Displaying publications 1 - 20 of 57 in total

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  1. Tan DY, Hair Bejo M, Aini I, Omar AR, Goh YM
    Virus Genes, 2004 Jan;28(1):41-53.
    PMID: 14739650
    Base usage and dinucleotide frequency have been extensively studied in many eukaryotic organisms and bacteria, but not for viruses. In this paper, a comprehensive analysis of these aspects for infectious bursal disease virus (IBDV) was presented. The analysis of base usage indicated that all of the IBDV genes possess equivalent overall nucleotide distributions. However when the base usage at each codon positions was analysed by using cluster analysis, the VP5 open reading frame (ORF) formed a different cluster isolated from the other genes. The unusual base usage of VP5 ORF may indicate that the gene was originated by the virus "overprinting strategy", a strategy in which virus may create novel gene by utilizing the unused reading frames of its existing genes. Meanwhile, the GC content of the IBDV genes and the chicken's coding sequences was comparable; suggesting the virus imitation of the host to increase its translational efficiency. The analysis of dinucleotide frequency indicated that IBDV genome had dinucleotide bias: the frequencies of CpG and TpA were lower and the TpG was higher than the expected. Classical methylation pathway, a process where CpG converted to TpG, may explain the significant correlation between the CpG deficiency and TpG abundance. "Principal component analysis of the dinucleotide frequencies" (DF-PCA) was used to analyse the overall dinucleotide frequencies of IBDV genome. DF-PCA on the hypervariable region and polyprotein (VPX-VP4-VP3) gene showed that the very virulent IBDV (vvIBDV) was segregated from other strains; which meant vvIBDV had a unique dinucleotide pattern. In summary, the study of base usage and dinucleotide frequency had unravelled many overlooked genomic properties of the virus.
    Matched MeSH terms: Poultry Diseases/virology
  2. Bande F, Arshad SS, Omar AR, Hair-Bejo M, Mahmuda A, Nair V
    Anim Health Res Rev, 2017 Jun;18(1):70-83.
    PMID: 28776490 DOI: 10.1017/S1466252317000044
    The poultry industry faces challenge amidst global food security crisis. Infectious bronchitis is one of the most important viral infections that cause huge economic loss to the poultry industry worldwide. The causative agent, infectious bronchitis virus (IBV) is an RNA virus with great ability for mutation and recombination; thus, capable of generating new virus strains that are difficult to control. There are many IBV strains found worldwide, including the Massachusetts, 4/91, D274, and QX-like strains that can be grouped under the classic or variant serotypes. Currently, information on the epidemiology, strain diversity, and global distribution of IBV has not been comprehensively reported. This review is an update of current knowledge on the distribution, genetic relationship, and diversity of the IBV strains found worldwide.
    Matched MeSH terms: Poultry Diseases/virology*
  3. Li S, Zhang L, Wang Y, Wang S, Sun H, Su W, et al.
    Virus Res, 2013 Jan;171(1):238-41.
    PMID: 23116594 DOI: 10.1016/j.virusres.2012.10.019
    Duck Tembusu virus (TMUV) is a recently identified pathogenic flavivirus that causes severe egg drop and encephalitis in Chinese ducks and geese. It has been found to be most closely related to the mosquito-origin Tembusu virus and chicken Sitiawan virus reported in Malaysia. However, the ecological characteristics and the pathogenesis of duck TMUV are largely unknown. We report the construction of full-length cDNA clone of duck TMUV strain JXSP. The virus genome was reverse transcribed, amplified as seven overlapping fragments and successively ligated into the low copy number vector pWSK29 under the control of a T7 promoter. Transfection of BHK-21 cells with the transcribed RNA from the full-length cDNA clone resulted in production of highly infectious progeny virus. In vitro growth characteristics in BHK-21 cells and virulence in ducklings and BALB/c mice were similar for the rescued and parental viruses. This stable infectious cDNA clone will be a valuable tool for studying the genetic determinants of duck TMUV.
    Matched MeSH terms: Poultry Diseases/virology*
  4. Khanh NP, Tan SW, Yeap SK, Lee HJ, Choi KS, Hair-Bejo M, et al.
    J Comp Pathol, 2018 May;161:43-54.
    PMID: 30173857 DOI: 10.1016/j.jcpa.2018.04.006
    Infectious bronchitis viruses (IBVs) circulating in Malaysia are classified into two groups as Malaysian QX-like and variant strains. In this study, the pathogenicity of IBS130/2015 (QX-like) and IBS037A/2014 (variant) IBVs in 1-day-old and 30-day-old specific pathogen free (SPF) chickens was characterized. Both strains caused respiratory and kidney infections based on immunohistochemistry (IHC), real-time quantitative polymerase chain reaction (qPCR) and a ciliostasis study; however, the results showed that the QX-like strain was more pathogenic, caused higher mortality and showed higher tissue tropism for the kidney than the variant strain. In contrast, despite causing low or no mortality depending on the age of the infected chickens, the Malaysian variant strain showed high tissue tropism for the respiratory tract compared with the QX-like strain. IHC and qPCR indicated the presence of both IBV strains in the epithelial lining of villi in the jejunum and the caecal tonsil; however, no pathological changes were detected in these organs. Both the Malaysian QX-like and variant IBV strains are able to infect the respiratory tract and kidney of chickens irrespective of age.
    Matched MeSH terms: Poultry Diseases/virology*
  5. Aljumaili OA, Bello MB, Yeap SK, Omar AR, Ideris A
    Onderstepoort J Vet Res, 2020 Sep 28;87(1):e1-e7.
    PMID: 33054260 DOI: 10.4102/ojvr.v87i1.1865
    Despite the availability of Newcastle disease (ND) vaccines for more than six decades, disease outbreaks continue to occur with huge economic consequences to the global poultry industry. The aim of this study is to develop a safe and effective inactivated vaccine based on a recently isolated Newcastle disease virus (NDV) strain IBS025/13 and evaluate its protective efficacy in chicken following challenge with a highly virulent genotype VII isolate. Firstly, high titre of IBS025/13 was exposed to various concentrations of binary ethylenimine (BEI) to determine the optimal conditions for complete inactivation of the virus. The inactivated virus was then prepared in form of a stable water-in-oil emulsion of black seed oil (BSO) or Freund's incomplete adjuvant (FIA) and used as vaccines in specific pathogen-free chicken. Efficacy of various vaccine preparations was also evaluated based on the ability of the vaccine to protect against clinical disease, mortality and virus shedding following challenge with highly virulent genotype\VII NDV isolate. The results indicate that exposure of NDV IBS025/13 to 10 mM of BEI for 21 h at 37 °C could completely inactivate the virus without tempering with the structural integrity of the viral hemagglutin-neuraminidase protein. More so, the inactivated vaccines adjuvanted with either BSO- or FIA-induced high hemagglutination inhibition antibody titre that protected the vaccinated birds against clinical disease and in some cases virus shedding, especially when used together with live attenuated vaccines. Thus, genotype VII-based NDV-inactivated vaccines formulated in BSO could substantially improve poultry disease control particularly when combined with live attenuated vaccines.
    Matched MeSH terms: Poultry Diseases/virology
  6. Palya V, Kovács EW, Marton S, Tatár-Kis T, Felföldi B, Forró B, et al.
    Emerg Infect Dis, 2019 06;25(6):1110-1117.
    PMID: 31107212 DOI: 10.3201/eid2506.181661
    During 2014-2017, we isolated a novel orthobunyavirus from broiler chickens with severe kidney lesions in the state of Kedah, Malaysia; we named the virus Kedah fatal kidney syndrome virus (KFKSV). Affected chickens became listless and diarrheic before dying suddenly. Necropsies detected pale and swollen kidneys with signs of gout, enlarged and fragile livers, and pale hearts. Experimental infection of broiler chickens with KFKSV reproduced the disease and pathologic conditions observed in the field, fulfilling the Koch's postulates. Gene sequencing indicated high nucleotide identities between KFKSV isolates (99%) and moderate nucleotide identities with the orthobunyavirus Umbre virus in the large (78%), medium (77%), and small (86%) genomic segments. KFKSV may be pathogenic for other host species, including humans.
    Matched MeSH terms: Poultry Diseases/virology*
  7. Choi KS, Kye SJ, Kim JY, To TL, Nguyen DT, Lee YJ, et al.
    Trop Anim Health Prod, 2014 Jan;46(1):271-7.
    PMID: 24061688 DOI: 10.1007/s11250-013-0475-3
    Newcastle disease virus (NDV) causes significant economic losses to the poultry industry in Southeast Asia. In the present study, 12 field isolates of NDV were recovered from dead village chickens in Vietnam between 2007 and 2012, and were characterized. All the field isolates were classified as velogenic. Based on the sequence analysis of the F variable region, two distinct genetic groups (Vietnam genetic groups G1 and G2) were recognized. Phylogenetic analysis revealed that all the 12 field isolates fell into the class II genotype VII cluster. Ten of the field isolates, classified as Vietnam genetic group G1, were closely related to VIIh viruses that had been isolated from Indonesia, Malaysia, and Cambodia since the mid-2000s, while the other two field isolates, of Vietnam genetic group G2, clustered with VIId viruses, which were predominantly circulating in China and Far East Asia. Our results indicate that genotype VII viruses, especially VIIh viruses, are predominantly responsible for the recent epizootic of the disease in Vietnam.
    Matched MeSH terms: Poultry Diseases/virology
  8. Tan SW, Ideris A, Omar AR, Yusoff K, Hair-Bejo M
    Arch Virol, 2010;155(1):63-70.
    PMID: 19898736 DOI: 10.1007/s00705-009-0540-4
    Sequence analysis of the fusion (F) gene of eight Malaysian NDV isolates showed that all the isolates were categorized as velogenic viruses, with the F cleavage site motif (112)R-R-Q-K-R(116) or (112)R-R-R-K-R(116) at the C-terminus of the F(2) protein and phenylalanine (F) at residue 117 at the N-terminus of the F(1) protein. Phylogenetic analysis revealed that all of the isolates were grouped in two distinct clusters under sub-genotype VIId. The isolates were about 4.8-11.7% genetically distant from sub-genotypes VIIa, VIIb, VIIc and VIIe. When the nucleotide sequences of the eight Malaysian isolates were compared phylogenetically to those of the old published local isolates, it was found that genotype VIII, VII, II and I viruses exist in Malaysia and caused sporadic infections. It is suggested that genotype VII viruses were responsible for most of the outbreaks in recent years.
    Matched MeSH terms: Poultry Diseases/virology*
  9. Hairul Aini H, Omar AR, Hair-Bejo M, Aini I
    Microbiol Res, 2008;163(5):556-63.
    PMID: 16971101
    The current available molecular method to detect infectious bursal disease virus (IBDV) is by reverse transcriptase-polymerase chain reaction (RT-PCR). However, the conventional PCR is time consuming, prone to error and less sensitive. In this study, the performances of Sybr Green I real-time PCR, enzyme-linked immunosorbent assay (ELISA) and conventional agarose detection methods in detecting specific IBDV PCR products were compared. We found the real-time PCR was at least 10 times more sensitive than ELISA detection method with a detection limit of 0.25pg. The latter was also at least 10 times more sensitive than agarose gel electrophoresis detection method. The developed assay detects both very virulent and vaccine strains of IBDV but not other RNA viruses such as Newcastle disease virus and infectious bronchitis virus. Hence, Sybr Green I-based real-time PCR is a highly sensitive assay for the detection of IBDV.
    Matched MeSH terms: Poultry Diseases/virology*
  10. Jaganathan S, Ooi PT, Phang LY, Allaudin ZN, Yip LS, Choo PY, et al.
    BMC Vet Res, 2015;11:219.
    PMID: 26293577 DOI: 10.1186/s12917-015-0537-z
    Newcastle disease virus remains a constant threat in commercial poultry farms despite intensive vaccination programs. Outbreaks attributed to ND can escalate and spread across farms and states contributing to major economic loss in poultry farms.
    Matched MeSH terms: Poultry Diseases/virology*
  11. He C, Ding N, Li J, Li Y
    Wei Sheng Wu Xue Bao, 2002 Aug;42(4):436-41.
    PMID: 12557549
    A Chicken anemia virus has been isolated from a chicken flock in Harbin of China. The genome of the ivrus was cloned through polymerase chain reaction(PCR) and sequence of the genome was analyzed. The cycle genome is made of 2298 base pairs including three overlapping open reading frames(vp1, vp2, vp3) and a regulative region. Comparing sequence of the genome through BLAST in GenBank, this sequence exhibits 96.9% identity with other genome of CA Vs and least. Multiple alignment of this genome of this virus, 26p4, strain isolated in Germany, strain isolated in Malaysia and Cux-1 found that this sequence exhibits 98.2% (42/2298), 98.2% (42/2298), 96.9% (72/2298) and 97.5% (60/2319) identify with them, respectively. A new CAV strain was isolated and it has better identify with CAV isolated in Europe countries than is Asia country Malaysia. Multiple alignment of VP1, VP2, VP3 of 26p4, strain isolated in Germany, strain isolated in Malaysia, Cux-1 and strain isolated in Harbin of China found the VP2 the most conservative.
    Matched MeSH terms: Poultry Diseases/virology*
  12. Ismail MI, Wei TS, Hair-Bejo M, Omar AR
    Arch Virol, 2020 Dec;165(12):2777-2788.
    PMID: 32964293 DOI: 10.1007/s00705-020-04812-2
    Besides the vaccine strains, the Malaysian variant (MV) and QX-like are the predominant IBVs detected on commercial poultry farms. These two virus strains are distinct based on genomic and pathogenicity studies. In this study, we determined the sequence of the S1 gene and compared the pathogenicity of serial passage 70 (P70) of Malaysian QX-like (QX/P70) and MV (MV/P70) strains with that of their respective wild-type viruses. The nucleotide and amino acid sequences of the complete S1 genes of QX/P70 and MV/P70 showed 1.4 to 1.6% and 3.0 to 3.3% variation, respectively, when compared to the wild-type virus. Most of the mutations were insertions and substitutions in the hypervariable regions (HVRs), primarily in HVR 3. Furthermore, selection pressure analysis showed that both viruses are under purifying selection. A pathogenicity study in specific-pathogen-free (SPF) chickens showed a reduction in respiratory and kidney lesions in chickens inoculated with MV/P70, but not with QX/P70, when compared to the respective wild-type viruses. However, MV/P70 is still pathogenic and can cause ciliary damage. In conclusion, the MV IBV strain is more responsive than the QX-like IBV strain following the attenuation process used for the development of a live attenuated IBV vaccine.
    Matched MeSH terms: Poultry Diseases/virology*
  13. Molouki A, Mehrabadi MHF, Bashashati M, Akhijahani MM, Lim SHE, Hajloo SA
    Trop Anim Health Prod, 2019 Jun;51(5):1247-1252.
    PMID: 30689157 DOI: 10.1007/s11250-019-01817-1
    BACKGROUND: Based on our previous work, it was discovered that some Newcastle disease virus (NDV) isolates from backyard poultry between 2011 and 2013 in Iran formed a new separate cluster when phylogenetic analysis based on the complete F gene sequence was carried out. The novel cluster was designated subgenotype VII(L) and published.

    AIM: In the current study, for further validation, we initiated a comprehensive epidemiological study to identify the dominant NDV genotype(s) circulating within the country. Collection of samples was executed between October 2017 and February 2018 from 108 commercial broiler farms which reported clinical signs of respiratory disease in their broilers.

    RESULT: We report that 38 of the farms (> 35%) tested positive for NDV. The complete F gene sequences of seven of the isolates are shown as representative sequences in this study. According to the phylogenetic tree constructed, the recent broiler farm isolates clustered into the newly designated cluster VII(L) together with the older Iranian backyard poultry isolates in our previous work. All the sequences shared the same virulence-associated F cleavage site of 112RRQKR↓F117.

    CONCLUSION: Our phylogenetic analysis suggested that the NDV subgenotype VII(L) may have been derived from subgenotype VIId, and contrary to popular belief, subgenotype VIId may not be the dominant subgenotype in Iran. Tracking of the subgenotype on BLAST suggested that the NDV subgenotype VII(L), although previously unidentified, may have been circulating in this region as an endemic virus for at least a decade. Other NDV genotypes, however, have also been reported in Iran in recent years. Hence, ongoing study is aimed at determining the exact dominant NDV genotypes and subgenotypes in the country. This will be crucial in effective mitigation of outbreaks in Iranian broiler farms.

    Matched MeSH terms: Poultry Diseases/virology*
  14. Fadhilah AS, Kai TH, Lokman HI, Yasmin NAR, Hafandi A, Hasliza AH, et al.
    Poult Sci, 2020 Jun;99(6):2937-2943.
    PMID: 32475428 DOI: 10.1016/j.psj.2020.01.026
    Infectious bronchitis virus (IBV) infection is highly infectious respiratory disease in poultry industry with significant economic importance. The prevalence of IBV in quail industry in Malaysia was not well documented; therefore, its actual role in the epidemiology of the disease is relatively unknown. This study was to determine the susceptibility of Japanese quail, as one of the species in commercial poultry industry, toward IBV. In addition, it will also give a potential impact on the overall health management in the quail industry even though it had been established that quail are resistant to diseases affecting poultry. Moreover, to the best of our knowledge, it is the first experimental study on IBV inoculation in quail. In this experimental study, 20 quails were divided into 4 groups (n = 5 for group A, B, and C, n = 5 for control group). The quails in group A, B, and C were infected via intraocular and intranasal routes with 0.2 mL of 10 × 5 EID50 of the virus. Clinical signs, gross lesions, positive detection of virus, and trachea histopathological scoring were used to assess the susceptibility of these Japanese quails. The results have indicated mild ruffled feathers and watery feces in these inoculated birds. Trachea, lung, and kidney were subjected to one-step reverse transcription polymerase chain reaction for virus detection. The virus was found from trachea and lung samples, whereas it was absent from all kidney samples. Only 3 quails were found with gross lesions. There was a significant difference of tracheal lesion by 0.009 ± 0.845 (P < 0.05) within the treatment groups. In summary, Japanese quails might be susceptible to IBV.
    Matched MeSH terms: Poultry Diseases/virology
  15. Hussein EA, Hair-Bejo M, Liew PS, Adamu L, Omar AR, Arshad SS, et al.
    Microb Pathog, 2019 Apr;129:195-205.
    PMID: 30738178 DOI: 10.1016/j.micpath.2019.01.049
    Infectious bursal disease is one of an OIE list of notifiable diseases. Chicken is the only host that manifests clinical signs and its pathogenicity is correlated with the distribution of antigens in organs. This study was conducted to determine disease pathogenesis and virus tissue tropism by in situ PCR, immunoperoxidase staining (IPS), and HE staining. Twenty four chickens were infected with very virulent Infectious Bursal Disease Virus (vvIBDV). Fifteen chickens were kept as a control group. Infected chickens were sacrificed at hrs 2, 4, 6, 12, days 1, 2, 4, and 6 post-inoculation (pi). While, control chickens were euthanized on days 0, 1, 2, 4, and 6 pi. Different tissues were collected, fixed in 10% buffered formalin, and processed. At hr 2 pi, virus was detected in intestinal, junction of the proventriculus and gizzard, cecal tonsil, liver, kidney, and bursa of Fabricius. At hr 4 pi, virus reached spleen, and at hr 6 pi, it entered thymus. At hr 12 pi, virus concentration increased in positive tissues. The latest invaded tissue was muscle on day 1 pi. Secondary viraemia occurred during 12-24 h pi. In situ PCR was the most sensitive technique to highlight obscure points of infection in this study.
    Matched MeSH terms: Poultry Diseases/virology*
  16. Craig MI, Rimondi A, Delamer M, Sansalone P, König G, Vagnozzi A, et al.
    Avian Dis, 2009 Sep;53(3):331-5.
    PMID: 19848068
    Chicken infectious anemia virus (CAV) is a worldwide-distributed infectious agent that affects commercial poultry. Although this agent was first detected in Argentina in 1994, no further studies on CAV in this country were reported after that. The recent increased occurrence of clinical cases of immunosuppression that could be caused by CAV has prompted this study. Our results confirmed that CAV is still circulating in commercial flocks in Argentina. Phylogenetic analysis focusing on the VP1 nucleotide sequence showed that all Argentinean isolates grouped together in a cluster, sharing a high similarity (> 97%) with genotype B reference strains. However, Argentinean isolates were distantly related to other strains commonly used for vaccination in this country, such as Del-Ros and Cux-1. Sequence analysis of predicted VP1 peptides showed that most of the Argentinean isolates have a glutamine residue at positions 139 and 144, suggesting that these isolates might have a reduced spread in cell culture compared with Cux-1. In addition, a particular amino acid substitution at position 290 is present in all studied Argentinean isolates, as well as in several VP1 sequences from Malaysia, Australia, and Japan isolates. Our results indicate that it is possible to typify CAV strains by comparison of VPI nucleotide sequences alone because the same tree topology was obtained when using the whole genome sequence. The molecular analysis of native strains sheds light into the epidemiology of CAV in Argentinean flocks. In addition, this analysis could be considered in future control strategies focused not only on breeders but on broilers and layer flocks.
    Matched MeSH terms: Poultry Diseases/virology*
  17. Yasmin AR, Omar AR, Farhanah MI, Hiscox AJ, Yeap SK
    Avian Dis, 2019 06 01;63(2):275-288.
    PMID: 31251527 DOI: 10.1637/11936-072418-Reg.1
    Chicken dendritic cells (DCs) have been demonstrated to be susceptible to infectious bursal disease virus (IBDV), a causative agent of acute and immunosuppressed disease in young chicks known as infectious bursal disease. Further functional characterization of IBDV-infected DCs of chickens is required to provide a better understanding on the influence of the virus on chicken bone marrow-derived dendritic cells (BM-DCs) following very virulent (vv) IBDV infection. Membrane proteins of BM-DCs were extracted and the proteins were further denatured and reduced before performing labeling with isobaric tags for relative and absolute quantitation. The differential expression protein profiles were identified and quantified using liquid chromatography coupled with tandem mass spectrometry, and later validated using flow cytometry and real-time reverse transcriptase PCR. The analysis has identified 134 differentially regulated proteins from a total of 283 proteins (cutoff values of ≤0.67, ≥1.5, and ProtScore >1.3 at 95% confidence interval), which produced high-yield membrane fractions. The entry of vvIBDV into the plasma membrane of BM-DCs was observed at 3 hr postinfection by the disruption of several important protein molecule functions, namely apoptosis, RNA/DNA/protein synthesis, and transport and cellular organization, without the activation of proteins associated with signaling. At the later stage of infection, vvIBDV induced expression of several proteins, namely CD200 receptor 1-A, integrin alpha-5, HSP-90, cathepsin, lysosomal-associated membrane protein, and Ras-related proteins, which play crucial roles in signaling, apoptosis, stress response, and antigen processing as well as in secretion of danger-associated proteins. These findings collectively indicated that the chicken DCs are expressing various receptors regarded as potential targets for pathogen interaction during viral infection. Therefore, fundamental study of the interaction of DCs and IBDV will provide valuable information in understanding the role of professional antigen-presenting cells in chickens and their molecular interactions during IBDV infection and vaccination.
    Matched MeSH terms: Poultry Diseases/virology
  18. Nurulfiza I, Hair-Bejo M, Omar AR, Aini I
    J Vet Diagn Invest, 2011 Mar;23(2):320-4.
    PMID: 21398455
    The immunochromatographic assay is an alternative method for simple and rapid detection of Infectious bursal disease virus (IBDV) in chickens using colloidal gold-antibody conjugate. The whole-virus antigen of IBDV (UPM04190 isolate) and the high-affinity polyclonal antibodies directed against IBDV were blotted onto nitrocellulose membranes for test and control lines, respectively. Evaluation of the strip was performed using serum samples from experimentally and naturally infected chickens. The results showed that the test strip was more sensitive than the commercial enzyme-linked immunosorbent assay (ELISA) because it could detect a dilution factor up to 120,000 (250 ELISA units) for positive samples. It was also specific, in that it detected IBDV antibodies and did not cross-react with antibodies to other chicken viruses. The method was rapid (2 min) in both clinical and field environments with samples needing only a minimum amount (50 µl) of blood to produce an acceptable detection signal. The pen-site test strip proved successful in monitoring the immune status of chickens against the IBDV infection.
    Matched MeSH terms: Poultry Diseases/virology*
  19. Sabarudin NS, Tan SW, Phang YF, Omar AR
    J Vet Sci, 2021 Jul;22(4):e42.
    PMID: 34313038 DOI: 10.4142/jvs.2021.22.e42
    BACKGROUND: Inclusion body hepatitis (IBH) is an economically important viral disease primarily affecting broiler and breeder chickens. All 12 serotypes of fowl adenovirus (FAdV) can cause IBH.

    OBJECTIVES: To characterize FAdV isolates based on phylogenetic analysis, and to study the pathogenicity of FAdV-8b in specific-pathogen-free (SPF) chickens following virus inoculation via oral and intramuscular (IM) routes.

    METHODS: Suspected organ samples were subjected to virus isolation and polymerase chain reaction (PCR) for FAdV detection. Hexon gene sequencing and phylogenetic analysis were performed on FAdV-positive samples for serotype identification. One FAdV-8b isolate, UPM/FAdV/420/2017, was selected for fiber gene characterization and pathogenicity study and was inoculated in SPF chickens via oral and IM routes.

    RESULTS: The hexon gene phylogenetic analysis revealed that all isolates belonged to FAdV-8b. The fiber gene-based phylogenetic analysis of isolate UPM/FAdV/420/2017 supported the grouping of that isolate into FAdV species E. Pathogenicity study revealed that, chickens infected with UPM/FAdV/420/2017 via the IM route had higher clinical score values, higher percent mortality, higher degree of the liver lesions, higher antibody response (p < 0.05), and higher virus shedding amounts (p < 0.05) than those infected via the oral route. The highest virus copy numbers were detected in liver and gizzard.

    CONCLUSIONS: FAdV-8b is the dominant FAdV serotype in Malaysia, and pathogenicity study of the FAdV-8b isolate UPM/FAdV/420/2017 indicated its ability to induce IBH in young SPF chickens when infected via oral or IM routes.

    Matched MeSH terms: Poultry Diseases/virology*
  20. Ninvilai P, Nonthabenjawan N, Limcharoen B, Tunterak W, Oraveerakul K, Banlunara W, et al.
    Transbound Emerg Dis, 2018 Oct;65(5):1208-1216.
    PMID: 29520997 DOI: 10.1111/tbed.12859
    Duck Tembusu virus (DTMUV), a newly emerging virus in ducks, was first reported in China in 2010. However, an unknown severe contagious disease associated with severe neurological signs and egg production losses in ducks, resembling to DTMUV infection, was observed in Thailand since 2007. To determine the presence of DTMUV in 2007, the clinical samples from affected ducks collected in 2007 were tested for DTMUV using pathological and virological analyses. Gross and histopathological lesions of affected ducks were mostly restricted to the ovary, brain and spinal cord, and correlated with the presence of flavivirus antigen in the brain and spinal cord samples. Subsequently, DTMUV was identified by RT-PCR and nucleotide sequencing of the polyprotein gene. Phylogenetic analysis of the polyprotein gene sequence revealed that the 2007 Thai DTMUV was a unique virus, belonged within DTMUV cluster 1, but distinctively separated from the Malaysian DTMUV, which was the most closely related DTMUV. It is interesting to note that the 2007 Thai DTMUV was genetically different from the currently circulating Thai and Chinese DTMUVs, which belonged to cluster 2. Our findings indicated that the 2007 Thai DTMUV emerged earlier from a common ancestor with the recently reported DTMUVs; however, it was genetically distinctive to any of the currently circulating DTMUVs. In conclusion, our data demonstrated the presence of DTMUV in the Thai ducks since 2007, prior to the first report of DTMUV in China in 2010. This study indicates that DTMUV may have circulated in the region long before 2010 and highlights high genetic diversity of DTMUVs in Asia.
    Matched MeSH terms: Poultry Diseases/virology
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