Pentanol and Benzyl Alcohol Attack Bacterial Surface Structures Differently

Area of Science:

• Microbiology and Public Health
• Antimicrobial Resistance

Background:

• The genus Methylobacterium poses a public health concern due to its tolerance to hygiene agents like benzalkonium chloride (BAC).
• Understanding mechanisms to overcome BAC tolerance is crucial for infection control.

Purpose of the Study:

• To investigate the synergistic effects of BAC combined with alcohols on Methylobacterium viability.
• To elucidate the mechanisms by which alcohols enhance BAC efficacy.

Main Methods:

• Bacterial viability assays were performed after exposure to BAC and alcohol combinations.
• Raman spectroscopy was used to analyze BAC cellular accumulation.
• Fluorescence spectroscopy and giant vesicle assays assessed membrane interactions.
• Membrane protein inactivation was investigated using fluorescent spectroscopic assays.

Main Results:

• Combinations of BAC with pentanol (PeA) or benzyl alcohol (BzA) at nonlethal concentrations significantly reduced bacterial viability within 5 minutes.
• PeA and BzA accelerated cellular accumulation of BAC.
• BzA increased membrane fluidity and destabilized structures, while PeA had minimal membrane attack.
• Both PeA and BzA inactivated bacterial membrane proteins, including BAC efflux pumps.

Conclusions:

• Alcohols, particularly PeA and BzA, enhance BAC efficacy by inactivating membrane proteins responsible for BAC transport.
• BzA further boosts BAC penetration through membrane fluidization, leading to greater bacterial killing.
• These findings offer potential strategies for combating BAC-tolerant Methylobacterium infections.