Infectious pancreatic necrosis virus (IPNV) serotype Sp is prevalent in Turkish rainbow trout farms

Abstract

Infectious pancreatic necrosis virus (IPNV) is a common pathogen of rainbow trout (Oncorhynchus mykiss) in Turkey. We found that 455 of 1,676 sample pools tested were IPNV positive. Positive samples were found in all geographical regions where sampling was conducted. Sequence and phylogenetic analyses of VP2 from 30 isolates representing all regions showed that the viruses were highly similar in sequence and grouped within Genogroup 5 (serotype Sp-A2). No correlations between sequences, sampling sites or geographical origins were identified. Although clinical disease was evident in several farms, analyses of the amino acid sequence of VP2 showed that all virus strains harboured the P 217 T 221 motif, assumed to be associated with low virulence. We conclude that IPNV is prevalent in Turkish rainbow trout farms and that the viruses are very homogenous and likely to be of European origin. Frequent exchange of eggs and live fish within the farming industry may explain the homogeneity of the IPNV.

The Infectious Pancreatic Necrosis Virus (IPNV) and its Virulence Determinants: What is Known and What Should be Known

“…In Mexico [102], IPNV isolates showed Thr at position 221 ( Figure 6L) which is indicative of persistence; however, although most isolates were from asymptomatic carriers-which confirms the predictions-one corresponded to an isolation from diseased rainbow trout. Something similar was reported in Chile [103], Turkey [104], and Taiwan [105], with isolates from clinical cases showing Thr at aa 221 . More recently, a discordance was also observed by Holopainen et al [80] in Finnish strains ( Figure 6P); they sequenced isolates obtained during a few decades and observed that all of them showed the aa Thr at position 221, in spite of the increasing virulence observed over recent years in Finish farms.…”

The determination of the infectious status and prevalence of motile Aeromonas species isolated from disease cases in rainbow trout (Oncorhynchus mykiss) and aquarium fish

“…() reported that these IPNV associated isolates are avirulent, so we could describe these species as dominant pathogens when present in a mixed infection with IPNV. Considering that IPNV is mostly isolated from rainbow trout with ascites (Büyükekiz et al., ), there is a question as to which agent is responsible for the ascites. A. salmonicida (A5) isolated from dorsal lesions of broodstock rainbow trout (3,000 g) was combined with Y. ruckeri and IPNV.…”

“…( E. cloacae, M. psychrotolerans and Flavobacterium articles in process). (Table ; Büyükekiz et al., ; Duman, Altun et al., ; Duman, Saticioglu et al., ; Duman, Buyukekiz et al., ). In some cases, only A. sobria, A. media, A. bestiarum and A. salmonicida isolates were seen as primary infectious agents in rainbow trout showing dorsal lesions and from water temperatures between 9.5 and 19.1°C.…”

“…( Table 1; Büyükekiz et al, 2017;. In some cases, only A. sobria, A. media, A. bestiarum and A. salmonicida isolates were seen as primary infectious agents in rainbow trout showing dorsal lesions and from water temperatures between 9.5 and 19.1°C.…”

“…These species have been determined as highly possible pathogens for rainbow trout as mentioned in other research (Beaz-Hidalgo & Figueras, 2012; Igbinosa et al, 2012; Zepeda-Velázquez et al, 2017). Four A. sobria (A26, A151, A159and A186) and one A. bestiarum (A9) were isolated from rainbow trout showing disease signs along with IPNV, butBüyükekiz et al (2017) reported that these IPNV associated isolates are avirulent, so we could describe these species as dominant pathogens when present in a mixed infection with IPNV. Considering that IPNV is mostly isolated from rainbow trout with ascites(Büyükekiz et al, 2017), there is a question as to which agent is responsible for the ascites.…”