Genetic Diversity of Major Piroplasm Surface Protein Genes and Their Allelic Variants of Theileria Parasites in Thai Cattle.

Abstract

ABSTRACT. Twenty-eight field isolated Theileria parasite DNAs obtained from dairy and beef cattle in distinct geographical areas of Thailand were characterized by using polymerase chain reaction (PCR) amplification with six sets of oligonucleotide primers. Three sets of them were modified from two genes of immunodominant major piroplasm surface protein (MPSP) coding for 32 kDa (p32) of T. sergenti and 33/34 kDa (p33/34) of T. buffeli, and MPSP of Theileria spp.(Thai-isolate). The other three sets of primers were basically generated from three alleles of MPSP which were specific for Japanese T. sergenti-Ikeda stock (I-type), Japanese T. sergenti-Chitose stock (C-type) and Australian T. buffeli-Warwick stock (B1-type), respectively. The results indicated that 14 out of 28 isolates were amplified by the Thai-specific primer whereas 6 isolates were amplified by the p32 specific primer and the other 5 isolates were amplified by the p32 and Thai-specific primers. In addition, by using the allele-specific PCR, 14 out of 28 isolates contained C-type MPSP whereas 3 isolates contained B1 type parasites. Interestingly, 20 out of 28 isolates could be amplified by the Thai-specific primer. The majority of Theileria parasites distributed in Thailand contained Thai type parasites, whereas C-type parasites showed the mixed population with B1 and Thai type parasites. No I type parasite was detected.-KEY WORDS: major piroplasm surface protein, PCR, Theileria.J. Vet. Med. Sci. 61(9): 991-994, 1999 well as B1-type MPSP allele. This study revealed that T.

Survey of Benign Theileria Parasites of Cattle and Buffaloes in Thailand using Allele-Specific Polymerase Chain Reaction of Major Piroplasm Surface Protein Gene.

“…The molecular weight of MPSP ranges from 30 to 40 kDa [8,19]. Recently, the nucleotide sequences of MPSP genes were used in epidemiological and phylogenetic research [4,5,9,12,13,17]. The populations of benign Theileria parasites differentiated by using allelic MPSP gene types are listed in Table 1.…”

“…In Thailand, different species or variants of Theileria parasites were found and designated as Thai-type, C-type and B-type [7,17]. However, the distribution of benign Theileria parasites in this country has not been fully studied.…”

Survey of Theileria Parasite Infection in Cattle in Cambodia and Vietnam Using Piroplasm Surface Protein Gene-Specific Polymerase Chain Reaction.

“…For further analysis of parasite populations, field isolates were collected from Asian countries (Korea, China, Taiwan and Thailand) and others (Australia and Italy). This analysis showed that the I type parasites were commonly found in Korean isolates [3,7,8,10] but not in Taiwan [18], Thailand [14,15], Australia [9] and Italy [16]. In the present study, we characterized field-collected isolates of Theileria in cattle from Cambodia and Vietnam using allele-specific PCR in order to obtain further epidemiological information of T. orientalis in Southeast Asia.…”

“…In Korea, all Theileria isolates contained the I type pathogenic than the C and the B type parasites and infected cattle manifest severe clinical symptoms [3,8], whereas the non-pathogenic C type is documented in Taiwan [18] and Italy [16]. In Thailand, where the Thai and C types exist, theileriosis has never been reported [15]. On the basis of these epidemiological studies, C type parasite is considered to be an universal and apathogenic type.…”

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“…2 Recent studies using the major piroplasm surface protein (MPSP) and small subunit ribosomal RNA (ssrRNA) gene indicated that Thai isolates of Theileria are more closely related to the T. sergenti/buffeli/orientalis group parasites than to malignant species of Theileria. [2][3][4] Since the pathogenesis of the benign Theileria species is found to be related to the proliferation of the parasites in the host's red blood cells, chemotherapy of the benign theileriosis has mainly been focused on destroying the intraerythrocytic stages. Although some drugs are currently available for the treatment of bovine theileriosis, they are not necessarily satisfactory because of their adverse effects and the emergence of parasite with increased drug resistance.…”