N-acetyl-glucosamine correlates with Pseudomonas aeruginosa priming through type IV pili/FimV in Drosophila melanogaster

Toxin-antitoxin pairs are widely spread in bacteria, toxins of which have been reported to be involved in bacteria persistence by inducing growth arrest. However, we know less about the mechanism of toxins inhibiting bacteria growth. Most importantly, proper animal model needed to decipher whether toxins control bacterial pathogens transitionbetween acute andchronic status since bacterial persisters are actually due to growth arrest. We have developed a novel P. aeruginosalatent infection model in Drosophilapreviously to explore function and mechanism of type II TA pair higBAby constructing mutants deficient to single higBor higArespectively. Antitoxin HigA was degraded to liberate toxin HigB controllinglatent P. aeruginosavirulence, however, toxin HigB was later validated to control P. aeruginosavirulence unrelated to bacteria persistence in the acute infection route. Furthermore, we proved that HigB inhibits P. aeruginosapropagation dependent on the synergistic effect of antimicrobial peptides in Drosophila. Since we did not observe HigB leads P. aeruginosa to bemore susceptible to AMPs killing, we explored that wt P. aeruginosagets fitness in Drosophilabut HigB-free strain failed. Proteomics reveals that toxin HigB inhibits P. aeruginosafitness under AMPs by repressing Chp chemotaxis signaling, which produce cAMP signal involved in cell division. Strikingly, canonical cell division genes involved in cell wall remodeling during bacteria fission could not rescue HigB-free strain virulence but inversely repress wt P. aeruginosafitness under AMPs inDrosophila. We further observed that morphology of P. aeruginosamaintained by cell wall was expectantly correlated to their virulence. In this research, we uncover a new mechanism of toxin HigB controlling P. aeruginosavirulence in vivo, highlighting that toxin HigBas a conservative factor holds bacteria in the stressful and changing environment. It also indicates that we need to reassess the way of antibacterial drugs designing since bacteria could get fitness to elude attacks.