In vivo repressed genes of <i>Vibrio cholerae</i> reveal inverse requirements of an H ⁺ /Cl ⁻ transporter along the gastrointestinal passage

Abstract

Significance Bacterial infection is still a global threat to human health. Gene expression profiling of pathogenic bacteria during infection may aid in a better understanding of the pathophysiological events. Here, we present a reporter-based technology to identify in vivo repressed ( ivr ) genes of Vibrio cholerae . Our data demonstrate that constitutive expression of ivr genes reduces colonization fitness, indicating a pivotal role of gene silencing. A comprehensive characterization of an H + /Cl − transporter revealed a defined spatiotemporal expression pattern, being induced in the stomach to facilitate survival under low pH, but silenced under alkaline pH in the lower gastrointestinal tract to avoid detrimental effects. Thus, previously understudied ivr genes could reveal new insights into host–pathogen interaction and alternative therapeutic strategies.