Abstract
Complement has been considered as an important factor impacting the host–pathogen association of spirochetes belonging to the Borrelia burgdorferi sensu lato complex, and may play a role in the spirochete’s ecology. Birds are known to be important hosts for ticks and in the maintenance of borreliae. Recent field surveys and laboratory transmission studies indicated that certain avian species act as reservoir hosts for different Borrelia species. Nevertheless, our current understanding of the molecular mechanisms determining host tropism of Borrelia is still in its fledgling stage. Concerning the role of complement in avian-host tropism, only a few bird species and Borrelia species have been analysed so far. Here, we performed in vitro serum bactericidal assays with serum samples collected from four bird species including the European robin Erithacus rubecula, the great tit Parus major, the Eurasian blackbird Turdus merula, and the racing pigeon Columba livia, as well as four Borrelia species (B. afzelii, B. garinii, B. valaisiana, and B. burgdorferi sensu stricto). From July to September 2019, juvenile wild birds were caught using mist nets in Portugal. Racing pigeons were sampled in a loft in October 2019. Independent of the bird species analysed, all Borrelia species displayed an intermediate serum-resistant or serum-resistant phenotype except for B. afzelii challenged with serum from blackbirds. This genospecies was efficiently killed by avian complement, suggesting that blackbirds served as dead-end hosts for B. afzelii. In summary, these findings suggest that complement contributes in the avian–spirochete–tick infection cycle and in Borrelia-host tropism.
Highlights
Complement has been considered as an important factor impacting the host–pathogen association of spirochetes belonging to the Borrelia burgdorferi sensu lato complex, and may play a role in the spirochete’s ecology
Data gathered from serum susceptibility studies with pheasants (Phasianus colchicus), blackbird (Turdus merula), seabird, and quail (Coturnix sp.) indicated that (i) B. valaisiana and B. garinii are mainly resistant to avian complement, (ii) B. burgdorferi s.s. displayed an intermediate serum resistance phenotype, and (iii) B. afzelii, B. bavariensis, and B. lusitaniae were largely susceptible to avian sera
To gain further insight into the complementhost association pattern, we performed serum-bactericidal assays with avian sera collected from juveniles of four bird species captured in Portugal: European robin Erithacus rubecula, great tit Parus major, Eurasian blackbird Turdus merula, and racing pigeon Columba livia and four Borrelia species (B. afzelii, B. garinii, B. valaisiana, and B. burgdorferi)
Summary
Complement has been considered as an important factor impacting the host–pathogen association of spirochetes belonging to the Borrelia burgdorferi sensu lato complex, and may play a role in the spirochete’s ecology. To gain further insight into the complementhost association pattern, we performed serum-bactericidal assays with avian sera collected from juveniles of four bird species captured in Portugal: European robin Erithacus rubecula (hereafter robin), great tit Parus major, Eurasian blackbird Turdus merula (hereafter blackbird), and racing pigeon Columba livia and four Borrelia species (B. afzelii, B. garinii, B. valaisiana, and B. burgdorferi).
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.
