Establishment of a molecular tool for blood meal identification in Malaysia

Objective: To establish a polymerase chain reaction (PCR) technique based on cytochrome b (cytb) gene of mitochondria DNA (mtDNA) for blood meal identification.

Methods: The PCR technique was established based on published information and validated using blood sample of laboratory animals of which their whole gene sequences are available in GenBank. PCR was next performed to compile gene sequences of different species of wild rodents. The primers used were complementary to the conserved region of the cytb gene of vertebrate's mtDNA. A total of 100 blood samples, both from laboratory animals and wild rodents were collected and analyzed. The obtained unknown sequences were compared with those in the GenBank database using BLAST program to identify the vertebrate animal species.

Results: Gene sequences of 11 species of wild animals caught in 9 localities of Peninsular Malaysia were compiled using the established PCR. The animals involved were Rattus (rattus) tanezumi, Rattus tiomanicus, Leopoldamys sabanus, Tupaia glis, Tupaia minor, Niviventor cremoriventor, Rhinosciurus laticaudatus, Callosciurus caniseps, Sundamys muelleri, Rattus rajah and Maxomys whiteheadi. The BLAST results confirmed the host with exact or nearly exact matches (>89% identity). Ten new gene sequences have been deposited in GenBank database since September 2010.

Conclusions: This study indicates that the PCR direct sequencing system using universal primer sets for vertebrate cytb gene is a promising technique for blood meal identification.