Molecular study of Anaplasma spp. in horses, sheep, and goats with phylogenetic analysis in northwest Iran

Anaplasmosis is a tick-borne disease with worldwide distribution, affecting ruminants, equines, carnivores, and humans. This study aimed to investigate Anaplasma phagocytophilum (A. phagocytophilum) in horses from Ardabil province and Anaplasma ovis (A. ovis) in small ruminants from East Azerbaijan province using the Nested PCR method. Blood samples were collected from the jugular vein of 100 healthy horses in the Ardabil province and 156 healthy sheep and goats (116 sheep and 40 goats) in the East Azerbaijan Province during the spring and summer seasons of 2016 in northwest Iran. The gathered blood samples were stored at -20°C until the molecular experiments were conducted. Nested PCR was employed to detect A. phagocytophilum in horses and A. ovis in small ruminants using extracted DNA and amplifying 16S rRNA and msp4 genes. The Chi-square test of independence was used to determine the relationship between Anaplasma spp., infection, and independent variables, including age, gender, animal species, and sampling location. None of the 100 samples collected from horses in the Ardabil province were positive for A. phagocytophilum. In the East Azerbaijan province, 11 out of the 156 (7.05%) blood samples collected from sheep and goats tested positive for A. ovis. In addition, A. ovis infection was not significantly related to the independent variables. Phylogenetic analysis showed that the sequence obtained in the present study (MH790273) has 100% homology with the sequence obtained from sheep infected with Anaplasma in Ahvaz (JQ621903.1). The study’s findings can aid in preventing and controlling anaplasmosis in farm animals in northwestern Iran.