Antibacterial effect of Coffea canephora ethanolic extract through potassium and magnesium efflux mechanism.

The resistance of some bacteria towards current antibiotics calls for a new development of antibiotics. Robusta coffee (Coffea canephora) contains active compounds with antibacterial effects such as chlorogenic acid, caffeine, caffeic acid, and quinic acid. Intracellular ions such as potassium and magnesium have important roles in bacterial life. This study aims to investigate the potential antibacterial effect of Coffea canephora and its possibility in damaging bacterial cell walls and membranes through efflux of potassium and magnesium ions. This experimental study used three types of bacteria Methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, and Pseudomonas aeruginosa, each divided into a control group and an experimental group with different concentrations. Efflux of potassium and magnesium ions in bacteria was measured using an atomic absorption spectrophotometer (AAS), while changes in bacterial cell wall morphology were observed using a scanning electron microscope (SEM). Coffea canephora is found to significantly increase the magnesium efflux of all bacteria compared to the control group (p < 0.05), while the potassium efflux only significantly increases in MRSA and Klebsiella pneumoniae. In observations using SEM, changes in the morphology of bacterial cell walls are found in the experimental group, indicating a damaging effect caused by Coffea canephora. [ABSTRACT FROM AUTHOR]