Multispacer sequence typing relapsing fever Borreliae in Africa

Area of Science:

• Microbiology
• Genetics
• Epidemiology

Background:

• Relapsing fevers in Africa are neglected arthropod-borne infections caused by Borrelia species.
• These infections cause undifferentiated fever, posing significant risks, especially to pregnant women.
• Limited genotyping tools hinder understanding of Borrelia reservoirs and epidemiology.

Purpose of the Study:

• To develop and evaluate a novel genotyping tool for African relapsing fever Borrelia species.
• To improve the understanding of Borrelia epidemiology and reservoirs in Africa.

Main Methods:

• Genome sequence analysis identified 5 intergenic spacers from 10 chromosomal genes.
• These spacers were incorporated into a multispacer sequence typing (MST) approach.
• MST was applied to human blood specimens infected with Borrelia recurrentis, Borrelia duttonii, and Borrelia crocidurae.

Main Results:

• The MST approach successfully resolved 60 strains and 3 type strains into 13 species-specific spacer types.
• Borrelia crocidurae yielded 8 spacer types, Borrelia duttonii 3, and Borrelia recurrentis 2.
• Phylogenetic analysis suggested these species are variants of a single ancestral Borrelia species.

Conclusions:

• Multispacer sequence typing (MST) is a suitable method for identifying and genotyping African relapsing fever borreliae.
• The developed MST approach can be applied to both clinical specimens and vectors.
• This advancement facilitates research into the epidemiology and reservoirs of these neglected infections.