title: Assessment of sequence variability in a p23 gene region within and among three genotypes of the Theileria orientalis complex from south-eastern Australia.
abstract: Oriental theileriosis is a tick-borne, protozoan disease of cattle caused by one or more genotypes of Theileria orientalis complex. In this study, we assessed sequence variability in a region of the 23kDa piroplasm membrane protein (p23) gene within and among three T. orientalis genotypes (designated buffeli, chitose and ikeda) in south-eastern Australia. Genomic DNA (n=100) was extracted from blood of infected cattle from various locations endemic for oriental theileriosis and tested by polymerase chain reaction (PCR)-coupled mutation scanning (single-strand conformation polymorphism (SSCP)) and targeted sequencing analysis. Eight distinct sequences represented all DNA samples, and three genotypes were found: buffeli (n=3), chitose (3) and ikeda (2). Nucleotide pairwise comparisons among these eight sequences revealed considerably higher variability among the genotypes (6.6-11.7%) than within them (0-1.9%), indicating that the p23 gene region allows the accurate identification of T. orientalis genotypes. In the future, we will combine this gene with other molecular markers to study the genetic structure of T. orientalis populations in Australasia, which will pave the way to establish a highly sensitive and specific PCR-based assay for genotypic diagnosis of infection and for assessing levels of parasitaemia in cattle.
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, Australia.
authors.forename: Piyumali K
authors.initials: PK
authors.lastname: Perera
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, Australia.
authors.forename: Robin B
authors.initials: RB
authors.lastname: Gasser
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, Australia. Electronic address: jabbara@unimelb.edu.au.
authors.forename: Abdul
authors.initials: A
authors.lastname: Jabbar
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000469:parasitology; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D018512:Parasitemia; D010802:Phylogeny; D018807:Polymorphism, Single-Stranded Conformational; D015800:Protozoan Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013021:South Australia / Q000453:epidemiology; D016794:Theileria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D013801:Theileriasis / Q000453:epidemiology* / Q000469:parasitology; D014904:Western Australia / Q000453:epidemiology
chemical_list: D016054:DNA, Protozoan; D008565:Membrane Proteins; D015800:Protozoan Proteins; C085175:piroplasm surface protein p32, Theileria sergenti
keywords: Genetic variation; Single-strand conformation polymorphism (SSCP); Theileria orientalis; p23 piroplasm surface protein