First case of ranavirus-associated mass mortality in a natural population of the Huanren frog (Rana huanrenensis) tadpoles in South Korea

First detection of ranavirus in a wild population of Dybowski’s brown frog (Rana dybowskii) in South Korea

“…Out of 22 PCR products, we obtained 13 partial MCP DNA sequences (> 500 bp) due to low sample quality. The obtained MCP DNA sequences (505 bp) were identical and had 100% sequence similarity to the haplotype (accession number KY264205) collected from a ranavirus-infected Huanren frog (R. huanrenensis; Kwon et al 2017). In addition, the MCP sequence showed 99.8% similarity with ranavirus KRV-1 (HM133594) from South Korea, Rana catesbeiana virus (AB474588) from Japan, and 99.6% similarity for FV3 (FJ459783) a soft-shelled turtle iridovirus (DQ335253; Table 2).…”

“…For ranavirus strain identification, the partial sequence of major capsid protein gene (MCP) was amplified using the specific primer pairs (MCP4 and MCP5; Mao et al 1997). We ran polymerase chain reactions (PCR) following Mao et al (1997) with a negative control using nuclease-free water and confirmed PCR products on 1% agarose gel by electrophoresis (Mao et al 1997;Kwon et al 2017). PCR was run on each sample at least twice to minimize viral false-positive detection.…”

“…In addition, ranavirus, a double-stranded DNA virus, has also been identified as a major emerging infectious disease and is associated with global amphibian declines (Green et al 2002;Carey et al 2003). In Northeast Asia, across China, Japan, and Korea, ranavirus infections have caused mortality in 17, native and invasive, amphibian species (4 urodelan and 13 anuran species) as well as amphibians in the pet trade (Zhang et al 1996;Weng et al 2002;Kim et al 2009;Une et al 2009a;Kolby et al 2014;Une et al 2014;Duffus et al 2015;Kwon et al 2017;Park et al 2017). Out of the 21 reported ranavirus infection cases, 18 have been linked to mass mortality events (Table 1).…”

“…Within Korea, studies on amphibian infectious diseases have focused on B. dendrobatidis, the fungal agent causing chytridiomycosis (Yang et al 2009;O'hanlon et al 2018). In contrast, studies of ranavirus infections are limited to a handful of reported mortality events between four anuran species including Gold-spotted pond frog (Pelophylax chosenicus) tadpoles (Kim et al 2009), Huanren brown frog (R. huanrenensis) tadpoles (Kwon et al 2017), adult Boreal digging frogs (Kaloula borealis), and Japanese tree frog (Hyla japonica) tadpoles (Park et al 2017). To date, all reported ranavirus strains detected in Korean amphibians share the major capsid protein (MCP) DNA sequence, similar to frog virus 3 (FV3), originally identified from Lithobates pipiens (formerly R. pipiens; Granoff et al 1965) and Atelognathus patagonicus samples (Fox et al 2006).…”

When Micro Drives the Macro: A Fresh Look at Disease and its Massive Contributions in the Hindu Kush-Himalaya

“…Among these underlying factors, the role of ms is critical because they may induce immediate and rapid mass mortality of MS leading susceptibility to endangerment and extinction (Field et al 2009;Fey et al 2015;González-Suárez and Revilla 2014;Smith et al 2006;Pedersen et al 2007;Adams et al 2017). For example, mass elimination of Mongolian saigas by Peste des Petits Virus (PPRV) (Chimeddorj and Buuveibaatar 2017), of amphibian populations by Ranavirus, Batrachochytrium dendrobatidis, and Perkinsea (Fey et al 2015;Cheng et al 2011;Duffus et al 2015;Isidoro-Ayza et al 2017;Kwon et al 2017;Geng et al 2011), and of humans and animals by TB, influenza, acute respiratory, and diarrheal pathogens has been already reported around the world (NRC 1993;Gates 2014;DoAH 2016b;DoHS 2017). In these contexts, although several causes might exist, extreme virulence, toxicity, and the pathogenicity of the pathogens actually govern the disease appearance and outbreaks.…”