Our lab is interested in how exogenous factors and secreted immune effectors shape the ecology of gut microbiomes. Our research includes understanding the developmental ontogeny of human microbiomes and investigating gut host-microbe interactions with an invertebrate chordate model system, Ciona robusta.

Our lab maintains very close collaborative ties with several faculty throughout the USF system, for example, Dr. Mya Breitbart, USF College of Marine Sciences. With Dr. Breitbart, we co-advise several students and collaborate on some projects involving bacteriophage.
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Larry J. Dishaw, Ph.D.
Principle Investigator

Associate Professor,
University of South Florida
Department of Pediatrics, Molecular Genetics
Children’s Research Institute in St. Petersburg,
801 Sixth Street South, CRI3008
St. Petersburg, Fl 33701

ldishaw [at] health.usf.edu
office: 727-553-3601

Online profiles:
Google Scholar
ORCID: 0000-0002-2705-4573
Loop profile: 28944
ResearcherID: A-9930-2010

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Our lab, as of Summer 2019. From Left to Right: Ojas Natarajan, Caleb Poock, Larry Dishaw, Gail Mueller, Celine Atkinson, and Alexis Peterson. Missing from this photo is Gio Duca and Cheri Lotfi.
Post Doctoral Fellow
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Dr. Ojas Natarjan earned his PhD at Clemson in 2018 studying nutraceuticals and aging in C. elegans. Ojas will now be focusing on studying the role of secreted immune effectors, such as VCBPs in Ciona, in modulating the ecology and biology of gut microbiomes. As a postdoc, Ojas will help develop a variety of our programs, co-lead our mentorship efforts, and help steer the ship! He will also get unique opportunities to teach within USF and at St. Petersburg College.We are very lucky to have Ojas join our lab. Welcome!

Graduate Students
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Celine Atkinson graduated from the University of South Florida and is joining our team to work on the impact of prophages on the gut microbiome in Ciona. Like Ojas, she is also investigating the role of VCBPs... Celine will also be competing for a NSF graduate research fellowship award, help in our lab's mission to improve science communication, and also help develop and implement our outreach programs. We are so happy to have Celine join us! Welcome!
Undergraduate Students
Current undergraduate interns include: Cheri Lotfii and Gio Duca.

Summer interns 2019: Caleb Poock from U. North Florida and Alexis Peterson, our REU student on the NSF-MCB project.

Former recent undergrads: Elliana Walster, Michael Schepps, and Julie Voelschow. Good luck to Jessica Kramarz on her mission with the Peace Corps.
Former Post Doctoral Scientists
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Dr. Assunta ("Susy") Liberti is our postdoc on the NSF phage award. Susy received her PhD training at the world-renowned marine station Stazione Zoologica Anton Dohrn in Naples, Italy, where she worked on Ciona development and immunity. She was instrumental in our work to understand the developmental expression patterns of VCBPs. In her current work, Susy is helping us develop methods and approaches to using bacteriophage to remodel the gut microbiota and influence the formation of mucosal-associated biofilms. Susy is also leading the way in some very important gene knockdown and knockout experiments.
Former Graduate Students
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Brittany Leigh was our first PhD student, who helped establish collaborative ties between the USF College of Medicine and College of Marine Sciences. Britt was co-advised with Mya Breitbart. Britt took on many roles in the lab but as senior grad student, really helped us launch, develop, and refine our germ-free mariculture system, as well as our bacteriophage and biofilm experiments. Britt, working together with Dr. John Cannon in USF Pediatrics, helped developed many skills in our lab including recombinant protein expression and purification using the FPLC.

Britt was supported by the NSF Graduate Research Fellowship Program. She is now a postdoc at Vanderbilt with Seth Bordenstein.

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Alexandria "Lexi" Creasy was a masters student (finished Summer 2018) also co-advised with Mya Breitbart. Lexi worked on on developing, together with mentorship from Dr. Cannon, some of our most complex in vitro 3D matrix assays involving various microbial ecology concepts including phage, biofilms, and direct bacterial competition & succession. Lexi's main project was to characterize single stranded viruses from isolated from the Ciona gut.
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Zachary Graham was a masters student (finished Summer 2018). Zach's main project involved studying prophages in the gut of Ciona and also investigated differential prophage induction. He is very talented in the lab and is currently staying on as a technician and works on all sorts of bacteriology experiments, including some very important phage-mediated lytic assays and prophage-induction experiments.
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Congrats to Shreya Nirmalan, who graduated with her master's degree Summer 2019. Shreya worked on two projects: a lung virome project and also helped assemble two bacterial genomes using Illumina and PacBio sequencing data and then mapped prophages along with nearby metabolic genes.
Our lab works closely with Dr. John Cannon, who is an immunologist and molecular genetics specialist in our division. Currently, he is working with us to help develop most of our recombinant efforts including protein expression and purification as well as the development of genetically manipulated Ciona. John is definitely an essential component of our group!

Our collaborators

  • Jeff Gralnick, Ph.D, University of Minnesota, Microbial Engineering
  • John Dennehy, Ph.D, Queens College, Bacteriophage Ecology
  • Bill Baker,Ph.D, USF Chemistry
  • Les Shaw, Ph.D, USF Cell Biology, Microbiology, and Molecular Biology
  • John Cannon, Ph.D, at USF Pediatrics, Molecular Genetics
  • Gary Litman, Ph.D, at USF Pediatrics, Molecular Genetics (now Emeritus Professor)
  • Mya Brietbart, Ph.D, at USF Marine Sciences
  • Maureen Groer, Ph.D, at USF College of Nursing
  • Jack Gilbert, Ph.D, at U. Chicago and Argonne National Labs
  • Hans Peter Grossart, Ph.D, Aquatic Microbial Ecology and Biodiversity, Potsdam University
  • At USF include Stephen Kornfeld, M.D, Panida Sriaroon, M.D., Jenn Leiding, M.D. and Jolan Walter, M.D.
  • At JH-ACH, Katie Wasylik, M.D., and Suzanne Jackman, M.D.
  • Rosaria De Santis, Ph.D, and Maria Rosaria Pinto, Ph.D, at the Stazione Zoologica Anton Dorhn, Naples, Italy. These collaborators (both now emeritus professors) first introduced us to Ciona and the rest is history!
  • Several additional collaborations and projects are just developing.
*This website is not an official University of South Florida website. Only the Dishaw Lab is responsible for its content.

Our research is or has been supported by:
National Science Foundation (IOS and MCB)
National Institutes of Health (our collaboration with Dr. Groer in USF Nursing)
All Children’s Hospital Johns Hopkins Medicine Foundation (several studies)
University of South Florida College of Medicine Deans Office (several early studies in