Stella Cascioferro
Three different classes of heterocyclic compounds 1, 2 and 3were synthesized and evaluated for their capability to inhibit biofilm formation of the Gram-positive bacterial reference strainsStaphylococcus aureus ATCC 25923, S. aureus ATCC 6538 and Staphylococcus epidermidis ATCC 12228, andthe Gram-negative strains Pseudomonas aeruginosa ATCC 15442 and Escherichia coli ATCC 25922. Many of these new compounds, showed potent anti-biofilm activity exhibiting BIC50 lower than 10 μg/ ml, and in some cases lower than 1μg/ml. All compounds elicited higher potency toward Gram-positive strains, showing a typical anti-virulence profile. In fact, the new derivatives did not interfere with bacterial vital processes (MIC > 100 μg/ml) but they inhibit the bacterial biofilm formation, that is considered one of the most relevant bacterial virulence factor. The 1,2,4-oxadiazole topsentinanalogs3proved toact by inhibiting the transpeptidase- Sortase A, interfering, consequently, with the bacterial adhesion, which represents the first step of biofilm formation and bacterial pathogenesis.