Antibacterial and therapeutic effects of low energy shock waves on uropathogenic E. coli investigated by in vitro and in vivo cystitis rat model.

Aims: Low-energy shock waves (LESWs) are known to alter cell-membrane permeability. This study aimed to investigate the effect of LESWs on Escherichia coli and E. coli-induced cystitis in rats.

Main methods: Standardized suspensions of E. coli ATCC25922 were treated with or without LESWs (100 or 300 pulses; 0.12 mJ/mm²; 2 pulses/s) followed by bacterial counting, an antibiotic sensitivity test, and gene ontology analysis and gene-set enrichment analysis. Intravesical administration of saline or E. coli (0.5 mL with 10⁸ CFU/mL) for 30 min was performed in female Sprague-Dawley rats. The rats were treated with or without LESWs (300 pulses; 0.12 mJ/mm²; 2 pulses/s) on days 4 and 5. The changes in inflammatory reactions, uroplakin IIIa staining, and correlation with urodynamic findings were assessed on day 8.

Key findings: LESW treatment induced a decrease in CFU and the autoaggregation rate and increased the inhibition zone sizes in a cefazolin-sensitivity study. These changes were associated with gene expression in regulation of cellular membrane components, biofilm formation, and the ATP-binding cassette transporter pathway. E. coli induced bladder hyperactivity and an inflammatory reaction as well as decreased uroplakin IIIa staining; these effects were partially reversed by LESW treatment.

Significance: The LESW antibacterial effect occurs by altering bacterial cell-membrane gene expression, enhancing antibiotic sensitivity, and inhibiting bladder inflammatory reaction and overactivity. These findings support the potential benefits of LESWs for treatment of recurrent or refractory bacterial cystitis.