In vitro propagation of tilapia lake virus in cell lines developed from Oreochromis mossambicus

Abstract

Tilapia lake virus (TiLV)‐suspected samples of tilapia were collected from grow‐out ponds located with clinical signs and mortality ranged from 5% to 50%. The reverse transcription–polymerase chain reaction (RT‐PCR) assay revealed the presence of TiLV in the disease outbreak ponds. Cell lines were developed from heart, gill and eye of Mozambique tilapia and characterized. Morphologically, these cell lines are composed of epithelioid cells. The optimum growth of these cells was observed at 28°C and 20% concentration of FBS. After cryopreservation, 70%–90% of cells were found to be viable. The cells of all three cell lines were found to be positive to fibronectin and pancytokeratin. PCR amplification of 16S rRNA and COI of O. mossambicus confirmed the origin of these cell lines from O. mossambicus. Heart and gill cell lines were found to be highly susceptible to TiLV and found to be useful for its isolation from infected fish samples. The experimental infection was carried out in O. niloticus and O. mossambicus using the TiLV propagated in susceptible cell lines. The RT‐PCR results revealed the presence of TiLV in brain, gill, liver, kidney, spleen, eye, muscle, intestine and heart of experimentally infected O. niloticus and O. mossambicus.

Tilapia lake virus: The story so far

“…Different cell lines are used for isolation and propagation of TiLV including E‐11 (derived from snakehead, Ophicephalus striatus ) (Eyngor et al., 2014; Tattiyapong et al., 2017); CFF (from Pristolepis fasciatus ) (Behera et al., 2018); OmB (from Oreochromis mossambicus ) and TmB (from Tilapia mossambica ) (Kembou Tsofack et al., 2017); On1B (from the brain of tilapia) and On1L (from the liver of tilapia) (Thangaraj et al., 2018); PHF (from caudal fin of Pangasianodon hypophthalmus ) (Soni, Pradhan, Swaminathan, & Sood, 2018); cell lines from the heart, gills and eyes of Mozambique tilapia (Nanthini et al., 2019); TiB (from tilapia brain) (Wang et al., 2018); cell lines (CAMB) from the brain of the hybrid snakehead ( Channa argus × Channa maculate ) (Wang, Li, et al, 2020); and primary tilapia brain cell line (Eyngor et al., 2014). The E‐11 cell line exhibited prominent cytopathic effect (CPE) within 5–7 days post‐inoculation (dpi) with vacuoles and plaque formation and subsequent disintegration of cell monolayer within 9–10 days (Eyngor et al., 2014; Tattiyapong et al., 2017).…”

Comprehensive update on inventory of finfish cell lines developed during the last decade (2010–2020)

“…Successful isolation of TiLV has been reported using OmB cell line (Gardell et al 2014). Further, tilapia gill cell line (TG), tilapia heart cell line (TH) and tilapia eye cell line (TE) was developed which served useful for both propagation and isolation of TiLV (Nanthini et al 2019). Brain cell line (CAMB) from hybrid snakehead fish, was developed to study the pathogenesis of TiLV induced disease in tilapia (Wang et al 2020b).…”

Cell Culture-Derived Tilapia Lake Virus-Inactivated Vaccine Containing Montanide Adjuvant Provides High Protection against Viral Challenge for Tilapia

“…TiLV is a major threat for Nile tilapia [ 12 , 25 , 31 , 32 ] as well as other farmed tilapias including red tilapia ( Oreochromis spp.) [ 23 ], Mozambique tilapia ( Oreochromis mossambicus ) [ 33 ], and the hybrids O. niloticus × Oreochromis aureus [ 12 , 15 , 33 ] and O. niloticus × O. mossambicus [ 34 ]. TiLV infections have now been detected in wild tilapia in Israel, Malaysia, Peru, and Lake Victoria in Tanzania and Uganda [ 28 ].…”

“…In experimental trials, TiLV infections of tilapia are associated with a high mortality of 70–90%. TiLV can be transmitted horizontally by cohabitation with infected fish [ 12 , 23 , 33 , 36 ] and possibly vertically from broodstock to progeny [ 37 ]. In addition, the virus can also occur as a co-infection with other pathogenic microorganisms increasing the severity of TiLV infection [ 15 , 26 , 38 ].…”