Baculovirus-Assisted Production of Bartonella bacilliformis Proteins: A Potential Strategy for Improving Serological Diagnosis of Carrion’s Disease

Carrion's disease, caused by <i>Bartonella bacilliformis</i>, is a neglected tropical disease prevalent in the Andean region of South America. Without antimicrobial treatment, this disease has a mortality rate of up to 88% in infected patients. The most common method for diagnosing <i>B. bacilliformis</i> infection is serological testing. However, the current serological assays are limited in sensitivity and specificity, underscoring the need for the development of novel and more accurate diagnostic tools. Recombinant proteins have emerged as promising candidates to improve the serological diagnosis of Carrion's disease. So, we focused on evaluating the conditions for producing two previously predicted proteins of <i>B. bacilliformis</i> using the baculovirus-insect cell expression system, mainly the flashBAC ULTRA technology. We assessed various parameters to identify the conditions that yield the highest protein production, including cell lines, temperature, and hours post-infection (hpi). The results showed that the expression conditions for achieving the highest yields of the Prot_689 and Prot_504 proteins were obtained using High Five™ cells at 21 °C and harvesting at 120 hpi. Subsequently, the seroreactivity of recombinant proteins was evaluated using positive sera from patients diagnosed with Carrion's disease. These findings offer valuable insights into the production conditions of <i>B. bacilliformis</i> recombinant proteins using the baculovirus system, which could significantly contribute to developing more precise diagnostic tools for Carrion's disease. Therefore, this research provides implications for improving diagnostics and potentially developing therapeutic strategies.