Genetic diversity within : mitochondrial genome analysis reveals a clear African and Asian division.

Following the recent report of strongyloidiasis caused by within a semi-captive colony of baboons in a UK safari park, we investigated the genetic relationships of this isolate with other isolates across the world. Whole-genome sequencing data were generated with later phylogenetic analysis of mitochondrial (mt) cytochrome oxidase subunit 1 () and nuclear ribosomal 18S sequences against 300 published reference genotypes. The putative African origin of the UK was confirmed and full-length mt genome sequences were assembled to facilitate a more detailed phylogenetic analysis of 14 mt coding regions against all available species. Our analyses demonstrated that the UK isolate represented a novel African lineage not previously described. Additional complete mt genomes were assembled for several individual UK safari park worms to reveal a slightly altered mt genome gene arrangement, allowing clear separation from Asian . Furthermore, these UK worms possessed expanded intergenic regions of unknown function that increase their mt genome size to approximately 24 kilobases (kb) as compared with some 16 kb for Asian ; this may have arisen from unique populational founder and genetic drift effects set within the peculiar mixed species baboon and drill ancestry of this semi-captive primate colony. A maximum likelihood phylogeny constructed from 14 mt coding regions also supported an evolutionary distinction between Asian and African .