Displaying publications 21 - 40 of 129 in total

Abstract:
Sort:
  1. An optimized method for extraction and detection of Coconut cadang-cadang viroid(CCCVd) from oil palm
    Mohammadi MR, Vadamalai G, Joseph H
    Commun. Agric. Appl. Biol. Sci., 2010;75(4):777-81.
    PMID: 21534490
    Coconut cadong-cadong viroid (CCCVd) causes the Lethal cadang-cadang disease of coconut palms in the Philippines and it is recently reported to be associated with the orange spotting disease on oil palm in Malaysia. The low concentration of the viroid RNA in oil palm as well as the high content of polyphenols and polysaccharides in this plant which interfere with the purification steps makes it difficult to extract and detect this viroid from oil palm. A previously described method was modified and optimized for extraction and detection of CCCVd from infected oil palms. Briefly, 7 g of leaf material was homogenized in a mortar or a blender using liquid nitrogen. 10 ml of extraction buffer (100 mM Tris-HCl pH 7.5, 100 mM NaCl, 10 mM EDTA) along with 100 mM 2-mercaptoethanol and 10 ml water saturated phenol was added to the frozen powder. After centrifuging at 4 degrees C, 4000 g for 30 min, the aqueous phase was extracted once more with phenol then once with chloroform-isoamyl alcohol (24:1). After adding sodium acetate, pH 5.6 to 200 mM, the mixture was precipitated with 2.5 vol ethanol overnight in -20 freezer and then the pellet was washed with 70% ethanol and air-dried. One milliliter of 8 M LiCl was added to the dried pellet and after shaking overnight at 4 degrees C and another centrifugation step the supernatant was collected and precipitated again with ethanol and then the resulting pellet was washed and air-dried. To carry out northern blotting, samples equivalent to 40 g of plant tissue were mixed with formamide buffer and loaded onto a 12% polyacrylamide gel containing 7 M urea and after separation by electrophoresis, were electroblotted onto membrane and fixed by UV cross-linking. Pre-hybridization and hybridization using hybridization buffer (50% formamide, 25%SSPE, 0.1% Ficol and PVP, 0.1 % SDS, 0.02 % DNA (5mg/ml)) was carried out at 45 degrees C for 90 min and 16 h, respectively followed by two low stringency washes (0.5 X SSC, 0.1% SDS, at room temperature for 5 min) and one high stringency wash (0.1X SSC, 0.1% SDS at 60 degrees C for 1 hour). In vitro synthesized DIG-labeled full-length CCCVd(-) RNA probe was used in hybridization step. DIG Nucleic Acid Detection Kit (Roche) instructions were followed for detection procedure and as a result the blue bands corresponding to the position of the viroid were appeared on the membrane. The result of this study showed the ability of DIG labeled probe in detection of the viroid and also provided a suitable extraction and hybridization method for the detection of CCCVd from oil palm.
    Matched MeSH terms: RNA, Viral/genetics
  2. Variants of Coconut cadang-cadang viroid isolated from an African oil palm (Elaies guineensis Jacq.) in Malaysia
    Vadamalai G, Hanold D, Rezaian MA, Randles JW
    Arch Virol, 2006 Jul;151(7):1447-56.
    PMID: 16470341
    Variants of Coconut cadang-cadang viroid have been identified in a plantation oil palm growing in Malaysia. Three size classes are described, comprising 297, 293, and 270 nt. Compared with the 296-nt form of coconut cadang-cadang viroid (CCCVd), all variants substituted C31 --> U in the pathogenicity domain and A175 --> C in the right-hand terminus. Other mutations and deletions accounted for the different sizes. These are the first sequences reported for variants of Coconut cadang-cadang viroid in a species other than coconut palm, and this is the first evidence that variants closely related to CCCVd occur outside the Philippines.
    Matched MeSH terms: RNA, Viral/genetics
  3. Fulltext Rotavirus RNA electropherotype in different states in Malaysia for the year 2000 and 2001
    Zuridah H, Bahaman AR, Mohd Azmi ML, Mutalib AR
    Med J Malaysia, 2004 Jun;59(2):153-9.
    PMID: 15559163 MyJurnal
    A total of 157 stool samples were examined for Group A rotaviruses in diarrheic children admitted to 8 different major hospitals in Malaysia. The overall incidence rate in this study was 19.7% (31 of 157) with a variation of 9.5% to 39.1% in different locations. Majority of the infections detected were in those under 2 years of age and there were fewer admissions in the older age group. The stool samples were initially screened for rotavirus Group A by latex agglutination method and followed by RNA electrophoresis. The size and the characteristics wheel-shaped morphology of the viral preparations when examined by electron-microscopy further confirmed the presence of rotaviruses in the positive stool samples. Analysis of the RNA pattern showed that majority of the isolates, 51.6% (16 of 31) were Type IIC ('long' with comigration of RNA segments 7 and 8), 35.5% (11 of 31) with Type IIG ('long' with comigration of segments 7, 8, 9), 9.7% (3 of 31) with Type IG ('short' with comigration of RNA segments 7, 8, 9) and 3.2% (1 of 31) of mixed or atypical pattern. It appeared that over a 12 year interval, only one new or unusual rotavirus electropherotype was found. This is the first comprehensive report on the electropherotypes of rotaviruses covering eight different geographical locations in Malaysia and the data obtained is useful for understanding the geographic distribution and types of rotaviruses transmitting in Malaysia.
    Matched MeSH terms: RNA, Viral/genetics
  4. Divergence of the dengue virus type 2 Cosmopolitan genotype associated with two predominant serotype shifts between 1 and 2 in Surabaya, Indonesia, 2008-2014
    Kotaki T, Yamanaka A, Mulyatno KC, Churrotin S, Sucipto TH, Labiqah A, et al.
    Infect Genet Evol, 2016 Jan;37:88-93.
    PMID: 26553170 DOI: 10.1016/j.meegid.2015.11.002
    Indonesia is one of the biggest dengue endemic countries, and, thus, is an important place to investigate the evolution of dengue virus (DENV). We have continuously isolated DENV in Surabaya, the second biggest city in Indonesia, since 2008. We previously reported sequential changes in the predominant serotype from DENV type 2 (DENV-2) to DENV type 1 (DENV-1) in November 2008 and from DENV-1 to DENV-2 in July 2013. The predominance of DENV-2 continued in 2014, but not in 2015. We herein phylogenetically investigated DENV-2 transitions in Surabaya between 2008 and 2014 to analyze the divergence and evolution of DENV-2 concomitant with serotype shifts. All DENV-2 isolated in Surabaya were classified into the Cosmopolitan genotype, and further divided into 6 clusters. Clusters 1-3, dominated by Surabaya strains, were defined as the "Surabaya lineage". Clusters 4-6, dominated by strains from Singapore, Malaysia, and many parts of Indonesia, were the "South East Asian lineage". The most recent common ancestor of these strains existed in 1988, coinciding with the time that an Indonesian dengue outbreak took place. Cluster 1 appeared to be unique because no other DENV-2 isolate was included in this cluster. The predominance of DENV-2 in 2008 and 2013-14 were caused by cluster 1, whereas clusters 2 and 3 sporadically emerged in 2011 and 2012. The characteristic amino acids of cluster 1, E-170V and E-282Y, may be responsible for its prevalence in Surabaya. No amino acid difference was observed in the envelope region between strains in 2008 and 2013-14, suggesting that the re-emergence of DENV-2 in Surabaya was due to the loss or decrease of herd immunity in the 5-year period when DENV-2 subsided. The South East Asian lineage primarily emerged in Surabaya in 2014, probably imported from other parts of Indonesia or foreign countries.
    Matched MeSH terms: RNA, Viral/genetics*
  5. Detection and Quantification of Chikungunya Virus by Real-Time RT-PCR Assay
    Wang SM, Ali UH, Sekaran SD, Thayan R
    Methods Mol Biol, 2016;1426:105-17.
    PMID: 27233265 DOI: 10.1007/978-1-4939-3618-2_10
    Real-time PCR assay has many advantages over conventional PCR methods, including rapidity, quantitative measurement, low risk of contamination, high sensitivity, high specificity, and ease of standardization (Mackay et al., Nucleic Acids Res 30:1292-1305, 2002). The real-time PCR system relies upon the measurement of a fluorescent reporter during PCR, in which the amount of emitted fluorescence is directly proportional to the amount of the PCR product in a reaction (Gibsons et al., Genome Res 6:995-1001, 1996). Here, we describe the use of SYBR Green I-based and TaqMan(®) real-time reverse transcription polymerase chain reaction (RT-PCR) for the detection and quantification of Chikungunya virus (CHIKV).
    Matched MeSH terms: RNA, Viral/genetics
  6. Fulltext Genotypic distribution of hepatitis C virus in Thailand and Southeast Asia
    Wasitthankasem R, Vongpunsawad S, Siripon N, Suya C, Chulothok P, Chaiear K, et al.
    PLoS One, 2015;10(5):e0126764.
    PMID: 25962112 DOI: 10.1371/journal.pone.0126764
    The majority of hepatitis C virus (HCV) infection results in chronic infection, which can lead to liver cirrhosis and hepatocellular carcinoma. Global burden of hepatitis C virus (HCV) is estimated at 150 million individuals, or 3% of the world's population. The distribution of the seven major genotypes of HCV varies with geographical regions. Since Asia has a high incidence of HCV, we assessed the distribution of HCV genotypes in Thailand and Southeast Asia. From 588 HCV-positive samples obtained throughout Thailand, we characterized the HCV 5' untranslated region, Core, and NS5B regions by nested PCR. Nucleotide sequences obtained from both the Core and NS5B of these isolates were subjected to phylogenetic analysis, and genotypes were assigned using published reference genotypes. Results were compared to the epidemiological data of HCV genotypes identified within Southeast Asian. Among the HCV subtypes characterized in the Thai samples, subtype 3a was the most predominant (36.4%), followed by 1a (19.9%), 1b (12.6%), 3b (9.7%) and 2a (0.5%). While genotype 1 was prevalent throughout Thailand (27-36%), genotype 3 was more common in the south. Genotype 6 (20.9%) constituted subtype 6f (7.8%), 6n (7.7%), 6i (3.4%), 6j and 6m (0.7% each), 6c (0.3%), 6v and 6xa (0.2% each) and its prevalence was significantly lower in southern Thailand compared to the north and northeast (p = 0.027 and p = 0.030, respectively). Within Southeast Asia, high prevalence of genotype 6 occurred in northern countries such as Myanmar, Laos, and Vietnam, while genotype 3 was prevalent in Thailand and Malaysia. Island nations of Singapore, Indonesia and Philippines demonstrated prevalence of genotype 1. This study further provides regional HCV genotype information that may be useful in fostering sound public health policy and tracking future patterns of HCV spread.
    Matched MeSH terms: RNA, Viral/genetics
  7. Direct nucleotide sequencing using total cellular RNA from dengue-virus-infected mosquito cells
    Kautner IM, Lam SK
    Res. Virol., 1992 May-Jun;143(3):193-7.
    PMID: 1355609
    In recent years, a large amount of nucleotide sequence data for dengue viruses has been published. Most of it was derived by sequencing cDNA synthesized from highly purified genomic viral RNA. This paper presents a simple and rapid method for the isolation of total RNA from mosquito cells infected with dengue viruses. This RNA can be used for direct nucleotide sequencing with specific primers without the need for further purification.
    Matched MeSH terms: RNA, Viral/genetics*
  8. Molecular characterization of the Japanese encephalitis serocomplex of the flavivirus genus
    Poidinger M, Hall RA, Mackenzie JS
    Virology, 1996 Apr 15;218(2):417-21.
    PMID: 8610471
    The Japanese encephalitis (JE) serocomplex of flaviviruses comprises 10 members, 9 of which: Alfuy (ALF); Koutango (KOU); Kokobera (KOK); Kunjin (KUN); Murray Valley encephalitis (MVE); JE; Stratford (STR); Usutu (USU); and West Nile (WN) have been isolated from Africa, southern Europe, Middle East, Asia, and Australia. The tenth member, St. Louis encephalitis (SLE) virus, is confined to North, Central, and South America. For ALF, KOK, KOU, STR, and USU, no sequence data have as yet been reported, and little molecular phylogeny has been determined for this complex as a whole. Using a rapid, one-step RT-PCR and universal primers, we have amplified and sequenced a 450-600 base pair region of the virus genome encompassing the N terminus of the nonstructural protein NS5 and the 5' end of the 3' noncoding region, for several strains of all of these viruses, except USU and SLE viruses. These data, as well as published sequence data for other flaviviruses, were analyzed with the ClustalW and Phylip computer packages. The resultant phylogenetic data were consistent with some of the current flavivirus serological classification, showing a close relationship between ALF and MVE viruses and between KOK and STR viruses, but suggested that KOK and STR are distantly related to the other viruses and should perhaps be reclassified in their own serocomplex. The data also confirmed the close relationship between KUN and WN viruses and showed that an isolate of KUN virus from Sarawak may represent a "link" between these two virus species. In addition, the primary sequence data revealed a polymorphic region just downstream of the stop codon in the 3' end of the viral genomes.
    Matched MeSH terms: RNA, Viral/genetics
  9. Oligonucleotide fingerprint analysis of strains of Getah virus isolated in Japan and Malaysia
    Morita K, Igarashi A
    J Gen Virol, 1984 Nov;65 ( Pt 11):1899-908.
    PMID: 6094708
    Eighteen strains of Getah virus isolated from mosquitoes, swine and horses in Japan (1956 to 1981), and one strain isolated in Malaysia (1955), were analysed by RNase T1-resistant oligonucleotide fingerprinting. All fingerprints showed a poly(A) tract. The fingerprint pattern of the Malaysian strain was quite different from those of the Japanese strains. Although most of the recent Japanese isolates shared many large oligonucleotide spots in common, the patterns were not identical even among the strains obtained in one locality in the same year. These results suggest that the Getah virus genome undergoes mutation rather frequently. However, there is a tendency for the isolates of the same year to show greater similarity. The fingerprint patterns of certain host-dependent temperature-sensitive (ts) mutants differed from that of the parental strain. Also, there were some differences in large oligonucleotide spots between strain JaNAr12380M isolated in suckling mouse brain (SMB) and strain JaNAr12380A isolated in C6/36 cells, despite the fact that both strains were derived from the same wild mosquito homogenate. In addition, many host-dependent ts mutants were present in strain JaNAr12380A, whereas no such mutants were observed in strain JaNAr12380M. It is concluded that there is considerable variation in the strains of Getah virus infecting mosquitoes in the wild, and also that the variants or mutants present in mosquitoes might be subject to selection during viral multiplication in the mammalian host.
    Matched MeSH terms: RNA, Viral/genetics*
  10. Genetic variation of Japanese encephalitis virus in nature
    Chen WR, Tesh RB, Rico-Hesse R
    J Gen Virol, 1990 Dec;71 ( Pt 12):2915-22.
    PMID: 2273391
    Forty-six strains of Japanese encephalitis (JE) virus from a variety of geographic areas in Asia were examined by primer-extension sequencing of the RNA template. A 240 nucleotide sequence from the pre-M gene region was selected for study because it provided sufficient information for determining genetic relationships among the virus isolates. Using 12% divergence as a cutoff point for virus relationships, the 46 isolates fell into three distinct genotypic groups. One genotypic group consisted of JE virus isolates from northern Thailand and Cambodia. A second group was composed of isolates from southern Thailand, Malaysia, Sarawak and Indonesia. The remainder of the isolates, from Japan, China, Taiwan, the Philippines, Sri Lanka, India and Nepal, made up a third group. The implications of these findings in relation to the epidemiology of JE are discussed. Results of this study demonstrate that the comparison of short nucleotide sequences can provide insight into JE virus evolution, transmission and, possibly, pathogenesis.
    Matched MeSH terms: RNA, Viral/genetics*
  11. Fulltext A Sensitive Reverse Transcription Loop-Mediated Isothermal Amplification Assay for Direct Visual Detection of SARS-CoV-2
    Lau YL, Ismail IB, Izati Binti Mustapa N, Lai MY, Tuan Soh TS, Hassan AH, et al.
    Am J Trop Med Hyg, 2020 Dec;103(6):2350-2352.
    PMID: 33098286 DOI: 10.4269/ajtmh.20-1079
    A simple and rapid reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of SARS-CoV-2. The RT-LAMP assay was highly specific for SARS-CoV-2 and was able to detect one copy of transcribed SARS-CoV-2 RNA within 24 minutes. Assay validation performed using 50 positive and 32 negative clinical samples showed 100% sensitivity and specificity. The RT-LAMP would be valuable for clinical diagnosis and epidemiological surveillance of SARS-CoV-2 infection in resource-limited areas as it does not require the use of sophisticated and costly equipment.
    Matched MeSH terms: RNA, Viral/genetics*
  12. Fulltext Application of Reverse Genetics in Functional Genomics of Potyvirus
    Kannan M, Zainal Z, Ismail I, Baharum SN, Bunawan H
    Viruses, 2020 07 26;12(8).
    PMID: 32722532 DOI: 10.3390/v12080803
    Numerous potyvirus studies, including virus biology, transmission, viral protein function, as well as virus-host interaction, have greatly benefited from the utilization of reverse genetic techniques. Reverse genetics of RNA viruses refers to the manipulation of viral genomes, transfection of the modified cDNAs into cells, and the production of live infectious progenies, either wild-type or mutated. Reverse genetic technology provides an opportunity of developing potyviruses into vectors for improving agronomic traits in plants, as a reporter system for tracking virus infection in hosts or a production system for target proteins. Therefore, this review provides an overview on the breakthroughs achieved in potyvirus research through the implementation of reverse genetic systems.
    Matched MeSH terms: RNA, Viral/genetics
  13. Complete nucleotide sequence of RNA segment 3 of bluetongue virus serotype 2 (Ona-A). Phylogenetic analyses reveal the probable origin and relationship with other orbiviruses
    Pritchard LI, Gould AR, Wilson WC, Thompson L, Mertens PP, Wade-Evans AM
    Virus Res, 1995 Mar;35(3):247-61.
    PMID: 7785314
    The nucleotide sequence of the RNA segment 3 of bluetongue virus (BTV) serotype 2 (Ona-A) from North America was determined to be 2772 nucleotides containing a single large open reading frame of 2703 nucleotides (901 amino acid). The predicted VP3 protein exhibited general physiochemical properties (including hydropathy profiles) which were very similar to those previously deduced for other BTV VP3 proteins. Partial genome segment 3 sequences, obtained by polymerase chain reaction (PCR) sequencing, of BTV isolates from the Caribbean were compared to those from North America, South Africa, India, Indonesia, Malaysia and Australia, as well as other orbiviruses, to determine the phylogenetic relationships amongst them. Three major BTV topotypes (Gould, A.R. (1987) Virus Res. 7, 169-183) were observed which had nucleotide sequences that differed by approximately 20%. At the molecular level, geographic separation had resulted in significant divergence in the BTV genome segment 3 sequences, consistent with the evolution of distinct viral populations. The close phylogenetic relationship between the BTV serotype 2 (Ona-A strain) from Florida and the BTV serotypes 1, 6 and 12 from Jamaica and Honduras, indicated that the presence of BTV serotype 2 in North America was probably due to an exotic incursion from the Caribbean region as previously proposed by Sellers and Maaroof ((1989) Can. J. Vet. Res. 53, 100-102) based on trajectory analysis. Conversely, nucleotide sequence analysis of Caribbean BTV serotype 17 isolates suggested they arose from incursions which originated in the USA, possibly from a BTV population distinct from those circulating in Wyoming.
    Matched MeSH terms: RNA, Viral/genetics*
  14. Fulltext Characterization of a novel orthoreovirus isolated from fruit bat, China
    Hu T, Qiu W, He B, Zhang Y, Yu J, Liang X, et al.
    BMC Microbiol, 2014;14:293.
    PMID: 25433675 DOI: 10.1186/s12866-014-0293-4
    In recent years novel human respiratory disease agents have been described for Southeast Asia and Australia. The causative pathogens were classified as pteropine orthoreoviruses with a strong phylogenetic relationship to orthoreoviruses of bat origin.
    Matched MeSH terms: RNA, Viral/genetics
  15. Fulltext Mass spectrometry-based identification and whole-genome characterisation of the first pteropine orthoreovirus isolated from monkey faeces in Thailand
    Kosoltanapiwat N, Reamtong O, Okabayashi T, Ampawong S, Rungruengkitkun A, Thiangtrongjit T, et al.
    BMC Microbiol, 2018 10 17;18(1):135.
    PMID: 30332986 DOI: 10.1186/s12866-018-1302-9
    BACKGROUND: The pteropine orthoreovirus (PRV) was isolated from monkey (Macaca fascicularis) faecal samples collected from human-inhabited areas in Lopburi Province, Thailand. These samples were initially obtained to survey for the presence of hepatitis E virus (HEV).

    RESULTS: Two virus isolates were retrieved by virus culture of 55 monkey faecal samples. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was successfully used to identify the viruses as the segmented dsRNA orthoreovirus. Phylogenetic analysis of the Lopburi orthoreovirus whole-genomes revealed relationships with the well-characterised PRVs Pulau (segment L1), Cangyuan (segments L2, M3 and S3), Melaka (segments L3 and M2), Kampar (segments M1 and S2) and Sikamat (segments S1 and S4) of Southeast Asia and China with nucleotide sequence identities of 93.5-98.9%. RT-PCR showed that PRV was detected in 10.9% (6/55) and HEV was detected in 25.5% (14/55) of the monkey faecal samples.

    CONCLUSIONS: PRV was isolated from monkey faeces for the first time in Thailand via viral culture and LC-MS/MS. The genetic diversity of the virus genome segments suggested a re-assortment within the PRV species group. The overall findings emphasise that monkey faeces can be sources of zoonotic viruses, including PRV and HEV, and suggest the need for active virus surveillance in areas of human and monkey co-habitation to prevent and control emerging zoonotic diseases in the future.

    Matched MeSH terms: RNA, Viral/genetics
  16. Fulltext The indonesian variants of CRF33_01B: Near-full length sequence analysis
    SahBandar IN, Takahashi K, Motomura K, Djoerban Z, Firmansyah I, Kitamura K, et al.
    AIDS Res Hum Retroviruses, 2011 Jan;27(1):97-102.
    PMID: 20958201 DOI: 10.1089/aid.2010.0163
    Cocirculation of subtype B and CRF01_AE in Southeast Asia has led to the establishment of new recombinant forms. In our previous study, we found five samples suspected of being recombinants between subtype B and CRF01_AE, and here, we analyzed near full-length sequences of two samples and compared them to known CRFs_01B, subtype B, and CRF01_AE. Five overlapped segments were amplified with nested PCR from PBMC DNA, sequenced, and analyzed for genome mosaicism. The two Indonesian samples, 07IDJKT189 and 07IDJKT194, showed genome-mosaic patterns similar to CRF33_01B references from Malaysia, with one short segment in the 3' end of the p31 integrase-coding region, which was rather more similar to subtype B than CRF01_AE, consisting of unclassified sequences. These results suggest gene-specific continuous diversification and spread of the CRF33_01B genomes in Southeast Asia.
    Matched MeSH terms: RNA, Viral/genetics*
  17. Methods in Screening Antiviral Drugs Against Enterovirus 71
    Bajaber NAOA, Ramanathan B
    Methods Mol Biol, 2021;2296:167-184.
    PMID: 33977447 DOI: 10.1007/978-1-0716-1358-0_9
    Enteroviruses 71 (EV71) is a single-stranded, neurotrophic RNA virus responsible for the numerous outbreaks of hand, foot, and mouth disease (HFMD) in the Asia-Pacific regions. HFMD primarily affects children to cause range of infection, from mild symptoms to acute flaccid paralysis, and hemorrhage. Despite increased incidence of EV71 epidemics globally and research against EV71 becoming prioritized, no antiviral agent against EV71 has yet been licensed and approved worldwide. In this chapter, detailed EV71 antiviral screening techniques are described, including plaque assay which determines viral titers through the use of a semisolid overlay, carboxymethyl cellulose to allow even viral spread and infection across the host cellular monolayers as well as a crystal violet, a distinct counterstain to visualize circular regions of infectious zones-plaques. qRT-PCR is used to quantify the viral genomic RNA in the infected samples and MTS cell viability assay to quantify the cell viability after infection or toxicity of the compound on the cells. Furthermore, various antiviral inhibition assays including prophylactic, post infection, and virucidal assays are demonstrated for estimation of the antiviral activity of potential antiviral drugs against EV71. These methods can be effectively utilized in virology laboratories for effective high-throughput screening of antiviral molecules against EV71 that can assist in the future development of antiviral drugs.
    Matched MeSH terms: RNA, Viral/genetics
  18. Fulltext Dengue serotype surveillance among patients admitted for dengue in two major hospitals in Selangor, Malaysia, 2010-2011
    Ab-Fatah M, Subenthiran S, Abdul-Rahman PS, Saat Z, Thayan R
    Trop Biomed, 2015 Mar;32(1):187-91.
    PMID: 25801270 MyJurnal
    Dengue serotype surveillance is important as any changes in serotype distribution may result in an outbreak or increase in severe dengue cases. This study aimed to determine circulating dengue serotypes in two hospitals in Selangor. Serum samples were collected from patients admitted for dengue at these two major public hospitals i.e. Hospital Sungai Buloh (HSB) and Hospital Tunku Ampuan Rahimah (HTAR) between November 2010 and August 2011 and subjected to real-time RT-PCR using SYBR® Green. All four dengue serotypes were detected in samples from both hospitals. The predominating serotype was dengue 1 in samples from both hospitals (HSB, DENV-1; 25.53 % and HTAR, DENV-1; 32.1 %).
    Matched MeSH terms: RNA, Viral/genetics
  19. The appearance of a second genotype of Japanese encephalitis virus in the Australasian region
    Pyke AT, Williams DT, Nisbet DJ, van den Hurk AF, Taylor CT, Johansen CA, et al.
    Am J Trop Med Hyg, 2001 Dec;65(6):747-53.
    PMID: 11791969
    In mid-January 2000, the reappearance of Japanese encephalitis (JE) virus activity in the Australasian region was first demonstrated by the isolation of JE virus from 3 sentinel pigs on Badu Island in the Torres Strait. Further evidence of JE virus activity was revealed through the isolation of JE virus from Culex gelidus mosquitoes collected on Badu Island and the detection of specific JE virus neutralizing antibodies in 3 pigs from Saint Pauls community on Moa Island. Nucleotide sequencing and phylogenetic analyses of the premembrane and envelope genes were performed which showed that both the pig and mosquito JE virus isolates (TS00 and TS4152, respectively) clustered in genotype I, along with northern Thai, Cambodian, and Korean isolates. All previous Australasian JE virus isolates belong to genotype II, along with Malaysian and Indonesian isolates. Therefore, for the first time, the appearance and transmission of a second genotype of JE virus in the Australasian region has been demonstrated.
    Matched MeSH terms: RNA, Viral/genetics
  20. Fulltext Isolation and Identification of Inter-Species Enterovirus Recombinant Genomes
    Bentley K, Tee HK, Pearson A, Lowry K, Waugh S, Jones S, et al.
    Viruses, 2021 11 29;13(12).
    PMID: 34960659 DOI: 10.3390/v13122390
    Positive-strand RNA virus evolution is partly attributed to the process of recombination. Although common between closely genetically related viruses, such as within species of the Enterovirus genus of the Picornaviridae family, inter-species recombination is rarely observed in nature. Recent studies have shown recombination is a ubiquitous process, resulting in a wide range of recombinant genomes and progeny viruses. While not all recombinant genomes yield infectious progeny virus, their existence and continued evolution during replication have critical implications for the evolution of the virus population. In this study, we utilised an in vitro recombination assay to demonstrate inter-species recombination events between viruses from four enterovirus species, A-D. We show that inter-species recombinant genomes are generated in vitro with polymerase template-switching events occurring within the virus polyprotein coding region. However, these genomes did not yield infectious progeny virus. Analysis and attempted recovery of a constructed recombinant cDNA revealed a restriction in positive-strand but not negative-strand RNA synthesis, indicating a significant block in replication. This study demonstrates the propensity for inter-species recombination at the genome level but suggests that significant sequence plasticity would be required in order to overcome blocks in the virus life cycle and allow for the production of infectious viruses.
    Matched MeSH terms: RNA, Viral/genetics
Related Terms
Filters
Contact Us

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

External Links