Why is repurposing FDA-approved drugs a more effective development strategy for identifying new antibiotics rather than starting over from the beginning with the creation of an entirely new antibiotic?
Hi Morgan! The typical time it takes for a completely new antibiotic to be found to the time it would become shelf available is 13 years, and that is if you were able to identify a new compound the first time it was tested. The 1950-1960’s were considered the “golden age” for antibiotics and many compounds were found in soil. Overtime, it has become more difficult to identify potential new sources for antibiotics, a new class has not been discovered since 1980! Using an FDA-approved drug is helpful because we already know a lot about it’s mechanism of action, and how that could potentially effect bacterial growth. Thanks for your comment, and I hope I answered it well!
Hi Avery! We added salmonella to all of the well plates, as well as our compound in duplicate, a negative control (DMSO) in 1 row, and a positive control (ampicillin) in 1 row. The spectrophotometer measures light absorbance in the wells, the higher the absorbance level, the higher concentration of bacteria in the well. This means that for ampicillin, a known bactericidal agent, a low absorbance value is expected. For DMSO, we expect a high absorbance value because we know that it does not effect the growth of Salmonella. We calculated a mean absorbance value from our negative control (DMSO) and it was used as a universal comparison. If the absorbance value was 2 standard deviations below the DMSO mean, that suggested the presence of a bactericidal agent, because less light was being absorbed. Thanks for you question, and I hope I answered it well!
Hi Layla! Mefenamic Acid is a NSAID. NSAIDs are known COX inhibitors which lead to decreased prostaglandin synthesis. Prostaglandin inhibition has been shown to increase T- cell mediated immunity in response to bacterial infections. Mefenamic acid resulted in maximum biofilm removal against Pseudomonas aeruginosa, and was also effective in
removing biofilms formed by Staphylococcus epidermidis.
Why is repurposing FDA-approved drugs a more effective development strategy for identifying new antibiotics rather than starting over from the beginning with the creation of an entirely new antibiotic?
Hi Morgan! The typical time it takes for a completely new antibiotic to be found to the time it would become shelf available is 13 years, and that is if you were able to identify a new compound the first time it was tested. The 1950-1960’s were considered the “golden age” for antibiotics and many compounds were found in soil. Overtime, it has become more difficult to identify potential new sources for antibiotics, a new class has not been discovered since 1980! Using an FDA-approved drug is helpful because we already know a lot about it’s mechanism of action, and how that could potentially effect bacterial growth. Thanks for your comment, and I hope I answered it well!
How does measuring the absorbance value of the well allow predictions about the growth of bacteria?
Hi Avery! We added salmonella to all of the well plates, as well as our compound in duplicate, a negative control (DMSO) in 1 row, and a positive control (ampicillin) in 1 row. The spectrophotometer measures light absorbance in the wells, the higher the absorbance level, the higher concentration of bacteria in the well. This means that for ampicillin, a known bactericidal agent, a low absorbance value is expected. For DMSO, we expect a high absorbance value because we know that it does not effect the growth of Salmonella. We calculated a mean absorbance value from our negative control (DMSO) and it was used as a universal comparison. If the absorbance value was 2 standard deviations below the DMSO mean, that suggested the presence of a bactericidal agent, because less light was being absorbed. Thanks for you question, and I hope I answered it well!
What properties have the antimicrobial peptides that helps you to understand understand more the effectiveness of the drug?
Hi Layla! Mefenamic Acid is a NSAID. NSAIDs are known COX inhibitors which lead to decreased prostaglandin synthesis. Prostaglandin inhibition has been shown to increase T- cell mediated immunity in response to bacterial infections. Mefenamic acid resulted in maximum biofilm removal against Pseudomonas aeruginosa, and was also effective in
removing biofilms formed by Staphylococcus epidermidis.
https://pubmed.ncbi.nlm.nih.gov/31622303/
Thanks for your question!
What were the main differences between your experimental setup and the literature experimental setup that you were unable to match?