Comparative genomics of the Western Hemisphere soft tick-borne relapsing fever borreliae highlights extensive plasmid diversity

Autor(es)

Kneubehl, Alexander R. ; Krishnavajhala, Aparna ; Leal, Sebastian Munoz ; Replogle, Adam J. ; Kingry, Luke C. ; Bermudez, Sergio E. ; Labruna, Marcelo B. ; Lopez, Job E.

• Tipo de documento: Artigo Científico
• Fonte: BMC Genomics; v. 23, n. 1, p. 22-pg., 2022-05-31.

Resumo

Background: Tick-borne relapsing fever (TBRF) is a globally prevalent, yet under-studied vector-borne disease transmitted by soft and hard bodied ticks. While soft TBRF (sTBRF) spirochetes have been described for over a century, our understanding of the molecular mechanisms facilitating vector and host adaptation is poorly understood. This is due to the complexity of their small (similar to 1.5 Mb) but fragmented genomes that typically consist of a linear chromosome and both linear and circular plasmids. A majority of sTBRF spirochete genomes' plasmid sequences are either missing or are deposited as unassembled sequences. Consequently, our goal was to generate complete, plasmid-resolved genomes for a comparative analysis of sTBRF species of the Western Hemisphere. Results: Utilizing a Borrelia specific pipeline, genomes of sTBRF spirochetes from the Western Hemisphere were sequenced and assembled using a combination of short- and long-read sequencing technologies. Included in the analysis were the two recently isolated species from Central and South America, Borrelia puertoricensis n. sp. and Borrelia venezuelensis, respectively. Plasmid analyses identified diverse sequences that clustered plasmids into 30 families; however, only three families were conserved and syntenic across all species. We also compared two species, B. venezuelensis and Borrelia turicatae, which were isolated similar to 6,800 km apart and from different tick vector species but were previously reported to be genetically similar. Conclusions: To truly understand the biological differences observed between species of TBRF spirochetes, complete chromosome and plasmid sequences are needed. This comparative genomic analysis highlights high chromosomal synteny across the species yet diverse plasmid composition. This was particularly true for B. turicatae and B. venezuelensis, which had high average nucleotide identity yet extensive plasmid diversity. These findings are foundational for future endeavors to evaluate the role of plasmids in vector and host adaptation. (AU)

• Processo FAPESP: 19/17960-3 - Técnicas de cultivo avançadas, sequenciamento de última geração e inmunoblot aplicado ao estudo de uma espiroqueta do grupo da febre recorrente brasileira
• Beneficiário: Sebastián Alejandro Munoz Leal
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 18/02521-1 - Pesquisa de espiroquetas do grupo da febre recorrente (Spirochaetaceae: Borrelia) em carrapatos do gênero Ornithodoros (Acari: Argasidae) parasitas de humanos no Brasil
• Beneficiário: Sebastián Alejandro Munoz Leal
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado