# The ability of relapsing fever Borrelia species to survive in chicken serum in vitro and its correlation to interaction with serum components reactive to a polyclonal anti-complement regulator factor H antibody

## TL;DR

This study shows that relapsing fever Borrelia bacteria can survive in chicken serum and interact with specific serum components.

## Contribution

The study demonstrates that Borrelia species without known avian associations can survive in chicken serum and bind serum components reactive to anti-factor H antibodies.

## Key findings

- All tested Borrelia strains survived in chicken serum in vitro.
- Borrelia species bound serum components reactive to anti-factor H antibodies.
- Serum survival did not depend on binding to these serum components.

## Abstract

Bacteria belonging to the relapsing fever-causing genus Borrelia, are important causes of zoonotic veterinary and human infections. The genus contains both species with a specific avian association and species with a suggested wider host range, including avian hosts. Despite this, existing studies exploring the Borrelia-avian interaction are relatively few. In this short communication, we report on the in vitro survival of eight strains of relapsing fever from seven species in chicken serum and its correlation to bacterial binding of serum components reactive to a polyclonal anti-complement regulator factor H antibody. All tested relapsing fever strains exhibited the capability to survive in chicken serum in vitro. Components of chicken serum reactive to polyclonal anti-factor H antibodies were found to bind to the surface of spirochetes and to whole cell lysates, but this was not mandatory for serum survival.

Image 1

•Relapsing fever Borrelia isolates survive in complement active chicken serum in-vitro.•Borrelia species with no known avian association survive in chicken serum.•Borrelia spp. bind components of chicken serum reactive to polyclonal anti-factor H antibody.

Relapsing fever Borrelia isolates survive in complement active chicken serum in-vitro.

Borrelia species with no known avian association survive in chicken serum.

Borrelia spp. bind components of chicken serum reactive to polyclonal anti-factor H antibody.