Antimicrobial activities of essential oils from three species of citrus fruits against six infectious tropical bacteria: implications for the care and control of common bacterial tropical diseases in developing countries

Abstract

The burden of bacterial infections and the failure of antimicrobial agents are increasing worldwide, especially in sub-Saharan Africa. This raises the need for novel therapeutic agents to combat bacterial infectious diseases. The sensitivity of several common pathogenic bacteria to essential oils from the peels of three species of citrus plants was investigated. Essential oils (EOs) were extracted from the fresh and dried peels of the citrus species using standard techniques. The antimicrobial activities of the EOs were determined using agar well diffusion and broth microdilution methods, and the activities of the EOs were compared to those of twelve conventional antibiotics. The results showed that the essential oils had high inhibitory effects. The minimum inhibitory concentrations (MICs) of the EOs ranged between 0.025 and 0.15 mg/ml. The activities of the EOs against the tested microorganisms were comparable to those of conventional antibiotics. Processing techniques did not affect the antibacterial activities of the EOs. Thus, the essential oils from the citrus species used against the investigated microorganisms were comparable to conventional antibiotics, and these findings showed that the oils could be widely applied in the health and pharmaceutical industries, where they could help in combating the menace of bacterial infections and therapeutic failure from drug resistance worldwide and especially in developing countries with limited resources available to combat these infections.