PHYLOGENY OF BENIGN THEILERIA SPECIES FROM CATTLE IN THAILAND, CHINA AND THE USA BASED ON THE MAJOR PIROPLASM SURFACE PROTEIN AND SMALL-SUBUNIT RIBOSOMAL-RNA GENES

The major piroplasm surface protein and small subunit ribosomal RNA ge nes of benign Theileria species isolated from cattle in China, Thailan d and the U.S.A. were amplified by polymerase chain reaction, cloned a nd sequenced. The major piroplasm surface protein genes of these three isolates were more than 89% identical at amino-acid level. Several de letions in the gene from the Thai isolate led to considerable structur al change through frame shifts of the major piroplasm surface protein. Phylogenetic analyses based on both of the major piroplasm surface pr otein and small subunit ribosomal RNA genes suggest that there may be a second cosmopolitan benign Theileria species infecting cattle in add ition to the Theileria sergenti/buffeli/orientalis complex. (C) 1998 A ustralian Society for Parasitology. Published by Elsevier Science Ltd.