Bioprospecting by Phage Display of Mimetic Peptides of for Use in Laboratory Diagnosis.

BACKGROUND

infection is a major public health problem and the most common sexually transmitted infection in the world. Although highly prevalent, 70% to 80% of cases are asymptomatic and undiagnosed.

PURPOSE

To overcome some limitations in terms of rapid diagnosis, phage display technology was used to bioprospect peptide mimetics of immunoreactive and immunogenic antigens to be selected for the production of synthetic peptides.

METHODS

Initially, IgG from 22 individuals with and 30 negative controls was coupled to G protein magnetic beads. The phage display technique consisted of biopanning, genetic sequencing, bioinformatics analysis and phage ELISA.

RESULTS

Clones G1, H5, C6 and H7 were selected for testing with individual samples positive and negative for . Reactions were statistically significant (p < 0.05), with a sensitivity of 90.91, a specificity of 54.55, and AUC values >0.8. One-dimensional analysis with components indicated that the G1 clone aligned with cell wall-associated hydrolase domain-containing protein, the H5 clone aligned with glycerol-3-phosphate acyltransferase PlsX protein, the C6 clone aligned with a transposase and inactivated derivatives, and the H7 clone aligned with GTP-binding protein. Molecular modeling and three-dimensional analysis indicated the best fit of the four clones with a protein known as chlamydial protease/proteasome-like activity factor (CPAF), an important virulence factor of the bacterium.

CONCLUSION

The peptides produced by phage display are related to the metabolic pathways of , indicating that they can be used to understand the pathogenesis of the infection. Because of their high sensitivity and AUC values, the peptides present considerable potential for use in platforms for screening infections.