Displaying publications 141 - 160 of 164 in total

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  1. Fulltext Pteropid bats are confirmed as the reservoir hosts of henipaviruses: a comprehensive experimental study of virus transmission
    Halpin K, Hyatt AD, Fogarty R, Middleton D, Bingham J, Epstein JH, et al.
    Am J Trop Med Hyg, 2011 Nov;85(5):946-51.
    PMID: 22049055 DOI: 10.4269/ajtmh.2011.10-0567
    Bats of the genus Pteropus have been identified as the reservoir hosts for the henipaviruses Hendra virus (HeV) and Nipah virus (NiV). The aim of these studies was to assess likely mechanisms for henipaviruses transmission from bats. In a series of experiments, Pteropus bats from Malaysia and Australia were inoculated with NiV and HeV, respectively, by natural routes of infection. Despite an intensive sampling strategy, no NiV was recovered from the Malaysian bats and HeV was reisolated from only one Australian bat; no disease was seen. These experiments suggest that opportunities for henipavirus transmission may be limited; therefore, the probability of a spillover event is low. For spillover to occur, a range of conditions and events must coincide. An alternate assessment framework is required if we are to fully understand how this reservoir host maintains and transmits not only these but all viruses with which it has been associated.
    Matched MeSH terms: Genome, Viral
  2. Fulltext Dengue virus serotype 2 from a sylvatic lineage isolated from a patient with dengue hemorrhagic fever
    Cardosa J, Ooi MH, Tio PH, Perera D, Holmes EC, Bibi K, et al.
    PLoS Negl Trop Dis, 2009;3(4):e423.
    PMID: 19399166 DOI: 10.1371/journal.pntd.0000423
    Dengue viruses circulate in both human and sylvatic cycles. Although dengue viruses (DENV) infecting humans can cause major epidemics and severe disease, relatively little is known about the epidemiology and etiology of sylvatic dengue viruses. A 20-year-old male developed dengue hemorrhagic fever (DHF) with thrombocytopenia (12,000/ul) and a raised hematocrit (29.5% above baseline) in January 2008 in Malaysia. Dengue virus serotype 2 was isolated from his blood on day 4 of fever. A phylogenetic analysis of the complete genome sequence revealed that this virus was a member of a sylvatic lineage of DENV-2 and most closely related to a virus isolated from a sentinel monkey in Malaysia in 1970. This is the first identification of a sylvatic DENV circulating in Asia since 1975.
    Matched MeSH terms: Genome, Viral
  3. Hendra and Nipah viruses: different and dangerous
    Eaton BT, Broder CC, Middleton D, Wang LF
    Nat Rev Microbiol, 2006 Jan;4(1):23-35.
    PMID: 16357858
    Hendra virus and Nipah virus are highly pathogenic paramyxoviruses that have recently emerged from flying foxes to cause serious disease outbreaks in humans and livestock in Australia, Malaysia, Singapore and Bangladesh. Their unique genetic constitution, high virulence and wide host range set them apart from other paramyxoviruses. These features led to their classification into the new genus Henipavirus within the family Paramyxoviridae and to their designation as Biosafety Level 4 pathogens. This review provides an overview of henipaviruses and the types of infection they cause, and describes how studies on the structure and function of henipavirus proteins expressed from cloned genes have provided insights into the unique biological properties of these emerging human pathogens.
    Matched MeSH terms: Genome, Viral
  4. Genetic variability of genome segments 3 and 9 of Fiji disease virus field isolates
    Jiang J, Ridley AW, Tang H, Croft BJ, Johnson KN
    Arch Virol, 2008;153(5):839-48.
    PMID: 18299794 DOI: 10.1007/s00705-008-0058-1
    Fiji leaf gall is an important disease of sugarcane in Australia and other Asia-Pacific countries. The causative agent is the reovirus Fiji disease virus (FDV). Previous reports indicate that there is variation in pathology between virus isolates. To investigate the amount of genetic variation found in FDV, 25 field isolates from Australia, Papua New Guinea and Malaysia were analysed by partial sequencing of genome segments S3 and S9. There was up to 15% divergence in the nucleotide sequence among the 25 isolates. A similar amount of divergence and pattern of relationships was found for each of the two genomic segments for most of the field isolates, although reassortment of genome segments seems likely for at least one of the Papua New Guinean isolates. The finding of a high level of variation in FDV isolated in different regions has implications for quarantine and disease management.
    Matched MeSH terms: Genome, Viral
  5. Continuous crossover(s) events of HIV-1 CRF01_AE and B subtype strains in Malaysia: evidence of rapid and extensive HIV-1 evolution in the region
    Lau KA, Wang B, Kamarulzaman A, Ngb KP, Saksena NK
    Curr HIV Res, 2008 Mar;6(2):108-16.
    PMID: 18336258
    The Asian HIV epidemic appears to be complex, characterized by the prevalence of multiple subtypes and circulating recombinant forms with gradual replacement of pure HIV-1 subtypes in several geographical regions. The main objectives of the present study are to identify and analyse the full-length viral genomes of three unique recombinant forms (URFs); the HIV-1 isolates 07MYKLD47, 07MYKLD48 and 07MYKLD49 from Malaysia. Long-range polymerase chain reaction (PCR) amplification of seven overlapping reading frames was used to derive near full-length HIV-1 genomes. Detailed phylogenetic and bootscanning analyses were performed to determine phylogenetic associations and subtypic assignments. We further confirmed the mosaic composition of these CRF01_AE/B inter-subtype recombinant forms, which are composed of B-subtype fragment(s) in the backbone of CRF01_AE. Both 07MYKLD47 and 07MYKLD48 have an insertion of B subtype (880 bp and 532 bp) in the gag-pol and gp41-env gene regions, respectively. Whereas the isolate 07MYKLD49 has three B-subtype fragments inserted in different gene region along the genome; one each in the gag-pol (1862 bp) and pol-vif (1935 bp) regions, and a short B-subtype insertion (541 bp) in the 5' LTR-gag region. This highlights the public health relevance of newly emerging second generation HIV-1 recombinant forms and their dispersal, along with their rapid and continuous evolution in the region.
    Matched MeSH terms: Genome, Viral
  6. [Molecular-genetic analysis of the genomes of porcine reproductive and respiratory syndrome virus and porcine circovirus type 2 circulating in the area of Russian Federation]
    Bulgakov AD, Grebennikova TV, Iuzhakov AG, Aliper TI, Nepoklonov EA
    Mol. Gen. Mikrobiol. Virusol., 2014.
    PMID: 25845139
    The molecular genetic analysis of the genomes of the virus of porcine reproductive respiratory syndrome (VPRRS) and porcine circovirus type 2 (PCV-2) circulating in the area of the Russian Federation was discussed. The results of this work showed the circulation of the strains of the European genotype VPRRS similar to those found in France and Denmark from 1998 to 2001. The homology of the fragment of one of the genes between the Russian isolates and the vaccine strain Porcilis PRRS (Intervet) was found. It requires further study. The strains representing the North American genotype VPRRS were not found. The PCV-2 genomes fall into three separate goups. One (genotype 2b) is formed by isolates in Malaysia, Brazil, Switzerland, China, Slovakia, UK, USA, isolated during the period from 2004 to the present time. The second group consists of sequences of the viruses isolated in 2000-2012 in Canada, the U.S., China, and South Korea (genotype 2a). The third group is formed by highly pathogenic isolates in 2013 from China (highly pathogenic genotype 2c). The circulation of all three known genotypes of PCV-2: 2a, 2b, and 2c in Russian Federation was demonstrated.
    Matched MeSH terms: Genome, Viral
  7. Molecular characterization of measles viruses in Turkey (2010-2011): first report of genotype D9 involved in an outbreak in 2011
    Kalaycioglu AT, Baykal A, Guldemir D, Bakkaloglu Z, Korukluoglu G, Coskun A, et al.
    J Med Virol, 2013 Dec;85(12):2128-35.
    PMID: 23959542 DOI: 10.1002/jmv.23714
    Genetic characterization of measles viruses (MVs) combined with acquisition of epidemiologic information is essential for measles surveillance programs used in determining transmission pathways. This study describes the molecular characterization of 26 MV strains (3 from 2010, 23 from 2011) obtained from urine or throat swabs harvested from patients in Turkey. MV RNA samples (n = 26) were subjected to sequence analysis of 450 nucleotides comprising the most variable C-terminal region of the nucleoprotein (N) gene. Phylogenetic analysis revealed 20 strains from 2011 belonged to genotype D9, 3 to D4, 2 strains from 2010 to genotype D4 and 1 to genotype B3. This study represents the first report describing the involvement of MV genotype D9 in an outbreak in Turkey. The sequence of the majority of genotype D9 strains was identical to those identified in Russia, Malaysia, Japan, and the UK. Despite lack of sufficient epidemiologic information, the presence of variants observed following phylogenetic analysis suggested that exposure to genotype D9 might have occurred due to importation more than once. Phylogenetic analysis of five genotype D4 strains revealed the presence of four variants. Epidemiological information and phylogenetic analysis suggested that three genotype D4 strains and one genotype B3 strain were associated with importation. This study suggests the presence of pockets of unimmunized individuals making Turkey susceptible to outbreaks. Continuing molecular surveillance of measles strains in Turkey is essential as a means of acquiring epidemiologic information to define viral transmission patterns and determine the effectiveness of measles vaccination programs designed to eliminate this virus.
    Matched MeSH terms: Genome, Viral
  8. A systematic review on current approaches in bat virus discovered between 2018 and 2022
    Mo Y, Lim LS, Ng SK
    J Virol Methods, 2024 Sep;329:115005.
    PMID: 39128772 DOI: 10.1016/j.jviromet.2024.115005
    Zoonotic viruses are widely seen as the primary threat for future pandemics. Bats are the most diverse group of mammals, with more than 1400 species distributed across most habitats on Earth. So far, 31 known virus families were associated with bats, although the understanding of most viruses were insufficient. Continuous efforts to discover, understand and monitor these bats viruses, is thereby an area of public health interest. This systematic review was designed to catalogue publications reporting novel bat virus discoveries within PubMed, SCOPUS, and Web of Science databases, within a 5-year period from 2018 to 2022. Various experimental parameters, including sampling locations, methodology, bat species diversity, similarity to known viruses, species demarcation of new viruses, and genomic sequencing strategies, were extracted from 41 publications and analyzed. In total, 72 novel viruses from 19 virus families were identified between 2018 and 2022, particularly from Genomoviridae (DNA viruses) and Coronaviridae (RNA viruses). That said, only a limited number of bat families featured extensively despite noticeable shift towards next generation sequencing methods and metagenomics pipeline for virus identification across different sampling methods. This review aims to provide a comprehensive analysis of the global efforts made over the past five years to identify and characterize emerging viruses in bat species, and to provide a detailed overview of the current technologies and methodologies used in these studies.
    Matched MeSH terms: Genome, Viral
  9. Fulltext The Conserved Molecular Determinants of Virulence in Dengue Virus
    Ahmad Z, Poh CL
    Int J Med Sci, 2019;16(3):355-365.
    PMID: 30911269 DOI: 10.7150/ijms.29938
    Dengue virus belongs to the Flaviviridae family which also includes viruses such as the Zika, West Nile and yellow fever virus. Dengue virus generally causes mild disease, however, more severe forms of the dengue virus infection, dengue haemorrhagic fever (DHF) and dengue haemorrhagic fever with shock syndrome (DSS) can also occur, resulting in multiple organ failure and even death, especially in children. The only dengue vaccine available in the market, CYD-TDV offers limited coverage for vaccinees from 9-45 years of age and is only recommended for individuals with prior dengue exposure. A number of mutations that were shown to attenuate virulence of dengue virus in vitro and/or in vivo have been identified in the literature. The mutations which fall within the conserved regions of all four dengue serotypes are discussed. This review hopes to provide information leading to the construction of a live attenuated dengue vaccine that is suitable for all ages, irrespective of the infecting dengue serotype and prior dengue exposure.
    Matched MeSH terms: Genome, Viral
  10. Flavivirus infection-A review of immunopathogenesis, immunological response, and immunodiagnosis
    Chong HY, Leow CY, Abdul Majeed AB, Leow CH
    Virus Res, 2019 12;274:197770.
    PMID: 31626874 DOI: 10.1016/j.virusres.2019.197770
    Flaviviruses are group of single stranded RNA viruses that cause severe endemic infection and epidemics on a global scale. It presents a significant health impact worldwide and the viruses have the potential to emerge and outbreak in a non-endemic geographical region. Effective vaccines for prophylaxis are only available for several flaviviruses such as Yellow Fever virus, Tick-borne Encephalitis Virus, Dengue Virus and Japanese Encephalitis Virus and there is no antiflaviviral agent being marketed. This review discusses the flavivirus genome, replication cycle, epidemiology, clinical presentation and pathogenesis upon infection. Effective humoral response is critical to confer protective immunity against flaviviruses. Hence, we have also highlighted the immune responses elicited upon infection, various diagnostic facilities available for flaviviral disease and monoclonal antibodies available to date against flavivirus infection.
    Matched MeSH terms: Genome, Viral
  11. Fulltext Nipah shell disorder, modes of infection, and virulence
    Goh GK, Dunker AK, Foster JA, Uversky VN
    Microb Pathog, 2020 Apr;141:103976.
    PMID: 31940461 DOI: 10.1016/j.micpath.2020.103976
    The Nipah Virus (NiV) was first isolated during a 1998-9 outbreak in Malaysia. The outbreak initially infected farm pigs and then moved to humans from pigs with a case-fatality rate (CFR) of about 40%. After 2001, regular outbreaks occurred with higher CFRs (~71%, 2001-5, ~93%, 2008-12). The spread arose from drinking virus-laden palm date sap and human-to-human transmission. Intrinsic disorder analysis revealed strong correlation between the percentage of disorder in the N protein and CFR (Regression: r2 = 0.93, p viral transmission. Analysis of the NiV and related viruses suggests links between modes of transmission and disorder of not just the N protein but, also, of M shell protein. The links among shell disorder, transmission modes, and virulence suggest mechanisms by which viruses are attenuated as they passed through different cell hosts from different animal species. These have implications for development of vaccines and epidemiological molecular analytical tools to contain outbreaks.
    Matched MeSH terms: Genome, Viral
  12. Genomic analysis of some Japanese isolates of Getah virus
    Wekesa SN, Inoshima Y, Murakami K, Sentsui H
    Vet Microbiol, 2001 Nov 08;83(2):137-46.
    PMID: 11557154
    Using the reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing, capsid protein and non-structural protein 1 (nsP1) regions of Sagiyama virus and eight Getah virus strains were analysed. The viruses were isolated from Malaysia and various areas of Japan over a period of 30 years. Based on the available published sequence data, oligonucleotide primers were designed for RT-PCR and the sequences were determined. Our findings showed that though there were differences in the nucleotide sequences in the nsP1 region, there was 100% amino acid homology. On the other hand, in the capsid region, the nucleotide differences caused a major difference in the amino acid sequence. Therefore, the difference in the capsid region is one of the useful markers in the genetic classification between Sagiyama virus and strains of Getah virus, and might be responsible for the serological difference in complement fixation test. The genomic differences among the Getah virus strains are due to time factor rather than geographical distribution.
    Matched MeSH terms: Genome, Viral
  13. Inhibition of tumour promotion by various palm-oil tocotrienols
    Goh SH, Hew NF, Norhanom AW, Yadav M
    Int J Cancer, 1994 May 15;57(4):529-31.
    PMID: 8181855
    Inhibition of tumour promotion by various vitamin E compounds (tocopherols and tocotrienols) and some of their dimers was examined by an in vitro assay utilizing the activation of Epstein-Barr virus (EBV) early antigen (EA) expression in EBV-genome-carrying human lymphoblastoid cells. The results reveal that gamma- and delta-tocotrienols derived from palm oil exhibit a strong activity against tumour promotion by inhibiting EBV EA expression in Raji cells induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). However, alpha- and gamma-tocopherols and dimers of gamma-tocotrienol or gamma-tocopherol lack this activity.
    Matched MeSH terms: Genome, Viral
  14. Fulltext Shigella flexneri serotype 1c derived from serotype 1a by acquisition of gtrIC gene cluster via a bacteriophage
    Tang SS, Carlin NI, Talukder KA, Cam PD, Verma NK
    BMC Microbiol, 2016 Jun 27;16(1):127.
    PMID: 27349637 DOI: 10.1186/s12866-016-0746-z
    BACKGROUND: Shigella spp. are the primary causative agents of bacillary dysentery. Since its emergence in the late 1980s, the S. flexneri serotype 1c remains poorly understood, particularly with regard to its origin and genetic evolution. This article provides a molecular insight into this novel serotype and the gtrIC gene cluster that determines its unique immune recognition.

    RESULTS: A PCR of the gtrIC cluster showed that serotype 1c isolates from different geographical origins were genetically conserved. An analysis of sequences flanking the gtrIC cluster revealed remnants of a prophage genome, in particular integrase and tRNA(Pro) genes. Meanwhile, Southern blot analyses on serotype 1c, 1a and 1b strains indicated that all the tested serotype 1c strains may have had a common origin that has since remained distinct from the closely related 1a and 1b serotypes. The identification of prophage genes upstream of the gtrIC cluster is consistent with the notion of bacteriophage-mediated integration of the gtrIC cluster into a pre-existing serotype.

    CONCLUSIONS: This is the first study to show that serotype 1c isolates from different geographical origins share an identical pattern of genetic arrangement, suggesting that serotype 1c strains may have originated from a single parental strain. Analysis of the sequence around the gtrIC cluster revealed a new site for the integration of the serotype converting phages of S. flexneri. Understanding the origin of new pathogenic serotypes and the molecular basis of serotype conversion in S. flexneri would provide information for developing cross-reactive Shigella vaccines.

    Matched MeSH terms: Genome, Viral
  15. Fulltext Characterization of Nipah virus from outbreaks in Bangladesh, 2008-2010
    Lo MK, Lowe L, Hummel KB, Sazzad HM, Gurley ES, Hossain MJ, et al.
    Emerg Infect Dis, 2012 Feb;18(2):248-55.
    PMID: 22304936 DOI: 10.3201/eid1802.111492
    Nipah virus (NiV) is a highly pathogenic paramyxovirus that causes fatal encephalitis in humans. The initial outbreak of NiV infection occurred in Malaysia and Singapore in 1998-1999; relatively small, sporadic outbreaks among humans have occurred in Bangladesh since 2001. We characterized the complete genomic sequences of identical NiV isolates from 2 patients in 2008 and partial genomic sequences of throat swab samples from 3 patients in 2010, all from Bangladesh. All sequences from patients in Bangladesh comprised a distinct genetic group. However, the detection of 3 genetically distinct sequences from patients in the districts of Faridpur and Gopalganj indicated multiple co-circulating lineages in a localized region over a short time (January-March 2010). Sequence comparisons between the open reading frames of all available NiV genes led us to propose a standardized protocol for genotyping NiV; this protcol provides a simple and accurate way to classify current and future NiV sequences.
    Matched MeSH terms: Genome, Viral
  16. Molecular characterization of serotype A foot-and-mouth disease viruses circulating in Vietnam in 2009
    Le VP, Nguyen T, Lee KN, Ko YJ, Lee HS, Nguyen VC, et al.
    Vet Microbiol, 2010 Jul 29;144(1-2):58-66.
    PMID: 20097490 DOI: 10.1016/j.vetmic.2009.12.033
    Foot-and-mouth disease (FMD) is a major cause of endemic outbreaks in Vietnam in recent years. In this work, six serotype A foot-and-mouth disease viruses (FMDV), collected from endemic outbreaks during January and February of 2009 in four different provinces in Vietnam, were genetically characterized for their complete genome sequences. Genetic analysis based on the complete viral genome sequence indicated that they were closely related to each other and shared 99.0-99.8% amino acid (aa) identity. Genetic and deduced aa analysis of the capsid coding gene VP1 showed that the six Vietnamese strains were all classified into the genotype IX from a total of 10 major genotypes worldwide, sharing 98.1-100% aa identity each other. They were most closely related to the type A strains recently isolated in Laos (A/LAO/36/2003, A/LAO/1/2006, A/LAO/6/2006, A/LAO/7/2006, and A/LAO/8/2006), Thailand (A/TAI/2/1997 and A/TAI/118/1987), and Malaysia (A/MAY/2/2002), sharing 88.3-95.5% nucleotide (nt) identities. In contrast, Vietnamese type A strains showed low nt identities with the two old type A FMDVs, isolated in 1960 in Thailand (a15thailand iso43) and in 1975 in the Philippines (aphilippines iso50), ranging from 77.3 to 80.9% nt identity. A multiple alignment based on the deduced amino acid sequences of the capsid VP1 coding gene of type A FMDV revealed three amino acid substitutions between Vietnamese strains and the strains of other Southeast Asian countries (Laos, Thailand, Malaysia, and the Philippines). Alanine was replaced by valine at residue 24, asparagine by arginine at residue 85, and serine by threonine at residue 196. Furthermore, type A FMDV strains recently isolated in Vietnam, Laos, Thailand, and Malaysia all have one amino acid deletion at residue 140 of the capsid VP1 protein compared with the two old type A FMDV strains from Thailand and the Philippines as well as most other type A representatives worldwide. This article is the first to report on the comprehensive genetic characterization of type A FMDV circulating in Vietnam.
    Matched MeSH terms: Genome, Viral
  17. Fulltext Molecular epidemiology of coxsackievirus A16: intratype and prevalent intertype recombination identified
    Chen X, Tan X, Li J, Jin Y, Gong L, Hong M, et al.
    PLoS One, 2013;8(12):e82861.
    PMID: 24340064 DOI: 10.1371/journal.pone.0082861
    Coxsackievirus A16 (CVA16) is responsible for nearly 50% of all the confirmed hand, foot, and mouth disease (HFMD) cases in mainland China, sometimes it could also cause severe complications, and even death. To clarify the genetic characteristics and the epidemic patterns of CVA16 in mainland China, comprehensive bioinfomatics analyses were performed by using 35 CVA16 whole genome sequences from 1998 to 2011, 593 complete CVA16 VP1 sequences from 1981 to 2011, and prototype strains of human enterovirus species A (EV-A). Analysis on complete VP1 sequences revealed that subgenotypes B1a and B1b were prevalent strains and have been co-circulating in many Asian countries since 2000, especially in mainland China for at least 13 years. While the prevalence of subgenotype B1c (totally 20 strains) was much limited, only found in Malaysia from 2005 to 2007 and in France in 2010. Genotype B2 only caused epidemic in Japan and Malaysia from 1981 to 2000. Both subgenotypes B1a and B1b were potential recombinant viruses containing sequences from other EV-A donors in the 5'-untranslated region and P2, P3 non-structural protein encoding regions.
    Matched MeSH terms: Genome, Viral
  18. Evaluation of a lytic bacteriophage, Φ st1, for biocontrol of Salmonella enterica serovar Typhimurium in chickens
    Wong CL, Sieo CC, Tan WS, Abdullah N, Hair-Bejo M, Abu J, et al.
    Int J Food Microbiol, 2014 Feb 17;172:92-101.
    PMID: 24361838 DOI: 10.1016/j.ijfoodmicro.2013.11.034
    In this study, a Salmonella Typhimurium lytic bacteriophage, Φ st1, which was isolated from chicken faecal material, was evaluated as a candidate for biocontrol of Salmonella in chickens. The morphology of Φ st1 showed strong resemblance to members of the Siphoviridae family. Φ st1 was observed to be a DNA phage with an estimated genome size of 121 kbp. It was found to be able to infect S. Typhimurium and S. Hadar, with a stronger lytic activity against the former. Subsequent characterisation of Φ st1 against S. Typhimurium showed that Φ st1 has a latent period of 40 min with an average burst size of 22 particles per infective centre. Approximately 86.1% of the phage adsorbed to the host cells within the initial 5 min of infection. At the optimum multiplicity of infection (MOI) (0.1), the highest reduction rate of S. Typhimurium (6.6 log₁₀ CFU/ml) and increment in phage titre (3.8 log₁₀ PFU/ml) was observed. Φ st1 produced adsorption rates of 88.4-92.2% at pH7-9 and demonstrated the highest bacteria reduction (6.6 log₁₀ CFU/ml) at pH9. Φ st1 also showed an insignificant different (P>0.05) reduction rate of host cells at 37 °C (6.4 log₁₀ CFU/ml) and 42 °C (6.0 log₁₀ CFU/ml). The in vivo study using Φ st1 showed that intracloacal inoculation of ~10¹² PFU/ml of the phage in the chickens challenged with ~10¹⁰ CFU/ml of S. Typhimurium was able to reduce (P<0.05) the S. Typhimurium more rapidly than the untreated group. The Salmonella count reduced to 2.9 log₁₀ CFU/ml within 6h of post-challenge and S. Typhimurium was not detected at and after 24h of post-challenge. Reduction of Salmonella count in visceral organs was also observed at 6h post-challenge. Approximately 1.6 log₁₀ FU/ml Φ st1 was found to persist in the caecal wall of the chicks at 72 h of post-challenge. The present study indicated that Φ st1 may serve as a potential biocontrol agent to reduce the Salmonella count in caecal content of chickens.
    Matched MeSH terms: Genome, Viral
  19. Fulltext Genetic characterization of Enterovirus 71 strains circulating in Vietnam in 2012
    Donato C, Hoi le T, Hoa NT, Hoa TM, Van Duyet L, Dieu Ngan TT, et al.
    Virology, 2016 08;495:1-9.
    PMID: 27148893 DOI: 10.1016/j.virol.2016.04.026
    BACKGROUND: Enterovirus 71 subgenogroup C4 caused the largest outbreak of Hand, Foot and Mouth Disease (HFMD) in Vietnam during 2011-2012, resulting in over 200,000 hospitalisations and 207 fatalities.

    METHODS: A total of 1917 samples with adequate volume for RT-PCR analysis were collected from patients hospitalised with HFMD throughout Vietnam and 637 were positive for EV71. VP1 gene (n=87) and complete genome (n=9) sequencing was performed. Maximum-likelihood phylogenetic analysis was performed to characterise the B5, C4 and C5 strains detected.

    RESULTS: Sequence analyses revealed that the dominant subgenogroup associated with the 2012 outbreak was C4, with B5 and C5 strains representing a small proportion of these cases.

    CONCLUSIONS: Numerous countries in the region including Malaysia, Taiwan and China have a large influence on strain diversity in Vietnam and understanding the transmission of EV71 throughout Southeast Asia is vital to inform preventative public health measures and vaccine development efforts.

    Matched MeSH terms: Genome, Viral
  20. Fulltext Monoclonal antibody-escape variant of dengue virus serotype 1: Genetic composition and envelope protein expression
    Chem YK, Chua KB, Malik Y, Voon K
    Trop Biomed, 2015 Jun;32(2):344-51.
    PMID: 26691263 MyJurnal
    Monoclonal antibody-escape variant of dengue virus type 1 (MabEV DEN-1) was discovered and isolated in an outbreak of dengue in Klang Valley, Malaysia from December 2004 to March 2005. This study was done to investigate whether DEN152 (an isolate of MabEV DEN-1) is a product of recombination event or not. In addition, the non-synonymous mutations that correlate with the monoclonal antibody-escape variant were determined in this study. The genomes of DEN152 and two new DEN-1 isolates, DENB04 and DENK154 were completely sequenced, aligned, and compared. Phylogenetic tree was plotted and the recombination event on DEN152 was investigated. DEN152 is sub-grouped under genotype I and is closely related genetically to a DEN-1 isolated in Japan in 2004. DEN152 is not a recombinant product of any parental strains. Four amino acid substitutions were unique only to DEN 152. These amino acid substitutions were (Ser)[326](Leu), (Ser)[340](Leu) at the deduced E protein, (Ile)[250](Thr) at NS1 protein, and (Thr)[41](Ser) at NS5 protein. Thus, DEN152 is an isolate of the emerging monoclonal antibody-escape variant DEN-1 that escaped diagnostic laboratory detection.
    Matched MeSH terms: Genome, Viral
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