Main content area

Extensive genetic recombination occurs in the field between different genotypes of Ehrlichia ruminantium

Allsopp, M.T.E.P., Allsopp, B.A.
Veterinary microbiology 2007 v.124 no.1-2 pp. 58-65
heartwater, ehrlichiosis, Ehrlichia ruminantium, microbial genetics, genetic variation, phylogeny, center of origin, genotype, nucleotide sequences, genes, molecular genetics, genetic recombination, Africa, Caribbean
The intracellular bacterium Ehrlichia ruminantium is the causative agent of heartwater throughout sub-Saharan Africa, Madagascar, and some islands of the Caribbean. The disease is tick-borne and causes substantial livestock losses, threatening food security and productivity in both the commercial and small-scale farming sectors in endemic areas. Immunization by infection and treatment is currently practised in South Africa, and it is known that a variety of immunotypes of the organism occur in the field, and that cross-protection between them varies widely from total to minimal. Future vaccines may therefore need to incorporate components from different genotypes so it is essential to have information on the extent of genetic variation among isolates. To obtain this information we amplified and sequenced a panel of eight core function genes from 12 different cultured stocks originally isolated in different areas of Africa and the Caribbean.