Displaying publications 1 - 20 of 81 in total

Abstract:
Sort:
  1. Rajik M, Jahanshiri F, Omar AR, Ideris A, Hassan SS, Yusoff K
    Virol J, 2009;6:74.
    PMID: 19497129 DOI: 10.1186/1743-422X-6-74
    Avian influenza viruses (AIV) cause high morbidity and mortality among the poultry worldwide. Their highly mutative nature often results in the emergence of drug resistant strains, which have the potential of causing a pandemic. The virus has two immunologically important glycoproteins, hemagglutinin (HA), neuraminidase (NA), and one ion channel protein M2 which are the most important targets for drug discovery, on its surface. In order to identify a peptide-based virus inhibitor against any of these surface proteins, a disulfide constrained heptapeptide phage display library was biopanned against purified AIV sub-type H9N2 virus particles.
  2. Rajik M, Omar AR, Ideris A, Hassan SS, Yusoff K
    Int J Biol Sci, 2009 Aug 08;5(6):543-8.
    PMID: 19680476
    Avian influenza viruses (AIV), the causative agent of avian flu or bird flu, cause widespread morbidity and mortality in poultry. The symptoms of the disease range from mild flu like symptoms to death. These viruses possess two important surface glycoproteins, namely hemagglutinin (HA) and neuraminidase (NA) against which neutralizing antibodies are produced. Due to the highly mutative nature of the genes which encode these proteins, the viruses often confer resistance to the current anti-viral drugs making the prevention and treatment of infection challenging. In our laboratory, we have recently identified a novel anti-viral peptide (P1) against the AIV H9N2 from a phage displayed peptide library. This peptide inhibits the replication of the virus in ovo and in vitro by its binding to the HA glycoprotein. In the current study, we demonstrate that the peptide inhibits the virus replication by preventing the attachment to the host cell but it does not have any effect on the viral fusion. The reduction in the viral nucleoprotein (NP) expression inside the host cell has also been observed during the peptide (P1) treatment. This novel peptide may have the potential to be developed as a therapeutic agent for the treatment and control of avian influenza virus H9N2 infections.
  3. Kong LL, Omar AR, Hair Bejo M, Ideris A, Tan SW
    J Virol Methods, 2009 Nov;161(2):271-9.
    PMID: 19591873 DOI: 10.1016/j.jviromet.2009.06.023
    A SYBR Green I based one-step real-time reverse transcriptase polymerase chain reaction was developed for the detection and differentiation of very virulent (vv) and classical strains of infectious bursal disease virus (IBDV). The assay showed high PCR efficiency >93% and high reproducibility with coefficient of variation less than 0.5%. When tested on characterized IBDV strains, the very virulent and classical-specific primers detected accurately only vvIBDV and classical IBDV strains, respectively. The diagnostic efficacy of the assay was also tested on 140 bursal samples from experimental infection and 37 bursal samples from cases suspected of IBD. The assay was able to detect IBDV from bursal samples collected at days 3 and 5 post-infection with the vvIBDV strain UPM94/273 and the classical IBDV strain D78. The assay was also able to detect bursal samples infected dually with D78 and UPM94/273. The melting temperature values of the amplification products from the classical and very virulent viral infection were statistically significant (P<0.05). The specificity of the assay for detecting IBDV from suspected cases was confirmed by sequence analysis of the VP2 gene. The assay showed high sensitivity since bursal samples which were negative for IBDV were confirmed by virus isolation and PCR amplification. Hence, the new assay offers an attractive method for rapid detection of strains of IBDV.
  4. Mehrbod P, Ideris A, Omar AR, Hair-Bejo M, Tan SW, Kheiri MT, et al.
    Virol J, 2012;9:44.
    PMID: 22340010 DOI: 10.1186/1743-422X-9-44
    The influenza virus is still one of the most important respiratory risks affecting humans which require effective treatments. In this case, traditional medications are of interest. HESA-A is an active natural biological compound from herbal-marine origin. Previous studies have reported that the therapeutic properties of HESA-A are able to treat psoriasis vulgaris and cancers. However, no antiviral properties have been reported.
  5. Shah AUM, Safri SNA, Thevadas R, Noordin NK, Rahman AA, Sekawi Z, et al.
    Int J Infect Dis, 2020 Aug;97:108-116.
    PMID: 32497808 DOI: 10.1016/j.ijid.2020.05.093
    BACKGROUND: Coronavirus disease 2019 (COVID-19), a novel pneumonia disease originating in Wuhan, was confirmed by the World Health Organization on January 12, 2020 before becoming an outbreak in all countries.

    OUTBREAK SITUATION: A stringent screening process at all airports in Malaysia was enforced after the first case outside China was reported in Thailand. Up to April 14, 2020, Malaysia had reported two waves of COVID-19 cases, with the first wave ending successfully within less than 2 months. In early March 2020, the second wave occurred, with worrying situations.

    ACTIONS TAKEN: The Government of Malaysia enforced a Movement Control Order starting on March 18, 2020 to break the chain of COVID-19. The media actively spread the hashtag #stayhome. Non-governmental organizations, as well as prison inmates, started to produce personal protective equipment for frontliners. Various organizations hosted fundraising events to provide essentials mainly to hospitals. A provisional hospital was set up and collaborations with healthcare service providers were granted, while additional laboratories were assigned to enhance the capabilities of the Ministry of Health.

    ECONOMIC DOWNTURN: An initial financial stimulus amounting to RM 20.0 billion was released in February 2020, before the highlighted PRIHATIN Package, amounting to RM 250 billion, was announced. The PRIHATIN Package has provided governmental support to society, covering people of various backgrounds from students and families to business owners.

  6. Ideris A, Ibrahim AL, Spradbrow PB
    Avian Pathol, 1990 Apr;19(2):371-84.
    PMID: 18679945
    The Australian, heat-resistant, a virulent V4 strain of Newcastle disease (ND) virus was selected for further heat resistance to give a variant designated V4-UPM. V4-UPM was sprayed on to food pellets which were fed to chickens in amounts calculated to give about 10(6) EID50 per chicken. Chickens vaccinated only once by feeding developed no haemagglutination-inhibition (HI) antibodies and were not protected against challenge with a viscerotropic velogenic strain of ND virus. Chickens given food pellet vaccine at 3 and 6 weeks of age developed HI antibodies and were substantially protected against parenteral and contact challenge with virulent ND virus. Similar protection was achieved when the V4-UPM vaccine was given intranasally on two occasions or when the vaccine virus was allowed to spread by contact from intranasally vaccinated chickens to nonvaccinated chickens. Heat resistant ND vaccine incorporated in food pellets may provide a method for protecting village chickens against ND in tropical countries.
  7. Ali R, Alabsi AM, Ali AM, Ideris A, Omar AR, Yusoff K, et al.
    Neurochem Res, 2011 Nov;36(11):2051-62.
    PMID: 21671106 DOI: 10.1007/s11064-011-0529-8
    Newcastle disease virus (NDV) is a member of genus Avulavirus within the family Paramyxoviridae. Interest of using NDV as an anticancer agent has arisen from its ability to kill tumor cells with limited toxicity to normal cells. In this investigation, the cytotolytic properties of NDV strain AF2240 were evaluated on brain tumor cell line, anaplastic astrocytoma (U-87MG), by using MTT assay. Cytological observations were studied using fluorescence microscopy and transmission electron microscopy to show the apoptogenic features of NDV on U-87MG. DNA laddering in agarose gel electrophoresis and terminal deoxyribonucleotide transferase-mediated dUTP-X nick end-labeling staining assay confirmed that the mode of cell death was by apoptosis. However, analysis of the cellular DNA content by flowcytometery showed that there was a loss of treated U-87MG cells in all cell cycle phases (G1, S and G2/M) accompanied with increasing in sub-G1 region (apoptosis peak). Early apoptosis was observed 6 h post-inoculation by annexin-V flow-cytometry method. It could be concluded that NDV strain AF2240 is a potent antitumor agent that induce apoptosis and its cytotoxicity increasing while increasing of time and virus titer.
  8. Alsahami A, Ideris A, Omar A, Ramanoon SZ, Sadiq MB
    Int J Vet Sci Med, 2018 Dec;6(2):186-191.
    PMID: 30564594 DOI: 10.1016/j.ijvsm.2018.06.004
    Newcastle disease (ND) is an endemic disease in Oman's poultry industry and impacts negatively on food security. However, little is known regarding the potential risks of the disease in backyard poultry. The objectives of this study were to determine the seroprevalence of Newcastle disease virus (NDV) in backyard chickens and the herd-level risk factors in Oman. In total, 1383 serum samples were collected from chickens in 139 flocks from nine governorates. Information on associated risk factors was assessed using a semi-structured questionnaire. The samples were tested using commercial indirect ELISA kits.A logistic regression model was applied to assess the associated risk factors. The bird and flock-level NDV seroprevalence was 33.8% (95% Confidence Interval (CI): 12.8-38.6%) and 57.1% (95% CI: 35.7-71.4%), respectively. The highest seroprevalence of antibody to NDV at bird and flock levels was recorded in North Ash Sharqiyah (38.6%) and Al Buraimi (71.4%), respectively. Also, the lowest seroprevalence at bird and flock levels was recorded in Musandam (12.8%) and South Al Batinah (35.7%), respectively. A significant difference in NDV seroprevalence at flock and bird levels was only recorded in Ad Dakhliyah. Factors associated with higher seroprevalence to NDV included absence of a veterinarian in the farm (OR = 5.3; 95% CI: 2.1, 11.7), usage of dead ND vaccine (OR = 2.3; 95% CI: 1.2-4.2), employment of non-permanent staff (OR = 3.9; 95% CI: 1.5, 10.6) and free entry of visitors (OR = 6.2; 95% CI: 2.0, 20.3). In conclusion, the results of this study revealed a high exposure of backyard chickens to NDV and the identified risk factors could be vital in the prevention and control of the disease in Oman.
  9. Alsahami AA, Ideris A, Omar A, Ramanoon SZ, Sadiq MB
    Int J Vet Sci Med, 2018 Dec;6(2):248-252.
    PMID: 30564604 DOI: 10.1016/j.ijvsm.2018.08.007
    Newcastle disease (ND) remains an important enzootic disease in chickens in several parts of the world. With the increasing reports of virulence and genetic diversity of the causative agent; Newcastle disease virus (NDV), there is a need to identify the circulating NDV in specific regions. In Oman, to this moment, such information is still lacking. The aim of this study was to isolate and characterize the NDV from ND outbreaks from commercial farms in Oman. Following suspected outbreaks of ND in three commercial farms in 2017, a total of 30 carcasses (10 from each flock) of adult chickens were subjected to necropsy for gross and histopathological examination, virus isolation and molecular methods. Specifically, haemagglutination inhibition (HI) test and reverse transcription-polymerase chain reaction (RT-PCR) assay were used for the virus detection and confirmation, respectively. Lesions were suggestive of viscerotropic velogenic form of ND based on gross and histopathological examinations. Isolation of NDV was present in 4 cases and further confirmed by RT-PCR following the target of the partial fusion protein gene of the viral genome. The sequence of the partial fusion gene was determined and phylogenetic tree was constructed based on the partial length F gene of 4 Omani isolates and 65 previously published NDVs. The findings predicted that the Omani isolates had high homology (99%) with the isolate from Pakistan belonging to genotype VII. Subsequently, the isolated pathotype was identified as the virulent NDV. This study serves as a basic work for further research on the analysis and phenotyping of NDV in the Sultanate of Oman. Improved monitoring and surveillance of the disease is important for proper preventive measures.
  10. Abdullah JM, Ahmad F, Ahmad KA, Ghazali MM, Jaafar H, Ideris A, et al.
    Neurol Res, 2007 Apr;29(3):239-42.
    PMID: 17509221
    Brain tumorigenesis is a complex process involving multiple genetic alterations. Cyclin D1 and BAX genes are two of the most important regulators in controlling the normal proliferation and apoptosis of cells, respectively. In this study, we analysed the possibilities of involvement of cyclin D1 and BAX genes in the gliomagenesis.
  11. Roohani K, Tan SW, Yeap SK, Ideris A, Bejo MH, Omar AR
    J Vet Sci, 2015;16(4):447-57.
    PMID: 25643805 DOI: 10.4142/jvs.2015.16.4.447
    A Newcastle disease virus (NDV) isolate designated IBS002 was isolated from a commercial broiler farm in Malaysia. The virus was characterised as a virulent strain based on the multiple basic amino acid motif of the fusion (F) cleavage site (112)RRRKGF(117) and length of the C-terminus extension of the hemagglutinin-neuraminidase (HN) gene. Furthermore, IBS002 was classified as a velogenic NDV with mean death time (MDT) of 51.2 h and intracerebral pathogenicity index (ICPI) of 1.76. A genetic distance analysis based on the full-length F and HN genes showed that both velogenic viruses used in this study, genotype VII NDV isolate IBS002 and genotype VIII NDV isolate AF2240-I, had high genetic variations with genotype II LaSota vaccine. In this study, the protection efficacy of the recombinant genotype VII NDV inactivated vaccine was also evaluated when added to an existing commercial vaccination program against challenge with velogenic NDV IBS002 and NDV AF2240-I in commercial broilers. The results indicated that both LaSota and recombinant genotype VII vaccines offered full protection against challenge with AF2240-I. However, the LaSota vaccine only conferred partial protection against IBS002. In addition, significantly reduced viral shedding was observed in the recombinant genotype VII-vaccinated chickens compared to LaSota-vaccinated chickens.
  12. Lim KL, Jazayeri SD, Yeap SK, Alitheen NB, Bejo MH, Ideris A, et al.
    BMC Vet Res, 2012;8:132.
    PMID: 22866758 DOI: 10.1186/1746-6148-8-132
    DNA vaccines offer several advantages over conventional vaccines in the development of effective vaccines against avian influenza virus (AIV). However, one of the limitations of the DNA vaccine in poultry is that it induces poor immune responses. In this study, chicken interleukin (IL) -15 and IL-18 were used as genetic adjuvants to improve the immune responses induced from the H5 DNA vaccination in chickens. The immunogenicity of the recombinant plasmid DNA was analyzed based on the antibody production, T cell responses and cytokine production, following inoculation in 1-day-old (Trial 1) and 14-day-old (Trial 2) specific-pathogen-free chickens. Hence, the purpose of the present study was to explore the role of chicken IL-15 and IL-18 as adjuvants following the vaccination of chickens with the H5 DNA vaccine.
  13. Jazayeri SD, Ideris A, Zakaria Z, Shameli K, Moeini H, Omar AR
    J Control Release, 2012 Jul 10;161(1):116-23.
    PMID: 22549012 DOI: 10.1016/j.jconrel.2012.04.015
    DNA formulations provide the basis for safe and cost effective vaccine. Low efficiency is often observed in the delivery of DNA vaccines. In order to assess a new strategy for oral DNA vaccine formulation and delivery, plasmid encoding hemagglutinin (HA) gene of avian influenza virus, A/Ck/Malaysia/5858/04 (H5N1) (pcDNA3.1/H5) was formulated using green synthesis of sliver nanoparticles (AgNP) with polyethylene glycol (PEG). AgNP were successfully synthesized uniformly dispersed with size in the range of 4 to 18 nm with an average size of 11 nm. Cytotoxicity of the prepared AgNP was investigated in vitro and in vivo using MCF-7 cells and cytokine expression, respectively. At the concentration of -5 log₁₀AgNP, no cytotoxic effects were detected in MCF-7 cells with 9.5% cell death compared to the control. One-day-old specific pathogen-free (SPF) chicks immunized once by oral gavage with 10 μl of pcDNA3.1/H5 (200 ng/ml) nanoencapsulated with 40 μl AgNP (3.7×10⁻² μg of Ag) showed no clinical manifestations. PCR successfully detect the AgNP/H5 plasmid from the duodenum of the inoculated chicken as early as 1h post-immunization. Immunization of chickens with AgNP/H5 enhanced both pro inflammatory and Th1-like expressions, although no significant differences were recorded in the chickens inoculated with AgNP, AgNP/pcDNA3.1 and the control. In addition, serum samples collected from immunized chickens with AgNP/H5 showed rapidly increasing antibody against H5 on day 14 after immunization. The highest average antibody titres were detected on day 35 post-immunization at 51.2±7.5. AgNP/H5 also elicited both CD4+ and CD8+ T cells in the immunized chickens as early as day 14 after immunization, at 7.5±2.0 and 20±1.9 percentage, respectively. Hence, single oral administrations of AgNP/H5 led to induce both the antibody and cell-mediated immune responses as well as enhanced cytokine production.
  14. Jazayeri SD, Ideris A, Zakaria Z, Yeap SK, Omar AR
    Comp Immunol Microbiol Infect Dis, 2012 Sep;35(5):417-27.
    PMID: 22512819 DOI: 10.1016/j.cimid.2012.03.007
    This study evaluates the immune responses of single avian influenza virus (AIV) HA DNA vaccine immunization using attenuated Salmonella enterica sv. Typhimurium as an oral vaccine carrier and intramuscular (IM) DNA injection. One-day-old specific-pathogen-free (SPF) chicks immunized once by oral gavage with 10(9) Salmonella colony-forming units containing plasmid expression vector encoding the HA gene of A/Ck/Malaysia/5858/04 (H5N1) (pcDNA3.1.H5) did not show any clinical manifestations. Serum hemagglutination inhibition (HI) titer samples collected from the IM immunized chickens were low compared to those immunized with S. typhimurium.pcDNA3.1.H5. The highest average antibody titers were detected on day 35 post immunization for both IM and S. typhimurium.pcDNA3.1.H5 immunized groups, at 4.0±2.8 and 51.2±7.5, respectively. S. typhimurium.pcDNA3.1.H5 also elicited both CD4(+) and CD8(+) T cells from peripheral blood mononuclear cells (PBMCs) of immunized chickens as early as day 14 after immunization, at 20.5±2.0 and 22.9±1.9%, respectively. Meanwhile, the CD4(+) and CD8(+) T cells in chickens vaccinated intramuscularly were low at 5.9±0.9 and 8.5±1.3%, respectively. Immunization of chickens with S. typhimurium.pcDNA3.1.H5 enhanced IL-1β, IL-12β, IL-15 and IL-18 expressions in spleen although no significant differences were recorded in chickens vaccinated via IM and orally with S. typhimurium and S. typhimurium.pcDNA3.1. Hence, single oral administrations of the attenuated S. typhimurium containing pcDNA3.1.H5 showed antibody, T cell and Th1-like cytokine responses against AIV in chickens. Whether the T cell response induced by vaccination is virus-specific and whether vaccination protects against AIV infection requires further study.
  15. Jazayeri SD, Ideris A, Shameli K, Moeini H, Omar AR
    Int J Nanomedicine, 2013;8:781-90.
    PMID: 23459681 DOI: 10.2147/IJN.S39074
    In order to develop a systemically administered safe and effective nonviral gene delivery system against avian influenza virus (AIV) that induced cytokine expression, the hemagglutinin (H5) gene of AIV, A/Ck/Malaysia/5858/04 (H5N1) and green fluorescent protein were cloned into a coexpression vector pIRES (pIREGFP-H5) and formulated using green synthesis of silver nanoparticles (AgNPs) with poly(ethylene glycol) and transfected into primary duodenal cells taken from 18-day-old specific-pathogen-free chick embryos. The AgNPs were prepared using moderated temperature and characterized for particle size, surface charge, ultraviolet-visible spectra, DNA loading, and stability. AgNPs and AgNP-pIREGFP-H5 were prepared in the size range of 13.9 nm and 25 nm with a positive charge of +78 ± 0.6 mV and +40 ± 6.2 mV, respectively. AgNPs with a positive surface charge could encapsulate pIREGFP-H5 efficiently. The ultraviolet-visible spectra for AgNP-pIREGFP-H5 treated with DNase I showed that the AgNPs were able to encapsulate pIREGFP-H5 efficiently. Polymerase chain reaction showed that AgNP-pIREGFP-H5 entered into primary duodenal cells rapidly, as early as one hour after transfection. Green fluorescent protein expression was observed after 36 hours, peaked at 48 hours, and remained stable for up to 60 hours. In addition, green fluorescent protein expression generally increased with increasing DNA concentration and time. Cells were transfected using Lipocurax in vitro transfection reagent as a positive control. A multiplex quantitative mRNA gene expression assay in the transfected primary duodenal cells via the transfection reagent and AgNPs with pIREGFP-H5 revealed expression of interleukin (IL)-18, IL-15, and IL-12β.
  16. Bello MB, Yusoff KM, Ideris A, Hair-Bejo M, Peeters BPH, Jibril AH, et al.
    Adv Virol, 2018;2018:6097291.
    PMID: 30631359 DOI: 10.1155/2018/6097291
    Newcastle disease (ND) is one of the most important avian diseases with considerable threat to the productivity of poultry all over the world. The disease is associated with severe respiratory, gastrointestinal, and neurological lesions in chicken leading to high mortality and several other production related losses. The aetiology of the disease is an avian paramyxovirus type-1 or Newcastle disease virus (NDV), whose isolates are serologically grouped into a single serotype but genetically classified into a total of 19 genotypes, owing to the continuous emergence and evolution of the virus. In Nigeria, molecular characterization of NDV is generally very scanty and majorly focuses on the amplification of the partial F gene for genotype assignment. However, with the introduction of the most objective NDV genotyping criteria which utilize complete fusion protein coding sequences in phylogenetic taxonomy, the enormous genetic diversity of the virus in Nigeria became very conspicuous. In this review, we examine the current ecological distribution of various NDV genotypes in Nigeria based on the available complete fusion protein nucleotide sequences (1662 bp) in the NCBI database. We then discuss the challenges of ND control as a result of the wide genetic distance between the currently circulating NDV isolates and the commonest vaccines used to combat the disease in the country. Finally, we suggest future directions in the war against the economically devastating ND in Nigeria.
  17. Rasoli M, Yeap SK, Tan SW, Moeini H, Ideris A, Bejo MH, et al.
    Comp Immunol Microbiol Infect Dis, 2014 Jan;37(1):11-21.
    PMID: 24225159 DOI: 10.1016/j.cimid.2013.10.003
    Newcastle disease (ND) is a highly contagious avian disease and one of the major causes of economic losses in the poultry industry. The emergence of virulent NDV genotypes and repeated outbreaks of NDV in vaccinated chickens have raised the need for fundamental studies on the virus-host interactions. In this study, the profiles of B and T lymphocytes and macrophages and differential expression of 26 immune-related genes in the spleen of specific-pathogen-free (SPF) chickens, infected with either the velogenic genotype VII NDV strain IBS002 or the genotype VIII NDV strain AF2240, were evaluated. A significant reduction in T lymphocyte population and an increase in the infiltration of IgM+ B cells and KUL01+ macrophages were detected in the infected spleens at 1, 3 and 4 days post-infection (dpi) (P<0.05). The gene expression profiles showed an up-regulation of CCLi3, CXCLi1, CXCLi2 (IL-8), IFN-γ, IL-12α, IL-18, IL-1β, IL-6, iNOS, TLR7, MHCI, IL-17F and TNFSF13B (P<0.05). However, these two genotypes showed different cytokine expression patterns and viral load. IBS002 showed higher viral load than AF2240 in spleen at 3 and 4dpi and caused a more rapid up-regulation of CXCLi2, IFN-γ, IL-12α, IL-18, IL-1β, iNOS and IL-10 at 3dpi. Meanwhile, the expression levels of CCLI3, CXCLi1, IFN-γ, IL-12α, IL-1β and iNOS genes were significantly higher in AF2240 at 4dpi. In addition, the expression levels of IL-10 were significantly higher in the IBS002-infected chickens at 3 and 4dpi. Hence, infection with velogenic genotype VII and VIII NDV induced different viral load and production of cytokines and chemokines associated with inflammatory reactions.
  18. Bello MB, Yusoff K, Ideris A, Hair-Bejo M, Peeters BPH, Omar AR
    Biomed Res Int, 2018;2018:7278459.
    PMID: 30175140 DOI: 10.1155/2018/7278459
    Newcastle disease (ND) is one of the most devastating diseases that considerably cripple the global poultry industry. Because of its enormous socioeconomic importance and potential to rapidly spread to naïve birds in the vicinity, ND is included among the list of avian diseases that must be notified to the OIE immediately upon recognition. Currently, virus isolation followed by its serological or molecular identification is regarded as the gold standard method of ND diagnosis. However, this method is generally slow and requires specialised laboratory with biosafety containment facilities, making it of little relevance under epidemic situations where rapid diagnosis is seriously needed. Thus, molecular based diagnostics have evolved to overcome some of these difficulties, but the extensive genetic diversity of the virus ensures that isolates with mutations at the primer/probe binding sites escape detection using these assays. This diagnostic dilemma leads to the emergence of cutting-edge technologies such as next-generation sequencing (NGS) which have so far proven to be promising in terms of rapid, sensitive, and accurate recognition of virulent Newcastle disease virus (NDV) isolates even in mixed infections. As regards disease control strategies, conventional ND vaccines have stood the test of time by demonstrating track record of protective efficacy in the last 60 years. However, these vaccines are unable to block the replication and shedding of most of the currently circulating phylogenetically divergent virulent NDV isolates. Hence, rationally designed vaccines targeting the prevailing genotypes, the so-called genotype-matched vaccines, are highly needed to overcome these vaccination related challenges. Among the recently evolving technologies for the development of genotype-matched vaccines, reverse genetics-based live attenuated vaccines obviously appeared to be the most promising candidates. In this review, a comprehensive description of the current and emerging trends in the detection, identification, and control of ND in poultry are provided. The strengths and weaknesses of each of those techniques are also emphasised.
  19. Raji AA, Ideris A, Bejo MH, Omar AR
    Avian Pathol, 2022 Feb;51(1):51-65.
    PMID: 34726999 DOI: 10.1080/03079457.2021.2000939
    ABSTRACTChicken astrovirus (CAstV) has for over a decade been associated with runting stunting syndrome, severe kidney disease and visceral gout, and white chick syndrome. However, knowledge of the molecular characteristics and pathogenicity of the virus in day-old specific pathogen-free (SPF) chicks is scarce. This study focused on the characterization of near-complete genome of three Malaysian CAstV isolates following virus propagation in SPF embryonated chicken eggs and pathogenicity in day-old SPF chicks. The three isolates demonstrated unique features including a point mutation in their intergenic regions and an additional stem-loop II-like motif (s2m) in ORF-2. Pairwise sequence comparison and phylogenetic analysis of the ORF-2 amino acid sequence of the three isolates revealed an identity share of 86-91% with group B CAstVs while forming a new subgroup in addition to the known four subgroups (Bi, Bii, Biii and Biv) that exhibit high identity of between 95% and 100% within the subgroups. In the pathogenicity study, birds in the infected and exposed sentinel groups exhibited lethargy and diarrhoea 3 days post-inoculation (dpi) that declined by 6 dpi, and 20% growth retardation by 9 dpi. Mild lymphocytic aggregates in the duodenum, tubular degeneration and interstitial nephritis were observed in the intestines and kidneys, respectively, in both groups. In addition, the mean virus copy numbers of the cloacal swabs were log10 13.23 at 3 dpi and log10 9.04 at 6 dpi for the infected and exposed sentinels, respectively. The study suggests that the Malaysian isolates should be assigned to a new subgroup, Bv within group B CAstV. RESEARCH HIGHLIGHTSA single run of NGS protocol is capable of generating a near-complete genome sequence of CAstV.The Malaysian CAstV isolates cluster together and exhibit 86-91% identity with published group B CAstVs.The Malaysian CAstVs encode an additional stem-loop II-like motif (s2m) in ORF-2.The isolates are pathogenic to day-old SPF chicks with lesions mainly in the intestine and kidneys.
  20. Lim KL, Jazayeri SD, Yeap SK, Mohamed Alitheen NB, Bejo MH, Ideris A, et al.
    Res Vet Sci, 2013 Dec;95(3):1224-34.
    PMID: 23948357 DOI: 10.1016/j.rvsc.2013.07.013
    We had examined the immunogenicity of a series of plasmid DNAs which include neuraminidase (NA) and nucleoprotein (NP) genes from avian influenza virus (AIV). The interleukin-15 (IL-15) and interleukin-18 (IL-18) as genetic adjuvants were used for immunization in combination with the N1 and NP AIV genes. In the first trial, 8 groups of chickens were established with 10 specific-pathogen-free (SPF) chickens per group while, in the second trial 7 SPF chickens per group were used. The overall N1 enzyme-linked immunosorbent assay (ELISA) titer in chickens immunized with the pDis/N1+pDis/IL-15 was higher compared to the chickens immunized with the pDis/N1 and this suggesting that chicken IL-15 could play a role in enhancing the humoral immune response. Besides that, the chickens that were immunized at 14-day-old (Trial 2) showed a higher N1 antibody titer compared to the chickens that were immunized at 1-day-old (Trial 1). Despite the delayed in NP antibody responses, the chickens co-administrated with IL-15 were able to induce earlier and higher antibody response compared to the pDis/NP and pDis/NP+pDis/IL-18 inoculated groups. The pDis/N1+pDis/IL-15 inoculated chickens also induced higher CD8+ T cells increase than the pDis/N1 group in both trials (P<0.05). The flow cytometry results from both trials demonstrated that the pDis/N1+pDis/IL-18 groups were able to induce CD4+ T cells higher than the pDis/N1 group (P<0.05). Meanwhile, pDis/N1+pDis/IL-18 group was able to induce CD8+ T cells higher than the pDis/N1 group (P<0.05) in Trial 2 only. In the present study, pDis/NP was not significant (P>0.05) in inducing CD4+ and CD8+ T cells when co-administered with the pDis/IL-18 in both trials in comparison to the pDis/NP. Our data suggest that the pDis/N1+pDis/IL-15 combination has the potential to be used as a DNA vaccine against AIV in chickens.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links