First report on molecular prevalence and identification of Anaplasma platys in dogs in Khon Kaen, Thailand

Background and Aim: Anaplasma platys is a blood parasite that infects platelets, causing thrombocytopenia. Rhipicephalus sanguineus ticks are believed to transmit A. platys. To identify A. platys, nested polymerase chain reaction (PCR) has proven to be an effective diagnostic tool. In this study, the molecular prevalence of A. platys infection in dogs was investigated for the 1st time in the Khon Kaen region of Thailand. The association between risk factors and A. platys infection was also evaluated. Materials and Methods: A total of 130 blood samples were collected from dogs in Khon Kaen, Thailand. DNA from the samples was extracted and nested PCR was applied for molecular analysis. Platelet count and packed cell volume (PCV) levels were measured. Platelet counts were categorized into four grades: Non-thrombocytopenia (platelets >200,000 cells/μL), mild thrombocytopenia (platelets 150,000-200,000 cells/μL), moderate thrombocytopenia (platelets 100,000-150,000 cells/μL), and severe thrombocytopenia (platelets 37%, 30-37%, 20-29%, and <20% were defined as no anemia, mild anemia, moderate anemia, and severe anemia, respectively. DNA sequencing was analyzed using BTSeq™ (Barcode-Tagged Sequencing; CELEMICS, Seoul, South Korea) for similarity index. Results: Among the 130 samples, 9 (6.9%) were positive for A. platys infection. There was an association between low platelet count and infection (p<0.05). PCV level was also associated with A. platys infection (p