DNA Probes for Detection of Babesia ovata or the Babesia sp.1, A Newly Isolated Bovine Babesia Parasite in Japan

抄録

We have recently reported the presence of a Babesia ovata like large intraerythrocytic parasite, Babesia sp.1 in the cattle population of Hokkaido in Japan. A 5.5 kilobase(kb) DNA fragment that showed cross-hybridization with the BOZAP6, a DNA probe derived from B. ovata genome, was cloned from the Babesia sp.1 genome and characterized. Beside a sequence that conferred the cross-hybridization, the fragment contained the parasite-specific sequence that did not hybridize with DNAs from B. ovata, B. bigemina, B. bovis, Theileria sergenti, Anaplasma marginale, A. centrale, Eperythrozoon wenyoni and bovine white blood cells. The Babesia sp.1 specific region on the 5.5 kb fragment was excised and subcloned into a plasmid vector as parasite-specific DNA probe (SpS7). Babesia ovata-specific DNA probe (OvS9) was also obtained by deleting a sequence that confers the cross-hybridization with Babesia sp.1 from original BOZAP6 DNA. SpS7 or OvS9 was sensitive enough to detect 5 ng of DNA either from Babesia sp.1 or B. ovata, respectively. These DNA probes, sensitive and either specific for B. ovata or Babesia sp.1, could be useful tools in epidemiological studies to analyze the variations in the bovine Babesia species in Japan.