SEROTYPING AND MOLECULAR CHARACTERIZATION OF FOOT AND MOUTH DISEASE OF CATTLE IN CENTRAL ETHIOPIA

Abstract

Foot and mouth disease (FMD) is one of the most economically important, highly contagious and trans-boundary animal diseases in developing countries including Ethiopia causing huge amount of economical loses in different geographical areas of the country. However, the information about genetic characteristics and strains of FMD virus circulating in Ethiopia is scarce. A cross sectional study was conducted between September 2016 and April 2017 to undertake serotyping and molecular characterization of FMD virus from outbreak cases in central Ethiopia. A total of 105 samples (35 oral swabs, 6 epithelial tissues, 64 oro-pharyngeal fluids) were collected purposively from cattle outbreaks cases in central Ethiopia including Oromia Special Finfine Surrounding zone (Mulo woreda), North Shewa zone (Aleltu, Kimbibit and Wochale woredas), East Shewa zone (Adea woreda) and Addis Ababa (Kolfe Koraneyo sub city) and transported to NAHDIC Sebeta for laboratory investigation. All samples collected, stored, prepared in accordance with standard methods and subjected to RNA extraction and real-time RT-PCR. Positive samples for FMDV were further subjected to viral isolation (cell culture) and identification of isolated virus by antigen detection ELISA. Obtained data were entered into Ms-excel and interpreted by SPSS program. Out of the total 105 samples tested by real-time RT-PCR, 34 (32.38%) samples were found to be positive for FMD virus. Eight positive samples representing each outbreak areas were further cultured or inoculated into 25 cm 2 flask containing monolayer BHK-21 cell lines, the result showed the cytopathic effect (CPE) which is characterized by the rounding and flattening of the cells, breaking down of the intracellular bridges and finally cell death. Among the eight isolates, six samples were characterized by antigen detecting ELISA. Serotypes O (4) and A (3) were identified. In one of the isolates both serotype were identified. This study revealed that serotypes O and A of FMD virus were causing outbreaks in cattle in Ethiopia inflicting huge economic losses. Therefore, proper control and intervention should be designed and implemented to minimize the burden of the disease.