Morpholinium-based ionic liquids show antimicrobial activity against clinical isolates of Pseudomonas aeruginosa

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Pseudomonas aeruginosa is a major cause of hospital-acquired infections and is increasingly resistant to conventional antibiotics.
• The World Health Organization (WHO) identifies multi-drug resistant (MDR) P. aeruginosa as a critical threat.
• Novel antimicrobial strategies are urgently needed to combat MDR P. aeruginosa infections.

Purpose of the Study:

• To investigate the efficacy of ionic liquids (ILs) as potential novel antibiotics against MDR P. aeruginosa.
• To evaluate the growth inhibition and other effects of 12 different ILs on four P. aeruginosa strains.
• To identify specific ILs with potent antimicrobial activity against clinical isolates of P. aeruginosa.

Main Methods:

• Tested 12 ionic liquids (ILs) with varying cations (4,4-didecylmorpholinium [Dec2Mor]+ and 4-decyl-4-ethylmorpholinium [DecEtMor]+) and anions.
• Utilized a model strain (P. aeruginosa PAO1) and three clinical isolates from diverse infections (lung, burn, keratitis).
• Assessed bacterial growth inhibition, strain fitness, and virulence factor production.

Main Results:

• Ionic liquids featuring the 4,4-didecylmorpholinium [Dec2Mor]+ cation demonstrated the most significant inhibition of bacterial growth.
• These specific ILs also effectively reduced bacterial strain fitness and the production of virulence factors.
• Differential effects were observed across the four P. aeruginosa strains tested.

Conclusions:

• Ionic liquids, particularly those with 4,4-didecylmorpholinium [Dec2Mor]+ cations, represent a promising new class of antimicrobial agents against P. aeruginosa.
• These ILs show potential for developing novel therapeutic strategies to treat infections caused by MDR P. aeruginosa.
• Further research into ILs could lead to effective treatments for challenging nosocomial infections.