Genome Sequence of Tilapia Lake Virus Associated with Syncytial Hepatitis of Tilapia in an Ecuadorian Aquaculture Facility

Abstract

Here, we report the complete coding sequences of tilapia lake virus (TiLV) associated with syncytial hepatitis of tilapia (SHT). The TiLV strain was sequenced from the liver RNA extract of a moribund Nile tilapia (Oreochromis niloticus) fingerling from an Ecuadorian aquaculture facility in 2012.

Tilapia Lake Virus Does Not Hemagglutinate Avian and Piscine Erythrocytes and NH4Cl Does Not Inhibit Viral Replication In Vitro

“…Confluent monolayers were washed twice using PBS before treatment using various concentrations of NH 4 Cl. Experiments using NH 4 Cl treatment of E-11 cells were done in two parts, of which the first part was to determine the toxicity of different concentrations of NH 4 Cl on E-11 cells. To do this, the concentrations of NH 4 Cl tested were 1, 5, 20, 25, 30, and 50 mM.…”

“…The cells were cultured in normal growth media containing 5% FBS after NH 4 Cl treatment. Three negative control cell culture flasks without NH 4 Cl treatment and cells treated with NH 4 Cl but without virus infection were included in the study. The positive control group consisted of cells infected with the virus at MOI 1.0 without NH 4 Cl treatment.…”

“…Treatment of E-11 cells with different concentrations of NH 4 Cl showed that leaving the NH 4 Cl media for more than 24 h on the cells was toxic for concentrations of ≥50 mM NH 4 Cl. Lower concentrations, i.e., between 1 and 30 mM, had no toxic effect even when left on the cells until the end of the experiments.…”

“…Hence, a concentration of 30 mM was selected to test the effect of NH 4 Cl on TiLV replication, which was replaced with maintenance media after NH 4 Cl treatment. The choice of 30 mM was in the range of NH 4 Cl concentration used in several previous studies [34][35][36]. Therefore, in the pre-treatment group, NH 4 Cl-containing media was added 30 min before virus adsorption, NH 4 Cl treatment was performed during virus adsorption in the group designated as 0 hpi, and NH 4 Cl media was added after 1, 2, and 3 hpi and was later replaced with maintenance media in the post-infection groups.…”

“…The disease caused by TiLV was first reported in Israel in 2009, while the virus was first characterized in 2014 [1]. Since then, TiLV infections have been reported from different countries around the world [2][3][4][5]. It is an icosahedral virus made of a trilaminar capsid with a diameter of 55-110 nm, which is morphologically similar to orthomyxoviruses [1].…”