Abstract
Successful purification of multiple viruses from mixed infections remains a challenge. In this study, we investigated peste des petits ruminants virus (PPRV) and foot-and-mouth disease virus (FMDV) mixed infection in goats. Rather than in a single cell type, cytopathic effect (CPE) of the virus was observed in cocultured Vero/BHK-21 cells at 6th blind passage (BP). PPRV, but not FMDV could be purified from the virus mixture by plaque assay. Viral RNA (mixture) transfection in BHK-21 cells produced FMDV but not PPRV virions, a strategy which we have successfully employed for the first time to eliminate the negative-stranded RNA virus from the virus mixture. FMDV phenotypes, such as replication competent but noncytolytic, cytolytic but defective in plaque formation and, cytolytic but defective in both plaque formation and standard FMDV genome were observed respectively, at passage level BP8, BP15 and BP19 and hence complicated virus isolation in the cell culture system. Mixed infection was not found to induce any significant antigenic and genetic diversity in both PPRV and FMDV. Further, we for the first time demonstrated the viral interference between PPRV and FMDV. Prior transfection of PPRV RNA, but not Newcastle disease virus (NDV) and rotavirus RNA resulted in reduced FMDV replication in BHK-21 cells suggesting that the PPRV RNA-induced interference was specifically directed against FMDV. On long-term coinfection of some acute pathogenic viruses (all possible combinations of PPRV, FMDV, NDV and buffalopox virus) in Vero cells, in most cases, one of the coinfecting viruses was excluded at passage level 5 suggesting that the long-term coinfection may modify viral persistence. To the best of our knowledge, this is the first documented evidence describing a natural mixed infection of FMDV and PPRV. The study not only provides simple and reliable methodologies for isolation and purification of two epidemiologically and economically important groups of viruses, but could also help in establishing better guidelines for trading animals that could transmit further infections and epidemics in disease free nations.
Highlights
Occurrence of multiple virus infections is ubiquitous in natural populations, which may have significant epidemiological and biological effects [1,2]
Peste des petits ruminants virus (PPRV) is a negative stranded RNA virus that belongs to the genus Morbillivirus of the family Paramyxoviridae [10,11], whereas foot-and-mouth disease virus (FMDV) is a positive stranded RNA virus that belongs to the genus Apthovirus under the family Picornaviridae [12]
Except young animals which may die due to myocarditis, FMDV infected animals usually recovers after an acute infection without any significant mortality
Summary
Occurrence of multiple virus infections is ubiquitous in natural populations, which may have significant epidemiological and biological effects [1,2]. FMDV has seven distinct serotypes (O, A, C, Asia-1, SAT-1, SAT-2 and SAT-3) and multiple subtypes, and cross protection does not occur even within subtypes of a particular serotype [12,13] Both PPRV and FMDV cause an acute contagious infection that results in significant economic losses to the livestock industry [14,15] and both are classified as Office International des Epizootics (OIE)-listed disease. Clinical signs of both the diseases mimic and are characterized by fever, erosive lesions on mucous membranes of oral cavity and, salivary and nasal discharge which are difficult to differentiate clinically. PPRV infection on the other hand leads to high morbidity and mortality in small ruminants [17,18,19] with a sub-clinical infection in cattle and buffaloes [14]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
