Spatial patterns of Hyalomma marginatum -borne pathogens in the Occitanie region (France), a focus on the intriguing dynamics of Rickettsia aeschlimannii

• Published in: Microbiology spectrum 2024-08, Vol.12 (8), p.e0125624
• Main Authors: Joly-Kukla, Charlotte, Bernard, Célia, Bru, David, Galon, Clémence, Giupponi, Carla, Huber, Karine, Jourdan-Pineau, Hélène, Malandrin, Laurence, Rakotoarivony, Ignace, Riggi, Camille, Vial, Laurence, Moutailler, Sara, Pollet, Thomas
• Format: Article
• Language: English
• Subjects: Epidemiology; Hyalomma marginatum; Life Sciences; Research Article; Rickettsia aeschlimannii; spatial patterns; symbionts; tick-borne pathogens
• ISSN: 2165-0497; 2165-0497
• DOI: 10.1128/spectrum.01256-24

is an invasive tick species recently established in mainland southern France. This tick is known to host a diverse range of human and animal pathogens. While information about the dynamics of these pathogens is crucial to assess disease risk and develop effective monitoring strategies, few data on the spatial dynamics of these pathogens are currently available. We collected ticks in 27 sites in the Occitanie region to characterize spatial patterns of -borne pathogens. Several pathogens have been detected: (9.2%), (0.2%), (1.6%), (0.8%), and (87.3%). Interestingly, we found a spatial clustered distribution for the pathogen between two geographically isolated areas with infection rates and bacterial loads significantly lower in Hérault/Gard departments (infection rate 78.6% in average) compared to Aude/Pyrénées-Orientales departments (infection rate 92.3% in average). At a smaller scale, infection rates varied from one site to another, ranging from 29% to 100%. Overall, such high infection rates (87.3% on average) and the effective maternal transmission of might suggest a role as a tick symbiont in . Further studies are thus needed to understand both the status and the role of in ticks.IMPORTANCETicks are obligatory hematophagous arthropods that transmit pathogens of medical and veterinary importance. Pathogen infections cause serious health issues in humans and considerable economic loss in domestic animals. Information about the presence of pathogens in ticks and their dynamics is crucial to assess disease risk for public and animal health. Analyzing tick-borne pathogens in ticks collected in 27 sites in the Occitanie region, our results highlight clear spatial patterns in the -borne pathogen distribution and strengthen the postulate that it is essential to develop effective monitoring strategies and consider the spatial scale to better characterize the circulation of tick-borne pathogens.