First report of bovine anaplasmosis by Anaplasma centrale in Europe, molecular identification and phylogenetic analysis

Anaplasmataceae in wild ungulates and carnivores in northern Spain

Wild vertebrates are essential hosts for tick-borne diseases but data on the prevalence and diversity of Anaplasma spp. in wildlife are scarce. In this study, we used real-time PCR to investigate the distribution of Anaplasma species in spleen samples collected from 625 wild animals (137 cervids, 227 wild boar, and 261 carnivores) in two regions in northern Spain. A first generic real-time PCR assay was used to screen for the presence of Anaplasma spp. followed by a second species-specific multiplex real-time PCR or partial sequencing of the 16S rRNA gene for species identification. Anaplasma phagocytophilum was highly prevalent in cervids (64.2%), but it was absent from wild boar and carnivores. Interestingly, Anaplasma marginale and Anaplasma ovis were not detected in cervids, but Anaplasma centrale was identified in 1 roe deer and 1 red deer, A. bovis in 4 roe deer, and a novel Ehrlichia sp. in one badger. These findings were highly associated with the tick burden identified in the different hosts. Thus, Ixodes ricinus, the recognized vector of A. phagocytophilum in Europe, was the main tick species parasitizing cervids (93.5%, 1674/1791), whereas Dermacentor reticulatus was the most abundant in wild boar (76.1%, 35/46) and Ixodes hexagonus in carnivores (58.4%, 265/454). More investigations are needed to assess the impact of the different Anaplasma species in wildlife and the risk of transmission to domestic animals.

First molecular survey and novel genetic variants' identification of Anaplasma marginale, A. centrale and A. bovis in cattle from Tunisia

Few data are available about the presence and distribution of Anaplasma species in cattle in North African countries. In this study prevalence, co-infections, risk factors and genetic diversity of Anaplasma species were evaluated in bovines from Northern Tunisia. A total of 232 cattle from 36 randomly selected farms in three Tunisian localities were investigated for the presence of Anaplasma species in blood by Real-time PCR and/or nested PCR. Overall infection rates of Anaplasma spp., Anaplasma marginale, Anaplasma centrale and Anaplasma bovis were 34.9%, 25.4%, 15.1%, and 3.9%, respectively. Anaplasma phagocytophilum was not detected in cattle. The most common co-infection pattern was an association of A. marginale and A. centrale (11.2%). Five cattle (2.1%) all reared in the sub-humid bioclimatic area, were co-infected by the three Anaplasma species. Molecular prevalence of Anaplasma infection varied significantly according to locality, bioclimatic area, tick infestation and type of breeding. Animals of the Holstein breed were less infected by A. marginale and A. centrale than other breeds. Genetic analysis of A. marginale msp4 gene indicated a high sequence diversity of Tunisian strains, suggesting a multiple introduction of infected cattle from different origins. Phylogenetic studies based on the 16S rRNA gene showed that the most prevalent A. centrale strains were closely related to the A. centrale vaccine strain. Moreover, all A. bovis variants clustered with other A. bovis sequences obtained from domestic and wild ruminant strains. This is the first molecular investigation on Anaplasma species in Tunisian cattle providing pivotal background for designing epidemiological studies and to develop control strategies in the country.