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Fulltext A comparative evaluation of dengue diagnostic tests based on single-acute serum samples for laboratory confirmation of acute dengue

Chua KB, Mustafa B, Abdul Wahab AH, Chem YK, Khairul AH, Kumarasamy V, et al.

Malays J Pathol, 2011 Jun;33(1):13-20.
PMID: 21874746

A prospective study was carried out to evaluate the sensitivity of dengue NS1 antigen-capture ELISA in comparison with dengue virus isolation, conventional RT-PCR and real-time RT-PCR for laboratory confirmation of acute dengue based on single-acute serum samples. Four primary healthcare centres were involved to recruit patients with clinical diagnosis of dengue illness. Patient's demographic, epidemiological and clinical information were collected on a standardized data entry form and 5 ml of venous blood was collected upon consent. In the laboratory, six types of laboratory tests were performed on each of the collected acute serum sample. Of the 558 acute serum samples collected from 558 patients with clinical diagnosis of dengue from mid-August 2006 to March 2009, 174 serum samples were tested positive by the dengue NS1 antigen-capture ELISA, 77 by virus isolation, 92 by RT-PCR and 112 by real-time RT-PCR. A total of 190 serum samples were tested positive by either one or a combination of the four methods whereas, only 59 serum samples were tested positive by all four methods. Thus, based on single-acute serum samples, 190 of the 558 patients (34.1%) were laboratory-confirmed acute dengue. The overall test sensitivity was 91.6%, 40.5%, 48.4% and 58.9% for dengue NS1 antigen-capture ELISA, virus isolation, conventional RT-PCR and real-time RT-PCR respectively. Statistically, dengue NS1 antigen-capture ELISA was the most sensitive and virus isolation was the least sensitive test for the laboratory confirmation of acute dengue based on single-acute serum specimens. Real-time RT-PCR was significantly more sensitive than the conventional RT-PCR.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Fulltext A reverse transcription loop-mediated isothermal amplification for broad coverage detection of Asian and African Zika virus lineages

Teoh BT, Chin KL, Samsudin NI, Loong SK, Sam SS, Tan KK, et al.

BMC Infect Dis, 2020 Dec 11;20(1):947.
PMID: 33308203 DOI: 10.1186/s12879-020-05585-4

BACKGROUND: Early detection of Zika virus (ZIKV) infection during the viremia and viruria facilitates proper patient management and mosquito control measurement to prevent disease spread. Therefore, a cost-effective nucleic acid detection method for the diagnosis of ZIKV infection, especially in resource-deficient settings, is highly required.
METHODS: In the present study, a single-tube reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of both the Asian and African-lineage ZIKV. The detection limit, strain coverage and cross-reactivity of the ZIKV RT-LAMP assay was evaluated. The sensitivity and specificity of the RT-LAMP were also evaluated using a total of 24 simulated clinical samples. The ZIKV quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used as the reference assay.
RESULTS: The detection limit of the RT-LAMP assay was 3.73 ZIKV RNA copies (probit analysis, P ≤ 0.05). The RT-LAMP assay detected the ZIKV genomes of both the Asian and African lineages without cross-reacting with other arthropod-borne viruses. The sensitivity and specificity of the RT-LAMP assay were 90% (95% CI = 59.6-98.2) and 100% (95% CI = 78.5-100.0), respectively. The RT-LAMP assay detected ZIKV genome in 9 of 24 (37.5%) of the simulated clinical samples compared to 10 of 24 (41.7%) by qRT-PCR assay with a high level of concordance (κ = 0.913, P

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods
Fulltext A quantitative reverse transcription-polymerase chain reaction for detection of Getah virus

Sam SS, Teoh BT, Chee CM, Mohamed-Romai-Noor NA, Abd-Jamil J, Loong SK, et al.

Sci Rep, 2018 12 05;8(1):17632.
PMID: 30518924 DOI: 10.1038/s41598-018-36043-6

Getah virus (GETV), a mosquito-borne alphavirus, is an emerging animal pathogen causing outbreaks among racehorses and pigs. Early detection of the GETV infection is essential for timely implementation of disease prevention and control interventions. Thus, a rapid and accurate nucleic acid detection method for GETV is highly needed. Here, two TaqMan minor groove binding (MGB) probe-based quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assays were developed. The qRT-PCR primers and TaqMan MGB probe were designed based on the conserved region of nsP1 and nsP2 genes of 23 GETV genome sequences retrieved from GenBank. Only the qRT-PCR assay using nsP2-specific primers and probe detected all two Malaysia GETV strains (MM2021 and B254) without cross-reacting with other closely related arboviruses. The qRT-PCR assay detected as few as 10 copies of GETV RNA, but its detection limit at the 95% probability level was 63.25 GETV genome copies (probit analysis, P ≤ 0.05). Further validation of the qRT-PCR assay using 16 spiked simulated clinical specimens showed 100% for both sensitivity and specificity. In conclusion, the qRT-PCR assay developed in this study is useful for rapid, sensitive and specific detection and quantification of GETV.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Fulltext Early detection of dengue virus by use of reverse transcription-recombinase polymerase amplification

Teoh BT, Sam SS, Tan KK, Danlami MB, Shu MH, Johari J, et al.

J Clin Microbiol, 2015 Mar;53(3):830-7.
PMID: 25568438 DOI: 10.1128/JCM.02648-14

A method for the rapid diagnosis of early dengue virus (DENV) infection is highly needed. Here, a prototype reverse transcription-recombinase polymerase amplification (RT-RPA) assay was developed. The assay detected DENV RNA in <20 min without the need for thermocycling amplification. The assay enabled the detection of as few as 10 copies of DENV RNA. The designed RT-RPA primers and exo probe detected the DENV genome of at least 12 genotypes of DENV circulating globally without cross-reacting with other arboviruses. We assessed the diagnostic performance of the RT-RPA assay for the detection of DENV RNA in 203 serum samples of patients with clinically suspected dengue. The sera were simultaneously tested for DENV using a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay, quantitative RT-PCR (qRT-PCR), and IgM- and IgG-capture enzyme-linked immunosorbent assays (ELISA). Acute DENV infection was confirmed in 130 samples and 61 of the samples (46.9%) were classified as viremic with qRT-PCR. The RT-RPA assay showed good concordance (κ of ≥0.723) with the RT-LAMP and qRT-PCR assays in detecting the dengue viremic samples. When used in combination with ELISA, both the RT-RPA and RT-LAMP assays increased the detection of acute DENV infection to ≥95.7% (≥45/47) in samples obtained within 5 days of illness. The results from the study suggest that the RT-RPA assay is the most rapid molecular diagnostic tool available for the detection of DENV. Hence, it is possible to use the RT-RPA assay in a laboratory to complement routine serology testing for dengue.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Sequence analysis of Malaysian infectious bursal disease virus isolate and the use of reverse transcriptase nested polymerase chain reaction enzyme-linked immunosorbent assay for the detection of VP2 hypervariable region

Phong SF, Hair-Bejo M, Omar AR, Aini I

Avian Dis, 2003 Jan-Mar;47(1):154-62.
PMID: 12713171

The VP2 hypervariable region of P97/302 local infectious bursal disease virus (IBDV) isolate was amplified by the reverse transcriptase (RT) nested polymerase chain reaction (PCR) and cloned. This region of P97/302 local isolate was sequenced and compared with eight other reported IBDV sequences. The result showed that P97/302 IBDV was most identical to the reported very virulent IBDV strains because it has amino acid substitutions at positions 222, 256, 294, and 299, which encode alanine, isoleucine, isoleucine, and serine, respectively. This region can be digested with restriction enzymes of Taq1, Sty1, Ssp1 but not with Sac1. The P97/302 isolate was then used for the optimization of RT nested PCR enzyme-linked immunosorbent assay (ELISA). The RT nested PCR ELISA was able to detect 10(-4) dilution of the infected bursa homogenates and was 10 times more sensitive when compared with the agarose gel detection method. The RT nested PCR ELISA can detect up to 0.48 ng of the PCR product. The specificity of this nested PCR ELISA was also high (100%).

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Rapid detection of the UGT1A1 single nucleotide polymorphism G211A using real-time PCR with Taqman minor groove binder probes

Wong FL, Wang MK, Boo NY, Hamidah NH, Ainoon BO

J Clin Lab Anal, 2007;21(3):167-72.
PMID: 17506482

The UGT1A1 Taqman MGB probe single nucleotide polymorphism (SNP) genotyping assay was developed to detect nucleotide 211 of the UDP-glucoronocyltransferase 1A1 (UGT1A1) gene. Defects in this enzyme interfere with process of conjugation of bilirubin and cause unconjugated hyperbilirubinemia. Variation at nucleotide 211 in the coding region of the UGT1A1 gene has been shown to be prevalent in Japanese and Chinese. Using an ABI sequence detection system (SDS) 7000, an allele-specific real-time PCR-based genotyping method was established to detect nucleotide G211A. Cord blood from 125 infants without hyperbilirubinemia (controls) were compared with cord blood from 74 infants (cases) with severe hyperbilirubinemia (total serum bilirubin > 300 micromol/L). Homozygous variation of the UGT1A1 gene at nucleotide 211(A/A) is significantly more common in cases (14.9%) than in controls (0.8%) (P<0.001). Direct sequencing from 20 randomly selected samples showed eight samples with homozygous wild type, seven with homozygous variant, and five samples were heterozygous. The result from this assay was in complete concordance with the DNA sequencing result and clearly discriminate wild-type (G/G), homozygous variant (A/A), and heterozygous (G/A). This assay is rapid and robust for screening of SNP G211A to determine if this polymorphism plays a role in causing severe neonatal jaundice in the local context.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Real-time quantification for BCR-ABL transcripts in chronic myeloid leukaemia patients in UKMMC, Malaysia

Wong FL, Hamidah NH, Hawa AA, Nurul AN, Leong CF, Saw F, et al.

Malays J Pathol, 2011 Dec;33(2):107-12.
PMID: 22299211

Molecular pathogenesis of chronic myeloid leukemia (CML) is well established and molecular monitoring for patients with CML has become an important practice in the management of patients on imatinib therapy. In the present study, we report the use of RQ-PCR method for detection of BCR-ABL fusion gene for our CML cases. We performed a two-step RQ-PCR on bone marrow aspirates or peripheral blood of 37 CML patients. Quantitative expression of BCR-ABL fusion gene was carried out relative to the expression of a housekeeping gene as endogenous control to compensate for uneven cell numbers, RNA quality, or variations in reverse transcription efficiencies. Twenty-four of these patients were pre-treated with hydroxyurea or alpha interferon prior to the imatinib therapy. Their BCR-ABL fusion gene levels were monitored for 18 months. All samples processed were evaluable. The PCR amplification efficiency of the ABL gene is 90.5% (0.2158) and the BCR-ABL gene, 93.4% (0.1573).

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
A comparison of the VP1, VP2, and VP4 regions for molecular typing of human enteroviruses

Perera D, Shimizu H, Yoshida H, Tu PV, Ishiko H, McMinn PC, et al.

J Med Virol, 2010 Apr;82(4):649-57.
PMID: 20166171 DOI: 10.1002/jmv.21652

The VP4, VP2, and VP1 gene regions were evaluated for their usefulness in typing human enteroviruses. Three published RT-PCR primers sets targeting separately these three gene regions were used. Initially, from a total of 86 field isolates (36 HEV-A, 40 HEV-B, and 10 HEV-C) tested, 100% concordance in HEV-A was identified from all three gene regions (VP4, VP2, and VP1). However, for HEV-B and HEV-C viruses, only the VP2 and VP1 regions, and not VP4, showed 100% concordance in typing these viruses. To evaluate further the usefulness of VP4 in typing HEV-A enteroviruses, 55 Japanese and 203 published paired VP4 and VP1 nucleotide sequences were also examined. In each case, typing by VP4 was 100% in concordance with typing using VP1. Given these results, it is proposed that for HEV-A enteroviruses, all three gene regions (VP4, VP2, and VP1), would be useful for typing these viruses. These options would enhance the capability of laboratories in identifying these viruses and would greatly help in outbreaks of hand, foot, and mouth disease.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Incorrect identification of recent Asian strains of Coxsackievirus A16 as human enterovirus 71: improved primers for the specific detection of human enterovirus 71 by RT PCR

Perera D, Podin Y, Akin W, Tan CS, Cardosa MJ

BMC Infect Dis, 2004 May 4;4:11.
PMID: 15122971

Human enterovirus 71 has emerged as an important pathogen in the Asia Pacific region and it is important to be able to make a rapid and specific diagnosis for outbreak control. Recent Asian strains of Coxsackievirus A16 have changes in the VP1 gene which causes mispriming of widely used primers for human enterovirus 71 specific identification.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Implementation in Australia of molecular diagnostic techniques for the rapid detection of foot and mouth disease virus

Boyle DB, Taylor T, Cardoso M

Aust. Vet. J., 2004 Jul;82(7):421-5.
PMID: 15354851

OBJECTIVE: To evaluate and implement rapid molecular diagnostic techniques for the detection of foot and mouth disease virus (FMDV) suitable for use in Australia.
DESIGN: Two PCR TaqMan assays targeted to the FMDV internal ribosome entry site or the 3D polymerase coding region for the rapid detection of FMDV were evaluated using non-infectious materials to determine the test most appropriate for implementation as part of Australia's national preparedness for the rapid detection and diagnosis of FMD outbreaks.
RESULTS: Two published tests (PCR TaqMan assays targeted to the FMDV IRES region or the FMDV 3D polymerase coding region) were evaluated for their ability to detect FMDV genetic material in non-infectious FMDV ELISA antigen stocks held at Australian Animal Health Laboratory. Both tests were able to detect FMDV genetic material from strains O1 Manisa, O-3039, A22, A24, A Malaysia, C, Asia 1 and SAT 1, 2 and 3. With the exception of Asia 1, the TaqMan assay targeted to the FMD 3D polymerase coding region had Ct values equal to or lower than for the TaqMan assay targeted to the IRES region suggesting that this test may provide broader serotype detection and sensitivity. However, the TaqMan assay directed to the FMDV IRES is the only one to date to have undergone substantial evaluation using clinical samples collected during an outbreak. The greatest differences observed were for O-3039, SAT 1, and 3.
CONCLUSION: Given the ease of setting up both tests, AAHL currently runs both tests on highly suspect FMD investigations to provide independent confirmation of the absence of FMDV because the tests are focused on two independent regions of the FMDV genome. These tests add substantially to Australia's preparedness for FMD diagnosis complementing the already well-established virus isolation and antigen capture ELISA tests for index case diagnosis of FMD in Australia.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods
A modified in situ RT-PCR method for localizing fungal-specific gene expression in Candida-infected mice renal cells

Yong VC, Ong KW, Sidik SM, Rosli R, Chong PP

J Microbiol Methods, 2009 Nov;79(2):242-5.
PMID: 19737582 DOI: 10.1016/j.mimet.2009.08.019

In situ Reverse Transcriptase PCR (in situ RT-PCR) can amplify mRNA and localize gene expression in cells. However, this method is not feasible in fungi as the thick fungal cell wall constitutes a barrier to this procedure. We developed a two step in situ RT-PCR procedure which enabled the detection and localization of Candida tropicalis mRNA expression in formalin-fixed, paraffin-embedded (FFPE) mouse kidney sections. This in situ hybridization study revealed the first direct evidence for deposition of Candida tropicalis secreted aspartic proteinase 2 (CtSAP2) in the tip of pseudohyphae and its involvement in acute systemic candidiasis. We conclude that in situ RT-PCR can be successfully applied to FFPE tissues and will offer new perspectives in studying gene expression in Candida species.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Fulltext Isolation of monoclonal antibodies-escape variant of dengue virus serotype 1

Chua SK, Selvanesan S, Sivalingam B, Chem YK, Norizah I, Zuridah H, et al.

Singapore Med J, 2006 Nov;47(11):940-6.
PMID: 17075660

During an outbreak from December 2004 to March 2005, 138 isolates of dengue virus were prospectively obtained from acute-phase serum samples of 1,067 patients with the provisional clinical diagnosis of acute dengue illness admitted to the adult wards of Hospital Tengku Ampuan Rahimah, Klang, Malaysia. Of the 138 dengue virus isolates, 87, 11, 24 and 3 were typed as dengue serotypes 1, 2, 3 and 4, respectively, by a commercial dengue virus typing kit using monoclonal antibodies (Mab). 13 dengue virus isolates could not be assigned to any specific serotype by serotyping Mab and molecular typing using dengue-type specific molecular typing primer pairs. We report the associated clinical features and limited molecular genetics of this Mab-escape dengue virus variant.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Quantitative RT PCR approach to evaluate the neurogenic and gliagenic gene expression of cultured human amniotic epithelial cells

Tan GC, Simat SF, Abdul Rahman H, Tan AE, Chua KH

Med J Malaysia, 2008 Jul;63 Suppl A:51-2.
PMID: 19024979

The aim of the study is to determine the neuronal and glial gene expression of cultured human amniotic epithelial cells (HAECs) in serial passages. HAECs obtained from human term placentae were cultured in F12:DMEM (1:1) + 10% FBS +10ng/ml EGF in serial passages. Quantitative RT-PCR was used to assess the gene expression analysis. The results showed that the cultured HAECs expressed the neural stem cell genes (Nestin, NSE and Vimentin), mature neuronal genes (TH, MAP-2, beta-III-tubulin and NFM) and glial genes (CNPase, MBP and Olig). These neural stem cell genes increased with serial passages while the genes expression for mature neuronal and glial cells were downregulated. These results suggested that HAECs may promote or involve in neurogenesis and gliagenesis.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Specific detection of Nipah virus using real-time RT-PCR (TaqMan)

Guillaume V, Lefeuvre A, Faure C, Marianneau P, Buckland R, Lam SK, et al.

J Virol Methods, 2004 Sep 15;120(2):229-37.
PMID: 15288966

Nipah and Hendra viruses belong to the novel Henipavirus genus of the Paramyxoviridae family. Its zoonotic circulation in bats and recent emergence in Malaysia with fatal consequences for humans that were in close contact with infected pigs, has made the reinforcement of epidemiological and clinical surveillance systems a priority. In this study, TaqMan RT-PCR of the Nipah nucleoprotein has been developed so that Nipah virus RNA in field specimens or laboratory material can be characterized rapidly and specifically and quantitated. The linearity of the standard curve allowed quantification of 10(3) to 10(9) RNA transcripts. The sensitivity of the test was close to 1 pfu. The kinetics of Nipah virus production in Vero cells was monitored by the determination of infectious virus particles in the supernatant fluid and by quantitation of the viral RNA. Approximately, 1000 RNA molecules were detected per virion, suggesting the presence of many non-infectious particles, similar to other RNA viruses. TaqMan real-time RT-PCR failed to detect Hendra virus DNA. Importantly, the method was able to detect virus despite a similar ratio in viremic sera from hamsters infected with Nipah virus. This standardized technique is sensitive and reliable and allows rapid detection and quantitation of Nipah RNA in both field and experimental materials used for the surveillance and specific diagnosis of Nipah virus.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
A preliminary study of dengue infection in Brunei

Osman O, Fong MY, Devi S

Jpn J Infect Dis, 2007 Jul;60(4):205-8.
PMID: 17642533

The purpose of this study was to examine the extent of dengue infection in Brunei and to determine the predominant serotype circulating in the country. The study generated useful epidemiological data on dengue infection in Brunei. A total of 271 samples from patients suspected of having dengue infections were selected and analyzed. All patients were seen in clinics and hospitals in Brunei. The samples were collected from April 2005 to April 2006 and transported to the WHO Collaborating Centre for Arbovirus Reference and Research, University of Malaya, Malaysia. The following tests were used to achieve the objectives: in-house IgM-capture enzyme-linked immunosorbent assay, virus isolation in mosquito albopictus cell line (C6/36), and viral RNA detection and serotyping by reverse transcriptase-polymerase chain reaction (RT-PCR). The results show that 45 people were positive for dengue-specific IgM (27 males and 18 females), while RT-PCR detected dengue viral RNA in 12 patients, 3 identified as DEN-1 and 9 as DEN-2. Dengue virus was isolated from 6 patients using the C6/36 cell line; 3 were DEN-2 isolates and 3 were DEN-1 isolates. These data show that dengue virus is circulating in Brunei and the predominant infecting serotype for that period was DEN-2 followed by DEN-1. This study is the first to report the detection and isolation of dengue virus from Brunei using RT-PCR and culture in the C6/36 albopictus mosquito cell line.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods
Rapid detection, serotyping and quantitation of dengue viruses by TaqMan real-time one-step RT-PCR

Kong YY, Thay CH, Tin TC, Devi S

J Virol Methods, 2006 Dec;138(1-2):123-30.
PMID: 17000012 DOI: 10.1016/j.jviromet.2006.08.003

The use of the polymerase chain reaction (PCR) in molecular diagnosis is now accepted worldwide and has become an essential tool in the research laboratory. In the laboratory, a rapid detection, serotyping and quantitation, one-step real-time RT-PCR assay was developed for dengue virus using TaqMan probes. In this assay, a set of forward and reverse primers were designed targeting the serotype conserved region at the NS5 gene, at the same time flanking a variable region for all four serotypes which were used to design the serotype-specific TaqMan probes. This multiplex one-step RT-PCR assay was evaluated using 376 samples collected during the year 2003. These groups included RNA from prototype dengue virus (1-4), RNA from acute serum from which dengue virus was isolated, RNA from tissue culture supernatants of dengue virus isolated, RNA from seronegative acute samples (which were culture and IgM negative) and RNA from samples of dengue IgM positive sera. The specificity of this assay was also evaluated using a panel of sera which were positive for other common tropical disease agents including herpes simplex virus, cytomegalovirus, measles virus, varicella-zoster virus, rubella virus, mumps virus, WWF, West Nile virus, Japanese encephalitis virus, S. typhi, Legionella, Leptospira, Chlamydia, and Mycoplasma. The sensitivity, specificity and real-time PCR efficiency of this assay were 89.54%, 100% and 91.5%, respectively.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Fulltext A RT-PCR assay for the detection of coronaviruses from four genera

Xiu L, Binder RA, Alarja NA, Kochek K, Coleman KK, Than ST, et al.

J Clin Virol, 2020 07;128:104391.
PMID: 32403008 DOI: 10.1016/j.jcv.2020.104391

BACKGROUND: During the past two decades, three novel coronaviruses (CoVs) have emerged to cause international human epidemics with severe morbidity. CoVs have also emerged to cause severe epidemics in animals. A better understanding of the natural hosts and genetic diversity of CoVs are needed to help mitigate these threats.
OBJECTIVE: To design and evaluate a molecular diagnostic tool for detection and identification of all currently recognized and potentially future emergent CoVs from the Orthocoronavirinae subfamily.
STUDY DESIGN AND RESULTS: We designed a semi-nested, reverse transcription RT-PCR assay based upon 38 published genome sequences of human and animal CoVs. We evaluated this assay with 14 human and animal CoVs and 11 other non-CoV respiratory viruses. Through sequencing the assay's target amplicon, the assay correctly identified each of the CoVs; no cross-reactivity with 11 common respiratory viruses was observed. The limits of detection ranged from 4 to 4 × 102 copies/reaction, depending on the CoV species tested. To assess the assay's clinical performance, we tested a large panel of previously studied specimens: 192 human respiratory specimens from pneumonia patients, 5 clinical specimens from COVID-19 patients, 81 poultry oral secretion specimens, 109 pig slurry specimens, and 31 aerosol samples from a live bird market. The amplicons of all RT-PCR-positive samples were confirmed by Sanger sequencing. Our assay performed well with all tested specimens across all sample types.
CONCLUSIONS: This assay can be used for detection and identification of all previously recognized CoVs, including SARS-CoV-2, and potentially any emergent CoVs in the Orthocoronavirinae subfamily.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Clinical implications of conventional cytogenetics, fluorescence in situ hybridization (FISH) and molecular testing in chronic myeloid leukaemia patients in the tyrosine kinase inhibitor era - A review

Ankathil R, Ismail SM, Mohd Yunus N, Sulong S, Husin A, Abdullah AD, et al.

Malays J Pathol, 2020 Dec;42(3):307-321.
PMID: 33361712

Chronic myeloid leukaemia (CML) provides an illustrative disease model for both molecular pathogenesis of cancer and rational drug therapy. Imatinib mesylate (IM), a BCR-ABL1 targeted tyrosine kinase inhibitor (TKI) drug, is the first line gold standard drug for CML treatment. Conventional cytogenetic analysis (CCA) can identify the standard and variant Philadelphia (Ph) chromosome, and any additional complex chromosome abnormalities at diagnosis as well as during treatment course. Fluorescence in situ hybridization (FISH) is especially important for cells of CML patients with inadequate or inferior quality metaphases or those with variant Ph translocations. CCA in conjunction with FISH can serve as powerful tools in all phases of CML including the diagnosis, prognosis, risk stratification and monitoring of cytogenetic responses to treatment. Molecular techniques such as reverse transcriptase-polymerase chain reaction (RT-PCR) is used for the detection of BCR-ABL1 transcripts at diagnosis whereas quantitative reverse transcriptase-polymerase chain reaction (qRTPCR) is used at the time of diagnosis as well as during TKI therapy for the quantitation of BCR-ABL1 transcripts to evaluate the molecular response and minimal residual disease (MRD). Despite the excellent treatment results obtained after the introduction of TKI drugs, especially Imatinib mesylate (IM), resistance to TKIs develops in approximately 35% - 40% of CML patients on TKI therapy. Since point mutations in BCR-ABL1 are a common cause of IM resistance, mutation analysis is important in IM resistant patients. Mutations are reliably detected by nested PCR amplification of the translocated ABL1 kinase domain followed by direct sequencing of the entire amplified kinase domain. The objective of this review is to highlight the importance of regular and timely CCA, FISH analysis and molecular testing in the diagnosis, prognosis, assessment of therapeutic efficacy, evaluation of MRD and in the detection of BCR-ABL1 kinase mutations which cause therapeutic resistance in adult CML patients.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Detection of H5, H7 and H9 subtypes of avian influenza viruses by multiplex reverse transcription-polymerase chain reaction

Chaharaein B, Omar AR, Aini I, Yusoff K, Hassan SS

Microbiol Res, 2009;164(2):174-9.
PMID: 17336046

Subtype-specific multiplex reverse transcription-polymerase chain reaction (RT-PCR) was developed to simultaneously detect three subtypes (H5, H7 and H9) of avian influenza virus (AIV) type A. The sensitivity of the multiplex RT-PCR was evaluated and compared to that of RT-PCR-enzyme-linked immunosorbent assay (ELISA) and conventional RT-PCR. While the sensitivity of the multiplex RT-PCR is as sensitive as the conventional RT-PCR, it is 10 times less sensitive than RT-PCR-ELISA. The multiplex RT-PCR is also as sensitive as the virus isolation method in detecting H9N2 from tracheal samples collected at day 3 and 5 post inoculation. Hence, the developed multiplex RT-PCR assay is a rapid, sensitive and specific assay for detecting of AIV subtypes.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
Development of a multiplex real-time PCR assay using SYBR Green 1 chemistry for simultaneous detection and subtyping of H9N2 influenza virus type A

Ong WT, Omar AR, Ideris A, Hassan SS

J Virol Methods, 2007 Sep;144(1-2):57-64.
PMID: 17512062

Avian influenza viruses are pathogens of economical and public health concerns. However, infections caused by low pathogenic avian influenza particularly H9N2 subtype are not associated with clear clinical features. Hence, rapid detection and subtyping of the virus will enable immediate measures to be implemented for preventing widespread transmission. This study highlights the development of a multiplex real-time reverse-transcriptase polymerase chain reaction (RRT-PCR) assay using SYBR Green 1 chemistry for universal detection of avian influenza viruses and specific subtyping of H9N2 isolates based on melting temperatures (T(m)) discriminations. Three melting peaks generated simultaneously at temperatures 85.2+/-1.0, 81.9+/-0.9 and 78.7+/-0.9 degrees C represent NP, H9 and N2 gene products, respectively. The RRT-PCR assay was about 10-100-fold more sensitive when compared to the conventional RT-PCR method using reference H9N2 isolate. In addition, the RRT-PCR assay was 100% sensitive as well as 92% specific according to the standard virus isolation method in detecting experimentally infected specific-pathogen-free (SPF) chickens.

Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*

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