Abstract: The invention relates to compositions for inhibiting or agonizing quorum sensing (QS) pathways to repress biofilm formation, biofilm streamer formation, virulence factor production, and/or infections (including bacterial infections and bacterial infections with resistance to antibiotics) by: (a) a monotherapy using novel compounds, such as small molecule inhibitors or agonists, to inhibit or activate QS activation pathways and/or (b) a combination therapy including novel compounds to inhibit or activate QS and/or to sensitize bacteria to phage along with phage therapy. These compositions can be used to treat patients having infections. Additionally, these compositions can be used to treat surfaces/areas known to contain human pathogens notorious for causing hospital-acquired infections (such as intravenous catheters, implants, medical devices) as well as fatal infections that occur outside of health care settings.