Evaluation of PCR Assay Using Specific Primers in Diagnosis of Canine Ehrlichiosis and Babesiosis:A Study on Herd and Stray Dogs in Shiraz

Canine tick-borne diseases are regarded as emerging problems within Iran and throughout the world. The present article aims at investigating Ehrlichia canis and Babesia canis infections in herd and stray dogs in Iran. The present study is therefore an attempt to compare PCR assay with specific primers in order to detect the organisms at the species level. This study is based on PCR amplification of the 16S rRNA, 18S rRNA and p28 genes. Concerning Babesia canis, species-specific primers BAB3 and BAB1 are compared with genus-specific primers B-GA1B and 16S8FE. Moreover, for Ehrlichia canis, species-specific primers ECp28-F and ECp28-R are compared with genus-specific primers RLB - F2 and RLB - R2. For the purpose of this study, 280 herd and stray dogs from seven different regions in south of Iran were monitored. As the results revealed, molecular surveillance of tick-borne diseases was based on PCR amplification of the 16S rRNA, 18S rRNA and p28 genes. For Ehrlichia canis, PCR was positive with genus-specific primers (B-GA1B and 16S8FE ) and species-specific primers (ECp28-F and ECp28-R),1.4% (4 of 280) of blood samples. For Babesia canis, PCR was positive with genus-specific primers (RLB - F2 and RLB - R2), 1% (3 of 280) and species-specific primers for Babesia canis (BAB1 and BAB3) 0.4% (1 of 280) of blood samples, respectively. Sequencing results showed that one herd dog was infected with Babesia canis, four herd dogs were infected with Ehrlichia canis, and one herd dog showed co-infection with Ehrlichia canis and Babesia canis. This has been the first report of the co-infections of both Ehrlichia canis and Babesia canis in naturally infected dogs in South of Iran.