title: Detection and quantification of infectious hypodermal and hematopoietic necrosis virus and white spot virus in shrimp using real-time quantitative PCR and SYBR Green chemistry.
abstract: A rapid and highly sensitive real-time PCR detection and quantification method for infectious hypodermal and hematopoietic necrosis virus (IHHNV), a single-stranded DNA virus, and white spot virus (WSV), a double-stranded DNA (dsDNA) virus infecting penaeid shrimp (Penaeus sp.), was developed using the GeneAmp 5700 sequence detection system coupled with SYBR Green chemistry. The PCR mixture contains a fluorescence dye, SYBR Green, which upon binding to dsDNA exhibits fluorescence enhancement. The enhancement of fluorescence was proportional to the initial concentration of the template DNA. A linear relationship was observed between the amount of input plasmid DNA and cycle threshold (C(T)) values over a range of 1 to 10(5) copies of the viral genome. To control the variation in sampling and processing among samples, the shrimp beta-actin gene was amplified in parallel with the viral DNA. The C(T) values of IHHNV- and WSV-infected samples were used to determine absolute viral copy numbers from the standard C(T) curves of these viruses. For each virus and its beta-actin control, the specificity of amplification was monitored by using the dissociation curve of the amplified product. Using genomic DNA as a template, SYBR Green PCR was found to be 100- to 2000-fold more sensitive than conventional PCR, depending on the virus, for the samples tested. The results demonstrate that SYBR Green PCR can be used as a rapid and highly sensitive detection and quantification method for shrimp viruses and that it is amenable to high-throughout assay.
authors.affiliation: Super Shrimp, Inc., National City, California, 91950, USA.
authors.forename: A K
authors.initials: AK
authors.lastname: Dhar
authors.forename: M M
authors.initials: MM
authors.lastname: Roux
authors.forename: K R
authors.initials: KR
authors.lastname: Klimpel
mesh_terms: D000818:Animals; D052160:Benzothiazoles; D004267:DNA Viruses / Q000302:isolation & purification* / Q000502:physiology; D004279:DNA, Viral / Q000032:analysis; D033364:Decapoda / Q000821:virology*; D019223:Densovirinae / Q000302:isolation & purification* / Q000502:physiology; D003959:Diamines; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000378:metabolism; D009930:Organic Chemicals; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D011804:Quinolines; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D013698:Templates, Genetic; D019562:Viral Load
chemical_list: D052160:Benzothiazoles; D004279:DNA, Viral; D003959:Diamines; D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I