High genetic diversity and differentiation of theBabesia ovispopulation in Turkey

Abstract

Babesia ovis is a tick-transmitted protozoan hemoparasite causing ovine babesiosis in sheep and goats leading to considerable economic loss in Turkey and neighboring countries. There are no vaccines available, therapeutic drugs leave toxic residues in meat and milk, and tick vector control entails environmental risks. A panel of eight mini-and microsatellite marker loci was developed and applied to study genetic diversity and substructuring of B. ovis from western, central, and eastern Turkey. A high genetic diversity (H e = 0.799) was found for the sample of the overall B. ovis population (n = 107) analyzed. Principle component analysis (PCoA) revealed the existence of three parasite subpopulations: (i) a small subpopulation of isolates from Aydin, western Turkey, (ii) a second cluster predominantly generated by isolates from western Turkey, and (iii) a third cluster predominantly formed by isolates from central and eastern Turkey. Two B. ovis isolates from Israel included in the analysis clustered with isolates from central and eastern Turkey. This finding strongly suggests substructuring of a major Turkish population into western vs. central-eastern subpopulations, while the additional smaller B. ovis population found in Aydin could have been introduced, more recently, to Turkey. STRUCTURE analysis suggests a limited exchange of parasite strains between the western and the central-eastern regions and vice versa, possibly due to limited trading of sheep. Importantly, evidence for recombinant genotypes was obtained in regionally interchanged parasite isolates. Important climatic differences between the western and the central/eastern region, with average yearly temperatures of 21ºC versus 15ºC, correspond with the identified geographical substructuring. We hypothesize that the different climatic conditions may result in variation in the activity of subpopulations of Rhipicephalus spp. tick vectors, which, in turn, could selectively maintain and transmit different parasite populations. These findings may have important implications for vaccine development and the spread of drug resistance.

Analysis of genetic diversity and population structure of Babesia gibsoni

“…canis populations originating from distant continents ( 27 ). The phylogenetic and population differentiation of Babesia spp., which can parasitize cattle, sheep and horses, were explained by previous studies ( 28 , 29 , 32 ). Molecular detection of B. gibsoni has been broadly described around the world ( 20 , 22 , 33 – 36 ), but the genetic diversity of B. gibsoni in dogs was scarce.…”

First detection and molecular identification of Babesia sp. from the giant panda, Ailuropoda melanoleuca, in China

“…This Babesia sp. is likely to be a novel species based on the phylogenetic analysis which has been widely used to study the genetic diversity of Babesia [ 35 – 37 ]. This clearly suggests that this novel Babesia sp .…”

Anaemia in Sheep Caused by Babesia and Theileria Haemoparasites

“…Babesiosis in small ruminants may be caused by several species, Babesia ovis being the most prevalent species with a worlwide distribution [ 24 , 25 , 26 ], followed by B. motasi and B. crassa [ 17 ]. However, there could be differences in prevalence caused by the geographical distribution of each Babesia species and vector species.…”