Fachbereich Veterinärmedizin



    Human and animal Trypanosomes in Côte d'Ivoire form a single breeding population (2013)

    Zeitschriftenartikel / wissenschaftlicher Beitrag
    Capewell, Paul
    Cooper, Anneli
    Duffy, Craig W
    Tait, Andy
    Turner, C Michael R
    Gibson, Wendy
    Mehlitz, Dieter (WE 13)
    Macleod, Annette
    PLoS one; 8(7) — S. e67852
    ISSN: 1932-6203
    URL (Volltext): http://edocs.fu-berlin.de/docs/receive/FUDOCS_document_000000019486
    DOI: 10.1371/journal.pone.0067852
    Pubmed: 23844111
    Institut für Parasitologie und Tropenveterinärmedizin

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    Abstract / Zusammenfassung

    Trypanosoma brucei is the causative agent of African Sleeping Sickness in humans and contributes to the related veterinary disease, Nagana. T. brucei is segregated into three subspecies based on host specificity, geography and pathology. T. b. brucei is limited to animals (excluding some primates) throughout sub-Saharan Africa and is non-infective to humans due to trypanolytic factors found in human serum. T. b. gambiense and T. b. rhodesiense are human infective sub-species. T. b. gambiense is the more prevalent human, causing over 97% of human cases. Study of T. b. gambiense is complicated in that there are two distinct groups delineated by genetics and phenotype. The relationships between the two groups and local T. b. brucei are unclear and may have a bearing on the evolution of the human infectivity traits.

    A collection of sympatric T. brucei isolates from Côte d'Ivoire, consisting of T. b. brucei and both groups of T. b. gambiense have previously been categorized by isoenzymes, RFLPs and Blood Incubation Infectivity Tests. These samples were further characterized using the group 1 specific marker, TgSGP, and seven microsatellites. The relationships between the T. b. brucei and T. b. gambiense isolates were determined using principal components analysis, neighbor-joining phylogenetics, STRUCTURE, FST, Hardy-Weinberg equilibrium and linkage disequilibrium.

    Group 1 T. b. gambiense form a clonal genetic group, distinct from group 2 and T. b. brucei, whereas group 2 T. b. gambiense are genetically indistinguishable from local T. b. brucei. There is strong evidence for mating within and between group 2 T. b. gambiense and T. b. brucei. We found no evidence to support the hypothesis that group 2 T. b. gambiense are hybrids of group 1 and T. b. brucei, suggesting that human infectivity has evolved independently in groups 1 and 2 T. b. gambiense.