Molecular characterisation of the Theileria buffeli/orientalis group

Benign bovine Theileria parasites known as either Theileria buffeli, Theile ria orientalis or Theileria sergenti are classified on basis of their morph ology, vector specificity, pathogenicity anti 18S small subunit ribosomal R NA or major piroplasm protein (MPSP) sequences. Since most isolates have be en characterized on only some of these criteria and the existing confusion in nomenclature, an analysis was performed on eight different isolates to c ombine 18S rRNA data with MPSP data and the results were compared with avai lable biological parameters. A polymerase chain reaction-restriction fragme nt length polymorphism (PCR-RFLP) approach for both genes was used in combi nation with reverse line blot hybridisation For the 18S rRNA gene. Both MFS P and 18S rRNA genes were cloned and sequenced from parasites displaying ab errant MFSP RFLP profiles. Phylogeny based on published and determined 18S rRNA and MPSP sequences did correlate within the same isolate but there was no obvious correlation between molecular and biological data. Based on the se findings, we suggest that the appropriate name for all these parasites i s Theileria buffeli. A more specific nomenclature should be assigned when n ew molecular markers may become available. (C) 2000 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.