Molecular Detection and Phylogenetic Analysis of Anaplasma Spp. in Cattle in Al-Qadisiyah Province of Iraq

Abstract

Abstract Anaplasma spp. are widely spread rickettsial bacteria transmitted by ticks and placing high impacts on veterinary and public health. A limited number of studies have been carried out on Anaplasmosis in the central part of Iraq. This study was conducted to determine the presence of Anaplasma spp. in cattle in Al-Qadisiyah province, Iraq. A total of 400 blood specimens were collected from cattle suffering from heavy tick infestation. Cattle were blood-sampled from four hyper-endemic areas with ticks. Blood samples were screened using microscopic and polymerase chain reaction (PCR) methods. Diff-quick stained blood smears revealed Anaplasma-like inclusion bodies in 254 (63.5%) samples. According to the 16S rRNA-gene-based PCR analysis, Anaplasma spp. was detected in 124 of the 400 (31%) samples, divided as 96/254 (37.8%) among the microscopical positive samples and 28/146 (19.17%) among the microscopical negative samples. Phylogenetic analysis based on the partial 16S rRNA gene sequencing of ten-PCR positive samples were 99–97% identical to sequences deposited in the GenBank, revealing presence of A. phagocytophilum, A. marginale and unnamed Anaplasma spp. in 40%, 20%, and 40% samples, respectively. Relationships among Anaplasma spp. infections and cattle breed, age, and sex were analyzed. Calves less than one year old showed significantly higher rates (p<0.005) than those from other age groups, whereas sex and breed demonstrated no significant differences (p˃0.001). This study shows that a variety of Anaplasma spp., were endemic in central part of Iraq and is still a hidden problem in cattle in the hyperendemic areas of tick, which requires serious control strategies.