title: Development and evaluation of SYBR Green I-based one-step real-time RT-PCR assay for detection and quantitation of Japanese encephalitis virus.
abstract: One-step SYBR Green I-based real-time RT-PCR assay for rapid detection as well as quantitation of Japanese encephalitis virus (JEV) in acute-phase patient CSF samples by targeting the NS3 gene was developed. The assay developed in this study was found to be more sensitive as compared to conventional RT-PCR. The specificity of the reported assay system was established through melting curve analysis as well as by cross-reactivity studies with related members of Flavivirus. The applicability of Real-time PCR assay for clinical diagnosis was validated with 32 suspected acute-phase CSF samples of Gorakhpur epidemic, India, 2005. The improved sensitivity of real-time RT-PCR was reflected by picking up 10 additional samples with low copy number of template in comparison to conventional RT-PCR. The quantitation of the viral load in acute-phase CSF samples was done using a standard curve obtained by plotting cycle threshold (C(t)) values versus copy numbers of the RNA template. This is the first report on the application of real-time RT-PCR for detection as well as quantitation of JEV from patient CSF samples. These findings demonstrate the potential clinical application of the reported assay as a sensitive diagnostic test for rapid and real-time detection and quantitation of JEV in acute-phase clinical samples.
authors.affiliation: Division of Virology, Defence Research & Development Establishment, Jhansi Road, Gwalior, Madhya Pradesh 474002, India. santhuvet4u@rediffmail.com
authors.forename: S R
authors.initials: SR
authors.lastname: Santhosh
authors.forename: M M
authors.initials: MM
authors.lastname: Parida
authors.forename: P K
authors.initials: PK
authors.lastname: Dash
authors.forename: A
authors.initials: A
authors.lastname: Pateriya
authors.forename: B
authors.initials: B
authors.lastname: Pattnaik
authors.forename: H K
authors.initials: HK
authors.lastname: Pradhan
authors.forename: N K
authors.initials: NK
authors.lastname: Tripathi
authors.forename: S
authors.initials: S
authors.lastname: Ambuj
authors.forename: N
authors.initials: N
authors.lastname: Gupta
authors.forename: P
authors.initials: P
authors.lastname: Saxena
authors.forename: P V
authors.initials: PV
authors.lastname: Lakshmana Rao
mesh_terms: D052160:Benzothiazoles; D018929:Cell Culture Techniques; D003959:Diamines; D004664:Encephalitis Virus, Japanese / Q000302:isolation & purification*; D004672:Encephalitis, Japanese / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D006801:Humans; D007194:India; D009930:Organic Chemicals; D011804:Quinolines; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D052160:Benzothiazoles; D003959:Diamines; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I