Variant analysis of the sporozoite surface antigen gene reveals that asymptomatic cattle from wildlife-livestock interfa
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PROTOZOOLOGY - ORIGINAL PAPER
Variant analysis of the sporozoite surface antigen gene reveals that asymptomatic cattle from wildlife-livestock interface areas in northern Tanzania harbour buffalo-derived T. parva Micky M. Mwamuye 1 & David Odongo 2 & Yvette Kazungu 3 & Fatuma Kindoro 3 & Paul Gwakisa 3 & Richard P. Bishop 4 & Ard M. Nijhof 1 & Isaiah Obara 1 Received: 17 June 2020 / Accepted: 23 September 2020 / Published online: 3 October 2020 # The Author(s) 2020
Abstract Buffalo-derived Theileria parva can ‘break through’ the immunity induced by the infection and treatment vaccination method (ITM) in cattle. However, no such ‘breakthroughs’ have been reported in northern Tanzania where there has been long and widespread ITM use in pastoralist cattle, and the Cape buffalo (Syncerus caffer) is also present. We studied the exposure of vaccinated and unvaccinated cattle in northern Tanzania to buffalo-derived T. parva using p67 gene polymorphisms and compared this to its distribution in vaccinated cattle exposed to buffalo-derived T. parva in central Kenya, where vaccine ‘breakthroughs’ have been reported. Additionally, we analysed the CD8+ T cell target antigen Tp2 for positive selection. Our results showed that 10% of the p67 sequences from Tanzanian cattle (n = 39) had a buffalo type p67 (allele 4), an allele that is rare among East African isolates studied so far. The percentage of buffalo-derived p67 alleles observed in Kenyan cattle comprised 19% of the parasites (n = 36), with two different p67 alleles (2 and 3) of presumptive buffalo origin. The Tp2 protein was generally conserved with only three Tp2 variants from Tanzania (n = 33) and five from Kenya (n = 40). Two Tanzanian Tp2 variants and two Kenyan Tp2 variants were identical to variants present in the trivalent Muguga vaccine. Tp2 evolutionary analysis did not show evidence for positive selection within previously mapped epitope coding sites. The p67 data indicates that some ITM-vaccinated cattle are protected against disease induced by a buffalo-derived T. parva challenge in northern Tanzania and suggests that the parasite genotype may represent one factor explaining this. Keywords Theileria parva . p67 . Tp2 . Antigen diversity . Cape Buffalo . Live vaccine
Section Editor: Daniel K Howe Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00436-020-06902-1) contains supplementary material, which is available to authorized users. * Ard M. Nijhof [email protected]
Richard P. Bishop [email protected] Isaiah Obara [email protected]
Micky M. Mwamuye [email protected] David Odongo [email protected] Yvette Kazungu [email protected]
1
Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163 Berlin, Germany
2
School of Biological Sciences, University of Nairobi, Nairobi, Kenya
3
Genome Science Laboratory, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, P.O. Box 3
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