First detection of koi herpesvirus from koi, Cyprinus carpio L. experiencing mass mortalities in Iran: clinical, histopathological and molecular study

Abstract

Koi herpesvirus (KHV) is the aetiological agent of an emerging disease (KHVD) associated with mass mortalities in koi and common carp and reported from at least 30 countries. We report the first detection of KHV from koi in Iran using clinical, histopathological and molecular studies. KHV-infected fish showed reduced swimming activity, sunken eyes and increased mucus production on skin and fins. On post-mortem examination, gill necrosis was observed in the majority of fish. Histopathologically, the gill showed diffuse necrosis of the branchial epithelial cells. Margination of chromatin was detected in gills, kidney, heart, spleen, intestine and brain. In addition, sequence analyses of the TK gene, ORF 136 and marker I and II, demonstrates that Iranian KHV isolates were identical and classified as variant A1 of TUSMT1 (J strain) and displayed the I(++) II(+) allele of this Asian genotype.

Comparative Genomics of Tenacibaculum dicentrarchi and “Tenacibaculum finnmarkense” Highlights Intricate Evolution of Fish-Pathogenic Species

“…The rapid international spread of pathogens through the trade of fish and eggs or as a response to environmental changes has been documented ( Brynildsrud et al. 2014 ; Rahmati-Holasoo et al. 2016 ).…”

Pathognomonic features and ultrastructural of Koi Herpesvirus infected Oreochromis niloticus

“…Miwa et al (2015) state that the presence of cells whose nuclei experience chromatin margination indicates that the cell has been infected with KHV. Rahmati-Holasoo et al (2016) also report that KHVinfected Koi fish also suffers kidney damage in the form of necrosis and an intranuclear inclusion body that resembles a ring shape with clear chromatin borders. The presence of hemorrhage in the intestine indicates the discharge of blood from the blood vessels, either into or out of body tissues.…”

Validation of a serum neutralization test for detection of antibodies specific to cyprinid herpesvirus 3 in infected common and koi carp (Cyprinus carpio)

“…CyHV‐3 has spread rapidly worldwide particularly due to significant trade in koi and has now been described in more than 28 different countries (OIE ; Rahmati‐Holasoo et al . ). It is likely that this virus is present in many other countries where it has not yet been identified or reported.…”

“…To date, lineages J (Japan) and U/I (the United States/Israel) as well as two intermediates have been described by comparing complete genome sequences of strains from different geographical origins (Aoki et al 2007;Bigarr e et al 2009;Sunarto et al 2011). CyHV-3 has spread rapidly worldwide particularly due to significant trade in koi and has now been described in more than 28 different countries (OIE 2015;Rahmati-Holasoo et al 2016). It is likely that this virus is present in many other countries where it has not yet been identified or reported.…”