Molecular Detection, Phylogenetic Analysis, and Genetic Diversity of Theileria annulata, Babesia bigemina, and Anaplasma marginale in Cattle in Three Districts of Egypt.

BACKGROUND

Under the poor hygienic conditions, tick-borne pathogens cause severe economic losses to the cattle industry.

PURPOSE: The current study investigated the presence of Theileria annulata, Babesia bigemina, and Anaplasma marginale, the most relevant tick-borne pathogens in cattle, in 3 provinces of Egypt utilizing species-specific PCR assays.

METHODS

PCR was conducted, on bovine blood specimens, using primers targeting the T. annulata merozoite-piroplasm surface antigen (Tams1, 768 bp), A. marginale major surface protein-1b gene (msp1b, 265 bp), and B. bigemina small subunit ribosomal RNA gene (SSrRNA, 543 bp).

RESULTS

PCR findings revealed overall prevalences of T. annulata, B. bigemina, and A. marginale as 22.0% (33/150), 19.33% (29/150), and 10.6% (16/150), respectively. The co-infection with two or three pathogens was detected in 20.0% (30/150) of examined specimens. Sequence analyses indicated that T. annulata and A. marginale varied from those of corresponding GenBank sequences revealing percent identities ranging from 90.68 to 97.75% and from 94.98 to 98.63%, respectively. On the other hand, the obtained B. bigemina sequences showed a high similarity with those previously reported in GenBank with a percent identity ranging from 98.85 to 100%.

CONCLUSION

T. annulata was the most prevalent tick-borne pathogen in examined bovine specimens. The genetic diversity of markers used for identification of T. annulata and A. marginale should be highly considered.