A growing number of bacteria including Pseudomonas aeruginosa and Methicillin Resistant Staphylococcus aureus (MRSA) have increasing resistance to antibiotics. These pathogenic bacteria cause serious infections that can lead to severe recurring ulcers, and potentially limb amputation and death. Since both of these bacteria have developed a very strong resistance to antibiotics, an alternative method of treatment that can potentially avoid resistance mechanisms needs to be developed. Deep-eutectics and ionic liquids provide an alternative materials approach and have long been suspected of having the potential to inhibit the growth of antibiotic-resistant bacterial strains. Two deep-eutectic ionic liquids, Choline Geranate (CAGE) and Choline Citronellate (CACI), were tested to evaluate their inhibitory effect against P. aeruginosa and MRSA. The minimum inhibitory concentration (MIC) was tested using the disc method with various concentrations of CAGE and CACI was also performed to determine if either was effective in inhibiting the growth of the bacteria. It was found that CAGE and CACI had minimal inhibitory effect against the growth of MRSA in this type of environment. Both materials did have an inhibitory effect on the growth of P. aeruginosa. The growth medium and solvation of the ionic liquid materials both impacted efficacy as well. While the exact nature of that effect is still unknown, gram staining shows the bacteria within a certain radius of the disc exhibited degradation in the cell wall. The nature of the interaction of CAGE/CACI with the bacterial cells and this observed degradation mechanism is unknown at this time, and future experiments will help elucidate this mechanism and eventually allow the engineering of more effective materials.

Inhibitory effects of ionic liquids and deep eutectic materials on pathogenic bacteria

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.