Displaying publications 481 - 500 of 1514 in total

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  1. Khan A, Mushtaq MH, Ahmad MUD, Nazir J, Farooqi SH, Khan A
    Virus Res, 2017 08 15;240:56-63.
    PMID: 28757141 DOI: 10.1016/j.virusres.2017.07.022
    BACKGROUND: A widespread epidemic of equine influenza (EI) occurred in nonvaccinated equine population across multiple districts in Khyber Pakhtunkhwa Province of Pakistan during 2015-2016.

    OBJECTIVES AND METHODS: An epidemiological surveillance study was conducted from Oct 2015 to April 2016 to investigate the outbreak. EI virus strains were isolated in embryonated eggs from suspected equines swab samples and were subjected to genome sequencing using M13 tagged segment specific primers. Phylogenetic analyses of the nucleotide sequences were concluded using Geneious. Haemagglutinin (HA), Neuraminidase (NA), Matrix (M) and nucleoprotein (NP) genes nucleotide and amino acid sequences of the isolated viruses were aligned with those of OIE recommended, FC-1, FC-2, and contemporary isolates of influenza A viruses from other species.

    RESULTS: HA and NA genes amino acid sequences were very similar to Tennessee/14 and Malaysia/15 of FC-1 and clustered with the contemporary isolates recently reported in the USA. Phylogenetic analysis showed that these viruses were mostly identical (with 99.6% and 97.4% nucleotide homology) to, and were reassortants containing chicken/Pakistan/14 (H7N3) and Canine/Beijing/10 (H3N2) like M and NP genes. Genetic analysis indicated that A/equine/Pakistan/16 viruses were most probably the result of several re-assortments between the co-circulating avian and equine viruses, and were genetically unlike the other equine viruses due to the presence of H7N3 or H3N2 like M and NP genes.

    CONCLUSION: Epidemiological data analysis indicated the potential chance of mixed, and management such as mixed farming system by keeping equine, canine and backyard poultry together in confined premises as the greater risk factors responsible for the re-assortments. Other factors might have contributed to the spread of the epidemic, including low awareness level, poor control of equine movements, and absence of border control disease strategies.

    Matched MeSH terms: Horse Diseases/virology*; Orthomyxoviridae Infections/virology
  2. Yogarajah T, Ong KC, Perera D, Wong KT
    Sci Rep, 2017 07 19;7(1):5845.
    PMID: 28724943 DOI: 10.1038/s41598-017-05589-2
    Encephalomyelitis is a well-known complication of hand, foot, and mouth disease (HFMD) due to Enterovirus 71 (EV71) infection. Viral RNA/antigens could be detected in the central nervous system (CNS) neurons in fatal encephalomyelitis but the mechanisms of neuronal cell death is not clearly understood. We investigated the role of absent in melanoma 2 (AIM2) inflammasome in neuronal cell death, and its relationship to viral replication. Our transcriptomic analysis, RT-qPCR, Western blot, immunofluorescence and flow cytometry studies consistently showed AIM2 gene up-regulation and protein expression in EV-A71-infected SK-N-SH cells. Downstream AIM2-induced genes, CARD16, caspase-1 and IL-1β were also up-regulated and caspase-1 was activated to form cleaved caspase-1 p20 subunits. As evidenced by 7-AAD positivity, pyroptosis was confirmed in infected cells. Overall, these findings have a strong correlation with decreases in viral titers, copy numbers and proteins, and reduced proportions of infected cells. AIM2 and viral antigens were detected by immunohistochemistry in infected neurons in inflamed areas of the CNS in EV-A71 encephalomyelitis. In infected AIM2-knockdown cells, AIM2 and related downstream gene expressions, and pyroptosis were suppressed, resulting in significantly increased virus infection. These results support the notion that AIM2 inflammasome-mediated pyroptosis is an important mechanism of neuronal cell death and it could play an important role in limiting EV-A71 replication.
    Matched MeSH terms: Encephalomyelitis/virology; Neurons/virology*
  3. Amelia-Yap ZH, Chen CD, Sofian-Azirun M, Low VL
    Parasit Vectors, 2018 Jun 04;11(1):332.
    PMID: 29866193 DOI: 10.1186/s13071-018-2899-0
    Human arboviral diseases transmitted by Aedes aegypti such as dengue, Zika, chikungunya and yellow fever remain global public health threats to date. Of these diseases, dengue fever is particularly prevalent in Southeast Asia. Relentless vector control efforts are performed to curtail disease transmissions through which pyrethroid insecticides are broadly used as the first line of defense to control Ae. aegypti, especially in the course of disease outbreaks. Here, we compile the largest contemporary database for susceptibility profiles and underlying mechanisms involved in Ae. aegypti resistant to pyrethroids in Southeast Asia. The extensive use of pyrethroids inevitably elicit different levels of resistance to numerous populations despite the presence of geographical isolation. The most common mechanisms of pyrethroid resistance that have been identified in Ae. aegypti includes mutations in the voltage sensitive sodium channel gene (Vssc gene) and metabolic-mediated insecticide resistance. Aedes aegypti develops resistance to pyrethroids by acquisition of one or several amino acid substitution(s) in this Vssc gene. Enzymes involved in metabolic-mediated detoxification (i.e. monooxygenases, glutathione-S-transferases and esterases) have been reported to be related to pyrethroid resistance but many specific contributory enzymes are not completely studied. An inadequate amount of data from some countries indicates an urgent need for further study to fill the knowledge gaps. Perspectives and future research needs are also discussed.
    Matched MeSH terms: Aedes/virology; Mosquito Vectors/virology
  4. Senapin S, Dong HT, Meemetta W, Gangnonngiw W, Sangsuriya P, Vanichviriyakit R, et al.
    J Fish Dis, 2019 Jan;42(1):119-127.
    PMID: 30397913 DOI: 10.1111/jfd.12915
    In Southeast Asia, a new disease called scale drop disease (SDD) caused by a novel Megalocytivirus (SDDV) has emerged in farmed Asian sea bass (Lates calcarifer) in Singapore, Malaysia and Indonesia. We received samples from an Eastern Thai province that also showed gross signs of SDD (loss of scales). Clinical samples of 0.2-1.1 kg L. calcarifer collected between 2016 and 2018 were examined for evidence of SDDV infection. Histopathology was similar to that in the first report of SDDV from Singapore including necrosis, inflammation and nuclear pyknosis and karyorrhexis in the multiple organs. Intracytoplasmic inclusion bodies were also observed in the muscle tissue. In a density-gradient fraction from muscle extracts, TEM revealed enveloped, hexagonal megalocytiviral-like particles (~100-180 nm). By PCR using primers derived from the Singaporean SDDV genome sequence, four different genes were amplified and sequenced from the Thai isolate revealing 98.7%-99.9% identity between the two isolates. Since viral inclusions were rarely observed, clinical signs and histopathology could not be used to easily distinguish between SDD caused by bacteria or SDDV. We therefore recommend that PCR screening be used to monitor broodstock, fry and grow-out fish to estimate the current impact of SDDV in Southeast Asia and to prevent its spread.
    Matched MeSH terms: Bass/virology; Fish Diseases/virology*
  5. Atherstone C, Diederich S, Weingartl HM, Fischer K, Balkema-Buschmann A, Grace D, et al.
    Transbound Emerg Dis, 2019 Mar;66(2):921-928.
    PMID: 30576076 DOI: 10.1111/tbed.13105
    Hendra virus (HeV) and Nipah virus (NiV), belonging to the genus Henipavirus, are among the most pathogenic of viruses in humans. Old World fruit bats (family Pteropodidae) are the natural reservoir hosts. Molecular and serological studies found evidence of henipavirus infection in fruit bats from several African countries. However, little is known about the potential for spillover into domestic animals in East Africa, particularly pigs, which served as amplifying hosts during the first outbreak of NiV in Malaysia and Singapore. We collected sera from 661 pigs presented for slaughter in Uganda between December 2015 and October 2016. Using HeV G and NiV G indirect ELISAs, 14 pigs (2%) were seroreactive in at least one ELISA. Seroprevalence increased to 5.4% in October 2016, when pigs were 9.5 times more likely to be seroreactive than pigs sampled in December 2015 (p = 0.04). Eight of the 14 ELISA-positive samples reacted with HeV N antigen in Western blot. None of the sera neutralized HeV or NiV in plaque reduction neutralization tests. Although we did not detect neutralizing antibodies, our results suggest that pigs in Uganda are exposed to henipaviruses or henipa-like viruses. Pigs in this study were sourced from many farms throughout Uganda, suggesting multiple (albeit rare) introductions of henipaviruses into the pig population. We postulate that given the widespread distribution of Old World fruit bats in Africa, spillover of henipaviruses from fruit bats to pigs in Uganda could result in exposure of pigs at multiple locations. A higher risk of a spillover event at the end of the dry season might be explained by higher densities of bats and contact with pigs at this time of the year, exacerbated by nutritional stress in bat populations and their reproductive cycle. Future studies should prioritize determining the risk of spillover of henipaviruses from pigs to people, so that potential risks can be mitigated.
    Matched MeSH terms: Swine Diseases/virology; Henipavirus Infections/virology
  6. Mohd Abd Razak MR, Mohmad Misnan N, Md Jelas NH, Norahmad NA, Muhammad A, Ho TCD, et al.
    BMC Complement Altern Med, 2018 Dec 05;18(1):320.
    PMID: 30518360 DOI: 10.1186/s12906-018-2390-7
    BACKGROUND: Carica papaya leaf juice (CPLJ) was well known for its thrombocytosis activity in rodents and dengue patients. However, the effect of CPLJ treatment on other parameters that could contribute to dengue pathogenesis such as nonstructural protein 1 (NS1) production and viremia level have never been highlighted in any clinical and in vivo studies. The aim of this study is to investigate the effect of freeze-dried CPLJ treatment on NS1 and viremia levels of dengue fever mouse model.

    METHODS: The dengue infection in mouse model was established by inoculation of non-mouse adapted New Guinea C strain dengue virus (DEN-2) in AG129 mice. The freeze-dried CPLJ compounds were identified by Ultra-High Performance Liquid Chromatography High Resolution Accurate Mass Spectrometry analysis. The infected AG129 mice were orally treated with 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ, starting on day 1 post infection for 3 consecutive days. The blood samples were collected from submandibular vein for plasma NS1 assay and quantitation of viral RNA level by quantitative reverse transcription PCR.

    RESULTS: The AG129 mice infected with dengue virus showed marked increase in the production of plasma NS1, which was detectable on day 1 post infection, peaked on day 3 post-infection and started to decline from day 5 post infection. The infection also caused splenomegaly. Twenty-four compounds were identified in the freeze-dried CPLJ. Oral treatment with 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ did not affect the plasma NS1 and dengue viral RNA levels. However, the morbidity level of infected AG129 mice were slightly decreased when treated with freeze-dried CPLJ.

    CONCLUSION: Oral treatment of 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ at the onset of viremia did not affect the plasma NS1 and viral RNA levels in AG129 mice infected with non-mouse adapted New Guinea C strain dengue virus.

    Matched MeSH terms: Dengue/virology*; Viremia/virology*
  7. Tan LN, Cheung KW, Kilby MD
    J Obstet Gynaecol, 2019 May;39(4):556-557.
    PMID: 30634881 DOI: 10.1080/01443615.2018.1530740
    Matched MeSH terms: Pregnancy Complications, Infectious/virology; Hydrops Fetalis/virology
  8. Teck KS, Mac Guad R, Van Rostenberghe AH, Hua GS
    J Med Virol, 2019 09;91(9):1608-1615.
    PMID: 31074499 DOI: 10.1002/jmv.25500
    Respiratory syncytial virus (RSV) is a common pathogen affecting the respiratory tract in infants. To date, there is limited data on RSV occurrence in Malaysia especially in the northeast of Peninsular Malaysia which is significantly affected by the rainy (monsoon) season. This study aimed to determine the prevalence, risk factors (the presence of a male sibling and older school-age siblings, parental education level, monthly income, chronic lung disease, immunocompromised, being a passive smoker, multipara, breastfeeding, prematurity, congenital heart disease, nursery attendance, and rainy season) as well as clinical manifestations of RSV in hospitalized infants and children with lower respiratory tract infection (LRTI). Patients' nasopharyngeal aspirates were tested for RSV antigen, questionnaires, and seasonal variations were used to assess RSV infection. Approximately 22.6% of children were infected with RSV; mean age 7.68 ± 5.45 months. The peak incidence of RSV as a causative agent for LRTI in infants was less than or equal to 1-year old (83%) with approximately 50.5% of the affected children in the younger age group (6 months amd below). RSV infection was significantly but independently associated with the rainy season (odds ratio, 3.307; 95% confidence interval, 1.443-3.688; P 
    Matched MeSH terms: Respiratory Tract Infections/virology*; Respiratory Syncytial Virus Infections/virology*
  9. Tomlinson KR, Pablo-Rodriguez JL, Bunawan H, Nanyiti S, Green P, Miller J, et al.
    Mol Plant Pathol, 2019 08;20(8):1080-1092.
    PMID: 31154674 DOI: 10.1111/mpp.12813
    Cassava brown streak disease (CBSD) is a leading cause of cassava losses in East and Central Africa, and is currently having a severe impact on food security. The disease is caused by two viruses within the Potyviridae family: Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), which both encode atypical Ham1 proteins with highly conserved inosine triphosphate (ITP) pyrophosphohydrolase (ITPase) domains. ITPase proteins are widely encoded by plant, animal, and archaea. They selectively hydrolyse mutagenic nucleotide triphosphates to prevent their incorporation into nucleic acid and thereby function to reduce mutation rates. It has previously been hypothesized that U/CBSVs encode Ham1 proteins with ITPase activity to reduce viral mutation rates during infection. In this study, we investigate the potential roles of U/CBSV Ham1 proteins. We show that both CBSV and UCBSV Ham1 proteins have ITPase activities through in vitro enzyme assays. Deep-sequencing experiments found no evidence of the U/CBSV Ham1 proteins providing mutagenic protection during infections of Nicotiana hosts. Manipulations of the CBSV_Tanza infectious clone were performed, including a Ham1 deletion, ITPase point mutations, and UCBSV Ham1 chimera. Unlike severely necrotic wild-type CBSV_Tanza infections, infections of Nicotiana benthamiana with the manipulated CBSV infectious clones do not develop necrosis, indicating that that the CBSV Ham1 is a necrosis determinant. We propose that the presence of U/CBSV Ham1 proteins with highly conserved ITPase motifs indicates that they serve highly selectable functions during infections of cassava and may represent a euphorbia host adaptation that could be targeted in antiviral strategies.
    Matched MeSH terms: Plant Diseases/virology; Tobacco/virology
  10. Liang Y, Ahmad Mohiddin MN, Bahauddin R, Hidayatul FO, Nazni WA, Lee HL, et al.
    Comput Math Methods Med, 2019;2019:1923479.
    PMID: 31481976 DOI: 10.1155/2019/1923479
    In this paper, we will start off by introducing the classical Ross-Macdonald model for vector-borne diseases which we use to describe the transmission of dengue between humans and Aedes mosquitoes in Shah Alam, which is a city and the state capital of Selangor, Malaysia. We will focus on analysing the effect of using the Mosquito Home System (MHS), which is an example of an autodissemination trap, in reducing the number of dengue cases by changing the Ross-Macdonald model. By using the national dengue data from Malaysia, we are able to estimate λ, which represents the initial growth rate of the dengue epidemic, and this allows us to estimate the number of mosquitoes in Malaysia. A mathematical expression is also constructed which allows us to estimate the potential number of breeding sites of Aedes mosquitoes. By using the data available from the MHS trial carried out in Section 15 of Shah Alam, we included the potential effect of the MHS into the dengue model and thus modelled the impact MHS has on the spread of dengue within the trial area. We then extended our results to analyse the effect of the MHSs on reducing the number of dengue cases in the whole of Malaysia. A new model was constructed with a basic reproduction number, R0,MalaMHS, which allows us to identify the required MHSs coverage needed to achieve extinction in Malaysia. Numerical simulations and tables of results were also produced to illustrate our results.
    Matched MeSH terms: Aedes/virology; Mosquito Vectors/virology
  11. Lee CL, Veeramani S, Molouki A, Lim SHE, Thomas W, Chia SL, et al.
    Cancer Invest, 2019;37(8):393-414.
    PMID: 31502477 DOI: 10.1080/07357907.2019.1660887
    Colorectal cancer (CRC) is one of the most common malignancies. In recent decades, early diagnosis and conventional therapies have resulted in a significant reduction in mortality. However, late stage metastatic disease still has very limited effective treatment options. There is a growing interest in using viruses to help target therapies to tumour sites. In recent years the evolution of immunotherapy has emphasised the importance of directing the immune system to eliminate tumour cells; we aim to give a state-of-the-art over-view of the diverse viruses that have been investigated as potential oncolytic agents for the treatment of CRC.
    Matched MeSH terms: Colonic Neoplasms/virology; Rectal Neoplasms/virology
  12. Al-Herz W, Essa S
    Front Immunol, 2019;10:1231.
    PMID: 31191561 DOI: 10.3389/fimmu.2019.01231
    Objective: To present the frequency and spectrum of viral infections in primary immunodeficient children. Methods: The data was obtained from the Kuwait National Primary Immunodeficiency Disorders (PIDs) Registry during the period of 2004-2018. Results: A total of 274 PID children were registered in KNPIDR during the study period with predominance of immunodeficiencies affecting cellular and humoral immunity, followed by combined immunodeficiencies with associated syndromic features and diseases of immune dysregulation. Overall infectious complications affected 82.4% of the patients, and viral infections affected 31.7% of the registered patients. Forty-five patients (16.4%) developed viral infections caused by at least 2 organisms, among those 20 patients were affected by three or more viral infections. There was a statistically significant association between viral infections and PID category. However, there was no statistically significant association between viral infections and gender or the patients' onset age. There was a total of 170 viral infections during the study period and the causes of these infections were predominated by CMV (22.2%), adenovirus (11.7%), EBV (11.1%), and enteroviruses (7.4%). CMV and parainfluenza infections were more common in the group of immunodeficiencies affecting cellular and humoral immunity while EBV and human papilloma virus (HPV) were more common in the immune dysregulation group and combined immunodeficiencies with associated syndromic features, respectively. The most common presentation was viremia (28.8%) followed by pneumonia (28.2%) and skin infections (17.6%). The most common causes of viremia were CMV followed by adenovirus and EBV, while the most common organisms causing pneumonia were CMV followed by rhinovirus and parainfluenza. There were 80 deaths among the registered patients, 10% were caused by viral infections. Conclusions: Viral infections are common in PIDs and result into a wide-range of clinical manifestations causing significant morbidity and mortality.
    Matched MeSH terms: Viremia/virology; Virus Diseases/virology
  13. 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; Birnaviridae Infections/virology
  14. Zhang W, Jiang B, Zeng M, Duan Y, Wu Z, Wu Y, et al.
    J Virol, 2020 04 16;94(9).
    PMID: 32075929 DOI: 10.1128/JVI.01850-19
    Duck Tembusu virus (DTMUV), which is similar to other mosquito-borne flaviviruses that replicate well in most mammalian cells, is an emerging pathogenic flavivirus that has caused epidemics in egg-laying and breeding waterfowl. Immune organ defects and neurological dysfunction are the main clinical symptoms of DTMUV infection. Preinfection with DTMUV makes the virus impervious to later interferon (IFN) treatment, revealing that DTMUV has evolved some strategies to defend against host IFN-dependent antiviral responses. Immune inhibition was further confirmed by screening for DTMUV-encoded proteins, which suggested that NS2A significantly inhibited IFN-β and IFN-stimulated response element (ISRE) promoter activity in a dose-dependent manner and facilitated reinfection with duck plague virus (DPV). DTMUV NS2A was able to inhibit duck retinoic acid-inducible gene-I (RIG-I)-, and melanoma differentiation-associated gene 5 (MDA5)-, mitochondrial-localized adaptor molecules (MAVS)-, stimulator of interferon genes (STING)-, and TANK-binding kinase 1 (TBK1)-induced IFN-β transcription, but not duck TBK1- and interferon regulatory factor 7 (IRF7)-mediated effective phases of IFN response. Furthermore, we found that NS2A competed with duTBK1 in binding to duck STING (duSTING), impaired duSTING-duSTING binding, and reduced duTBK1 phosphorylation, leading to the subsequent inhibition of IFN production. Importantly, we first identified that the W164A, Y167A, and S361A mutations in duSTING significantly impaired the NS2A-duSTING interaction, which is important for NS2A-induced IFN-β inhibition. Hence, our data demonstrated that DTMUV NS2A disrupts duSTING-dependent antiviral cellular defenses by binding with duSTING, which provides a novel mechanism by which DTMUV subverts host innate immune responses. The potential interaction sites between NS2A and duSTING may be the targets of future novel antiviral therapies and vaccine development.IMPORTANCE Flavivirus infections are transmitted through mosquitos or ticks and lead to significant morbidity and mortality worldwide with a spectrum of manifestations. Infection with an emerging flavivirus, DTMUV, manifests with clinical symptoms that include lesions of the immune organs and neurological dysfunction, leading to heavy egg drop and causing serious harm to the duck industry in China, Thailand, Malaysia, and other Southeast Asian countries. Mosquito cells, bird cells, and mammalian cell lines are all susceptible to DTMUV infection. An in vivo study revealed that BALB/c mice and Kunming mice were susceptible to DTMUV after intracerebral inoculation. Moreover, there are no reports about DTMUV-related human disease, but antibodies against DTMUV and viral RNA were detected in serum samples of duck industry workers. This information implies that DTMUV has expanded its host range and may pose a threat to mammalian health. However, the pathogenesis of DTMUV is largely unclear. Our results show that NS2A strongly blocks the STING-induced signal transduction cascade by binding with STING, which subsequently blocks STING-STING binding and TBK1 phosphorylation. More importantly, the W164, Y167, or S361 residues in duSTING were identified as important interaction sites between STING and NS2A that are vital for NS2A-induced IFN production and effective phases of IFN response. Uncovering the mechanism by which DTMUV NS2A inhibits IFN in the cells of its natural hosts, ducks, will help us understand the role of NS2A in DTMUV pathogenicity.
    Matched MeSH terms: Ducks/virology; Flavivirus Infections/virology
  15. Bala JA, Balakrishnan KN, Jesse FFA, Abdullah AA, Noorzahari MSB, Ghazali MT, et al.
    Infect Genet Evol, 2020 01;77:104076.
    PMID: 31678648 DOI: 10.1016/j.meegid.2019.104076
    There is a little information on the characterization of Orf virus strains that are endemic in Malaysia. The relationship between the severity of disease and the molecular genetic profile of Orf virus strains has not been fully elucidated. This study documented the first confirmed report of contagious ecthyma causing by Orf virus in goats from a selected state of eastern peninsular Malaysia. The disease causes significant debilitation due to the inability of affected animals to suckle which brings a great economic loss to the farmers. A total of 504 animals were examined individually to recognize the affected animals with Orf lesion. Skin scrapping was used to collect the scab material from the infected animals. The presence of Orf virus was confirmed by combination of methods including virus isolation on vero cells, identification by Transmission Electron Microscopy (TEM) and molecular technique using PCR and Sanger sequencing. The results showed the successful isolation of four Orf virus strains with a typical cytopathic effects on the cultured vero cells line. The morphology was confirmed to be Orf virus with a distinctive ovoid and criss cross structure. The phylogenetic analysis revealed that these isolated strains were closely related to each other and to other previously isolated Malaysian orf viruses. In addition these Orf virus strains were closely related to Orf viruses from China and India. This study provides more valuable insight in terms of genotype of Orf virus circulating in Malaysia.
    Matched MeSH terms: Sheep Diseases/virology*; Goat Diseases/virology*
  16. Okamura T, Tsujimura Y, Soma S, Takahashi I, Matsuo K, Yasutomi Y
    J Gen Virol, 2016 Dec;97(12):3413-3426.
    PMID: 27902330 DOI: 10.1099/jgv.0.000641
    Simian immunodeficiency virus (SIV) infection models in cynomolgus macaques are important for analysis of the pathogenesis of immunodeficiency virus and for studies on the efficacy of new vaccine candidates. However, very little is known about the pathogenesis of SIV or simian human immunodeficiency virus (SHIV) in cynomolgus macaques from different Asian countries. In the present study, we analysed the infectivity and pathogenicity of CCR5-tropic SIVmac and those of dual-tropic SHIV89.6P inoculated into cynomolgus macaques in Indonesian, Malaysian or Philippine origin. The plasma viral loads in macaques infected with either SIVmac239 or SHIV89.6P were maintained at high levels. CD4+ T cell levels in macaques infected with SIVmac239 gradually decreased. All of the macaques infected with SHIV89.6P showed greatly reduced CD4+ T-cell numbers within 6 weeks of infection. Eight of the 11 macaques infected with SIVmac239 were killed due to AIDS symptoms after 2-4.5 years, while four of the five macaques infected with SHIV89.6P were killed due to AIDS symptoms after 1-3.5 years. We also analysed cynomolgus macaques infected intrarectally with repeated low, medium or high doses of SIVmac239, SIVmac251 or SHIV89.6P. Infection was confirmed by quantitative RT-PCR at more than 5000, 300 and 500 TCID50 for SIVmac239, SIVmac251 and SHIV89.6P, respectively. The present study indicates that cynomolgus macaques of Asian origin are highly susceptible to SIVmac and SHIV infection by both intravenous and mucosal routes. These models will be useful for studies on virus pathogenesis, vaccination and therapeutics against human immunodeficiency virus/AIDS.
    Matched MeSH terms: Acquired Immunodeficiency Syndrome/virology*; CD4-Positive T-Lymphocytes/virology
  17. Amaya M, Broder CC
    Annu Rev Virol, 2020 09 29;7(1):447-473.
    PMID: 32991264 DOI: 10.1146/annurev-virology-021920-113833
    Hendra virus (HeV) and Nipah virus (NiV) are bat-borne zoonotic para-myxoviruses identified in the mid- to late 1990s in outbreaks of severe disease in livestock and people in Australia and Malaysia, respectively. HeV repeatedly re-emerges in Australia while NiV continues to cause outbreaks in South Asia (Bangladesh and India), and these viruses have remained transboundary threats. In people and several mammalian species, HeV and NiV infections present as a severe systemic and often fatal neurologic and/or respiratory disease. NiV stands out as a potential pandemic threat because of its associated high case-fatality rates and capacity for human-to-human transmission. The development of effective vaccines, suitable for people and livestock, against HeV and NiV has been a research focus. Here, we review the progress made in NiV and HeV vaccine development, with an emphasis on those approaches that have been tested in established animal challenge models of NiV and HeV infection and disease.
    Matched MeSH terms: Chiroptera/virology; Communicable Diseases, Emerging/virology
  18. 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*; Coronavirus Infections/virology
  19. Mancini MV, Herd CS, Ant TH, Murdochy SM, Sinkins SP
    PLoS Negl Trop Dis, 2020 Mar;14(3):e0007926.
    PMID: 32155143 DOI: 10.1371/journal.pntd.0007926
    The global incidence of arboviral diseases transmitted by Aedes mosquitoes, including dengue, chikungunya, yellow fever, and Zika, has increased dramatically in recent decades. The release of Aedes aegypti carrying the maternally inherited symbiont Wolbachia as an intervention to control arboviruses is being trialled in several countries. However, these efforts are compromised in many endemic regions due to the co-localization of the secondary vector Aedes albopictus, the Asian tiger mosquito. Ae. albopictus has an expanding global distribution following incursions into a number of new territories. To date, only the wMel and wPip strains of Wolbachia have been reported to be transferred into and characterized in this vector. A Wolbachia strain naturally infecting Drosophila simulans, wAu, was selected for transfer into a Malaysian Ae. albopictus line to create a novel triple-strain infection. The newly generated line showed self-compatibility, moderate fitness cost and complete resistance to Zika and dengue infections.
    Matched MeSH terms: Aedes/virology*; Mosquito Vectors/virology
  20. Sudjaritruk T, Teeraananchai S, Kariminia A, Lapphra K, Kumarasamy N, Fong MS, et al.
    J Int AIDS Soc, 2020 Jul;23(7):e25550.
    PMID: 32628816 DOI: 10.1002/jia2.25550
    INTRODUCTION: The clinical relevance of low-level viraemia (LLV) and virological outcomes among children living with HIV (CLHIV) remains controversial. This study aimed to determine the impact of LLV on virological failure (VF) among Asian CLHIV on first-line combination antiretroviral therapy (cART).

    METHODS: CLHIV aged <18 years, who were on first-line cART for ≥12 months, and had virological suppression (two consecutive plasma viral load [pVL] <50 copies/mL) were included. Those who started treatment with mono/dual antiretroviral therapy, had a history of treatment interruption >14 days, or received treatment and care at sites with a pVL lower limit of detection >50 copies/mL were excluded. LLV was defined as a pVL 50 to 1000 copies/mL, and VF as a single pVL >1000 copies/mL. Baseline was the time of the second pVL 

    Matched MeSH terms: Viremia/virology; HIV Infections/virology*
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