A5024025171- Bacterial biofilms and quorum sensing
- Bacterial Genetics and Biotechnology
- Vibrio bacteria research studies
- Microfluidic and Bio-sensing Technologies
- Microfluidic and Capillary Electrophoresis Applications
- Lipid Membrane Structure and Behavior
- Genomics and Chromatin Dynamics
- Innovative Microfluidic and Catalytic Techniques Innovation
- Gut microbiota and health
- Yersinia bacterium, plague, ectoparasites research
- Pickering emulsions and particle stabilization
- RNA regulation and disease
- Cancer-related molecular mechanisms research
- Electrowetting and Microfluidic Technologies
- Biochemical and Structural Characterization
- 3D Printing in Biomedical Research
- Micro and Nano Robotics
- Microbial Community Ecology and Physiology
- RNA Interference and Gene Delivery
- Genomics and Phylogenetic Studies
- Plant and Biological Electrophysiology Studies
- CRISPR and Genetic Engineering
- MicroRNA in disease regulation
- Antibiotic Resistance in Bacteria
- Antimicrobial Peptides and Activities
École Polytechnique Fédérale de Lausanne
2016-2025
Bioengineering (Switzerland)
2023
Mechanics' Institute
2021
Washington University in St. Louis
2020
Princeton University
2014-2017
California Institute of Technology
2016
Stanford University
2007-2011
Howard Hughes Medical Institute
2010
Johns Hopkins University
2010
Significance In their natural environments, bacteria frequently transition from a free-swimming state to surface-associated state, attached substratum. As they encounter surface, may initiate developmental programs optimally colonize this new environment and induce pathways such as virulence. Here we demonstrate that the pathogen Pseudomonas aeruginosa uses fiber-like motorized appendages called type IV pili sense initial contact with surfaces. This leads signaling cascade results in...
Biofilm formation is generally recognized as a bacterial defense mechanism against environmental threats, including antibiotics, bacteriophages, and leukocytes of the human immune system. Here, we show that for pathogen Vibrio cholerae, biofilm not only protective trait but also an aggressive to collectively predate different cells. We find V. cholerae forms biofilms on eukaryotic cell surface using extracellular matrix comprising primarily mannose-sensitive hemagglutinin pili,...
Significance Single cells across kingdoms of life explore, prey, escape, or congregate using surface-specific motility. Motile eukaryotic use chemotaxis to direct migration on surfaces. However, how bacteria control surface motility remains underexplored. Pseudomonas aeruginosa twitches surfaces by successive extension and retraction extracellular filaments called type IV pili. Here, we show that P. directs twitching sensing mechanical input generated The Chp sensory system performs...
We review fundamental and applied acid–base equilibrium chemistry useful to microfluidic electrokinetics. present elements of reactions derive rules for pH calculation simple buffers. also a general formulation calculate more complex, arbitrary mixtures electrolytes, discuss the effects ionic strength temperature on calculation. More practically, we offer advice buffer preparation reporting. "real world" buffers likely contamination sources. In particular, atmospheric carbon dioxide systems,...
We present elements of electrolyte dynamics and electrochemistry relevant to microfluidic electrokinetics experiments. In Part I this two-paper series, we presented a review introduction the fundamentals acid–base chemistry. Here, first summarize coupling between equilibrium chemistry electrophoretic mobilities electrolytes, at both infinite finite dilution. then discuss effects electrode reactions on electrokinetic experiments derive model for pH changes in microchip reservoirs during...
We present and demonstrate a novel technique for the purification of nucleic acids from biological samples using isotachophoresis (ITP). simple rapid method to achieve ITP-based extraction, preconcentration, DNA nanoliter volumes whole blood. show that ITP yields genomic which can be quantitated with fluorescence measurements are immediately compatible polymerase chain reaction (PCR) (e.g., PCR-friendly solution free significant inhibitors). hypothesize is applicable processing wide range...
Summary Type IV pili (TFP) function as mechanosensors to trigger acute virulence programs in Pseudomonas aeruginosa . On surface contact, TFP retraction activates the Chp chemosensory system phosphorelay upregulate 3′, 5′‐cyclic monophosphate (cAMP) production and transcription of virulence‐associated genes. To dissect specific interactions mediating mechanochemical relay, we used affinity purification/mass spectrometry, directed co‐immunoprecipitations P. , single cell analysis...
Collective behavior in spatially structured groups, or biofilms, is the norm among microbes their natural environments. Though biofilm formation has been studied for decades, tracing mechanistic and ecological links between individual cell morphologies emergent features of groups still its infancy. Here we use single-cell–resolution confocal microscopy to explore biofilms human pathogen Vibrio cholerae conditions mimicking marine habitat. Prior reports have noted occurrence cellular...
During chronic infections and in microbiota, bacteria predominantly colonize their hosts as multicellular structures called biofilms. A common assumption is that biofilms exclusively interact with biochemically. However, the contributions of mechanics, while being central to process biofilm formation, have been overlooked a factor influencing host physiology. Specifically, how form on soft, tissue-like materials remains unknown. Here, we show pathogens Vibrio cholerae Pseudomonas aeruginosa...
Abstract Background Transposable element-embedded regulatory sequences (TEeRS) and their KRAB-containing zinc finger protein (KZFP) controllers are increasingly recognized as modulators of gene expression. We aim to characterize the contribution this system regulation in early human development germ cells. Results Here, after studying genes driven by long terminal repeat (LTR) endogenous retroviruses, we identify ape-restricted ZNF676 sequence-specific repressor a subset contemporary LTR12...
The opportunistic pathogen Pseudomonas aeruginosa causes antibiotic–recalcitrant pneumonia by forming biofilms in the respiratory tract. Despite extensive vitro experimentation, how P . forms at airway mucosa is unresolved. To investigate process of biofilm formation realistic conditions, we developed AirGels: 3D, optically accessible tissue–engineered human lung models that emulate mucosal environment. AirGels recapitulate important factors mediate host–pathogen interactions including mucus...
Bacterial gut commensals experience a biologically and physically complex mucosal environment. While many chemical factors mediate the composition structure of these microbial communities, less is known about role mechanics. Here, we demonstrate that fluid flow impacts spatial organization biofilm communities by shaping how different species interact metabolically. We first model community composed Bacteroides thetaiotaomicron ( Bt ) fragilis Bf ), two representative human commensals, can...
We present and demonstrate a novel assay for the detection quantification of microRNA (miRNA) that leverages isotachophoresis (ITP) molecular beacon (MB) hybridization. use ITP to selectively preconcentrate miRNA from total RNA. simultaneously focus MBs zone as 10 pL reactor with active mixing where fluoresce upon hybridization target miRNA. To increase both sensitivity selectivity, we leverage multistage strategy composed three discrete regions different concentrations denaturant, sieving...
Nanocharacterization plays a vital role in understanding the complex nanoscale organization of cells and organelles. Understanding cellular function requires high-resolution information about how structures evolve over time. A number techniques exist to resolve static structure great detail (super-resolution optical microscopy, EM, AFM). However, time-resolved imaging tend either have lower resolution, are limited small areas, or cause damage cells, thereby preventing long-term time-lapse...
ABSTRACT The human colon hosts hundreds of commensal bacterial species, many which ferment complex dietary carbohydrates. To transform these fibers into metabolically accessible compounds, microbes often express a series dedicated enzymes homologous to the starch utilization system (Sus) encoded in polysaccharide loci (PULs). genome Bacteroides thetaiotaomicron ( Bt ), common member gut microbiota, encodes nearly 100 PULs, conferring strong metabolic versatility. While structures and...
As the antimicrobial resistance crisis becomes a reality, we are only now realizing lack fundamental understanding of mechanisms by which major pathogens infect their human host. To address this, must employ novel methodologies that allow us to investigate microbial behavior in infection-like contexts. Here, present framework for studying host-microbe interactions integrating human-derived organoids with high-resolution live imaging and high-throughput sequencing technologies. This...
Most bacterial chemosensory systems encode enzymes that are predicted to methylate and demethylate their chemoreceptors control signaling activity. Here, we show a methyltransferase (PilK) methylesterase (ChpB) demethylate, respectively, the chemoreceptor PilJ in Pseudomonas aeruginosa (P. aeruginosa) Pil-Chp surface sensing system. methylation modulates amplitude of cAMP production frequency twitching motility reversals, outputs signaling. Dynamic imaging fluorescent fusion proteins...