Treatment of Shiga toxin-producing <i>E. coli</i> infection by CRISPR-Cas-targeted cleavage of the Shiga toxin gene in animal models.

Abstract

<i>Escherichia coli</i> is not only a ubiquitous gut commensal but also an opportunistic pathogen responsible for severe intestinal and extraintestinal infections. Shiga toxin-producing <i>E. coli</i> (STEC) poses a notable public health threat, particularly in children, where infections can lead to bloody diarrhea and progress to hemolytic uremic syndrome, a life-threatening condition with long-term complications. Antibiotics are contraindicated in STEC infections because of their potential to induce prophages carrying Shiga toxin (<i>stx</i>) genes, triggering toxin production. Here, we developed a CRISPR-based antimicrobial strategy using a Cas12 nuclease to selectively eliminate O157 STEC clinical isolates, cleaving more than 99% of <i>stx</i> variants, and prevent toxin release. To enable targeted delivery, we engineered a bacteriophage-derived capsid to specifically transfer a nonreplicative DNA payload to <i>E. coli</i> O157, preventing its dissemination. Our therapeutic candidate, EB003, reduced bacterial burden in a murine STEC colonization model. Moreover, EB003 mitigated clinical symptoms, abrogated Stx-mediated toxicity, and accelerated epithelial repair at therapeutically relevant doses in an infant rabbit disease model. These findings demonstrate the potential of CRISPR-based antimicrobials for treating STEC infections and support further clinical development of EB003 as a precision therapeutic against antibiotic-refractory bacterial pathogens.