Essential oils of Citrus limon, Cymbopogon citratus, and Lavandula officinalis disrupt E. coli biofilms by inducing cellular damage.

Biofilms by E. coli is not only the primary cause of recurrent urinary tract infections, but also lead to medical device-associated infections. Ever increasing antibiotic resistance due to biofilms has sparked a search for plant-based replacements. This study examines anti-biofilm potential of essential oils from lemon (Citrus limon), lemongrass (Cymbopogon citratus), and lavender (Lavandula officinalis) against 26 clinical isolates of E. coli. Essential oils (EOs) were extracted by using hydro-distillation and characterized by GC-MS and FT-IR. Biofilms were quantitatively and qualitatively evaluated. The extracted essential oils had yields ranging from 1.37 to 1.45 (w/v). The main constituents were limonene (94%) in lemon, citral (42%) and ketones (9%) in lemongrass, and linalool (35%) and linalyl anthranilate (20%) in lavender EO. MICs and MBCs of EOs were in the range of 3.13-50 µg/ml. The oils under investigation exhibited notable biofilm inhibition and eradication properties. The percent inhibition and eradication varied between 6-89% and 3-82.25% (p < 0.0001), respectively. These findings suggest that essential oils from lemon, lemongrass, and lavender may offer a promising natural approach to combat E. coli biofilms and associated infections. Further research is warranted to elucidate the underlying mechanisms of action and to explore their clinical applications.