Molecular mechanisms mediating a novel escherichia coli sibling inhibition, a specific form of intra-species inhibition

The National Institute of Allergy and Infectious Diseases awarded the Research Foundation of The City University of New York $142,237 on September 2, 2026, under the Allergy and Infectious Diseases Research program (CFDA 93.855) to characterize the molecular mechanisms of E. coli sibling inhibition and evaluate the bioactive potential of the E. coli sibling inhibitor compound.

The research examines a novel form of intra-species bacterial competition whereby genetically identical E. coli cells inhibit each other's growth when inoculated in soft agar, forming clear inhibitory borders between expanding colonies. Supernatant collected from these borders displays broad-spectrum antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Mycobacterium tuberculosis. Preliminary data characterize the active compound as a heat-stable, negatively charged, hydrophilic molecule. The project supports basic research aimed at identifying bioactive compounds arising from bacterial competitive interactions that may inform novel antibiotic development strategies to address multidrug-resistant pathogens.

Work is performed in Bronx, New York through August 31, 2030. The Research Foundation of The City University of New York serves as the legal research and sponsored programs management entity for the City University of New York system, with specific administrative focus on Lehman College, a Hispanic-Serving Institution.

Abstract

Bacterial competition plays a central role in regulating microbial populations in environments. Such interactions have historically yielded bioactive compounds of immense medical value, exemplified by fleming's discovery of penicillin and the ensuing "golden age" of antibiotic discovery. However, the rise of multidrug-resistant pathogens coupled with a stagnation in new antibiotic development has created an urgent public health crisis. We recently discovered that escherichia coli possesses a novel mechanism of "sibling inhibition," whereby genetically identical e. Coli and other gram-positive and gram-negative bacterial cells inhibit each other's growth. When e. Coli cells are inoculated in soft agar, they form clear inhibitory borders between expanding colonies. Supernatant collected from these borders displays broad-spectrum antibacterial activity, including activity against staphylococcus aureus, pseudomonas aeruginosa, and mycobacterium tuberculosis. Preliminary characterization indicates the active compound, termed the e. Coli sibling inhibitor, is a heat- stable, negatively charged, hydrophilic molecule