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Pathogen Detection in Ornithodoros sonrai Ticks and Invasive House Mice Mus musculus domesticus in Senegal
Basma Ouarti1,2, Moussa Sall3, El Hadji Ibrahima Ndiaye1,2,4
1Aix-Marseille University, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France.
Abstract:
Ornithodoros sonrai (O. sonrai) ticks are the only known vectors of Borrelia crocidurae, an agent of tick-borne relapsing fever (TBRF) borreliosis. Rodents serve as principal natural reservoirs for Borrelia. Our research objective was to detect TBRF Borrelia and other zoonotic bacterial infections in ticks and in house mice Mus musculus domesticus, an invasive species currently expanding in rural northern Senegal. Real-time and conventional PCR were utilized for detecting Borrelia and other bacterial taxa. The analyses were performed on 253 specimens of O. sonrai and 150 samples of brain and spleen tissue from rodents. Borrelia crocidurae was found in one O. sonrai tick and 18 Mus musculus domesticus samples, with prevalences of 0.39 percent and 12 percent, respectively, as well as Ehrlichia sp. in one Mus musculus domesticus. Further, we were able to detect the presence of a potentially infectious novel species belonging to the Anaplasmataceae family for the first time in O. sonrai ticks. More attention should be paid to the house mouse and O. sonrai ticks, as they can be potential hosts for novel species of pathogenic bacteria in humans.
Insights
The Ornithodoros sonrai tick and house mice in Senegal carry Borrelia crocidurae, the cause of tick-borne relapsing fever. Novel Anaplasmataceae bacteria were also found in ticks, posing potential risks to human health.
Area of Science:
- Veterinary Entomology
- Medical Microbiology
- Zoonotic Disease Epidemiology
Background:
- Ornithodoros sonrai ticks are the sole known vectors of Borrelia crocidurae, the causative agent of tick-borne relapsing fever (TBRF).
- Rodents are primary natural reservoirs for Borrelia species.
- House mice (Mus musculus domesticus), an invasive species, are expanding in rural northern Senegal, presenting a potential ecological niche for tick-borne pathogens.
Purpose of the Study:
- To detect TBRF Borrelia and other zoonotic bacterial infections in Ornithodoros sonrai ticks and house mice in Senegal.
- To investigate the role of invasive house mice as reservoirs for tick-borne pathogens.
- To identify novel bacterial species with potential public health implications.
Main Methods:
- Real-time and conventional PCR assays were employed for bacterial detection.
- Analysis included 253 Ornithodoros sonrai tick specimens.
- 150 samples of brain and spleen tissue from Mus musculus domesticus were analyzed.
Main Results:
- Borrelia crocidurae was detected in 0.39% of O. sonrai ticks and 12% of M. musculus domesticus samples.
- Ehrlichia sp. was identified in one M. musculus domesticus.
- A potentially infectious novel species of the Anaplasmataceae family was identified in O. sonrai ticks.
Conclusions:
- House mice and O. sonrai ticks in Senegal harbor Borrelia crocidurae and other zoonotic bacteria.
- The presence of a novel Anaplasmataceae species highlights potential emerging infectious disease risks.
- Further attention is warranted for house mice and O. sonrai ticks as reservoirs for pathogenic bacteria transmissible to humans.
