Detection of novel strains genetically related to Anaplasma platys in Tunisian one-humped camels (Camelus dromedarius)

Abstract

Introduction: Little information is currently available regarding the presence of Anaplasma species in North African dromedaries. To fill this gap in knowledge, the prevalence, risk factors, and genetic diversity of Anaplasma species were investigated in Tunisian dromedary camels. Methodology: A total of 226 camels from three different bioclimatic areas were sampled and tested for the presence of Anaplasma species by quantitative polymerase chain reaction (qPCR) and nested polymerase chain reaction (nPCR) assays. Detected Anaplasma strains were characterized by 16S rRNA sequence analysis. Results: Overall infection rate of Anaplasma spp. was 17.7%, and was significantly higher in females. Notably, A. marginale, A. centrale, A. bovis, and A. phagocytophilum were not detected. Animals were severely infested by three tick species belonging to the genus Hyalomma (H. dromedarii, H. impeltatum, and H. excavatum). Alignment, similarity comparison, and phylogenetic analysis of the 16S rRNA sequence variants obtained in this study suggest that Tunisian dromedaries are infected by more than one novel Anaplasma strain genetically related to A. platys. Conclusions: This study reports the presence of novel Anaplasma sp. strains genetically related to A. platys in dromedaries from various bioclimatic areas of Tunisia. Findings raise new concerns about the specificity of the direct and indirect diagnostic tests routinely used to detect different Anaplasma species in ruminants and provide useful molecular information to elucidate the evolutionary history of bacterial species related to A. platys.

Vector-borne bacteria in blood of camels in Iran: New data and literature review

“…We detected a strain of Anaplasma sp. in 15% of the tested camels which featured 16S sequences identical to Candidatus Anaplasma camelii isolated from camels in Saudi Arabia, Tunisia and Iran [11,12,15]. Phylogenetic analyses based on DNA sequencing in our study supports the assumption that the Candidatus Anaplasma camelii lineage is genetically divergent from A. platys and may present a novel species.…”

“…The lineage detected in the present study is identical to Candidatus Anaplasma camelii isolated from blood and spleen, respectively, of dromedary camels in Saudi Arabia (KF843823-28, [11]), Iran (KX765882 [15]), and Tunisia (KM401906-07 [12]). Moreover, the same lineage was found also in blood of Javanese rusa which is a deer native to the islands of Indonesia and East Timor (Rusa timorensis) (MG910989) and cattle (MG910990) in Malaysia [33], and in cattle in Bangladesh (MF576175 [34]).…”

“…We detected a strain of Anaplasma sp. identical to Candidatus Anaplasma camelii isolated from camels, cattle and deer in Asia and Africa [11,12,15,33,34].…”

“…Further studies for determining epidemiological role of camels and its zoonotic potential are recommended. This paper reviews the current knowledge on camels' tickborne bacteria including microscopy, serology and molecular studies.confirmed by DNA sequencing in camels are Candidatus Anaplasma camelii (genetically close to A. platys), A. phagocytophilum and A. ovis [10][11][12][13][14][15][16][17][18]. Clinical signs of natural infections are described as fever, pale and icteric conjunctiva suggestive of anaemia, dullness, anorexia, diarrhoea, loss of appetite, emaciation, coughing, lacrimation, rough hair coat, abortion, and/or infertility [7,19].…”

Bovine anaplasmosis and tick-borne pathogens in cattle of the Galapagos Islands

“…The detection of A. marginale was an expected result, but this is the first time an A. platys ‐like strain is reported infecting ruminants in South America. These strains are genetically closely related (at least for two genes) to the agent of cyclic thrombocytopenia in dogs, A. platys , and have been reported infecting ruminants in Sardinia (Zobba et al., ), Tunisia (Belkahia, Ben Said, Sayahi, Alberti, & Messadi, ; Ben Said et al., ) and China (Liu et al., ; Yang et al., ), as well as infecting cats in Italy (Zobba et al., ). Although there is no report of pathogenicity for this Anaplasma strain, it may be important to take into consideration the presence of this bacterium in the region when interpreting A. marginale test results.…”