Genetic polymorphism and population structure ofEchinococcus ortleppi

Abstract

SUMMARYThe zoonotic cestodeEchinococcus ortleppi(Lopez-Neyra and Soler Planas, 1943) is mainly transmitted between dogs and cattle. It occurs worldwide but is only found sporadically in most regions, with the notable exception of parts of southern Africa and South America. Its epidemiology is little understood and the extent of intraspecific variability is unknown. We have analysed in the present study the genetic diversity among 178E. ortleppiisolates from sub-Saharan Africa, Europe and South America using the complete mitochondrialcox1(1608 bp) andnad1(894 bp) DNA sequences. Genetic polymorphism within the loci revealed 15cox1and sixnad1haplotypes, respectively, and 20 haplotypes of the concatenated genes. Presence of most haplotypes was correlated to geographical regions, and only one haplotype had a wider spread in both eastern and southern Africa. Intraspecific microvariance was low in comparison withEchinococcus granulosussensu stricto, despite the wide geographic range of examined isolates. In addition, the various sub-populations showed only subtle deviation from neutrality and were mostly genetically differentiated. This is the first insight into the population genetics of the enigmatic cattle adaptedEchinococcus ortleppi. It, therefore, provides baseline data for biogeographical comparison amongE. ortleppiendemic regions and for tracing its translocation paths.