Advances in Detection Methods of Koi Herpes Virus

Koi herpes virus is a new virus found in the aquaculture production of Cryprinus carpiod and common carp in recent years. Currently, virus isolation and identification is still the traditional method for the detection of Koi herpes virus, while molecular biology detection method has become the current developmental di- rection due to its characteristics of more sensitive, specific and rapid. Furthermore, people are still committed to exploring new detection methods for the detection of Koi herpes vires. In this paper, traditional and newly-developed detection methods of Koi herpes vires in recent years were summarized, in order to provide refer- ence for further exploring rapid and accurate diagnostic detection method.

Establishment and Application of the TaqMan Real-Time Fluorescence Quantitative PCR Detection Assay for Koi Herpes Virus

[ Objective ] This study aimed to establish a rapid and effective quarantine method of Koi herpes virus. [ Method] Primers and corresponding TaqMan probe were designed based on the conserved sequence of Koi herpes virus （KHV） pol-ymerase gene （Sph） to establish a rapid and effective fluorescence quantitative PCR method for Koi herpes virus detection. The cell cultures were detected by using the established fluorescence quantitative PCR assay, and the results were com- pared with that of conventional PCR. [ Result] The sensitivity of fluorescence quantitative PCR was higher than that of conventional PCR. The minimum copy num- ber that could be detected was 1.6 - 102 copies/p.1. The established method was adopted for sample detection, and a reliable diagnostic result could be obtained within 4 h. [Conclusion] The established method is rapid, sensitive, specific and repeatable, which is conducive to the rapid detection of Koi herpes virus. Key words Koi herpes virus; Fluorescence quantitative PCR; Detection

Preliminary Study on Effects of Anthraquinone Extract of Polygonum cuspidatum on KHV

[Objectives]To study the toxic effect and antiviral activity of anthraquinone extract of Polygonum cuspidatum on infection of Koi herpes virus(KHV).[Methods]The MTT method and CPE microscopy were used to detect the common carp brain(CCB)cytotoxicity of the P.cuspidatum anthraquinone extract in 48 h.Eight groups of different concentrations of the P.cuspidatum anthraquinone extract 1.96,3.91,7.28,15.63,31.25,62.5,125,250μg/mL experimental groups and a control group without drug effect were set up.After determining the maximum non-toxic range of the P.cuspidatum anthraquinone extract,the viral replication inhibition test was carried out.[Results]The concentration of the P.cuspidatum anthraquinone extract 31.25μg/mL was recognized as the maximum non-toxic concentration.The survival rate of CCB cells was higher than 80%,and the toxic dose(CC50)of the drug for 50%cell death was(72.67±2.12)μg/mL.The maximum inhibition rate of the P.cuspidatum anthraquinone extract was 78.63%±5.47%at a concentration of 31.25μg/mL,and the 50%effective drug dose(IC50)for inhibiting the virus was(13.67±0.47)μg/mL,and the therapeutic index(TI)was 5.48±0.49.In the direct virus killing test,the highest virus inhibition rate was 32.21%.[Conclusions]Under the experimental conditions,it can be concluded that the P.cuspidatum anthraquinone extract has high anti-KHV activity,and at the same time.It is expected to lay a theoretical foundation for the research of P.cuspidatum anthraquinone extract against KHV.