New insights into the genomic information of an overlooked human pathogen: Bartonella rochalimae causative agent of Carrion’s disease

The Bartonella genus includes over twenty species, most transmitted by arthropods and possibly eleven related to human diseases, though some currently lack specific vectors or hosts. Bartonella rochalimae, a Gram-negative pleomorphic bacterium, was first isolated in 2007 from a woman who traveled to Peru and developed Carrion's disease-like symptoms. Hence, this study aims to report on bacterial isolates from patients diagnosed with Carrion's disease, which were found to be caused by B. rochalimae rather than B. bacilliformis, and to characterize the genomic aspects of B. rochalimae as a human pathogen. Five strains of B. rochalimae were identified using pangenomic and phylogenetic analysis. Additional analyses included core and clade-specific genes, gene ontology (GO), virulence factors (VF), and subcellular localization. This study identified five B. rochalimae strains from the regions of Ancash, Cajamarca, and Huanuco in Peru, suggesting regional circulation. The findings emphasize the importance of further research on B. rochalimae gene functions and its role in outbreak developments, highlighting the importance of improved diagnostics and enhanced surveillance.