Emerging Researchers National (ERN) Conference

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Novel Peptides Possess Broad Spectrum Antibacterial Activity

Undergraduate #98
Discipline: Biological Sciences
Subcategory: Microbiology/Immunology/Virology

Brett Barlow - Alabama State University
Co-Author(s): Vincent Onyilo, Atul A. Chaudhari, Shree R. Singh, and Shreekumar Pillai


Resistance of bacteria to several existing antibiotics is a serious public health concern globally, and thus requires immediate attention. Over the past few years, peptides are being investigated as effective alternatives due to their strong antibacterial properties. In the present study, we investigated the antibacterial activity of five novel antimicrobial peptides from Therapeutics Inc. (designated as TP226, TP359, TP373, TP556, and TP557). The antibacterial activity was tested by 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. TP226 was further investigated against Escherichia coli and Staphylococcus aureus by growth curve analysis and scanning electron microscopy (SEM). Our results indicated that all the peptides showed excellent antibacterial properties against all four bacterial pathogens (MIC 7.8-3.9 µg/ml) and the growth of the bacteria was hampered in a dose dependent manner. SEM analysis of Escherichia coli and Staphylococcus aureus exposed to TP226 showed lysis of the bacterial cells. We are currently investigating the antimicrobial activity of TP226 on Salmonella Typhimurium and Streptococcus pyogenes using growth curve analysis, SEM, and qRTPCR. The long term goal of this project is to define molecular mechanism of action for TP226 against Gram-positive and Gram-negative bacteria.

Funder Acknowledgement(s): NSF HBCU-UP (HRD-1135863)

Faculty Advisor: Shreekumar Pillai,

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This material is based upon work supported by the National Science Foundation (NSF) under Grant No. DUE-1930047. Any opinions, findings, interpretations, conclusions or recommendations expressed in this material are those of its authors and do not represent the views of the AAAS Board of Directors, the Council of AAAS, AAAS’ membership or the National Science Foundation.