Suramin, Congo Red, and Antibiotic Resisance
St George's School
Floor Location : S 192 L
Objective: To test the effectiveness of Congo Red and Suramin on E.coli and bacillus subtilis cells used conjunction with antibiotics in preventing bacteria from developing resistance to antibiotics.rnrnIntroduction:rnAntibiotic resistance is a major problem in health. It is tied to the LexA and the RecA proteins. Normally, LexA represses SOS response genes that code for particular DNA polymerases which have the ability to bypass lesions and errors in DNA, encouraging DNA mutations. When repressor enzyme LexA is inactivated, an error-prone DNA replication mechanism is activated. This new mechanism allows mutations to develop, allow bacteria the chance to develop antibiotic resistance. When bacteria are expressed to a stress, such as antibiotics, DNA damage occurs and single-stranded DNA (ssDNA) regions accumulate and DNA polymerase is blocked. RecA forms filaments around these single strands, catalyses ATP to ADP, and releases energy that activates RecA. The activated RecA cleaves the LexA repressor, thereby enabling the error-prone SOS response.rnPrevious studies have attempted to over express LexA and suppress RecA in bacteria, which showed a very significant decrease in antibiotic resistance, despite experimental conditions which encouraged resistance to develop in the bacteria. In June 15 2008, Wigle and Singleton tested 18 small molecules in assays and found that Suramin and Congo Red prevented ATP hydrolysis by RecA, which would prevent SOS response. They did not test the molecules in cell environments, assuming impermeability.rnrnSuramin is a drug used to treat sleeping sickness, onchocerciasis, and other diseases caused by certain protozoa and worms. In a study where when rat cells were given doses of Suramin, Suramin was found to inhibit telemerases and cell proliferation, to a degree dependent on dosage. Permeable to eukaryotic cells, Suramin may be permeable to bacteria cells. Congo Red is used to stain cell cytoplasms and red blood cells. Ampicillin is an antibiotic used extensively since 1961 to treat bacterial infections, but many bacteria have since become resistant to Ampicillin.rnrnRelevant Application: If a small molecule is found to be able to penetrate the cell and inhibit RecA in some way, the molecule could be used in conjunction with antibiotic treatments to prevent bacteria from developing resistance to the antibiotics. Thus, the effectiveness of antibiotics will be increased and help in patient care.