Rapid and Sensitive Method for Detection of Newly Isolated Babesia Parasite (Babesia sp.1) in the Anticipated Vector-Tick Using the Polymerase Chain Reaction Technique.

抄録

We recently reported that the presence of a Babesia ovata-like large intraerythrocytic parasite, Babesia sp.1 in cattle population of Hokkaido area in Japan, and the development of DNA probe (SpS7) for the parasite. A nucleic acid probe is a powerful tool for direct detection and identification of parasites in animals and vector insects. However, polymerase chain reaction (PCR) technique has advantages over hybridization technique. In this paper we report the development of PCR and nested-PCR techniques for amplification of the SpS7 sequence from Babesia sp.1 DNA. The PCR with one set of primers was specific for Babesia sp.1, since no amplification detected with DNA from bovine white blood cell, Theileria sergenti, Anaplasma marginale, A. centrale, Eperythrozoon wenyoni, B. bovis, B. bigemina, and B. ovata. The nested-PCR, which reamplified 470-base-pair (bp) in the internal region of the first primer set (670 bp), enabled the detection of less than 10 parasites on calculation. The technique was 10-fold more sensitive than the one-step PCR, and detected Babesia sp.1 in larval ticks that had been generated from the parasite-infected adults Haemaphysalis longicoronis.