Discipline: Biological Sciences
Brett Barlow - Alabama State University
Co-Author(s): Vincent Onyilo, Atul A. Chaudhari, Vida Dennis, Komal Vig, Shree R. Singh, and Shreekumar Pillai, Alabama State University, Montgomery Al
Bacteria are quickly developing resistance to several of the existing antibiotics that are widely used. To solve this issue, researchers are hunting for feasible alternatives to traditional antibiotics and have found that antimicrobial peptides are worth further examination. In the present study, we investigated the antibacterial activity of five novel antimicrobial peptides purchased from Therapeutic Peptides Inc. (designated as TP226, TP359, TP373, TP556, and TP557). The antibacterial abilities of these peptides were quantified by the minimum inhibitory concentration (MIC) assay against two Gram-negative (Escherichia coli and Salmonella enterica serovar Typhimurium) and two Gram-positive (Streptococcus pyogenes and Staphylococcus aureus) bacteria. Our results indicated that all the peptides showed excellent antibacterial properties against all four bacterial pathogens (MIC 7.8-3.9 µg/ml). TP226 was chosen for further investigation against each of the bacterial strains by growth curve analysis and scanning electron microscopy (SEM).The growth curves showed that TP226 hampered the growth of the bacteria in a dose dependent manner. SEM analysis of Escherichia coli and Staphylococcus aureus exposed to TP226 showed not only lysis of the bacterial cells, but also hampered cell division. We are currently investigating the antimicrobial activity of TP226 on Salmonella Typhimurium and Streptococcus pyogenes using SEM and qRT-PCR. The long term goal of this project is to delineate the molecular mechanisms of action of TP226 against Gram-positive and Gram-negative bacteria.
Funder Acknowledgement(s): This research was supported by NSF-CREST (HRD-1241701), NSF-HBCU-UP (HRD-1135863), and NIH-MBRS-RISE (1R25GM106995-01) grants.
Faculty Advisor: Shreekumar Pillai, firstname.lastname@example.org
Role: I did all of the work dealing with the peptide TP226. That includes the MIC, SEM imaging, growth curves, and qRT-PCR work.