scholarly journals Real time PCR. Application in dengue studies

2011 ◽  
pp. 243-258 ◽  
Author(s):  
Jeanette Prada-Arismendy ◽  
Jaime E Castellanos

PCR (polymerase chain reaction) is a routinely used tool in every diagnostic and research laboratory. This technique has been used in detection of mutations and pathogens, forensic investigation, and even is the base tool for human genome sequencing. A modification of PCR technique, real time PCR, allows the quantification of nucleic acids with higher sensibility, specificity and reproducibility. This article is intended to clarify the foundations of real-time PCR, using an application model for virology. In the actual work, it was quantified the viral load of dengue virus serotype 2 produced from infected murine macrophages; the obtained results in this work established that murine strain BALB/c presents a greater susceptibility to dengue virus infection, which establishes BALB/c murine strain as a best model of study for investigation of dengue virus infection physiopathology.

2016 ◽  
Vol 4 (4) ◽  
Author(s):  
Man Kwan Ooi ◽  
Han Ming Gan ◽  
Ahmad Rohani ◽  
Sharifah Syed Hassan

Here, we report the complete genome sequence of a chikungunya virus coinfection strain isolated from a dengue virus serotype 2-infected patient in Malaysia. This coinfection strain was determined to be of the Asian genotype and contains a novel insertion in the nsP3 gene.


Blood ◽  
2010 ◽  
Vol 115 (9) ◽  
pp. 1823-1834 ◽  
Author(s):  
Nattawat Onlamoon ◽  
Sansanee Noisakran ◽  
Hui-Mien Hsiao ◽  
Alexander Duncan ◽  
Francois Villinger ◽  
...  

AbstractLack of a dengue hemorrhagic animal model recapitulating human dengue virus infection has been a significant impediment in advancing our understanding of the early events involved in the pathogenesis of dengue disease. In efforts to address this issue, a group of rhesus macaques were intravenously infected with dengue virus serotype 2 (strain 16 681) at 1 × 107 PFU/animal. A classic dengue hemorrhage developed 3 to 5 days after infection in 6 of 6 animals. Blood chemistry appeared to be normal with exception of creatine phosphokinase, which peaked at 7 days after infection. A modest thrombocytopenia and noticeable neutropenia concomitant with slight decrease of hemoglobin and hematocrit were registered. In addition, the concentration of D-dimer was elevated significantly. Viremia peaked at 3 to 5 days after infection followed by an inverse relationship between T and B lymphocytes and a bimodal pattern for platelet-monocytes and platelet-neutrophil aggregates. Dengue virus containing platelets engulfed by monocytes was noted at 8 or 9 days after infection. Thus, rhesus macaques inoculated intravenously with a high dose of dengue virus produced dengue hemorrhage, which may provide a unique platform to define the early events in dengue virus infection and help identify which blood components contribute to the pathogenesis of dengue disease.


Author(s):  
Suci Andriani ◽  
Aryati Aryati ◽  
Usman Hadi

The clinical manifestation of dengue virus infection is often not clear, varies widely from mild to severe. Exposure of dengue virus which serotype is different from a previous infection is a risk factor for the severe manifestation of dengue virus infection. Dengue hemorrhagic fever is classified into four degrees of severity based on clinical manifestations and laboratory results. Real-time RT-PCR Dengue can detect dengue virus serotype in early dengue virus infection. The aimed of this study was to prove the correlation between dengue virus serotype and degree of severity in adult patients. This study was a cross-sectional observational design done in February until July 2016. Subjects consisted of 100 dengue virus infection patients. Serum of the patients was examined using Real-time RT-PCR Dengue (Simplexa™ Dengue). It was shown that from 46 patients with DENV-3 serotype was 63%, DENV-2 serotype 17.4%, DENV-1 serotypes 17.4% and mixed infection of DENV-1 and DENV-3 serotype 2.2%. There was not any DENV-4 serotype. Dengue Hemorrhagic Fever (DHF) stage I was 47.8%, DHF stage II was 30.4%, DHF stage III was 10.9% and Dengue Fever was 10.9%. There was not any DHF stage IV. There was not enough evidence that DENV-3 correlated with the degree of severity (p= 0.510). Based on this research, DENV-3 serotype was the dominant serotype prevalent at the Dr. Soetomo Hospital. There was no correlation between viral dengue serotype and severity in dengue adult patients in this study. 


2018 ◽  
Vol 17 (4) ◽  
pp. 669-673
Author(s):  
Mahmuda Siddiqua ◽  
Ahmed Nawsher Alam ◽  
AKM Muraduzzaman ◽  
Tahmina Shirin

Introduction: Detection of dengue virus infection as soon as possible is critical for management of dengue virus infected patients. Immuno-chromatographic (ICT) tests are easy, cost effective method for dengue virus antigen detection.The sensitivity and specificity of ICT should compare with a gold standard test like RT-PCR. Aim of this study was to compare two test methods (ICT and RT-PCR), observe dengue serotype and seasonal impact on dengue infection.Methodology & result: The patients of Ibn Sina Medical College Hospital from October 2015 to October 2017 were tested for dengue NS1 antigen by ICT method. Out of 3201 sample tested 32.39% were found positive and 89 of which were re-tested for RT-PCR for comparison. Eighty eight of 89 NS1 positive cases showed positive by RT-PCR method giving an accuracy of 98.87%. Among the RT-PCR positive cases 45 were further analyzed for serotype. DEN-1, DEN-2 or both DEN- 1 and DEN-2 were found in 21, 23 and 1cases respectively. No cases of DEN-3 or DEN-4 were detected.Conclusion: This study showed that easily available and cost effective dengue NS1 antigen detection method (ICT) is as effective as molecular test (RT-PCR). DEN-1 and DEN-2 serotype were prevalent during last few years in Bangladesh. Continuous monitoring of dengue virus serotype is important for prevention and control of sudden epidemic by other serotype. Alert to be more during post monsoon when the peak of dengue virus infection was observed.Bangladesh Journal of Medical Science Vol.17(4) 2018 p.669-673


2017 ◽  
Vol 9 (04) ◽  
pp. 296-302 ◽  
Author(s):  
Jayanthi Shastri ◽  
Manita Williamson ◽  
Nilima Vaidya ◽  
Sachee Agrawal ◽  
Om Shrivastav

Abstract INTRODUCTION: Dengue virus (DENV) causes a wide range of diseases in humans, from acute febrile illness Dengue fever (DF) to life-threatening Dengue hemorrhagic fever (DHF) or Dengue shock syndrome (DSS). Factors believed to be responsible for spread of Dengue virus infection include explosive population growth, unplanned urban overpopulation with inadequate public health systems, poor standing water and vector control, climate changes and increased international recreational, business, military travel to endemic areas. All of these factors must be addressed to control the spread of Dengue and other mosquito-borne infections. The detection of Dengue virus RNA by reverse transcriptase PCR (RT-PCR) in human serum or plasma samples is highly indicative of acute Dengue fever. Moreover, the method is able to identify the Dengue virus serotype by demonstrating defined sequence homologies in the viral genomic RNA. METHODS AND RESULTS: During the nine year period of this study analysis, 6767 strongly suspected cases were tested by RT-PCR. 1685 (24.9%) were Dengue PCR positive and confirmed as Dengue cases. Observations on the seasonality were based on the nine year's data as the intensity of sampling was at its maximum during monsoon season. Dengue typing was done on 100 positive samples after storage of Dengue RNA at – 80°C. Dengue serotypes were detected in 69 samples of which Dengue 2 was most predominant. 576 samples were processed for NS1 antigen and PCR simultaneously. 19/576 were positive (3.3 %) for NS1 as well as by PCR. 23/576 samples were negative for NS1 antigen, but were positive by RT-PCR. The remaining 534 samples which were negative for NS1 antigen were also negative by Dengue RT-PCR. CONCLUSION: In this study we sought to standardize rapid, sensitive, and specific fluorogenic probe-based RT-PCR assay to screen and serotype a representative range of Dengue viruses that are found in and around Mumbai. Qualitative Dengue virus TaqMan assays could have tremendous utility for the epidemiological investigation of Dengue illness and especially for the study of the viremic response with candidate live-attenuated dengue virus vaccines.


2008 ◽  
Vol 80 (8) ◽  
pp. 1426-1433 ◽  
Author(s):  
Harryson Wings Godoy dos Santos ◽  
Telma Regina Ramos Silva Poloni ◽  
Kelly Paula Souza ◽  
Vanessa Danielle Menjon Muller ◽  
Flávia Tremeschin ◽  
...  

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 654
Author(s):  
Molly Butler ◽  
Nunya Chotiwan ◽  
Connie D. Brewster ◽  
James E. DiLisio ◽  
David F. Ackart ◽  
...  

Dengue virus infection is associated with the upregulation of metabolic pathways within infected cells. This effect is common to infection by a broad array of viruses. These metabolic changes, including increased glucose metabolism, oxidative phosphorylation and autophagy, support the demands of viral genome replication and infectious particle formation. The mechanisms by which these changes occur are known to be, in part, directed by viral nonstructural proteins that contact and control cellular structures and metabolic enzymes. We investigated the roles of host proteins with overarching control of metabolic processes, the transcriptional regulators, cyclin-dependent kinase 8 (CDK8) and its paralog, CDK19, as mediators of virally induced metabolic changes. Here, we show that expression of CDK8, but not CDK19, is increased during dengue virus infection in Huh7 human hepatocellular carcinoma cells, although both are required for efficient viral replication. Chemical inhibition of CDK8 and CDK19 with Senexin A during infection blocks virus-induced expression of select metabolic and autophagic genes, hexokinase 2 (HK2) and microtubule-associated protein 1 light chain 3 (LC3), and reduces viral genome replication and infectious particle production. The results further define the dependence of virus replication on increased metabolic capacity in target cells and identify CDK8 and CDK19 as master regulators of key metabolic genes. The common inhibition of CDK8 and CDK19 offers a host-directed therapeutic intervention that is unlikely to be overcome by viral evolution.


2015 ◽  
Vol 3 (1) ◽  
pp. 5
Author(s):  
Soegeng Soegijanto ◽  
Helen Susilowati ◽  
Kris Cahyo Mulyanto ◽  
Eryk Hendrianto ◽  
Atushi Yamanaka

Background: Dengue (DEN) virus, the most important arthropod-borne human pathogen, represents a serious public health threat. DEN virus is transmitted to humans by the bite of the domestic mosquito, Aedes aegypti, and circulates in nature as four distinct serological types DEN-1 to 4). The aim of Study: To identify Dengue Virus Serotype I which showed mild clinical performance in fiveyears before and afterward showed severe clinical performance. Material and Method: Prospective and analytic observational study had been done in Dr. Soetomo Hospital and the ethical clearance was conduct on January 01, 2009. The population of this research is all cases of dengue virus infection. Diagnosis were done based on WHO 1997. All of these cases were examined for IgM & IgG anti Dengue Virus and then were followed by PCR examination to identify Dengue Virus serotype. Result and Discussion: DEN 2 was predominant virus serotype with produced a spectrum clinical illness from asymptomatic, mild illness to classic dengue fever (DF) to the most severe form of illness (DHF). But DEN 1 usually showed mild illness. Helen at al (2009–2010) epidemiologic study of Dengue Virus Infection in Health Centre Surabaya and Mother and Child Health Soerya Sidoarjo found many cases of Dengue Hemorrhagic Feverwere caused by DEN 1 Genotype IV. Amor (2009) study in Dr. Soetomo Hospital found DEN 1 showed severe clinical performance of primary Dengue Virus Infection as Dengue Shock Syndrome two cases and one unusual case.Conclusion: The epidemiologic study of Dengue Virus Infection in Surabaya and Sidoarjo; in the year 2009 found changing predominant Dengue Virus Serotype from Dengue Virus II to Dengue Virus 1 Genotype IV which showed a severe clinical performance coincident with primary infection.


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