Preliminary Analysis of the Presence of Bacterial Azurin Coding Gene in CRC Patients and Correlation with the Microbiota Composition

Background: Azurin, a bacterial cupredoxin firstly isolated from the bacterium Pseudomonas aeruginosa, is considered a potential alternative therapeutic tool against different types of cancer. Aims: In this work we have explored the relationship possibly existing between azurin and colorectal cancer (CRC), in light of the evidence that microbial imbalance can lead to CRC progression. Methodology/Results: To this aim, the presence of azurin coding gene in the DNA extracted from saliva, stool, and biopsy samples of 10 CRC patients and 10 healthy controls was evaluated by real-time PCR using primers specifically designed to target the azurin coding gene from different bacterial groups. The correlation of the previously obtained microbiota data with real-time PCR results evidenced a "preferential" enrichment of seven bacterial groups in some samples than in others, even though no statistical significance was detected between controls and CRC. The subset of azurin gene-harbouring bacterial groups was representative of the entire community. Conclusions: Despite the lack of statistical significance between healthy and diseased patients, HTS data analysis highlighted a kind of "preferential" enrichment of seven bacterial groups harbouring the azurin gene in some samples than in others.