Karine Gibbs, PhD

Assistant Professor

Department of Molecular and Cellular Biology, Faculty of Arts and Sciences

Explores Identity and Territory in the Social World of Bacteria

Investigate the molecular mechanisms underlying the ability of bacterial cells to discriminate self from non-self; study the bacterium Proteus mirabilis, a Gram-negative opportunistic pathogen that forms biofilms and causes urinary tract infections and kidney stones in patients.

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Commercial Opportunities

The Gibbs laboratory focuses on Proteus mirabilis, a Gram-negative opportunistic pathogen that forms biofilms and causes urinary tract infections, most significantly in patients with long-term indwelling catheters. Every year, millions of health care dollars were spent on fighting resistant infections caused by biofilms. Self-recognition may play an important role in maintaining clonal Proteus infections. Other species of bacteria may also have genes encoding self-recognition.

Bacterial biofilms are a major cause of persistent infections worldwide, and are resistant to both antibiotics and host defenses. Studies being performed in the Gibbs laboratory are laying the groundwork for future therapeutics and other industrial solutions related to biofilms and social behavior of bacteria.

Current Research Interests
  • Investigate the molecular mechanisms underlying the ability of bacterial cells to discriminate self from non-self and to understand social behaviors in bacteria.
  • Study the bacterium Proteus mirabilis, a Gram-negative opportunistic pathogen that forms biofilms and causes urinary tract infections, most significantly in patients with long-term indwelling catheters.
  • Explore P. mirabilis as a genetic model to provide a simplified system to further examine the molecular mechanisms of self/non-self recognition in biology.
Research Expertise

Prof. Gibbs and her collaborators have identified a novel set of five self-recognition genes (ids -“identification of self ”) in the social bacterium Proteus mirabilis that encodes components necessary for self vs non-self recognition and for the definition of strain-specific identity. It is perhaps the most primitive form of self/non-self recognition ever known, like the major histocompatability complex (MHC) proteins in vertebrates.  P. mirabilis is a bacterial pathogen which forms biofilms on urinary catheters and causes the formation of kidney stones in patients. P. mirabilis populations display a remarkable phenomenon when migrating as a swarm across a surface: a visible boundary forms between swarms of different P. mirabilis strains. With this visible read out for self/non-self recognition, the Gibbs laboratory uses P. mirabilis as a genetically tractable model system for asking direct questions about how cells recognize self from non-self in a way that one cannot begin to answer in organisms with complex genetics.