RNA chaperone hfq mediates persistence to multiple antibiotics in Aeromonas veronii

Area of Science:

• Microbiology
• Bacterial Pathogenesis
• Molecular Biology

Background:

• Pathogenic *Aeromonas veronii* causes significant health and economic losses in fish and humans.
• Bacterial persister cells, exhibiting multiple drug tolerance, are a major cause of recurrent infections.
• The ubiquitous RNA-binding protein Hfq is implicated in antibiotic tolerance and persister production.

Purpose of the Study:

• To investigate the role of Hfq in *Aeromonas veronii*.
• To determine the impact of *hfq* deletion on antibiotic tolerance and persister formation.
• To elucidate the molecular mechanisms underlying Hfq-mediated effects.

Main Methods:

• Gene deletion of *hfq* in *Aeromonas veronii*.
• Assessment of bacterial growth rates.
• Evaluation of antibiotic tolerance and persister cell formation.
• Quantitative gene expression analysis (qRT-PCR) for key regulatory genes.

Main Results:

• Deletion of *hfq* in *A. veronii* significantly retarded bacterial growth.
• The *hfq* deletion mutant exhibited reduced tolerance to various antibiotics.
• Persistence levels were significantly lowered in the absence of functional Hfq.
• Downregulation of *relE*, *cspD*, *clpB*, *rpoS*, and *oxyR*, and upregulation of *oppB* were observed in the *hfq* deletion mutant.

Conclusions:

• Hfq plays a critical role in promoting antibiotic tolerance and persister formation in *Aeromonas veronii*.
• The observed effects are likely mediated by Hfq's regulation of specific genes involved in stress response and survival.
• Understanding Hfq's function provides potential targets for combating recalcitrant *A. veronii* infections.