Cornell Center for Antimicrobial Resistance Research & Education Fall Seminar Series 2024

“Molecular mechanisms underlying biofilm formation in non-tuberculous mycobacteria”

Infections caused by non-tuberculous mycobacteria (NTM) are on the rise across the globe. In the clinic, NTM infections have become increasingly problematic as they are the primary cause of pulmonary lung infections and are difficult to clear due to biofilm formation. Biofilms occur when bacteria colonize surfaces and aggregate in a self-secreted exopolysaccharide matrix. NTM biofilms are a public health threat as they colonize medical devices, are implicated in many nosocomial infections, and are difficult to eradicate due to increased resistance to various antimicrobial agents. Novel therapeutic approaches are therefore urgently needed to mediate disruption of NTM biofilms. Cyclic-di-GMP (c-di-GMP) signaling and quorum sensing are well established regulators of biofilm formation in gram-negative bacteria. Despite their importance, the role of these mechanisms in NTM biofilm formation remains largely unexplored. Using Mycobacterium abscessus (Mab) as a model organism, my research program focuses on investigating what molecular mechanisms drive NTM biofilm formation. Like gram-negative bacteria, Mab commonly exists in the biofilm state and it’s genome is predicted to encode both c-di-GMP processing enzymes and quorum sensing-based transcriptional regulators. We therefore hypothesize that both c-di-GMP signaling and quorum sensing likely play key roles in regulating Mab biofilm formation. Using genetic, biochemical and metabolite quantification-based approaches, current work will focus on testing these hypotheses with the goal of providing insight into whether these mechanisms could be utilized for future anti-biofilm applications against Mab and other NTM overall. 

Lisa-Marie Nisbett Bio:

Dr. Lisa-Marie Nisbett is an Assistant Research Professor in the Department of Microbiology at Cornell University. Her research group investigates mechanisms that non-tuberculous mycobacteria use to regulate biofilm formation. Dr. Nisbett received both a B.S and M.S in Biology from the LIU Post Campus of Long Island University in 2009 and 2012 respectively, a Ph.D. in Biochemistry and Structural Biology from Stony Brook University in 2018, and was a IRACDA NY-CAPS postdoctoral scholar with Dr. Jessica Seeliger at Stony Brook University.