Analyses of genes encoding Theileria parva p104 and polymorphic immunodominant molecule (PIM) reveal evidence of the presence of cattle-type alleles in the South African T. parva population

Abstract

Restriction fragment length polymorphism analysis of PCR products (PCR-RFLP) and sequencing of the variable region of the p104 and PIM genes was performed on samples obtained from South African T. parva parasites originating from cattle on farms with suspected theileriosis and from buffalo. p104 and PIM PCR-RFLP profiles similar to those of the T. parva Muguga stock, an isolate that causes ECF in Kenya, were obtained from three of seven cattle samples collected on a farm near Ladysmith in KwaZulu-Natal Province. Amino acid sequences of the p104 and PIM genes from two of these samples were almost identical to the T. parva Muguga p104 and PIM sequences.This result supports findings from a recent p67 study in which p67 alleles similar to those of the T.parva Muguga stock were identified from the same samples. While these results suggest the presence of a cattle-derived T. parva parasite, reports of cattle-to-cattle transmission could not be substantiated and ECF was not diagnosed on this farm. Although extensive diversity of p104 and PIM gene sequences from South African T. parva isolates was demonstrated, no sequences identical to known cattle-type p104 and PIM alleles were identified from any of the buffalo T. parva samples analyzed. 'Mixed' PIM alleles containing both cattle-and buffalo-type amino acid motifs were identified for the first time, and there appeared to be selection of cattle-type and 'mixed'-type PIM sequences in the cattle samples examined. Keywords:Theileria parva, p104, polymorphic immunodominant molecule (PIM), characterization, Corridor disease, East Coast fever 3 IntroductionCattle theileriosis caused by Theileria parva is a disease of major economic importance in eastern, central and parts of southern Africa (Young et al., 1988). Infections of cattle by T. parva parasites result in three recognized disease syndromes, East Coast fever (ECF), January disease and Corridor disease. The natural tick vectors of T. parva in South Africa are Rhipicephalus appendiculatus and R. zambeziensis (Lawrence et al., 1983), and, in the presence of T. parva-infected buffalo, the vector ticks can transmit the parasite to naïve cattle, resulting in Corridor disease outbreaks.Corridor disease remains important in South Africa where it is a controlled disease. et al., 2008). This finding is of concern to the cattle industry in South Africa, as Potgieter et al. (1988) showed that buffalo-derived T. parva parasites, causing Corridor disease, can be maintained by passage between cattle and the tick vector. The persistence of T. parva infections in cattle in South Africa could eventually result in the selection of T. parva parasites adapted to cattle. It remains a concern that ECF could re-emerge and therefore a serious need exists to establish if there are cattle-type T. parva parasites in buffalo in South Africa.Restriction fragment length polymorphism analyses of PCR products (PCR-RFLP) of T. parva antigen genes, PIM, p104, p150 and p67, have been used for characterization of T. parva stocks (Geysen et ...

Conservation and variation in the region of the Theileria parva p104 antigen coding gene used for PCR surveillance of the parasite

“…However, it is also important to note that in the present study, the analysis of all sequences highlights that South African buffalo–derived T. parva have p104 alleles that are distinct from other buffalo- and cattle-derived T. parva . This finding is consistent with genome and other antigen gene sequence data (Maboko et al 2021 ; Sibeko et al 2011 ) and is discussed in the next section with respect to single-base mismatches within the p104 primer target sequences.…”

“…The most frequent p104 variants also match those in the Marikebuni vaccine developed by the National Veterinary Research Institute in Kenya, which has not been sufficiently widely used for ITM in the field to provide support for the vaccination dissemination hypothesis. It is also relevant to note that analysis of variation in the T. parva sporozoite surface antigen p67 in South African field isolates has also shown that alleles similar to those of the T. parva Muguga stock were circulating naturally in the field in KwaZulu-Natal Province (Sibeko et al 2011 ).…”

“…These comprised six buffalo-derived T. parva isolates from Kruger National Park (KNP) in Mpumalanga province (KNPAB7, KNPB10, KNP W8, KNP Y4) and Hluhluwe-iMfolozi Park in KwaZulu-Natal province (HIP 05, HIP 19). A cattle-derived isolate from Bloemfontein, Free State Province (BloeB) was also selected (Sibeko et al 2011 ).…”

Population genetic analysis of Theileria parva isolated in cattle and buffaloes in Tanzania using minisatellite and microsatellite markers

“…This is supported by larger mean number of different alleles, effective alleles, private alleles and expected heterozygosity than other populations, followed by Lushoto. Buffaloes are believed to carry a heterogeneous population of parasites (Sibeko et al, 2011), therefore; these results were not surprising. The presence of unique alleles in all populations indicate that there is a unique set of isolates in the populations used in this study as each allele is a representative of a different isolate.…”

South African Buffalo-Derived Theileria parva Is Distinct From Other Buffalo and Cattle-Derived T. parva

“…Naturally recovered life-long carriers of T. parva are common in African countries where cattle-cattle transmission is common (Kariuki et al, 1995). Asymptomatic T. parva positive cattle (Yusufmia et al, 2010) as well as strains with antigenic gene sequences identical to the Muguga isolate (Sibeko et al, 2010(Sibeko et al, , 2011 have been reported in KwaZulu-Natal, raising concerns of the possible circulation of ECF strains in South Africa. The animals, however, lost their parasite load approximately 120 days post infection and could not transmit the parasite (Mbizeni et al, 2013).…”