Abstract
Borrelia persica, a bacterium transmitted by the soft tick Ornithodoros tholozani, causes tick-borne relapsing fever in humans in the Middle East, Central Asia and the Indian peninsula. Immunocompetent C3H/HeOuJ mice were infected intradermally with B. persica at varying doses: 1 x 106, 1 x 104, 1 x 102 and 4 x 100 spirochetes/mouse. Subsequently, blood samples were collected and screened for the presence of B. persica DNA. Spirochetes were detected in all mice infected with 1 x 106, 1 x 104 and 1 x 102 borrelia by real-time PCR targeting the flaB gene of the bacterium. Spirochetemia developed with a one- to two-day delay when 1 x 104 and 1 x 102 borrelia were inoculated. Mice injected with only four organisms were negative in all tests. No clinical signs were observed when infected mice were compared to negative control animals. Organs (heart, spleen, urinary bladder, tarsal joint, skin and brain) were tested for B. persica-specific DNA and cultured for the detection of viable spirochetes. Compiled data show that the target organs of B. persica infections are the brain and the skin. A newly developed serological two-tiered test system (ELISA and western blot) for the detection of murine IgM, IgG and IgA antibody titers against B. persica showed a vigorous antibody response of the mice during infection. In conclusion, the infection model described here for B. persica is a platform for in vivo studies to decipher the so far unexplored survival strategies of this Borrelia species.
Highlights
Spirochetes of the genus Borrelia (B.) are vector-borne, spiral-shaped bacteria that can be divided into two functional groups [1]
DNA was extracted from murine blood samples and the flaB gene of B. persica was detected with a real-time PCR
After day 14, the majority of the mice tested negative for spirochetes in the blood, while during the same period three mice showed reduced numbers of borrelia and only one of them produced a positive signal on the final day of the experiment
Summary
Spirochetes of the genus Borrelia (B.) are vector-borne, spiral-shaped bacteria that can be divided into two functional groups [1]. B. persica is transmitted by the soft tick Ornithodoros tholozani during blood meals [4]. These ticks are prevalent in areas such as the Middle East, Central Asia and the Indian peninsula and feed on humans as well as on animals (reviewed in [5]). For other RF borrelia species the mouse is usually considered to be the appropriate animal model [16,17,18,19] and Babudieri investigated relapsing fever in Jordan by injecting blood of diseased patients into mice in order to confirm TBRF spirochetosis [20]. In order to gain insight into the infection with these TBRF spirochetes, we investigated (a) whether this laboratory strain of B. persica is able to establish an infection in immunocompetent mice; (b) whether the mice develop clinical signs; (c) when and in which quantity the spirochetes appear
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
