High genetic diversity of Anaplasma ovis in sheep from Bosnia and Herzegovina.

BACKGROUND

Ovine anaplasmosis (sensu stricto) is a rickettsial blood disease caused by the tick-borne species Anaplasma ovis. The disease is characterized by mild anemia, fever, and icterus. A more severe clinical presentation is possible in non-endemic areas. There is no existing data on the presence of Anaplasma ovis in Bosnia and Herzegovina. However, given the country's location within the Mediterranean Basin and the recent molecular detection of Babesia ovis, it is plausible that sheep in the region could naturally be infected with this tick-borne pathogen.

METHODS AND RESULTS

Blood samples from 81 sheep in the Podrinje and Herzegovina areas were examined by PCR. PCR positivity was found in 38 (46.9%) cases indicating a high number of infected sheep. Mixed infections with Babesia ovis and A.ovis were observed in 63.3% of cases. A higher number of positive sheep was recorded in the area of Herzegovina. Phylogenetic analysis of the gltA, groEL, and msp4 genes of A. ovis revealed numerous genotypes and significant genetic variability. This diversity was not related to geographic origin, tick-borne infection status, or sheep breeding practices in Podrinje and Herzegovina.

CONCLUSIONS

The data obtained in this study suggest that the emergence of new genotypes and the high genetic variability of A. ovis are driven by specific local and micro-environmental factors.