B. K. Hammer

The biophysical basis of bacterial colony growth

This study shows that the horizontal expansion rate of bacterial colonies is controlled by the contact angle at the biofilm edge, validated through experimental measurements and theoretical modeling.

Spatial constraints subvert microbial arms race

This paper shows that community size affects bacterial competition outcomes, with slow-killing strains performing better in small spaces when rare and better in large spaces when common.

Constitutive expression of the Type VI secretion system carries no measurable fitness cost in Vibrio cholerae

This study finds that constitutive expression of the Type VI Secretion System in Vibrio cholerae has a negligible fitness cost, with minimal impact on growth.

Trade-offs constrain adaptive pathways to T6 survival

This study uses experimental evolution to show that Escherichia coli evolves resistance to Vibrio cholerae's Type VI Secretion System (T6) through specific mutations, but these mutations come with fitness costs.

Vertical growth dynamics of biofilms

The paper measures biofilm height dynamics with high precision and shows that interface-based models better capture growth than logistic or nutrient depletion models.

Evolution of a cis-acting SNP that controls Type VI Secretion in Vibrio cholerae

This study identifies a cis-acting SNP in Vibrio cholerae that controls Type VI Secretion System activity, switching between constitutive and inducible states based on environmental cues.

A new contact killing toxin permeabilizes cells and belongs to a large protein family

This paper identifies TpeV, a novel T6SS toxin from V. cholerae that permeabilizes cells and belongs to a widespread protein family.

Glucose promotes resistance of human commensal Escherichia coli against contact-killing by pandemic Vibrio cholerae

This study shows glucose enhances E. coli resistance to T6SS attacks from V. cholerae through CRP-mediated metabolic changes, independent of immunity proteins.

Accumulation of dead cells from contact killing facilitates coexistence in bacterial biofilms

The paper shows that dead cell debris from T6SS-mediated killing limits contact between bacterial strains, preventing population elimination and enabling coexistence.

Analysis of Vibrio cholerae genomes using a novel bioinformatic tool identifies new, active Type VI Secretion System gene clusters

The paper develops a bioinformatic tool to identify new T6SS gene clusters in V. cholerae and demonstrates the function of a newly discovered effector protein.

The Vibrio cholerae Type VI Secretion System Can Modulate Host Intestinal Mechanics to Displace Commensal Gut Bacteria

This study shows Vibrio cholerae uses its Type VI Secretion System to enhance zebrafish intestinal motility, displacing commensal bacteria without killing them.

Horizontal Gene Transfer of Functional Type VI Killing Genes by Natural Transformation

The paper demonstrates that Vibrio cholerae can acquire and utilize new Type VI secretion system effector genes via horizontal gene transfer to outcompete its parent and neighbors.