New Anti-Adhesion Agents In The Development of Antivirulence Drugs

Abstract

Gram-positive bacteria are a significant cause of nosocomial and community-acquired infections associated with diseases of high morbidity and mortality. Moreover, antibiotic resistance of important Gram-positive pathogens, such as Staphylococcus aureus, Streptococcus pneumoniae and Enterococcus faecalis is one of the major worldwide health problems. Over the last decade, many studies have focused on agents that target the virulence of important pathogens without killing or inhibiting their growth therefore imposing limited selective pressure to promote the development and spread of resistance mechanisms [1]enterococci and streptococci, sortase A plays a critical role in Gram-positive bacterial pathogenesis. It is thus considered a promising target for the development of new anti-infective drugs that aim to interfere with important Gram-positive virulence mechanisms, such as adhesion to host tissues, evasion of host defences, and biofilm formation. The additional properties of sortase A as an enzyme that is not required for Gram-positive bacterial growth or viability and is conveniently located on the cell membrane making it more accessible to inhibitor targeting, constitute additional reasons reinforcing the view that sortase A is an ideal target for anti-virulence drug development. Many inhibitors of sortase A have been identified to date using high-throughput or in silico screening of compound libraries (synthetic or natural. We synthesized two classes of molecules: curcumin analogues and N-phenyl-1H-pyrazole-4-carboxamides able to interfere with the bacterial adhesion, a fundamental step of Gram-positive pathogenesis [2].All derivatives obtained were tested for both the planktonic growth inhibition activity and the inhibition of biofilm formation against the following reference bacterial strains: S. aureus ATCC 6538, S. aureus ATCC 25923 and S. aureus ATCC 29213.