A new work by the Nb4D group, led by M.- Pilar Marco in IQAC-CSIC and CIBER-BBN, has managed to develop a highly sensitive, specific and reliable immunochemical assay to detect pyocyanin (PYO), one of the most important virulence factors of Pseudomonas aeruginosa, a common multidrug resistant pathogen that causes both acuses and chronic infeccions.

“P. aeruginosa has developed a multidrug resistance to multiple antobiotics, which poses significant difficulties in treating this type of infection. Current culture-based microbiological diagnostic methods require more than 24-48h to identify the pathogen, which motivates the use of broad-spectrum to treat the infection without having identified the microorganism causing the infection, a practice that greatly contributes to incresing the antimicrobial resistance. There is a clear need to develop diagnostic methods capable of identifying the pathogen in a short time in order to be able to prescribe specific treatments for each case”, explain Nb4D researchers. The research carried out aims to demosntrate the potencial value of these new biomarkers to quickly and effectovely identify caused by P. aeruginosa.

“The microplate ELISA developed for the detection of PYO is able to reach a limit of detection (LoD) of 0.07 nM, which is much lower than the concentrations reported for this biomarker in clinical samples (130 µM in sputum and 2.8 µM in ear secretions)” explains the head of group M Pilar Marco. ELISA has made it possible to investigate the release kinetics of PYO and 1-OHphz (the main metabolite of PYO) by clinical bacterial isolates from patients with respiratory infections caused by P. aeruginosa, finding significant differences in the levels of this biomarker depending on whether the patients suffered from an acute or chronic infection (~6,000 nM vs. ~8 nM PYO content, respectively).

“Our results point to a real potential of PYO as a biomarker of the infection by P. aeruginosa and the possibility of using this virulence factor as a biomarker for stratification of patients and for an effective management of this type of infections”, conclude the researchers.

To carry out this study, whose results have been published in Frontiers in Cellular and Infection Microbiology, the services of ICTS NANBIOSIS have been used, where a high-affinity monoclonal antibody produced by the unit 2 of the Personalized Antibody Service CAbSm directed by Núria Pascual.

Reference:

Rodriguez-Urretavizcaya, B., Pascual, N., Pastells, C., Martin-Gomez, M.-T., Vilaplana, Ll.*, Marco. M.-P. (2021). “Diagnosis and Stratification of Pseudomonas aeruginosa Infected Patients by Immunochemical Quantitative Determination of Pyocyanin From Clinical Bacterial Isolates.” Frontiers in Cellular and Infection Microbiology 11(1215). https://doi.org/10.1016/j.jmbbm.2021.104793

CIBER-BBN Communication

IQAC-CSIC Communication