Staphylococcus Aureus

Staphylococcus aureus is the most frequent cause of both healthcare-associated and community-acquired bloodstream infections worldwide. Infective endocarditis (IE) has been detected in 5-17% of cases and is a determinant of poor prognosis. The investigators developed a score (the VIRSTA score) based on patients' characteristics to rule out IE with high confidence (negative predictive value (NPV) above 99%) in patients with SAB. This score, with a cut-off of 3 has been externally validated by two international studies which have also established its high NPV. The 2023 European society of cardiology (ESC) guidelines state that echocardiography should be considered in all patients with Staphylococcus aureus bacteremia (SAB) using risk scores (including VIRSTA score) to guide the use or not of echocardiography. While recommended, the investigators think that VIRSTA score must be evaluated in terms of patients' outcome.

Hypothesis: The investigators hypothesize that in patients with CRSwNP who demonstrate sinus colonization with staphylococcus aureus, the administration of dupilumab will be associated with decreased staph colonization and an increase in microbial diversity. Primary Objective will be to demonstrate that dupilumab reduces staphylococcus aureus (phyla firmicutes) abundance while increasing microbial diversity in patients with CRSwNPs who are culture positive for staph aureus at enrollment. Secondary Objectives will be to correlate reduction in Staph aureus abundance and improved bacterial diversity with increased expression of anti-microbial proteins (ß-defensins1-4) and cathelicidin LL-37. In addition, the investigators will correlate improvements in microbial diversity/decreased staph abundance with clinical improvements as assessed via questionnaires and objective/subjective smell function and also as improvements in cellular/immune T2 inflammation as assessed by reduced expression of T2 cytokines/chemokines and eosinophil/eosinophil-derived proteins.

In this clinical trial we will test a new approach for decolonization of S. aureus. As innovative product HY-133 a recombinant chimeric bacteriophage endolysin will be sprayed in both nostrils of healthy subjects once or five times in one day. To avoid possible bias the subjects will be randomized 3:2 verum vs placebo, moreover the subject as well as the investigator will be blinded to the group assigned.