Department of Biology

Lab

Biology Bldg. 455
812-855-6055

Awards

American Society for Microbiology Award for Early Career Basic Research, 2022
Indiana University Outstanding Junior Faculty Award, 2019

Research

Microbes can rapidly adapt and evolve in the face of clinical interventions and environmental insults. One mechanism that promotes this evolution is horizontal gene transfer (HGT) through natural competence and transformation. During this process, microorganisms take up DNA from the extracellular environment and integrate it into their genome by homologous recombination. Natural transformation is a property of diverse microbial species and is often tightly regulated. In our lab, we study the mechanisms and regulation underlying this conserved evolutionary process.

One model organism we employ to study natural transformation is Vibrio cholerae - the causative agent of the diarrheal disease cholera. This pathogen naturally resides in the aquatic environment and causes disease when ingested in contaminated food or drinking water. In the environment, V. cholerae forms biofilms on the chitinous exoskeletons of crustacean zooplankton, which is critical for both the survival and waterborne transmission of this pathogen. Chitin also induces natural competence in this organism. In our lab, we are studying the mechanisms and regulation of Vibrio-chitin interactions to gain insight into how V. cholerae evolves in the aquatic environment and transitions from this site to infect its human host. It was recently found that clinical isolates of V. cholerae are poorly transformed by this mechanism of HGT. So, we are also studying natural transformation in clinical isolates of V. cholerae to determine the mechanisms and role of HGT in strains from the ongoing 7th pandemic of cholera.

In addition to studying mechanisms of HGT, we have also exploited this process to develop a novel method for multiplexed genome editing by natural transformation (MuGENT). This method allows for “accelerated evolution” of microbes through the integration of multiple unlinked fragments of DNA into the bacterial genome in a single step. This increases the pace of genetic studies, but also allows us to probe biological questions that were previously genetically intractable. We are currently employing this method to dissect the biology of bacterial pathogens, including V. cholerae. MuGENT also allows for rapid metabolic and phenotypic engineering of microbes, which we will employ to develop non-pathogenic naturally competent species for novel biotechnology applications.

We use genome-wide approaches (Tn-seq, RNA-seq, ChIP-seq, etc.), comparative genomics, genetics, molecular biology, microscopy, flow activated cell sorting (FACS), and biochemistry to achieve these goals.

Research areas

Evolution
Genomics and Bioinformatics
Microbial Cell Biology and Environmental Responses
Microbial Interactions and Pathogenesis