Biological Assay of Foot and Mouth Disease Virus (FMDV) Serotypes for Titrating BLRI Developed Trivalent FMD Vaccines Seed

Md Rezaul Karim,Eusha Islam,Md Zulfekar Ali,Mohammad Showkat Mahmud,Md Giasuddin,Mohammed Abdus Samad

doi:10.13189/iid.2018.060201

Abstract

Foot and Mouth Disease (FMD) is an important viral as well as transboundary disease affecting almost all cloven-hoofed animals. The aim of the present study is the focused on determination of biological titer by tissue culture infective dose50 (TCID50) assay of currently available FMD virus serotype in Bangladesh. For adaptation of FMD virus (FMDV), BHK-21 cell line was used. BHK-21 cell subculture was done from preserved cultured bottle of Foot and Mouth Disease (FMD) Research Laboratory of Bangladesh Livestock Research Institute (BLRI), Savar, Dhaka. RT-PCR confirmed selected three different positive serotypes (O, A and Asia 1) of FMD virus were inoculated into BHK-21 cell culture and cytopathic effects (CPE) were observed after adaptation into BHK-21 cell from 3rd to 5th passages. Clear infectious BHK-21 cell culture fluid was collected and preserved at -80℃ temperature. The TCID50 assay was performed to determine the biological titer of the three positive serotype of FMDV. The biological titer of this study was found 106.5/ml viral titer for O type, 106.75/ml viral titer for A type, 106.66/ml viral titer for Asia-1 type. These three specific serotypes can be used as vaccine seed against FMD virus. The effective vaccination of susceptible animals is considered to be the corner stone to the disease in our country Bangladesh. The findings of this study can be helpful for the trivalent vaccine development in Bangladesh and it may effective in limiting the spread of FMD.

Highlights

Foot and Mouth Disease (FMD) is a severe, highly contagious viral disease of livestock with significant economic impact
According to the antigenic properties of the capsid proteins, FMD virus (FMDV) are classified into 7 serological types, namely O, A, C, Asia 1 and SAT 1-3 [1]
Three FMDV positive samples were randomly selected from serotype O, A and Asia 1, and inoculated in BHK-21 cell line

Summary

Introduction

Foot and Mouth Disease (FMD) is a severe, highly contagious viral disease of livestock with significant economic impact. Outbreak of FMD causes severe economic losses to the livestock industries in terms of loss of draft power, meat and milk production, infant and adult animal mortality [3, 4, 5]. The FMD virus continually evolves and mutates, one of the difficulties in vaccinating against it is the huge variation between, and even within, serotypes. This means FMD vaccines must be highly specific to the strain involved. Every year vaccination is carried out throughout the country against FMD, still the disease outbreak occurs in many parts of Bangladesh [7]. A recent report from FAO has recommended that surveillance and reporting of FMD need to be improved throughout the country

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