Inhibition of Escherichia coli biofilm formation by natural extracts. (c2018)

Abstract

Biofilms are defined as a buildup of microorganisms in a mostly polysaccharide environment, rendering bacterial growth immotile and sessile. Biofilm formation is well known to facilitate bacterial adherence to multiple surfaces that may include live tissue as well as inert matter. Once microorganisms initially attach themselves to such surfaces they synthesize a dome like extracellular polymer that results in the formation of a highly hydrated matrix. Escherichia coli, a known biofilm former and a cause of many infections, over time, developed resistance against many antibacterial agents, creating a major problem in treating patients with infection caused by this organism. Uropathogenic E.coli strains that were isolated from patients in LAUMC-RH were definitively identified, tested for the production of extended spectrum beta lactamases (ESBL). and genetically characterized by PFGE. The strains of E. coli selected (10 ESBLs producing and 10 non-ESBLs producing) were those already tested for their ability to produce biofilms. A number of natural products was tested for their effect on the ability of the test strains to form their biofilm. Two of the tested plant extracts were proved to influence biofilm formation of the tested strains: namely: Salvia officinalis (sage) and Thymus vulgaris (thyme). The major organic compounds that mainly make up these two plants were individually tested for their ability to inhibit the biofilm formation of the tested strains. Camphor from sage and terpinene from thyme demonstrated a clear effect to inhibit biofilm formation of the two groups of E.coli tested at different molar concentrations (0.025, 0.05, and 0.10) The use of combinations of these compounds did not demonstrate synergism in their ability to inhibit biofilm formation.