A naturally occurring cowpox virus with an ectromelia virus A-type inclusion protein gene displays atypical A-type inclusions

Infect Genet Evol. 2012 Jan;12(1):160-8. doi: 10.1016/j.meegid.2011.09.017. Epub 2011 Sep 29.


Human orthopoxvirus (OPV) infections in Europe are usually caused by cowpox virus (CPXV). The genetic heterogeneity of CPXVs may in part be due to recombination with other OPV species. We describe the characterization of an atypical CPXV (CPXV-No-H2) isolated from a human patient in Norway. CPXV-No-H2 was characterized on the basis of A-type inclusion (ATI) phenotype as well as the DNA region containing the p4c and atip open reading frames. CPXV-No-H2 produced atypical V(+/) ATI, in which virions are on the surface of ATI but not within the ATI matrix. Phylogenetic analysis showed that the atip gene of CPXV-No-H2 clustered closely with that of ectromelia virus (ECTV) with a bootstrap support of 100% whereas its p4c gene is diverged compared to homologues in other OPV species. By recombination analysis we identified a putative crossover event at nucleotide 147, downstream the start of the atip gene. Our results suggest that CPXV-No-H2 originated from a recombination between CPXV and ECTV. Our findings are relevant to the evolution of OPVs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Base Sequence
  • Cowpox virus / genetics*
  • Cowpox virus / isolation & purification
  • DNA Primers
  • DNA, Viral / genetics
  • Ectromelia virus / genetics*
  • Humans
  • Inclusion Bodies, Viral / genetics
  • Inclusion Bodies, Viral / metabolism
  • Male
  • Molecular Sequence Data
  • Norway
  • Open Reading Frames
  • Phenotype
  • Phylogeny*
  • Recombination, Genetic
  • Sequence Analysis, DNA
  • Viral Proteins / genetics*
  • Virion / genetics


  • A-type inclusion protein, poxvirus
  • DNA Primers
  • DNA, Viral
  • Viral Proteins