title: Differential Persistence of Foot-and-Mouth Disease Virus in African Buffalo Is Related to Virus Virulence.
abstract: Foot-and-mouth disease (FMD) virus (FMDV) circulates as multiple serotypes and strains in many regions of endemicity. In particular, the three Southern African Territories (SAT) serotypes are maintained effectively in their wildlife reservoir, the African buffalo, and individuals may harbor multiple SAT serotypes for extended periods in the pharyngeal region. However, the exact site and mechanism for persistence remain unclear. FMD in buffaloes offers a unique opportunity to study FMDV persistence, as transmission from carrier ruminants has convincingly been demonstrated for only this species. Following coinfection of naive African buffaloes with isolates of three SAT serotypes from field buffaloes, palatine tonsil swabs were the sample of choice for recovering infectious FMDV up to 400 days postinfection (dpi). Postmortem examination identified infectious virus for up to 185 dpi and viral genomes for up to 400 dpi in lymphoid tissues of the head and neck, focused mainly in germinal centers. Interestingly, viral persistence in vivo was not homogenous, and the SAT-1 isolate persisted longer than the SAT-2 and SAT-3 isolates. Coinfection and passage of these SAT isolates in goat and buffalo cell lines demonstrated a direct correlation between persistence and cell-killing capacity. These data suggest that FMDV persistence occurs in the germinal centers of lymphoid tissue but that the duration of persistence is related to virus replication and cell-killing capacity.
  
  
  
  Foot-and-mouth disease virus (FMDV) causes a highly contagious acute vesicular disease in domestic livestock and wildlife species. African buffaloes (Syncerus caffer) are the primary carrier hosts of FMDV in African savannah ecosystems, where the disease is endemic. We have shown that the virus persists for up to 400 days in buffaloes and that there is competition between viruses during mixed infections. There was similar competition in cell culture: viruses that killed cells quickly persisted more efficiently in passaged cell cultures. These results may provide a mechanism for the dominance of particular viruses in an ecosystem.
authors.affiliation: Transboundary Animal Disease Programme, ARC-Onderstepoort Veterinary Institute, Onderstepoort, South Africa.|South Africa Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa.
authors.forename: Francois
authors.initials: F
authors.lastname: Maree
authors.affiliation: Office of the State Veterinarian, Department of Agriculture, Forestry and Fisheries, Skukuza, South Africa.
authors.forename: Lin-Mari
authors.initials: LM
authors.lastname: de Klerk-Lorist
authors.affiliation: The Pirbright Institute, Woking, Surrey, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Gubbins
authors.affiliation: The Pirbright Institute, Woking, Surrey, United Kingdom.
authors.forename: Fuquan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: The Pirbright Institute, Woking, Surrey, United Kingdom.
authors.forename: Julian
authors.initials: J
authors.lastname: Seago
authors.affiliation: The Pirbright Institute, Woking, Surrey, United Kingdom.
authors.forename: Eva
authors.initials: E
authors.lastname: Pérez-Martín
authors.affiliation: The Pirbright Institute, Woking, Surrey, United Kingdom.
authors.forename: Liz
authors.initials: L
authors.lastname: Reid
authors.affiliation: Transboundary Animal Disease Programme, ARC-Onderstepoort Veterinary Institute, Onderstepoort, South Africa.
authors.forename: Katherine
authors.initials: K
authors.lastname: Scott
authors.affiliation: Office of the State Veterinarian, Department of Agriculture, Forestry and Fisheries, Skukuza, South Africa.
authors.forename: Louis
authors.initials: L
authors.lastname: van Schalkwyk
authors.affiliation: Office of the State Veterinarian, Department of Agriculture, Forestry and Fisheries, Skukuza, South Africa.
authors.forename: Roy
authors.initials: R
authors.lastname: Bengis
authors.affiliation: The Pirbright Institute, Woking, Surrey, United Kingdom bryan.charleston@pirbright.ac.uk.
authors.forename: Bryan
authors.initials: B
authors.lastname: Charleston
authors.affiliation: The Pirbright Institute, Woking, Surrey, United Kingdom.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Juleff
mesh_terms: D000349:Africa / Q000453:epidemiology; D000818:Animals; D000835:Animals, Wild / Q000821:virology; D000914:Antibodies, Viral / Q000097:blood; D002020:Buffaloes / Q000821:virology*; D002353:Carrier State / Q000662:veterinary* / Q000821:virology; D060085:Coinfection / Q000453:epidemiology / Q000662:veterinary / Q000821:virology; D004797:Enzyme-Linked Immunosorbent Assay; D005536:Foot-and-Mouth Disease / Q000453:epidemiology / Q000276:immunology / Q000635:transmission / Q000821:virology*; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity* / Q000502:physiology*; D016679:Genome, Viral; D014066:Palatine Tonsil / Q000821:virology; D065288:Serogroup; D014774:Virulence; D014779:Virus Replication
chemical_list: D000914:Antibodies, Viral