Comparative Sensitivity of LFBK and LFBK αVβ6 Cell Lines for Isolation of Foot and Mouth Disease Virus from Riverine Buffaloes by Using Oro-Pharyngeal Fluids
Foot and mouth disease (FMD) is a major Transboundary Animal Disease (TAD) which causes major economics losses to the developing countries. In Pakistan the disease is considered endemic and outbreaks are still being reported. Rapid diagnosis of the disease and Isolation of FMD virus is important to confirm viral subtyping and allow for the development of effective vaccines against the specific subtypes. Carrier animals are the major source of current outbreaks of FMD in Pakistan. Current study was planned and conducted for isolation of FMD virus from persistently infected animals by using LFBK cell line and comparison of LFBK and LFBK αVβ6 for isolation of FMDV isolates from recent FMD outbreaks. A total of 120 serum samples were collected from persistently infected riverine buffaloes and examined for the presence of FMD virus Non-Structural Proteins by using NSP-ELISA. Of 120 sera samples 23 animals were found positive for NSP’s. The Oro-pharyngeal fluids (OP) were collected from NSP-ELISA positive animals. The OP fluids samples were treated with Tri-cholo-Tri-flouro-Ethane (TTE) and inoculated onto LFBK cell line. Out of 23 OP fluid samples 11 exhibited CPE’s. A total of six (06) FMD viruses were confirmed by rRT-PCR and characterized by Indirect Sandwich ELISA as type O, Asia-1and A. The FMD virus isolates were acquired from FAO-UN project on FMD in Pakistan. All isolates were inoculated on both of the cell lines and observed for the development of CPEs. We found that the newly modified LFBK αVβ6 cell line exhibited CPEs more rapidly after 18-20 hours, while LFBK cell line CPEs developed after 24 to 48 hours. TCID50 calculated on LFBK αVβ6 was higher for the all the serotypes tested than LFBK cell line. Percentage of CPEs in LFBK αVβ6 per plate resulted higher than over LFBK cell line.