Immunogenic Peptides from Pap31 and SCS-α of Bartonella bacilliformis: One Step Closer to a Rapid Diagnostic Tool for Carrion's Disease

Bartonella bacilliformis is the causal agent of Carrion's disease, an overlooked illness endemic in the Andean Mountains with Peru being the most affected country. The diagnostic of this illness is a challenge due to the limited resources and the common symptomatology with other infectious diseases. The goal of this study was to identify immunogenic peptides from Pap31 and succinyl-CoA synthetase alpha (SCS-alpha) of B. bacilliformis that might be suitable for developing a serologic tool. The immunodominant character of Pap31 and SCS-alpha was determined by Western blotting and in-silico analysis. Subsequently, 35 peptides were selected for epitope mapping and their immunoreactivity was tested by enzyme-linked immunosorbent assay (ELISA). A total of 30 sera were tested including pre-exposed people with high IgM levels for Pap31/SCS-alpha (23 sera), patients (2 sera) as well as 5 sera with no reactivity to Pap31/SCS-alpha. The results indicate that Pap31-8 ((187)QAIGSAILKGTKDTGT(202)) and SCS-alpha-12 ((59)IFASVAEGKEKTGANA(74)) are the most immunogenic peptides, with Pap31-8 showing potential to discriminate between B. bacilliformis and the remaining Bartonella spp., and SCS-alpha-12 differentiating Bartonella spp. from other microorganisms.

Automated summary

This study identified two immunogenic peptides from Bartonella bacilliformis, Pap31-8 and SCS-alpha-12, with the potential to differentiate between different Bartonella species. These peptides were found to be highly immunogenic and could be useful for developing serologic tools for diagnosing Carrion's disease.