{"id":6,"date":"2022-07-17T03:16:01","date_gmt":"2022-07-17T03:16:01","guid":{"rendered":"https:\/\/labs.bio.cmu.edu\/test\/?page_id=6"},"modified":"2026-04-29T13:06:39","modified_gmt":"2026-04-29T13:06:39","slug":"home","status":"publish","type":"page","link":"https:\/\/labs.bio.cmu.edu\/bridges\/","title":{"rendered":"Home"},"content":{"rendered":"
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Bridges Lab @ CMU<\/strong><\/h1>\n<\/div><\/div>\n\n
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About<\/h4>\n<\/div><\/div>\n\n

About Us<\/h2>\n<\/div><\/div>\n\n

In the Bridges lab we use diverse approaches to study how bacteria make developmental decisions based on extracellular sensory information. Read about our research<\/a><\/span> for more information. In addition, we strive to cultivate a healthy and productive scientific environment!<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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News<\/h4>\n<\/div><\/div>\n\n

Lab News<\/h2>\n<\/div><\/div>\n\n

Follow this thread for the latest lab news<\/p>\n<\/div><\/div>\n<\/div>\n\n

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April 25, 2026:\u00a0 New preprint on bioRxiv: A branching cell-fate decision in biofilm dispersal enables long-term surface persistence<\/a><\/em><\/h4>\n<\/div><\/div>\n\n
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Our work, entitled \"A branching cell-fate decision in biofilm dispersal enables long-term surface persistence<\/a>,\" was just preprinted on bioRxiv. <\/em>Biofilms are the most ancient multicellular communities on Earth, representing a primitive developmental system that protects microbes from threats. Biofilm dispersal, whereby bacteria exit biofilms, is critical for the spread of pathogens to new infection sites. Here, using Vibrio cholerae, we show that dispersal events are accompanied by a branching cell-fate decision. While \u223c90% of cells disperse, a viable subpopulation remains within a residual matrix. This post-dispersal biofilm community (PDBC) is established by the matrix protein RbmA and adopts a specialized anabolic program that enhances tolerance to antibiotics and bacteriophages. Our findings reveal that PDBCs act as a resilient \u201cseed-bank\u201d capable of rapidly re-populating the niche without requiring de novo matrix biosynthesis, providing a mechanistic basis for the recurrence and spread of chronic infections. Congrats to Sandhya and Jojo!<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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December 19, 2025:\u00a0 New paper out in Nature communications<\/em>.<\/h4>\n<\/div><\/div>\n\n
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Our work, entitled \"A small periplasmic protein governs broad physiological adaptations in Vibrio cholerae via regulation of the DbfRS two-component system<\/a>,\" was just preprinted on bioRxiv. <\/em>To survive in diverse niches, bacteria rely on two-component sensors to convert environmental stimuli into appropriate cellular responses. Here, we use a multidisciplinary approach to characterize a novel and conserved two-component system that controls the biofilm lifecycle of the global pathogen Vibrio cholerae<\/em>. The DbfRS two-component system is comprised of a third participant, a small, periplasmic protein, DbfQ, which directly interacts with and controls the activity of the receptor. Pathway activity is sensitive to membrane stress and globally regulates multicellularity, metabolism, and cell envelope biosynthesis. Together, our study positions DbfQRS as a stress-responsive circuit with broad physiological roles and highlights its potential as a target for anti-infective therapy. Check it out!<\/span><\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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The lab travels to Portland, OR for the ASM Biofilms Meeting<\/h3>\n<\/div>\n

Nov 13, 2025:<\/strong> The Bridges lab had a blast attending the American Society for Microbiology's Conference on Biofilms. Drew, Emmy, and Yangyang gave talks and Yangyang won the graduate student talk award!\u00a0
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New Preprint:

Label-free microscopy enables high-throughput identification of genes controlling biofilm development
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Sept 3, 2025:<\/strong> Biofilms are central to how microbes grow, persist, and cause disease, yet many of their molecular drivers remain unclear. This study introduces LFAB, a label-free imaging approach that uses time-lapse brightfield microscopy to track biofilm biomass in real time. LFAB is non-perturbative, high-throughput, and performs well across diverse microbes, correlating strongly with traditional assays. Applying LFAB to\u00a0<\/span>Streptococcus pneumoniae<\/em>, the team identified key genes influencing microcolony formation and highlighted important roles for CbpA and a neighboring regulatory system. Overall, the work establishes LFAB as a powerful platform for uncovering the factors that shape bacterial biofilm development. Fun collaboration with the Hiler lab at CMU!<\/span><\/p>\n

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The Bridges Lab Receives an NIH MIRA Award!<\/h3>\n<\/div>\n

August 12, 2025:<\/strong> The Bridges lab is grateful to receive a Maximizing Investigators' Research Award from the National Institute of General Medical Sciences on the topic of bacterial lysis sensing. More info here
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\n Drew Receives a Young Investigator Award from the Center for Biofilm Engineering!
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\n July 10, 2025:<\/strong> Drew was honored to receive a Young Investigator Award and to attend the Montana Biofilm Science & Technology Meeting and Workshop in beautiful Bozeman, Montana.<\/p>\n<\/div><\/div>\n\n

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Jojo and Darin head off to new adventures<\/h4>\n

Summer, 2025:\u00a0 The Bridges lab says farewell to Jojo Prentice and Darin Boyes.<\/h6>\n
Jojo was a founding member of the Bridges lab. Jojo and Drew initially worked together Bonnie Bassler's lab, where Jojo was an undergraduate. He came with Drew to CMU to work as a post-bac for three years! He is now off to graduate school in Ecology and Evolutionary Biology at Yale.<\/h6>\n
Darin recently finished his Master's degree in Computational Biology at CMU, where he worked in the Bridges lab throughout. Now, Darin is off to UCLA to start his PhD in Bioinformatics.<\/h6>\n
Thanks to Jojo and Darin for all of the fun science! Can't wait to see what you do in the future.<\/h6>\n<\/div><\/div>\n\n
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PhD student Jesse Derringer joins the lab!<\/h4>\n

May 2, 2025:\u00a0 The Bridges lab welcome Jesse Derringer as the latest PhD student to join our ranks. Jesse hails from Virginia and prior to enrolling in our graduate program completed his MS in Chemistry at William & Mary College. When he is not thinking about science, Jesse is probably out on a walk, asking random questions, or looking for humor in everyday life.<\/h6>\n<\/div><\/div>\n\n
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Irina takes on a new job at ASM!<\/h4>\n

April 28, 2025:\u00a0 The Bridges lab says goodbye to Irina, who has taken a position as Manuscript Transfer Editor at the American Society for Microbiology. Thank you for all of your hard work as a founding member of the Bridges lab!<\/h6>\n<\/div><\/div>\n\n
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April 2025:\u00a0 Jojo is awarded the NSF Graduate Research Fellowship\u00a0<\/h4>\n<\/div><\/div>\n\n
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Congratulations to Jojo Prentice, who received the NSF GRFP. This impressive accomplishment was especially competitive this year and is very well deserved. Jojo, a founding member of the Bridges lab has made strides as a post-baccalaureate researcher. In the Fall, he will start a new adventure as a PhD student in Ecology and Evolutionary Biology at Yale University. He will be missed!<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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March 24, 2025:\u00a0 New preprint!<\/h4>\n<\/div><\/div>\n\n
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Our work, entitled \"A small periplasmic protein governs broad physiological adaptations in Vibrio cholerae via regulation of the DbfRS two-component system<\/a>,\" was just preprinted on bioRxiv. <\/em>To survive in diverse niches, bacteria rely on two-component sensors to convert environmental stimuli into appropriate cellular responses. Here, we use a multidisciplinary approach to characterize a novel and conserved two-component system that controls the biofilm lifecycle of the global pathogen Vibrio cholerae<\/em>. The DbfRS two-component system is comprised of a third participant, a small, periplasmic protein, DbfQ, which directly interacts with and controls the activity of the receptor. Pathway activity is sensitive to membrane stress and globally regulates multicellularity, metabolism, and cell envelope biosynthesis. Together, our study positions DbfQRS as a stress-responsive circuit with broad physiological roles and highlights its potential as a target for anti-infective therapy. Check it out!<\/span><\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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Yangyang is a PhD Candidate!<\/h4>\n

Jan 10, 2025:\u00a0 Bridges Lab second year graduate student Yangyang Liu passes our graduate program preliminary exam with flying colors. Congratulations on achieving PhD candidacy!<\/h6>\n<\/div><\/div>\n\n
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November 26, 2024:\u00a0 New paper alert!<\/h4>\n<\/div><\/div>\n\n
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Our work, entitled \"Biofilm dispersal patterns revealed using far-red fluorogenic probes<\/a>,\" was just published in PLOS Biology. <\/em>Bacteria frequently colonize niches by forming multicellular communities called biofilms. To explore new territories, cells exit biofilms through an active process called dispersal. Biofilm dispersal is essential for bacteria to spread between infection sites, yet how the process is executed at the single-cell level remains mysterious due to the limitations of traditional fluorescent proteins, which lose functionality in large, oxygen-deprived biofilms. To overcome this challenge, we developed a cell-labeling strategy utilizing fluorogen activating proteins and cognate far-red dyes, which remain functional throughout biofilm development, enabling long-term imaging. Using this approach, we characterize dispersal at unprecedented resolution for the global pathogen Vibrio cholerae. We reveal that dispersal initiates at the biofilm periphery and ~25% of cells never disperse. We define novel micro-scale patterns that occur during dispersal, including biofilm compression during cell departure and regional heterogeneity in cell motions. These patterns are attenuated in mutants that reduce overall dispersal or that increase dispersal at the cost of homogenizing local mechanical properties. Collectively, our findings provide fundamental insights into the mechanisms of biofilm dispersal, advancing our understanding of how pathogens disseminate. Moreover, we demonstrate the broad applicability of fluorogen activating proteins as a powerful tool for high-resolution studies of microbial dynamics in complex environments. Check it out!<\/span><\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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November 8, 2024:\u00a0 Yangyang wins poster presentation award at the Rust Belt Microbiome meeting!<\/span><\/h4>\n<\/div><\/div>\n\n
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November 2, 2024:\u00a0 The lab attends Allegheny ASM Branch (ABASM) meeting in Greensberg, PA. Presentation awards abound!<\/span><\/h4>\n<\/div><\/div>\n\n
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October 23, 2024:\u00a0 Jojo presents his research on bacterial lysis sensing at the International Meeting on the Biology of Vibrios in Peru!<\/span><\/h4>\n<\/div><\/div>\n\n
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August 10, 2024:\u00a0 Graduate students present their work at the Molecular Genetics of Bacteria and Phages Meeting.<\/h4>\n<\/div><\/div>\n\n
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PhD students Emmy, Sandhya and Yangyang presented their work in Madison, Wisconsin this week. Emmy gave an oral presentation to a huge crowd while Sandhya and Yangyang gave marathon poster presentations! Sandhya won a poster award - a monumental achievement! We look forward to attending the meeting again soon.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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July 15, 2024:\u00a0 Preprint alert!<\/h4>\n<\/div><\/div>\n\n
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Our work, entitled \"Biofilm dispersal patterns revealed using far-red fluorogenic probes<\/a>,\" was just preprinted on biorXiv.<\/em> Biofilm dispersal is essential for bacteria to spread between infection sites, yet how the process is executed at the single-cell level remains mysterious. Here, we characterize dispersal at unprecedented resolution for the global pathogen Vibrio cholerae<\/em>. To do so, we first developed a far-red cell-labeling strategy that overcomes pitfalls of fluorescent protein-based approaches. We reveal that dispersal initiates at the biofilm periphery and \u223c25% of cells never disperse. We define novel micro-scale patterns that occur during dispersal, including biofilm compression and the formation of dynamic channels. These patterns are attenuated in mutants that reduce overall dispersal or that increase dispersal at the cost of homogenizing local mechanical properties. Collectively, our findings provide fundamental insights into the mechanisms of biofilm dispersal, advancing our understanding of how pathogens disseminate. Check it out!<\/span><\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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Gillian and Maddy graduate!<\/h4>\n

May 11, 2024:\u00a0 The first class of Bridges Lab undergraduate students Gillian Croteau and Maddy Burke have officially graduated! Both recieved honors for research credit in their senior year. Gillian is off to Northeastern University to pursue her PhD and Maddy is applying to medical school.\u00a0<\/h6>\n<\/div><\/div>\n\n
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Gillian wins the Carnegie Mellon Sigma Xi\u00a0<\/span>Poster<\/span>\u00a0Competition<\/span>!<\/h4>\n
May 2, 2024:\u00a0 Graduating senior Gillian Croteau wins the poster competition at the annual Meeting of the Minds event on campus! Congrats Gillian!<\/h6>\n<\/div><\/div>\n\n
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PhD student Yangyang Liu join the lab!<\/h4>\n

April 22, 2024:\u00a0 The Bridges Lab is delighted to welcome Yangyang Liu to the lab. Yangyang will study bacterial lysis sensing in diverse pathogens. We can't wait to see what Yangyang will discover!<\/h6>\n<\/div><\/div>\n\n
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The lab is thankful to receive support from the Shurl and Kay Curci Foundation!<\/h4>\n<\/div><\/div>\n\n
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Click here to read<\/a><\/span><\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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March 6, 2024:\u00a0 The first Bridges lab manuscript it out!<\/h4>\n<\/div><\/div>\n\n
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Our work, entitled \"Cell lysis sensing drives biofilm formation in Vibrio cholerae<\/em><\/a>,\" was published in Nature Communications.<\/em> We find that upon exposure to lytic phages, the pathogen V. cholerae<\/em> rapidly lyses, but then recovers, with surviving cells exhibiting robust biofilm formation. We find that the mechanism underlying this observation is a process we refer to as \"lysis sensing\"...whereby surviving cells sense a signal released by the death of their kin. We identify the cell lysis signal as an abundant cytoplasmic polyamine, norspermidine, which is detected by an inner-membrane receptor, MbaA, that in turn drives biofilm formation. We determine that additional pathogenic organisms also exhibit multicellular community formation in response to lysis. Given the pervasiveness of lysis in the environment, we propose that lysis sensing is a threat-agnostic mechanism by which bacteria can gauge endangerment.\u200b<\/span><\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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Feb 11, 2024:\u00a0 Irina hits the big time on CMU's Instagram. Happy International Women and Girls in Science day!<\/h4>\n<\/div><\/div>\n\n
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Sandhya and Emmy pass their qualifying exams!<\/h4>\n

Feb 7, 2024:\u00a0 Bridges Lab second year graduate students Sandhya Kasivisweswaran and Emmy Nguyen passed their preliminary exams with flying colors. Congratulations on achieving PhD candidacy!<\/h6>\n<\/div><\/div>\n\n
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Drew's mSphere of Influence commentary about biogeography is published.<\/h4>\n<\/div><\/div>\n\n
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Click here to read<\/a><\/span><\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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Check out a recent story about our lab by the MCS media team!<\/h4>\n<\/div><\/div>\n\n
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Click here to read.<\/a><\/span><\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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Graduate students Sandhya and Emmy join the lab!<\/h4>\n

May 1, 2023:\u00a0 The Bridges Lab is delighted to welcome graduate students Sandhya Kasivisweswaran and Emmy Nguyen, who will study signaling mechanisms that regulate Vibrio cholerae<\/em> biofilms. It will be an adventure!<\/h6>\n<\/div><\/div>\n\n
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Robert van de Weerd joins<\/h4>\n<\/div><\/div>\n\n

Nov 1, 2022:\u00a0 The latest member to join the group is Robert van de Weerd, originally from the Netherlands. Robert's interests include biotechnology development and molecular pathogenesis.<\/p>\n<\/div><\/div>\n<\/div>\n\n

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Irina Mikheyeva joins the lab<\/h4>\n<\/div><\/div>\n\n

Oct 1, 2022:\u00a0 The newest member of the lab is Irina Mikheyeva. Irina's interests include molecular pathogenesis, signal transduction, as well as hiking and biking.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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Sept 23, 2022:\u00a0 Drew is named a 2022 Blavatnik Regional Award Finalist for his postdoctoral research on Vibrio cholerae<\/em> biofilm dispersal.<\/h4>\n<\/div><\/div>\n\n

https:\/\/twitter.com\/BlavatnikAwards\/status\/1572596740548608006<\/p>\n<\/div><\/div>\n\n

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Jojo Prentice joins the lab<\/h4>\n<\/div><\/div>\n\n

The first lab member (other than Drew) has joined the lab! Jojo recently completed his undergraduate degree at Princeton University in the Department of Molecular Biology.<\/p>\n<\/div><\/div>\n<\/div>\n\n

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Bridges Lab opens!<\/h4>\n<\/div><\/div>\n\n

Sept 1, 2022:\u00a0 The Bridges lab has officially opened at CMU in the Department of Biological Sciences.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n

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