First molecular survey of Anaplasma bovis in small ruminants from Tunisia

To date, no information is available regarding the presence of Anaplasma bovis in the South Mediterranean area. In this study, prevalence, risk factors, and genetic diversity of A. bovis were assessed in small ruminants. A total of 563 healthy small ruminants (260 sheep and 303 goats), from 25 randomly selected flocks located in 5 localities from two bioclimatic areas in Tunisia, were investigated for the detection of A. bovis in blood by nested polymerase chain reaction (nPCR) assay. The overall infection rates of A. bovis were 42.7 and 23.8% in sheep and goats, respectively. Goats located in a sub-humid area were statistically more infected than those located in a humid area. A. bovis prevalence rate varied significantly according to sheep and goat flocks, and to the sheep breed. Infection with A. bovis was validated by sequencing. Sequence analysis based on the 16S rRNA gene showed that A. bovis from Tunisian goats and sheep clustered with other strain sequences detected from wild and domestic animals and published in GenBank. This study gives the first insight of presence of A. bovis DNA in small ruminants in Tunisia and suggests that these animal species may be playing an important role in the bovine anaplasmosis natural cycle caused by A. bovis in the South Mediterranean ecosystem.