Bassler Lab Members

Principal Investigator

Bonnie Bassler
Bonnie L. Bassler
bbassler@princeton.EDU

Research Interest:  Cell-to-cell communication in bacteria.
Bonnie L. Bassler Biography »

Curriculum Vitaepdf-icon-25x25


Postdoctoral Fellows

 
Nina Hoyland-Kroghsbo
 
Research Interest: The global threat of multi-drug resistant bacteria urgently demands alternatives to conventional antibiotics. Two promising alternatives to traditional antibiotics are bacteriophage (phage) therapy and inhibitors of bacterial cell-cell communication, known as quorum sensing (QS). Bacteria in high cell density maximally engage in QS. These cells are particularly vulnerable to phage infections, which could rapidly spread and kill the population. QS-control of antiphage activities would enable bacteria to specifically activate defenses when they are at the highest risk of infection. I am investigating to what extent bacteria use QS to regulate their antiphage defenses. Whereas QS-inhibitory compounds are generally studied for their capacity to inhibit bacterial virulence, I will study whether they additionally have the ability to increase the vulnerability of pathogenic bacteria to phages.

Matt Jemielita

 Research Interest: In Vibrio cholerae quorum sensing (QS) controls a diverse range of cellular processes including virulence and biofilm formation. While we know much of the QS pathway in V. cholerae, these insights have come from studies in well-mixed environments. As a result, we know little about the dynamics of QS within biofilms, which are structured environments that have distinct spatial scales. Using a combination of advanced microscopy, microfluidics, and genetics I aim to understand how spatial and temporal patterns of QS affect the overall development of a biofilm. 


 
Sampriti Mukherjee
 
Research Interest: Quorum sensing (QS) regulates biofilm development in various bacteria and biofilms play crucial role in bacterial infections as well as clog filters and reactors in industries. Sampriti investigates the spatio-temporal regulation of QS during biofilm development in realistic environments using microfluidics, live cell-imaging and genetic tools. Designing successful synthetic strategies to inhibit or to enhance biofilms in clinical or industrial settings hinges on our understanding of how quorum sensing controls biofilm development.

 
Jon Paczkowski
 
Research Interest: We are at a pivotal point in modern health care due to the presence and proliferation of antibiotic resistance in various pathogenic bacteria.  P. aeruginosa is an important pathogen that affects cystic fibrosis patients as well as the immunocompromised, such as cancer patients receiving chemotherapy.  It has a well-defined quorum sensing (QS) network that is directly linked to biofilm formation and virulence.  I am interested in understanding the molecular mechanism of small molecule activation and inhibition of the two main QS receptors, LasR and RhlR.  I am taking a biochemical and biophysical approach to understand how these receptors bind small molecules, how they are activated, and how their function can be modified to modulate the QS network thereby altering virulence and pathogenesis. 

 
Jing Yan
 
Research Interest: Many bacteria have the amazing ability to switch between different lifestyles, between living in the fluid and dwelling in a biofilm. This flexible strategy presumably increases their competence in a fluctuating environment. Using V. cholerae as the model organism and combing microscopy, microfluidic, and genetic tools, I am testing this ecological hypothesis that is naturally linked to the infectious cycle of V.cholerae. At the same time, I am uncovering the molecular mechanism of the less understood dispersal process. By developing fluorescent reporters, I wish to observe the spatial heterogeneity in the gene expression within a biofilm, which will reveal how the complicated processes of biofilm formation and disintegration are actively controlled, both spatially and temporally.

Graduate Students

 
Michaela Eickhoff
 
Research Interest: 
Different species of bacteria produce different acyl homoserine lactone (AHL) molecules to use as quorum sensing (QS) autoinducers. The Vibrio harveyi QS receptor, LuxN, is exquisitely specific for AHL Autoinducer-1 (AI-1). Though AHLs with longer acyl tails than AI-1 do not activate LuxN, they do bind to LuxN with high affinity to act as antagonists, competing with AI-1 for binding. This finding suggests that V. harveyi can use QS molecules to not only detect cell density but also the species composition of the environment. By co-culturing different Vibrio species, I am interested in how bacteria integrate information in autoinducer mixtures.  Understanding QS regulation of V. harveyi in the presence of other bacterial species will provide insight into how it uses QS to produce niche-specific behaviors in its native environment. 

Amanda Hurley
 
Research Interest: The autoinducer CAI-1 is produced, secreted and sensed by the transmembrane histidine kinase CqsS in Vibrio cholerae. CAI-1-mediated signaling induces quorum sensing and consequently represses virulence factors such as TCP and CTX. I am interested in the artificial activation of quorum sensing in V. cholerae using small molecules, which target either CqsS or the downstream transcription factor LuxO. I want to identify the mechanism by which these pro-quorum sensing molecules inhibit the CqsS and LuxO, which will illuminate how two-component signal transduction occurs in V. cholerae. In addition, these small molecules have the potential to be developed into therapeutics for the disease cholera.

 
 Minyoung Kevin Kim
 
Research Interest: In natural habitats and in industrial and medical settings, bacteria commonly live adhered to surfaces in biofilms and are exposed to fluid flow. QS controls biofilm formation, however it is not known how QS functions under constant or intermittent (e.g. pulsatile) flow, or how QS and biofilm formation vary as a function of position along a flow, nor is it known how surface topography impact QS-mediated communication in flow. In addition, it is also unknown how QS within biofilm formation vary as a function of depth in flow. Kevin explores these questions using Staphylococcus aureus and Vibrio cholerae; two pathogens in which QS regulates virulence. Understanding the ramifications of these spatially and temporally non-uniform QS responses will be crucial for successful deployment of synthetic pro- and anti-QS strategies to enhance beneficial bacteria and to combat harmful bacteria in medicine and industry.

 
Amelia McCready
 
Research Interest: For the opportunistic pathogen Pseudomonas aeruginosa, quorum sensing plays a pivotal role in pathogensis. The two main quorum sensing systems LasI/R and RhlI/R regulate a large portion of the genome and control the production of many virulence factors. However, there is much yet to learn about these two systems and their targets. I am working on identifying and characterizing inhibitors of the receptors LasR and RhlR. I am also interested in investigating how these inhibitors will effect P. aeruginosa biofilms and in vivo infections. Finally, I hope to use these inhibitors as tools to understand more about how LasR and RhlR function: including how they form homodimers, interact with DNA and interact with RNA polymerase.

 
Justin Silpe
 
Research Interest: Bacterial biofilms are collections of cells that form at liquid-solid interfaces and, in so doing, partially define the properties of the materials on which they form. Biofilms are relevant to the proper functioning of industrial and medical systems ranging from cathodes to catheters and cooling towers to colitis. I am interested in studying the molecular and chemical processes that dictate biofilm formation from a combined biological, chemical, and materials science perspective. To unravel these processes, I am working to develop optochemical and genetic tools capable of manipulating gene expression within a subset of a population and studying the cause and effect relationships associated with different perturbations on a microscopic scale.

 

Undergraduate Students

 Michael Delgado    

Research Associates

jian-ping
Jian-Ping Cong
jcong@princeton.EDU

 


Julie Valastyan

 


Vasiliki Stergioula
 

Faculty Assistant

Jennifer Munko
Jennifer Munko
jmunko@princeton.EDU
P (609) 258-5659

 


Collaborators

Fred Hughson
Fred Hughson
Princeton University, Molecular Biology
Hughson Lab

 


Semmelhack
Martin Semmelhack
Princeton University, Chemistry

 


Howard Stone
Howard Stone
Princeton University, Mechanical and Aerospace Engineering
Stone Lab

 


Ned Wingreen
Ned Wingreen
Princeton University, Molecular Biology
Wingreen Lab