title: Detection of cyprinid herpesvirus 3 DNA in river water during and after an outbreak.
abstract: The disease caused by cyprinid herpesvirus 3 (CyHV-3) brings catastrophic damages to cultivated carp and koi and to natural carp populations; however, the dynamics of the virus in environmental waters are unclear. In July 2007, CyHV-3 DNA was detected in a dead common carp collected from the Yura River in Kyoto Prefecture, Japan, and this was followed by mass mortality. We collected water samples at eight sites along the Yura River for 3 months immediately after confirmation of the disease outbreak and attempted to detect and quantify CyHV-3 DNA in the water samples using molecular biological methods. The virus concentration was carried out by the cation-coated filter method, while the purification of DNA from the samples was achieved using phenol-chloroform extraction and a commercial DNA extraction kit. CyHV-3 was detected by PCR using six sets of conditions, three sets of primers (SphI-5, AP, and B22Rh exon 1), and two volumes of template DNA, and was quantified using real-time PCR. Our results indicate broader distribution of CyHV-3, even though dead fish were found only in a limited area; moreover, the virus was present at high levels in the river not only during the mass mortality caused by the disease but also for at least 3 months after the end of mass mortality. Our results suggest the possibility of infection by CyHV-3 via environmental water. The sequences of CyHV-3 collected from the Yura River matched perfectly with that of the CyHV-3 Japanese strain, suggesting that they share the same origin.
authors.affiliation: Research Institute for Humanity and Nature (RIHN), 457-4 Motoyama, Kamigamo, Kita-ku, Kyoto 603-8047, Japan. minamoto@chikyu.ac.jp
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Minamoto
authors.forename: Mie N
authors.initials: MN
authors.lastname: Honjo
authors.forename: Kimiko
authors.initials: K
authors.lastname: Uchii
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamanaka
authors.forename: Alata A
authors.initials: AA
authors.lastname: Suzuki
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kohmatsu
authors.forename: Takaji
authors.initials: T
authors.lastname: Iida
authors.forename: Zen'ichiro
authors.initials: Z
authors.lastname: Kawabata
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000821:virology*; D017931:DNA Primers; D004279:DNA, Viral / Q000235:genetics* / Q000302:isolation & purification; D004196:Disease Outbreaks; D005393:Fish Diseases / Q000453:epidemiology / Q000821:virology*; D005618:Fresh Water / Q000821:virology*; D006566:Herpesviridae Infections / Q000453:epidemiology / Q000662:veterinary*; D007564:Japan / Q000453:epidemiology; D016133:Polymerase Chain Reaction / Q000379:methods; D045483:Rivers / Q000821:virology; D012621:Seasons; D012680:Sensitivity and Specificity; D013696:Temperature; D018140:Varicellovirus / Q000235:genetics* / Q000302:isolation & purification*
chemical_list: D017931:DNA Primers; D004279:DNA, Viral