title: Development and use of a real-time polymerase chain reaction for the detection of group II invertebrate iridoviruses in pet lizards and prey insects.
abstract: Members of the genus Iridovirus (invertebrate iridoviruses [IIVs]) of the Iridoviridae family infect a wide range of invertebrates, mainly arthropods, but there have also been a few reports from other taxa. The cricket iridovirus described recently has been shown to infect a wide host range among insect orders and has also been described in several diseased reptiles. This virus together with the type species Chilo iridescent virus form a distinct "group II" in the genus. The aim of this study was to develop a fast and easy real-time polymerase chain reaction [quantitative (q)PCR] for the detection of these group II iridoviruses. In silico and in vitro assays demonstrated that the designed TaqMan primer-probe combination targeting a portion of the major capsid protein is specific for this group of IIVs. A sensitivity assay showed that it is able to detect as little as one copy of viral DNA. Direct comparison of cell culture isolation, nested (n)PCR, and qPCR methods has shown that PCR methods are 10(2)-10(3) more sensitive compared with the isolation method. In testing the three methods on routine diagnostic samples from lizards (n = 22) and crickets (n = 11), the nPCR and qPCR results were consistent with 19 positive lizards and 10 positive crickets, respectively, whereas isolation on cell culture detected only seven and six positives, respectively. QPCR is a fast, sensitive, and specific diagnostic method. Furthermore, it requires fewer handling steps than were previously required. It also allows the quantitation and comparison of the amounts of IIV DNA in samples.
authors.forename: Tibor
authors.initials: T
authors.lastname: Papp
authors.forename: Dirk
authors.initials: D
authors.lastname: Spann
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Marschang
mesh_terms: D000818:Animals; D004279:DNA, Viral / Q000302:isolation & purification; D007313:Insecta / Q000821:virology*; D017994:Iridovirus / Q000302:isolation & purification*; D008116:Lizards / Q000821:virology*; D057805:Pets; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D012680:Sensitivity and Specificity
chemical_list: D004279:DNA, Viral