Assessing swine meat juice for the detection of foot-and-mouth disease virus by real-time reverse transcription polymerase chain reaction, enzyme-linked immunosorbant assays, and pen-side lateral flow immunoassays
Many infectious diseases concern agricultural sectors globally. Foot-and-Mouth Disease (FMD) is one of the most contagious diseases that causes severe infections in cloven-hoofed animals. Animals that become infected by Foot-and-Mouth Disease Virus (FMDV) should be slaughtered to prevent spread. Countries that endure endemic outbreaks or are free of the disease contribute large amounts of funding to combat and/or prevent FMD. FMD is diagnosed using sample types such as vesicular fluid, oropharyngeal swabs, lesions swabs, or serum. Situations may be encountered where these samples are not available. In these cases such as illegal importation or absence of the animal carcass, meat juice (MJ) can be alternatively used to test for the presence of FMDV. This was assessed using the biceps femoris from experimentally infected pigs. MJ, collected after freeze-thaw cycling, was found viable for the detection of FMDV directly by Real-time Reverse Transcription Polymerase Chain Reaction (rRT-PCR), Lateral Flow Immunoassay (LFI), sanger sequencing, and transfection. FMDV detection in RNA extracted from MJ was found as late as 21 days post infection (DPI) compared to 7 DPI in serum. LFI was able to detect FMDV antigen in MJ from 1-9 DPI. Isolation of FMDV from MJ was not possible, but was circumvented using transfection as an alternate recovery system. Indirect detection of FMDV was also possible through antibody detection by solid phase competitive enzyme-linked immunosorbent assay. MJ was found to have antibodies to the structural proteins (SP) of FMDV starting at 6 or 7 DPI, mirroring what is found in serum. Detection of antibodies to the non-structural proteins of FMDV did not give meaningful results. These results demonstrate that MJ is a capable sample type that can be used to detect FMDV RNA, antigen, and antibodies to SP.
Meat juice, Foot-and-mouth disease, Skeletal muscle, FMDV RNA, FMDV antigen, competitive ELISA
Yeo S., Yang M., Nyachoti M., Rauh R., Callahan J.D., Nfon C. Detection of Foot-and-Mouth Disease Virus in Swine Meat Juice. Pathogens. 2020. 9(6):424.