Molecular detection of Coxiella burnetii in blood and hard tick-infested Egyptian camels and the possibility of coinfections

Coxiella burnetii, a bacterium that causes Q fever. It can infect mammals and has a global geographical distribution, but data on its occurrence in Egyptian dromedaries and the associated ticks are limited. Therefore, this study aims to detect C. burnetii in the blood of infested camels and associated ticks collected from Egypt by using molecular techniques and to examine the possibility of coinfections with C. burnetii. A total of 133 blood samples and 1260 hard ticks infesting these camels were collected from Egyptian slaughterhouses. Nested PCR and sequencing were used based on the IS1111 gene for molecular detection of C. burnetii. The identification of tick species at the molecular level was performed using the COX1 gene. C. burnetii was detected in Hyalomma (H) dromedarii, H. anatolicum, H. marginatum, Amblyomma (Am) lipidium, and Am. cohaerens with an overall prevalence rate of 1.3% (16/1260), while in the camel blood samples, it was 15.8% (21/133). Out of C. burnetii-positive ticks, there were double infections by Borrelia species and C. burnetii in H. dromedarii and Am. lipidium and triple infections at one Am. cohaerens tick (C. burnetii, Borrelia spp., and Babesia microti). In addition, two positive camel blood samples were found to carry C. burnetii with Borrelia spp. Our research findings indicate the presence of Coxiella burnetii among camels and their associated ticks in Egypt and emphasize the potential of having coinfection. To prevent the transmission of this infection to other animal species or humans, appropriate control measures should be implemented.