Molecular and epidemiological investigation of lymphocystis disease virus in Egyptian marine aquaculture

Abstract

Lymphocystis disease (LCD) is an infectious viral disease of over 125 marine, brackish, and freshwater fish species all over the world that causes hypertrophy of connective tissue cells and usually occurs on the fins and skin. LCD is caused by Lymphocystis disease virus (LCDV). Gilthead seabream (Sparus aurata) is the most affected species by lymphocystis in the Mediterranean basin. LCD results in significant economic losses related to non-marketability, secondary infections and poor growth rate of fish. In the present study, the following points were achieved: 1. synthetic positive control standard for five main viral pathogens that threaten aquaculture species: LCDV was one of selected viruses was designed (in silico) and synthesized. In the design, we selected MCP gene segment for LCDV. 2. Synthetic positive control (Construct) was simulated using the selected specific reference primers (in silico). 3. Synthetic positive control (Construct) was validated after synthesis using the selected specific reference primers (in vitro). 4. Gilthead seabream which have signs of LCD were collected and prepared then preserved. 5. The preserved samples were tested and verified positive using specific reference primers with the aid of the synthetic MCP positive control. 6. Positive results were further confirmed by Histopathology and Electron microscopy.