Abstract
To eradicate canine babesiosis in epidemic areas, mass-screening of the infection situation of Babesia gibsoni including occult infection is necessary. The development of cost-effective method for storage and transport of blood samples is required. A highly efficient DNA extraction procedure from dried blood spots (DBS) onto Whatman 3MM filter paper was developed for the diagnosis of B. gibsoni infection in dog by PCR. In 3 extraction methods, Chelex-based method in combination with saponin washing and phenol-chloroform-isoamyl alcohol extraction (Saponin-PCI method) provided the best results. Sensitivity of the 4 previously described PCR methods for detection of B. gibsoni infection was also compared using serially diluted blood samples of B. gibsoni-infected dogs. The PCR method using Gib599F/Gib1270R primer pair provided the best performance. To evaluate the stability of DNA in DBS, DBS of B. gibsoni-infected dogs stored at room temperature for 2 months. The stability was superior to whole blood samples stored at -20°C for 2 months. This highly efficient DNA extraction method on DBS using Whatman 3MM filter paper has potential to be cost-effective and high performance tool for storage, and molecular diagnosis of clinical blood sample from dog. This procedure in combination with the PCR method using Gib599F/Gib1270R primer pair may greatly assist in diagnosis of B. gibsoni infection in dog populations that are geographically distant.
