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The African buffalo parasite Theileria. sp. (buffalo) can infect and immortalize cattle leukocytes and encodes divergent orthologues of Theileria parva antigen genes.

Bishop RP, Hemmink JD, Morrison WI, Weir W, Toye PG, Sitt T, Spooner PR, Musoke AJ, Skilton RA, Odongo DO - Int J Parasitol Parasites Wildl (2015)

Bottom Line: Collectively the data re-emphasise doubts regarding the value of rDNA sequence data alone for defining apicomplexan species in the absence of additional data. 'Deep 454 pyrosequencing' of DNA from two Theileria sporozoite stabilates prepared from Rhipicephalus appendiculatus ticks fed on buffalo failed to detect T. sp. (buffalo).This strongly suggests that R. appendiculatus may not be a vector for T. sp. (buffalo).Collectively, the data provides further evidence that T. sp. (buffalo). is a distinct species from T. parva.

View Article: PubMed Central - PubMed

Affiliation: International Livestock Research Institute (ILRI), PO Box 30709, Nairobi, 00100, Kenya.

ABSTRACT
African Cape buffalo (Syncerus caffer) is the wildlife reservoir of multiple species within the apicomplexan protozoan genus Theileria, including Theileria parva which causes East coast fever in cattle. A parasite, which has not yet been formally named, known as Theileria sp. (buffalo) has been recognized as a potentially distinct species based on rDNA sequence, since 1993. We demonstrate using reverse line blot (RLB) and sequencing of 18S rDNA genes, that in an area where buffalo and cattle co-graze and there is a heavy tick challenge, T. sp. (buffalo) can frequently be isolated in culture from cattle leukocytes. We also show that T. sp. (buffalo), which is genetically very closely related to T. parva, according to 18s rDNA sequence, has a conserved orthologue of the polymorphic immunodominant molecule (PIM) that forms the basis of the diagnostic ELISA used for T. parva serological detection. Closely related orthologues of several CD8 T cell target antigen genes are also shared with T. parva. By contrast, orthologues of the T. parva p104 and the p67 sporozoite surface antigens could not be amplified by PCR from T. sp. (buffalo), using conserved primers designed from the corresponding T. parva sequences. Collectively the data re-emphasise doubts regarding the value of rDNA sequence data alone for defining apicomplexan species in the absence of additional data. 'Deep 454 pyrosequencing' of DNA from two Theileria sporozoite stabilates prepared from Rhipicephalus appendiculatus ticks fed on buffalo failed to detect T. sp. (buffalo). This strongly suggests that R. appendiculatus may not be a vector for T. sp. (buffalo). Collectively, the data provides further evidence that T. sp. (buffalo). is a distinct species from T. parva.

No MeSH data available.


Related in: MedlinePlus

Maximum Likelihood phylogenetic tree generated using N-terminal sequences of T. sp. (buffalo) and T. parva PIM antigen genes. Maximum composite likelihood trees were constructed using 1000 bootstrap replicates as implemented in MEGA5; the optimal nucleotide substitution model was identified using data monkey. The tree constructed with RAxML (Stamatakis et al., 2014) using a GTR/G/I model with 100 bootstrap iterations.
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fig4: Maximum Likelihood phylogenetic tree generated using N-terminal sequences of T. sp. (buffalo) and T. parva PIM antigen genes. Maximum composite likelihood trees were constructed using 1000 bootstrap replicates as implemented in MEGA5; the optimal nucleotide substitution model was identified using data monkey. The tree constructed with RAxML (Stamatakis et al., 2014) using a GTR/G/I model with 100 bootstrap iterations.

Mentions: . Twelve PIM nucleotide sequences were determined, two from N18 and one from each of ten other cell lines from different infected animals and predicted protein alignments, including three reference sequences were generated (data not shown). Sequences obtained from N86 and N102, in which only T. sp. buffalo was detected, exhibited a significant level of amino acid identity with T. parva in the relatively conserved N and C termini of the protein, indicating that the PCR product represented the orthologue of PIM. The N-terminal 103 amino acids in T. parva Muguga and T. sp. buffalo PIM exhibited 61% identity at the amino acid level, as compared to 94% between the equivalent section of the T. parva Muguga and T. parva Buffalo 7014 PIM. The T. sp. buffalo PIM orthologue sequences from N86 and N102 were identical at the amino acid level. The PIM sequences obtained from two isolates derived from animal N18, designated, (N18 and N18a) were much more closely related to N86 and N102 in the conserved sections of the protein than to the other eight sequences, all of which were derived from different animals, suggesting that they represented a T. sp. (buffalo) PIM orthologue fortuitously selected from a parasite population that appeared mixed according to RLB (Fig. 1). However, there were significant differences in the central variable region between the predicted N18 PIM protein as compared to the N86 and N 102 sequences. This suggests that the PIM orthologue of T. sp. buffalo can vary between isolates in a similar manner to that of T. parva PIM. The level of sequence identity of the other eight PIM gene sequences to three T. parva reference PIM sequences (derived from the T. parva stocks Muguga, Marikebuni and Kiambu V) indicated that they likely originated from T. parva. Phylogenetic analysis of the relatively conserved N-terminal PIM coding sequences using a maximum likelihood algorithm revealed a clear separation of the T. sp. (buffalo) and T. parvasequences into two distinct clades in a tree, with high bootstrap support (Fig. 4). The C-terminal and concatenated N and C-terminal regions of the molecule generated trees with similar topology (data not shown). The alignment of the full length PIM sequences is available in Supplementary Fig. 1. The PIM sequences have been deposited in GenBank (see materials and methods for accession numbers).


The African buffalo parasite Theileria. sp. (buffalo) can infect and immortalize cattle leukocytes and encodes divergent orthologues of Theileria parva antigen genes.

Bishop RP, Hemmink JD, Morrison WI, Weir W, Toye PG, Sitt T, Spooner PR, Musoke AJ, Skilton RA, Odongo DO - Int J Parasitol Parasites Wildl (2015)

Maximum Likelihood phylogenetic tree generated using N-terminal sequences of T. sp. (buffalo) and T. parva PIM antigen genes. Maximum composite likelihood trees were constructed using 1000 bootstrap replicates as implemented in MEGA5; the optimal nucleotide substitution model was identified using data monkey. The tree constructed with RAxML (Stamatakis et al., 2014) using a GTR/G/I model with 100 bootstrap iterations.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4589832&req=5

fig4: Maximum Likelihood phylogenetic tree generated using N-terminal sequences of T. sp. (buffalo) and T. parva PIM antigen genes. Maximum composite likelihood trees were constructed using 1000 bootstrap replicates as implemented in MEGA5; the optimal nucleotide substitution model was identified using data monkey. The tree constructed with RAxML (Stamatakis et al., 2014) using a GTR/G/I model with 100 bootstrap iterations.
Mentions: . Twelve PIM nucleotide sequences were determined, two from N18 and one from each of ten other cell lines from different infected animals and predicted protein alignments, including three reference sequences were generated (data not shown). Sequences obtained from N86 and N102, in which only T. sp. buffalo was detected, exhibited a significant level of amino acid identity with T. parva in the relatively conserved N and C termini of the protein, indicating that the PCR product represented the orthologue of PIM. The N-terminal 103 amino acids in T. parva Muguga and T. sp. buffalo PIM exhibited 61% identity at the amino acid level, as compared to 94% between the equivalent section of the T. parva Muguga and T. parva Buffalo 7014 PIM. The T. sp. buffalo PIM orthologue sequences from N86 and N102 were identical at the amino acid level. The PIM sequences obtained from two isolates derived from animal N18, designated, (N18 and N18a) were much more closely related to N86 and N102 in the conserved sections of the protein than to the other eight sequences, all of which were derived from different animals, suggesting that they represented a T. sp. (buffalo) PIM orthologue fortuitously selected from a parasite population that appeared mixed according to RLB (Fig. 1). However, there were significant differences in the central variable region between the predicted N18 PIM protein as compared to the N86 and N 102 sequences. This suggests that the PIM orthologue of T. sp. buffalo can vary between isolates in a similar manner to that of T. parva PIM. The level of sequence identity of the other eight PIM gene sequences to three T. parva reference PIM sequences (derived from the T. parva stocks Muguga, Marikebuni and Kiambu V) indicated that they likely originated from T. parva. Phylogenetic analysis of the relatively conserved N-terminal PIM coding sequences using a maximum likelihood algorithm revealed a clear separation of the T. sp. (buffalo) and T. parvasequences into two distinct clades in a tree, with high bootstrap support (Fig. 4). The C-terminal and concatenated N and C-terminal regions of the molecule generated trees with similar topology (data not shown). The alignment of the full length PIM sequences is available in Supplementary Fig. 1. The PIM sequences have been deposited in GenBank (see materials and methods for accession numbers).

Bottom Line: Collectively the data re-emphasise doubts regarding the value of rDNA sequence data alone for defining apicomplexan species in the absence of additional data. 'Deep 454 pyrosequencing' of DNA from two Theileria sporozoite stabilates prepared from Rhipicephalus appendiculatus ticks fed on buffalo failed to detect T. sp. (buffalo).This strongly suggests that R. appendiculatus may not be a vector for T. sp. (buffalo).Collectively, the data provides further evidence that T. sp. (buffalo). is a distinct species from T. parva.

View Article: PubMed Central - PubMed

Affiliation: International Livestock Research Institute (ILRI), PO Box 30709, Nairobi, 00100, Kenya.

ABSTRACT
African Cape buffalo (Syncerus caffer) is the wildlife reservoir of multiple species within the apicomplexan protozoan genus Theileria, including Theileria parva which causes East coast fever in cattle. A parasite, which has not yet been formally named, known as Theileria sp. (buffalo) has been recognized as a potentially distinct species based on rDNA sequence, since 1993. We demonstrate using reverse line blot (RLB) and sequencing of 18S rDNA genes, that in an area where buffalo and cattle co-graze and there is a heavy tick challenge, T. sp. (buffalo) can frequently be isolated in culture from cattle leukocytes. We also show that T. sp. (buffalo), which is genetically very closely related to T. parva, according to 18s rDNA sequence, has a conserved orthologue of the polymorphic immunodominant molecule (PIM) that forms the basis of the diagnostic ELISA used for T. parva serological detection. Closely related orthologues of several CD8 T cell target antigen genes are also shared with T. parva. By contrast, orthologues of the T. parva p104 and the p67 sporozoite surface antigens could not be amplified by PCR from T. sp. (buffalo), using conserved primers designed from the corresponding T. parva sequences. Collectively the data re-emphasise doubts regarding the value of rDNA sequence data alone for defining apicomplexan species in the absence of additional data. 'Deep 454 pyrosequencing' of DNA from two Theileria sporozoite stabilates prepared from Rhipicephalus appendiculatus ticks fed on buffalo failed to detect T. sp. (buffalo). This strongly suggests that R. appendiculatus may not be a vector for T. sp. (buffalo). Collectively, the data provides further evidence that T. sp. (buffalo). is a distinct species from T. parva.

No MeSH data available.


Related in: MedlinePlus