Molecular characterization of Candidatus Anaplasma camelii in Tunisian dromedaries based on partial groEL and gltA sequence data.

Abstract

Candidatus Anaplasma camelii is a poorly identified Anaplasma species reported in dromedary camels (Camelus dromedarius). Although sequences from Ca. A. camelii had previously been detected in Tunisia, they were not accurately identified or taxonomically classified at that time. This study provides the first comprehensive molecular characterization of Ca. A. camelii in Tunisian dromedaries using a combined sequencing approach targeting 16S rRNA, the groEL gene and the gltA gene. Out of 229 dromedaries blood samples analysed 45 (19.7%) tested positive for Anaplasma spp. by 16S rRNA PCR. The presence of Ca. A. camelii was subsequently confirmed by groEL and gltA amplification. Phylogenetic analyses revealed a well-supported monophyletic clade grouping Tunisian isolates with strains previously reported in Egypt and in the United Arab Emirates (UAE). This study expands the known geographic distribution of Ca. A. camelii by introducing novel molecular data, thereby enhancing our understanding of its genetic diversity and evolutionary relationships. Findings highlight the importance of multi-gene molecular surveillance to elucidate the epidemiology of emerging Anaplasma species in Northern Africa.