Evaluation of Anti-Biofilm Activity of Enteromorpha Spp. Against Uropathogenic Pseudomonas aeruginosa

Abstract

Background:  Besides the well-known intrinsic and acquired genetic mechanisms involved in the bacterial resistance phenomenon, bacteria also exhibit an adaptive strategy that consists of the formation of a strongly structured cell assembly named “biofilm providing increased protection against conventional treatments. Thus, to overcome this, searching for new antibiofilm agents, especially of natural origin.

Objective: To highlight the ability of Enteromorpha extracts to prevent biofilm formation of Pseudomonas aeruginosa isolated from urinary tract infections.

Methods: Enteromorpha sp. extracts were prepared by successive maceration in three solvents; namely, distilled water, ethanol, and n-hexane by using Ultrasonic Bath. The MIC and sub-MIC of each extract were also determined using the broth microdilution method. The antibacterial activity of the extracts was performed using the method of measuring the zone of inhibition by disc diffusion agar method. The antibiofilm activity was performed using the microtiter plates method. The bioactive compounds in each extract were also identified using a GC-MS device.

Results:  All extracts showed an inhibitory ability on the growth of P. aeruginosa, and the highest inhibition zone was recorded in Hexanal extract at a concentration of 100% with a mean of 14.5±0.7mm. A significant reduction in biofilm formation was recorded when bacteria were treated with concentrations below the MIC of the extracts, with an inhibition rate reached 96% for the ethanolic extract. Several active chemical compounds in each extract were also identified using GC-MS.

Conclusion: These findings present new insights into the ability of the green alga Enteromorpha Spp. as a valuable source of antibacterial and antibiofilm agents for the pharmaceutical industries