SIMBA Method-Simultaneous Detection of Antimicrobial and Anti-biofilm Activity of New Compounds Using Salmonella Infantis

Bio Protoc. 2023 Aug 5;13(15):e4783. doi: 10.21769/BioProtoc.4783.

Abstract

The development of antimicrobial resistance and the formation of Salmonella biofilms are serious public health problems. For this reason, new natural compounds with antimicrobial and anti-biofilm activity are being sought, and wild fungi represent an untapped potential. Various extraction agents, including organic solvents and aqueous buffers, can be used to obtain bioactive compounds from natural sources. To evaluate their bioactivity, extensive screening studies are required to determine antimicrobial and anti-biofilm activity using methods such as broth microdilution or crystal violet assay, respectively, but none of these methods allow simultaneous evaluation of both activities against bacteria. Cold water extraction from wild fungi offers the advantage of extracting water-soluble compounds. The SIMultaneous detection of antiMicrobial and anti-Biofilm Activity (SIMBA) method combines the testing of both types of activity against bacteria with the evaluation of the 20 h growth curve of the Salmonella Infantis ŽM9 strain determined with absorbance measurements at 600 nm in a 96-well plate. SIMBA method thus shortens the time to determine the bioactivity of extracts, reduces material consumption, and eliminates the need for additional reagents. SIMBA enables rapid selection of bioactive extracts for their fractionation and shortens the time to determine new natural products with antimicrobial and anti-biofilm activity. Graphical overview.

Keywords: Absorbance; Anti-biofilm; Antimicrobial; Growth curve; High-throughput; New compounds; Salmonella Infantis; Screening.