First molecular evidence of Candidatus Anaplasma camelii in two dromedary camels from Qatar.

Abstract

Anaplasma species are intracellular pathogens that impact human and animal health. Despite Qatar having the highest density of dromedary camel (Camelus dromedarius) population, there have been no previous reports of anaplasmosis in dromedary camels in the country. Here, two cases of 5-year-old female dromedary camels presented symptoms like fever, reduced appetite, edema, and respiratory distress. These camels had a history of unsuccessful treatment for trypanosomiasis, on that basis diagnosis of possible anaplasmosis was made. DNA was extracted from the whole blood and then subjected to PCR testing and sequencing targeting 16S rRNA and groEL genes which confirmed both cases to be positive for Anaplasma. Phylogenetic analysis using 16S rRNA exhibited a 100% similarity with Candidatus Anaplasma camelii, while groEL gene showed a 100% match with A. platys-like. Phylogenetic analysis indicated that Candidatus Anaplasma camelii and A. platys-like sequences were grouped in the same cluster either in 16S RNA or groEL and were closely related to A. platys. The Infected cases highlight the need for a large-scale molecular diagnostic effort to monitor the clinical health of animals with a particular focus on camels in Qatar. Additionally, this report points to the role of dromedary camels in supporting the enzootic cycle of Anaplasma transmission within the region. This report marks the first instance of camel anaplasmosis in Qatar. Surveillance of Anaplasma among susceptible hosts (animals and human) in Qatar is required for assessing the zoonotic potential.