Standardization of an Escherichia coli adhesion assay for anti-biofilm agents screening

Abstract

Introduction: Biofilms are a key factor in the development of infectious diseases and drug resistance for their control. New therapeutic strategies include natural products as anti-biofilm agents. However, comparing results is often difficult due to the lack of homogeneity and standardization of the methods used to study biofilm formation in vitro.

Objective: To standardize an Escherichia coli microplate adhesion assay for potential anti-biofilm agents screening.

Methods: The microplate adhesion method and crystal violet staining were used. The influence of experimental conditions such as bacterial concentration, culture medium, and incubation time were evaluated.

Results: Optimal conditions for biofilm formation included: Luria Bertani (LB) medium, bacterial concentration at 10⁵ CFU/mL, and an incubation time of 24 hours.

Conclusions: The results showed that culture conditions influence biofilm formation. Optimal culture conditions for the formation of E. coli biofilms were determined, which could be used in further studies on the effect of natural products on the inhibition or destruction of biofilms.