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. 2018 Aug;145(9):1235-1242.
doi: 10.1017/S0031182017002359. Epub 2018 Jan 24.

Differential virulence of camel Trypanosoma evansi isolates in mice

Christine M Kamidi  1 , Joanna Auma  2 , Paul O Mireji  2 , Kariuki Ndungu  2 , Rosemary Bateta  2 , Richard Kurgat  2 , Collins Ouma  1 , Serap Aksoy  3 , Grace Murilla  2
Affiliations

Differential virulence of camel Trypanosoma evansi isolates in mice

Christine M Kamidi et al. Parasitology. 2018 Aug.

Abstract

This study assessed the virulence of Trypanosoma evansi, the causative agent of camel trypanosomiasis (surra), affecting mainly camels among other hosts in Africa, Asia and South America, with high mortality and morbidity. Using Swiss white mice, we assessed virulence of 17 T. evansi isolates collected from surra endemic countries. We determined parasitaemia, live body weight, packed cell volume (PCV) and survivorship in mice, for a period of 60 days' post infection. Based on survivorship, the 17 isolates were classified into three virulence categories; low (31-60 days), moderate (11-30 days) and high (0-10 days). Differences in survivorship, PCV and bodyweights between categories were significant and correlated (P < 0.05). Of the 10 Kenyan isolates, four were of low, five moderate and one (Type B) of high virulence. These findings suggest differential virulence between T. evansi isolates. In conclusion, these results show that the virulence of T. evansi may be region specific, the phenotype of the circulating parasite should be considered in the management of surra. There is also need to collect more isolates from other surra endemic regions to confirm this observation.

Keywords: Packed cell volume; Trypanosoma evansi; survival; virulence..

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Figures

Figure 1
Figure 1
(A and B) Parasitaemia profiles of individual mice infected with low virulence Trypanosoma evansi isolates; KETRI 3573 and 2737. (C and D) Parasitaemia profiles of mice infected with moderate virulence Trypanosoma evansi isolates; KETRI 3580 and 2446. (E and F) Parasitaemia profiles of individual mice infected with high virulence Trypanosoma evansi isolates; 4038 and 2479. (M = mouse).
Figure 2
Figure 2
Survival curves depicting the fraction of animals alive from the time (0) of parasite inoculation: (A) Survival curves of Trypanosoma evansi isolates of high virulence. (B) Survival curves of Trypanosoma evansi isolates of medium virulence. (C) Survival curves of Trypanosoma evansi isolates of low virulence.
Figure 3
Figure 3
(A and B) percent (%) Packed Cell Volume change profiles of individual mice infected with low virulence Trypanosoma evansi isolates; KETRI 3573 and 2737. (C and D) Percent (%) Changes in Packed Cell Volume of individual mice infected with moderate virulence Trypanosoma evansi isolates; KETRI 3580 and 2446. (M = mouse).
Figure 4
Figure 4
(A and B) bodyweight changes profiles of individual mice infected with low virulence Trypanosoma evansi isolates; KETRI 3573 and 2737. (C and D) bodyweight change profiles of individual mice infected with moderate virulence of Trypanosoma evansi isolates; KETRI 3580 and 2446. (M = mouse).
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References

    1. Alizon S, Hurford A, Mideo N, Van Baalen M. Virulence evolution and the trade-off hypothesis: History, current state of affairs and the future. Journal of Evolutionary Biology. 2009;22(2):245–259. doi: 10.1111/j.1420-9101.2008.01658.x. - DOI - PubMed
    1. Antoine-Moussiaux N, Biischer P, Desmecht D. Host-parasite interactions in trypanosomiasis: On the way to an antidisease strategy. Infection and Immunity. 2009;77(4):1276–1284. doi: 10.1128/IAI.01185-08. - DOI - PMC - PubMed
    1. Berngruber TW, Froissart R, Choisy M, Gandon S. Evolution of Virulence in Emerging Epidemics. PLoS Pathogens. 2013;9(3):e1003209. doi: 10.1371/journal.ppat.1003209. - DOI - PMC - PubMed
    1. Bezie M, Girma M, Dagnachew S, Tadesse D, Tadesse G. African Trypanosomes: Virulence Factors, Pathogenicity And Host Responses. Journal of Veterinary Advances. 2014;4(11):732–745. doi: 10.5455/jva.20141129012406. - DOI
    1. Birhanu H, Gebrehiwot T, Goddeeris BM, Büscher P, Van Reet N. New Trypanosoma evansi Type B Isolates from Ethiopian Dromedary Camels. PLoS Neglected Tropical Diseases. 2016;10(4):e0004556. doi: 10.1371/journal.pntd.0004556. - DOI - PMC - PubMed

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