Isolation and serotyping of foot-and-mouth disease virus in cattle collected from north central, Nigeria

Abstract

Foot-and-mouth disease (FMD) is a disease of socio-economic importance which affects cattle, swine, Sheep, goats, and more than 70 wildlife species causing loss of production and with high mortalities in the young animals.The aim of this study was to isolate and serotype foot-and mouth disease (FMD) viruses collected innorth central Nigeria, using the goat tongue cell line (ZZ-R 127). ZZ-R 127 cell line was used for the virus isolation and antigen Enzyme linked immunosorbent assay (ELISA) for FMDV serotypes O, A, SAT 1 & SAT 2 was used for the serotyping of the viruses. The ZZ-R 127 continuous cell line yielded rapid results with cytopathic effect (CPE) within 24 hours post inoculation. FMD viruses were isolated from twenty samples (n=20) out of the twenty two (n=22) collected. Antigen capture ELISA (Ag-ELISA) revealed thirteen (n=13) strains of serotype O, three (n=3) strains of serotype A, and four (n=4) strains of serotype SAT 2 with no virus detected in two samples.Therefore, the use of ZZ-R 127 continuous cell line yielded rapid results within 24 hours of post inoculation compared to BHK-21 that may not give result at first passages. The ZZ-R 27 cell line is relatively easy to handle, maintain and cheaper for FMDV diagnosis in endemic countries like Nigeria, compared to bovine thyroid gland (BYT).This study has confirmed the suitability of ZZ-R 127 in the primary isolation of viruses from clinical specimens with less turnaround time to generate results. Therefore, for rapid sensitive and specific laboratory assays, the use of ZZ-R 127 and Ag-ELISA for FMD diagnosis in endemic countries is strongly recommended.Keywords: Isolation, Foot-and-Mouth Disease Virus, field samples, cytopathic effect, Nigeria