DETECTION OF BABESIA-BOVIS USING A DIG-LABELED DNA-PROBE

A plasmid DNA containing the inserted Babesia bovis cDNA clone designa ted c51A was used to prepare a DNA probe for B. bovis. The purified 0. 6 kb specific DNA fragment was labeled by DIG DNA labeling. After dena turation, the probe was hybridised with the blotted target DNA extract ed from bovine red blood cells infected with B. bovis or other protozo a or bovine red blood cells plus extra white blood cells. It was found that the probe produced from purified 0.6 kb dna fragment could detec t sample of B. bovis DNA equivalent to 0.015 mu l of 10% whole infecte d blood. Compared to the same DNA fragment labeled with photobiotin, t his new probe is more sensitive giving a darker hybridization signal, a lighter hybridization background and without any non-specific reacti ons. These results indicated that this DIG-labeled B. bovis C51A probe could provide a sensitive and specific method to diagnose clinically suspected B. bovis infections and distinguish B. bovis DNA from other haemoprotozoan infections.