-IBD and T-cell subsets were analyzed. Both splenic and circulating CD8+ cell populations increased at 7 days postvaccination (dpv). Next, the expression of adap- tive immunity-related genes was analyzed in the spleen and lung of rHVT-IBD-vaccinated chickens. Upregulation of CD8 expression was observed at 7 dpv. Interestingly, a parallel increase in the transcrip- tion of granzymes A and K was also detected from 7 dpv. To our knowledge, the latter result is the first to be reported, and it suggests that cytotoxic activity of CD8+ T lymphocytes is activated. In contrast, expres- sion of the innate genes examined remained largely unchanged following vaccination. To further inves- tigate the IBD virus (IBDV)-specific responses triggered by rHVT-IBD vaccination, vaccinated chickens were inoculatedwith an attenuated IBDV strain with the aim of restimulating induced immune responses in vivo. The expression profiles of various genes associated with adaptive immune responses were sub- sequently analyzed in lung, spleen, and bursa of Fabricius samples. Significant upregulation of CD4, CD8, perforin, and IFNc expression were observed in the bursa samples 7 days postinoculation (dpi). In the lung, transcript levels of CD8, granzymes and perforin were also significantly higher in the rHVT- IBD-vaccinated chickens at 7 dpi, thereby suggesting that specific cellular immune responses were acti- vated. Overall, these results support the hypothesis that stimulation of specific CD8+ cell-mediated immunity contributes to the response against IBDV in rHVT-IBD-vaccinated chickens.

 

  1. Zhang, P., Liu, X., Liu, H., Wang, W., Liu, X., Li, X., & Wu, X. (2018). Astragalus polysaccharides inhibit avian infectious bronchitis virus infection by regulating viral replication. Microbial Pathogenesis, 114(October 2017), 124–128. https://doi.org/10.1016/j.micpath.2017.11.026

ABSTRACT

The avian coronavirus causes infectious bronchitis (IB), which is one of the most serious diseases affecting the avian industry worldwide. However, there are no effective strategies for controlling the IB virus (IBV) at present. Therefore, development of novel antiviral treatment strategies is urgently required. As reported, astragalus polysaccharides (APS) have potential antiviral effects against several viruses; however, the antiviral effect of APS against IBV remains unclear. In this study, we explored whether APS had the potential to inhibit IBV infectionby utilizing several in vitro experimental approaches. To this end, the effect of APS on the replication of IBV was examined in chicken embryo kidney (CEK) cells. Viral titers were calculated by using the plaque formation assay, and the cytotoxicity of APS was tested by utilizing a Cell Counting Kit-8 assay. The expression of viral mRNA and cytokine (IL-1β, IL-6, IL-8 and TNF-α) mRNA transcripts was determined by real-time quantitative RT-PCR(qRT-PCR). IBV titers in infected CEK cells treated with APS were significantly reduced in a dose-dependent manner, indicating that APS inhibited IBV replication in vitro. We also found that the decreased viral replication after APS treatment was associated with reduced mRNA levels of the cytokines IL-1B, IL-6, IL-8 and TNF-α. In conclusion, these results suggest that APS exhibit antiviral activities against IBV and it may represent a potential therapeutic agent for inhibiting the replication of IBV.

 

  1. Guo, Y., Zhang, Q., Zuo, Z., Chu, J., Xiao, H., Javed, M. T., & He, C. (2018). Protocatechuic acid (PCA) induced a better antiviral effect by immune enhancement in SPF chickens. Microbial Pathogenesis, 114(2), 233–238. https://doi.org/10.1016/j.micpath.2017.11.068

ABSTRACT

Protocatechuic acid (PCA) is an antiviral agent against Avian Influenza virus (AIV) and Infectious Bursal Disease (IBD) virus, but its antiviral mechanism is unknown. In this study, we evaluated the humoral and cellular responses to PCA in specific pathogen-free (SPF) chickens. One hundred forty 35-day-old SPF chickens were randomly divided into 7 groups. The birds were inoculated with the commercial, attenuated Newcastle Disease Virus (NDV) vaccine and then received orally with 10, 20 or 40 mg/kg body weight of PCA for 30 days. Immune organ indexes, anti-Newcastle Disease Virus (NDV) antibodies and lymphocyte proliferation, but not body weight, were significantly increased in chicken treated with 40 mg/kg PCA, compared to the control birds treated with Astragalus polysaccharide (ASP). Survival rate was 70% and 60%, respectively, in the chickens with 40 mg/kg PCA, 20 mg/kg PCA while 50% survival was found in the birds treated with 125 mg/kg ASP. PCA treatment resulted in significantly lower viral load and reduced shedding. These results indicate that PCA may improve poultry health by enhancing both the humoral and cellular immune response.

 

  1. Tang, N., Zhang, Y., Pedrera, M., Chang, P., Baigent, S., Moffat, K., … Yao, Y. (2017). A simple and rapid approach to develop recombinant avian herpesvirus vectored vaccines using CRISPR/Cas9 system. Vaccine. https://doi.org/10.1016/j.vaccine.2017.12.025

ABSTRACT

 

Herpesvirus of turkeys (HVT) has been successfully used as live vaccine against Marek’s disease (MD) worldwide for more than 40 years either alone or in combination with other serotypes. HVT is also widely used as a vector platform for generation of recombinant vaccines against a number of avian diseases such as infectious bursal disease (IBD), Newcastle disease (ND) and avian influenza (AI) using conventional recombination methods or recombineering tools on cloned viral genomes. In the present study, we describe the application of CRISPR/Cas9-based genome editing as a rapid and efficient method of generating HVT recombinants expressing VP2 protein of IBDV. This approach offers an efficient method to introduce other viral antigens into the HVT genome for rapid development of recombinant vaccines.

 

  1. Liu, L., Zhang, W., Song, Y., Wang, W., Zhang, Y., Wang, T., … Cui, H. (2017). Recombinant Lactococcus lactis co-expressing OmpH of an M cell-targeting ligand and IBDV-VP2 protein provide immunological protection in chickens. Vaccine. https://doi.org/10.1016/j.vaccine.2017.12.027

ABSTRACT

Infectious bursal disease virus (IBDV) is a highly contagious disease that results in enormous economic losses in the global poultry sector. Lactic acid bacteria are an appealing vehicle for the safe and effective delivery of heterologous protein antigens. Oral administration of the commensal bacterium Lactococcus lactis expressing recombinant fusion proteins has been used to elicit mucosal and systemic immune responses. In this study, a Lactococcus lactis NZ3900 strain co-expressing the outer membrane protein (Omp) H of the microfold (M) cell-targeting ligand and the viral capsid protein (VP)2 antigen of IBDV was genetically engineered, and its immunopotentiating capacity as an oral and injected vaccine in chickens was evaluated. Western blotting analysis demonstrated that VP2-OmpH was expressed in the cytoplasm of cells and had high immunoreactivity. An in vivo study showed that in the absence of any adjuvant, the recombinant L. lactis VP2-OmpH strain stimulated the immune response and protected against very virulent IBDV challenge in 100% and 80% of chickens immunized by injection and oral administration, respectively. Moreover, the antiviral neutralizing antibody titers induced by injection administration were higher than those induced by oral administration. Mucosal secretory IgA titers induced by oral administration were higher than those induced by injection administration. These results suggested that the recombinant L. lactis VP2-OmpH strain is a promising candidate vaccine to prevent IBDV infection.

 

  1. Baron, M. D., Iqbal, M., & Nair, V. (2018). Recent advances in viral vectors in veterinary vaccinology. Current Opinion in Virology, 29, 1–7. https://doi.org/10.1016/j.coviro.2018.02.002

ABSTRACT

Viral vectored vaccines, particularly using vectors such as adenovirus, herpesvirus and poxviruses, are used widely in veterinary medicine, where this technology has been adopted much more quickly than in human medicine. There are now a large number of programmes to develop viral vector vaccine platforms for humans and very similar or identical vectors are being developed for veterinary medicine. The shared experiences of developing these new vaccine platforms across the two disciplines is accelerating progress, a striking example of the value of a ‘One Health’ approach. In particular, there is growing use of adenoviruses, either replicating or replication-incompetent, to create new vaccines for use in livestock or companion animals. Live replicating avian herpesvirus vectors are increasingly used as vaccines against poultry diseases.

 

  1. Laamiri, N., Aouini, R., Marnissi, B., Ghram, A., & Hmila, I. (2018). A multiplex real-time RT-PCR for simultaneous detection of four most common avian respiratory viruses. Virology, 515(August 2017), 29–37. https://doi.org/10.1016/j.virol.2017.11.021

ABSTRACT

 

A one-step multiplex real-time reverse transcription-PCR (rRT-PCR) assay was developed forsimultaneous detection and quantification of four avian respiratory viruses: avian influenza virus (AIV), infectious bronchitis virus (IBV), Newcastle disease virus (NDV) and infectious laryngotracheitis virus (ILTV). In comparison with the singleplex rRT-PCR, the specificity, the sensitivity and the reproducibility of the new assay were evaluated and validated using 70 clinical samples. The optimal cutoff point, the corresponding limit of quantification (LoQ) and the limit of detection (LoD) were statistical established based on receiver operating characteristic (ROC) curve analysis. The results showed that the multiplex assay presents higher sensitivity and specificity. Correlation coefficients (R2) and amplification efficiencies (E) of all singleplex and multiplex rRT-PCR reactions are within the acceptable range. The 95% LoDs of multiplex assay were in the range [3–19] copies genomic/ µl, and its corresponding cutoff cycles were in the range [34.16–36.59]. No competitive inhibition for the detection of the four targets and no specific amplification or cross reactivity with other tested viruses was observed. Excellent results were attained in the inter-assay and intra-assay reproducibility evaluation. All identified samples by the multiplex rRT-PCR assay proved to be 100% concordant with the results of the singleplex assays. The results achieved showed that the multiplex assay is very suitable as a routine laboratory test for rapid and specific detection and quantification of co-infections in field samples.

 

 

 

 

 

  1. Onono, J. O., Alarcon, P., Karani, M., Muinde, P., Akoko, J. M., Maud, C., … Rushton, J. (2018). Identification of production challenges and benefits using value chain mapping of egg food systems in Nairobi, Kenya. Agricultural Systems, 159(August 2017), 1–8. https://doi.org/10.1016/j.agsy.2017.10.001

ABSTRACT

Commercial layer and indigenous chicken farming in Nairobi and associated activities in the egg value chains are a source of livelihood for urban families. A value chain mapping framework was used to describe types of inputs and outputs from chicken farms, challenges faced by producers and their disease control strategies. Commercial layer farms were defined as farms keeping exotic breeds of chicken, whereas indigenous chicken farms kept different cross breeds of indigenous chicken. Four focus group discussions were held with producers of these chickens in peri-urban area: Dagoretti, and one informal settlement: Kibera. Qualitative data were collected on interactions between farmers, sources of farm inputs and buyers of poultry products, simple ranking of production challenges, farmers’ perception on diseases affecting chicken and strategies for management of sick chicken and waste products. Value chain profiles were drawn showing sources of inputs and channels for distribution of chicken products. Production challenges and chicken disease management strategies were presented as qualitative summaries. Commercial layer farms in Dagoretti kept an average of 250 chickens (range 50–500); while flock sizes in Kibera were 12 chickens (range 5–20). Farms keeping indigenous chicken had an average of 23 chickens (range 8–40) in Dagoretti, and 10 chickens (range 5–16) in Kibera. Commercial layer farms in Dagoretti obtained chicks from distributors of commercial hatcheries, but farms in Kibera obtained chicks from hawkers who in turn sourced them from distributors of commercial hatcheries. Indigenous chicken farms from Dagoretti relied on natural hatching of fertilised eggs, but indigenous chicken farms in Kibera obtained chicks from their social connection with communities living in rural areas. Outlets for eggs from commercial layer farms included local shops, brokers, restaurants and hawkers, while eggs from indigenous chicken farms were sold to neighbours and restaurants. Sieved chicken manure from Dagoretti area was fed to dairy cattle; whereas non-sieved manure was used as fertilizer on crops. Production challenges included poor feed quality, lack of space for expansion, insecurity, occurrence of diseases and lack of sources of information on chicken management. In Kibera, sick and dead chickens were slaughtered and consumed by households; this practice was not reported in Dagoretti. The chicken layer systems contribute to food security of urban households, yet they have vulnerabilities and deficiencies with regard to disease management and food safety that need to be addressed with support on research and extension.

 

  1. Awais, M. M., Akhtar, M., Anwar, M. I., & Khaliq, K. (2018). Evaluation of Saccharum officinarum L. bagasse-derived polysaccharides as native immunomodulatory and anticoccidial agents in broilers. Veterinary Parasitology, 249(November 2017), 74–81. https://doi.org/10.1016/j.vetpar.2017.11.012

ABSTRACT

Coccidiosis is one of the most important protozoal diseases of the poultry industry, inflicting heavy economic losses in the form of high mortality and morbidity in affected birds. Under these circumstances, the development of nonchemical consumer-friendly strategies for its effective control is of paramount importance. Therefore, this study was conducted to evaluate the sugarcane (Saccharum officinarum L.) bagasse-derived polysaccharides as native immunomodulatory and anticoccidial agents in commercial broilers. Polysaccharides were recovered from sugarcane bagasse (PSCB) and analyzed by high-performance liquid chromatography (HPLC). Five different sugars including melezitose, maltose, glucose, mannose, and fructose were detected in hydrolyzed solution of PSCB. The isolated PSCB were orally administered to the broilers in three graded doses ranging from 10 to 50 mg/kg of body weight/day for 3 consecutive days, i.e., fifth through seventh days of life. Results showed significantly enhanced (p < 0.05) lymphoproliferative and humoral responses to T-cell mitogen (PHA-P) and sheep red blood cells (SRBCs) in PSCB-administered chickens. In a challenge experiment, percent protection and daily weight gains were significantly higher (p < 0.05), whereas mean oocyst counts and lesion scores were lower (p < 0.05) in PSCB-administered chickens as compared to control. ELISA showed that PSCB significantly enhanced (p < 0.05) antibody titers against the Eimeria species used for the induction of infection in chickens of PSCB-administered and control groups. In conclusion, PSCB showed the potential to modulate the immune responses in industrial broiler chickens with subsequent protection against coccidial infection.

 

 

 

 

 

 

  1. Olesen, M. L., Jørgensen, L. L., Blixenkrone-Møller, M., Sandberg, E., Frandsen, P. L., Østergaard, E., … Rosenstierne, M. W. (2017). Screening for viral extraneous agents in live-attenuated avian vaccines by using a microbial microarray and sequencing. Biologicals, (June), 0–1. https://doi.org/10.1016/j.biologicals.2017.10.005

ABSTRACT

The absence of extraneous agents (EA) in the raw material used for production and in finished products is one of the principal safety elements related to all medicinal products of biological origin, such as live-attenuated vaccines. The aim of this study was to investigate the applicability of the Lawrence Livermore Microbial detection array version 2 (LLMDAv2) combined with whole genome amplification and sequencing for screening for viral EAs in live-attenuated vaccines and specific pathogen-free (SPF) eggs.We detected positive microarray signals for avian endogenous retrovirus EAV-HP and several viruses belonging to the Alpharetrovirus genus in all analyzed vaccines and SPF eggs. We used a microarray probe mapping approach to evaluate the presence of intact retroviral genomes, which in addition to PCR analysis revealed that several of the positive microarray signals were most likely due to cross hybridization with the EAV-HPΔpol and ALV-E ev1, ev3 and ev6 loci sequences originating from the chicken genome.Sequencing of the vaccines on a MiSeq instrument verified the microarray findings and showed similar cross hybridization. Our results suggest that genomic microarrays and sequencing of avian attenuated vaccines may be applied in tests for EA.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INFECTIOUS BRONCHITIS:

 

  1. Cheng, J., Huo, C., Zhao, J., Liu, T., Li, X., Yan, S., … Zhang, G. (2018). Pathogenicity differences between QX-like and Mass-type infectious bronchitis viruses. Veterinary Microbiology, 213(2), 129–135. https://doi.org/10.1016/j.vetmic.2017.11.027

ABSTRACT

Infectious bronchitis is a highly contagious, acute viral respiratory disease of chickens, caused by infectious bronchitis virus (IBV). In recent years, the isolation rate of QX-like IBV has increased in the world. To clarify this phenomenon and better understand the pathogenicity of QX-like IBV, we examined differences in pathogenicity between two IBV strains, SD and M41, which belong to QX-like and Mass-type IBV, respectively. SD strain was more virulent in 3-week-old specific-pathogen-free chickens than M41 strain causing higher mortality with severe renal lesions. The tissue distribution of the two virus strains was tested by real-time RT-PCR. The results showed that the viral genome copy numbers in the tissues of chickens inoculated with SD strain were higher than those in chickens inoculated with M41 strain, with the exception of the trachea and lung. This study indicates that there are tremendous differences in pathogenicity and tissue tropism between the QX-like strain and Mass-type strain. These findings may benefit the prevention of infectious bronchitis in the poultry industry in China.

 

  1. van Beurden, S. J., Berends, A. J., Krämer-Kühl, A., Spekreijse, D., Chenard, G., Philipp, H. C., … Verheije, M. H. (2018). Recombinant live attenuated avian coronavirus vaccines with deletions in the accessory genes 3ab and/or 5ab protect against infectious bronchitis in chickens. Vaccine, 36(8), 1085–1092. https://doi.org/10.1016/j.vaccine.2018.01.017

ABSTRACT

Avian coronavirus infectious bronchitis virus (IBV) is a respiratory pathogen of chickens, causing severe economic losses in poultry industry worldwide. Live attenuated viruses are widely used in both the broiler and layer industry because of their efficacy and ability to be mass applied. Recently, we established a novel reverse genetics system based on targeted RNA recombination to manipulate the genome of IBV strain H52. Here we explore the possibilities to attenuate IBV in a rational way in order to generate safe and effective vaccines against virulent IBV (van Beurden et al., 2017). To this end, we deleted the nonessential group-specific accessory genes 3 and/or 5 in the IBV genome by targeted RNA recombination and selected the recombinant viruses in embryonated eggs. The resulting recombinant (r) rIBV-Δ3ab, rIBV-Δ5ab, and rIBV-Δ3ab5ab could be rescued and grew to the same virus titer as recombinant and wild type IBV strain H52. Thus, genes 3ab and 5ab are not essential for replication in ovo. When administered to one-day-old chickens, rIBV-Δ3ab, rIBV-Δ5ab, and rIBV-Δ3ab5ab showed reduced ciliostasis as compared to rIBV H52 and wild type H52, indicating that the accessory genes contribute to the pathogenicity of IBV. After homologous challenge with the virulent IBV strain M41, all vaccinated chickens were protected against disease based on reduced loss of ciliary movement in the trachea compared to the non-vaccinated but challenged controls. Taken together, deletion of accessory genes 3ab and/or 5ab in IBV resulted in mutant viruses with an attenuated phenotype and the ability to induce protection in chickens. Hence, targeted RNA recombination based on virulent IBV provides opportunities for the development of a next generation of rationally designed live attenuated IBV vaccines.

 

  1. Amarasinghe, A., Abdul-Cader, M. S., Almatrouk, Z., van der Meer, F., Cork, S. C., Gomis, S., & Abdul-Careem, M. F. (2018). Induction of innate host responses characterized by production of interleukin (IL)-1β and recruitment of macrophages to the respiratory tract of chickens following infection with infectious bronchitis virus (IBV). Veterinary Microbiology, 215(November 2017), 1–10. https://doi.org/10.1016/j.vetmic.2018.01.001

ABSTRACT

Infectious bronchitis virus (IBV) infection is a major cause of economic losses to the poultry industry. Due to limitations in current control measures, alternative approaches, based on thorough understanding of the host responses are required. As one of the key component of the avian immune system, the innate immune system has a crucial role in limiting virus replication at the initial stage of the infection. As parts of the innate host response, macrophages and cytokines, such as interleukin (IL)-1β are critical components as shown in other host-virus infection models. Since information on the importance of macrophages and IL-1β in IBV infection in chickens is limited, our objective was to determine the association of IL-1β originating from avian macrophages and IBV infection in the trachea and lung. Following experimental IBV infection in 6 days old chickens, we found increased production of IL-1β and increased recruitment of macrophages in the respiratory tract. Towards the end of the study (5 and 7 days following the IBV infection), the recruited macrophages appear to be a significant source IL-1β. However, only the recruitment of macrophages in the lung correlated with IBV genome loads in this tissue. In conclusion, the present study demonstrates that recruitment of macrophages and the production of IL-1β originating from macrophages, as well as other sources, occur following IBV infection in the respiratory tract suggesting potential roles of these mediators in the host responses to IBV infection. However, further studies are warranted to elucidate whether macrophages and IL-1β are the causes of reduced IBV genome loads in the respiratory tract and also to investigate whether immune mediators that were not measured in the current study were involved in reducing IBV genome load in the respiratory tract towards the end of the study.

 

  1. Elhamouly, M., Terada, T., Nii, T., Isobe, N., & Yoshimura, Y. (2018). Innate antiviral immune response against infectious bronchitis virus and involvement of prostaglandin E2 in the uterine mucosa of laying hens. Theriogenology, 110, 122–129. https://doi.org/10.1016/j.theriogenology.2017.12.047

ABSTRACT

Infectious bronchitis virus (IBV) is an enveloped RNA virus that causes deformities in eggshells. The aim of this study was to investigate the innate immune response to IBV, and to determine whether prostaglandin (PG) E2, which is synthesized during inflammation, is involved in the innate immune response in the uterine mucosa. The effects of intra-oviductal inoculation with attenuated IBV (aIBV) on the expression of viral RNA recognition receptors and innate antiviral factors were examined by real-time PCR and immunohistochemistry, and on PGE2 levels by ELISA. Then, the effects of PGE2 on the expression of innate antiviral factors in cultured uterine mucosal cells were examined. The results showed that the expression of RNA virus pattern recognition receptors (TLR3, 7, and MDA5), antimicrobial peptides (avian β-defensins, including AvBD1, 2, 4–6 and cathelicidins, including CATH1 and 3), and interferons (IFNα, β, γ, λ) were upregulated, and the expression of cyclooxygenase 2 (PG synthase) and the level of PGE2 were increased in the uterine mucosa following aIBV inoculation. The number of AvBD2-positive cells in the mucosa also increased in response to aIBV. In cultured mucosal cells (mainly epithelial), the expression of AvBD4, 10–13 and IFNα, β, and λ was upregulated following incubation with 500 nM PGE2. These results suggest that the expression of viral RNA-recognition receptors, AvBDs, CATHs, and IFNs and PGE2 are induced by the IBV antigen, and that the expression of a different set of AvBDs is also induced by PGE2 in the cultured uterine mucosal cells. These antiviral factors may play a role in the protection of the uterine mucosa from IBV infection.

 

  1. Zheng, J., Yamada, Y., Fung, T. S., Huang, M., Chia, R., & Liu, D. X. (2018). Identification of N-linked glycosylation sites in the spike protein and their functional impact on the replication and infectivity of coronavirus infectious bronchitis virus in cell culture. Virology, 513(July 2017), 65–74. https://doi.org/10.1016/j.virol.2017.10.003

ABSTRACT

Spike (S) glycoprotein on the viral envelope is the main determinant of infectivity. The S protein of coronavirus infectious bronchitis virus (IBV) contains 29 putative asparagine(N)-linked glycosylation sites. These post-translational modifications may assist in protein folding and play important roles in the functionality of S protein. In this study, we used bioinformatics tools to predict N-linked glycosylation sites and to analyze their distribution in IBV strains and variants. Among these sites, 8 sites were confirmed in the S protein extracted from partially purified virus particles by proteomics approaches. N-D and N-Q substitutions at 13 predicted sites were introduced into an infectious clone system. The impact on S protein-mediated cell-cell fusion, viral recovery and infectivity was assessed, leading to the identification of sites essential for the functions of IBV S protein. Further characterization of these and other uncharacterized sites may reveal novel aspects of N-linked glycosylation in coronavirus replication and pathogenesis.

 

  1. Jiang, L., Han, Z., Chen, Y., Zhao, W., Sun, J., Zhao, Y., & Liu, S. (2018). Characterization of the complete genome, antigenicity, pathogenicity, tissue tropism, and shedding of a recombinant avian infectious bronchitis virus with a ck/CH/LJL/140901-like backbone and an S2 fragment from a 4/91-like virus. Virus Research, 244(November 2017), 99–109. https://doi.org/10.1016/j.virusres.2017.11.007

ABSTRACT

In this study, we isolated an infectious bronchitis virus, designated I1101/16, from broiler breeders in China. Analysis of the S1 gene showed that isolate I1101/16 was genetically close to strain ck/CH/LJL/140901, which belongs to the TW I genotype (also known as lineage GI-7 based on the recent IBV classification), however the S2 gene showed genetic diversity comparing to that of S1 gene. Comparison of the genomic sequences showed that the genome of isolate I1101/16 was similar to that of strain ck/CH/LJL/140901 from the 5′ end of the genome to the 5′ end of the S2 gene and from the 5′ end of the 3a gene to the end of the genome, whereas the remaining parts of the genome sequences were more closely related to those of strain 4/91 than those of ck/CH/LJL/140901, thereby suggesting that recombination might have occurred during the origin of the virus. SimPlot and Bootscan analysis of the complete genomic sequence confirmed this hypothesis, where it showed that isolate I1101/16 arose through recombination events between ck/CH/LJL/140901- and 4/91-like viruses. Isolate I1101/16 and strain ck/CH/LJL/140901 shared identical amino acids in almost all five of their B cell epitopes, but the two viruses had a serotype relatedness value of 65, which is well below 80, i.e., the lower cutoff value for viruses of the same serotype. In addition, pathogenicity tests demonstrated that isolate I1101/16 was more pathogenic to 1-day-old specific-pathogen-free chickens than strain ck/CH/LJL/140901, according to analysis of the clinical signs, whereas strain ck/CH/LJL/140901 exhibited prolonged replication and shedding after challenge compared with isolate I1101/16. This study did not provide evidence that recombination can directly alter the antigenicity, virulence, replication, shedding, and tissue tropism of a virus, but it did show that recombination events are likely to be major determinants of viral evolution.

 

  1. Tan, Y. W., Fung, T. S., Shen, H., Huang, M., & Liu, D. X. (2018). Coronavirus infectious bronchitis virus non-structural proteins 8 and 12 form stable complex independent of the non-translated regions of viral RNA and other viral proteins. Virology, 513(July 2017), 75–84. https://doi.org/10.1016/j.virol.2017.10.004

ABSTRACT

In this study, we isolated an infectious bronchitis virus, designated I1101/16, from broiler breeders in China. Analysis of the S1 gene showed that isolate I1101/16 was genetically close to strain ck/CH/LJL/140901, which belongs to the TW I genotype (also known as lineage GI-7 based on the recent IBV classification), however the S2 gene showed genetic diversity comparing to that of S1 gene. Comparison of the genomic sequences showed that the genome of isolate I1101/16 was similar to that of strain ck/CH/LJL/140901 from the 5′ end of the genome to the 5′ end of the S2 gene and from the 5′ end of the 3a gene to the end of the genome, whereas the remaining parts of the genome sequences were more closely related to those of strain 4/91 than those of ck/CH/LJL/140901, thereby suggesting that recombination might have occurred during the origin of the virus. SimPlot and Bootscan analysis of the complete genomic sequence confirmed this hypothesis, where it showed that isolate I1101/16 arose through recombination events between ck/CH/LJL/140901- and 4/91-like viruses. Isolate I1101/16 and strain ck/CH/LJL/140901 shared identical amino acids in almost all five of their B cell epitopes, but the two viruses had a serotype relatedness value of 65, which is well below 80, i.e., the lower cutoff value for viruses of the same serotype. In addition, pathogenicity tests demonstrated that isolate I1101/16 was more pathogenic to 1-day-old specific-pathogen-free chickens than strain ck/CH/LJL/140901, according to analysis of the clinical signs, whereas strain ck/CH/LJL/140901 exhibited prolonged replication and shedding after challenge compared with isolate I1101/16. This study did not provide evidence that recombination can directly alter the antigenicity, virulence, replication, shedding, and tissue tropism of a virus, but it did show that recombination events are likely to be major determinants of viral evolution.

 

  1. Canonne, A. M., Peters, I., Roels, E., Desquilbet, L., & Clercx, C. (2018). Detection of specific bacterial agents by quantitative PCR assays in the bronchoalveolar lavage fluid of dogs with eosinophilic bronchopneumopathy vs. dogs with chronic bronchitis and healthy dogs. Veterinary Journal, 232, 52–56. https://doi.org/10.1016/j.tvjl.2017.12.014AVSTRACT

ABSTRACT

In humans, Mycoplasma pneumoniae and Bordetella pertussis infections are suggested to trigger or exacerbate asthma. Whether Mycoplasma or Bordetella are associated with chronic inflammatory bronchial diseases in dogs has not been investigated. The aim of this study was to assess detection rates of Mycoplasma canis (M. canis), M. cynos and Bordetella bronchiseptica (Bb), in dogs with eosinophilic bronchopneumopathy (EBP) and chronic bronchitis (CB), compared with healthy dogs. Specific quantitative PCR (qPCR) analysis for M. canis, M. cynos and Bb were retrospectively performed on bronchoalveolar lavage fluid (BALF) collected from 24 dogs with EBP, 21 dogs with CB and 15 healthy dogs. Possible associations between qPCR results and age, BALF cytology or clinical severity scores (CSS) in dogs with EBP were investigated. There was no difference in M. canis, M. cynos and Bb detection rates in dogs with EBP (n = 6, n = 2 and n = 6, respectively) and dogs with CB (n = 2, n = 2 and n = 2, respectively) compared with control dogs (n = 4, n = 2 and n = 2, respectively). In dogs with EBP, the proportion that were qPCR-positive for Bb was higher in dogs with higher CSS (P = 0.014) and BALF from Bb-positive dogs had higher percentage of neutrophils (P < 0.001). Among dogs that were qPCR-positive for Bb, moderate to high loads were only detected in dogs with EBP. M. canis and M. cynos detection was not associated with EBP or CB; higher Bb loads were only present in dogs with EBP and high CSS. A possible cause and effect relationship between Bb infection or load and EBP remains unclear and requires further investigation.

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