Viable But Not Culturable Bacteria Induced by Manuka Honey Compared to Conventional Antibiotics
Faculty Mentor
Andrea R Castillo
Presentation Type
Poster
Start Date
May 2025
End Date
May 2025
Location
PUB NCR
Primary Discipline of Presentation
Biology
Abstract
Development of novel antimicrobials is critical to treat the large number of recurring infections due to antibiotic resistant bacteria. Bacteria can develop antibiotic resistance by entry into the metabolically inactive Viable But Not Culturable state (VBNC), where the bacteria are alive but not culturable on standard growth media. This state is triggered by environmental stressors including antibiotic exposure. Since most antibiotics target metabolic processes, metabolically inactive bacteria will be resistant to their effects. A promising antimicrobial, Manuka Honey (MH), is being investigated due to its broad-spectrum antimicrobial activity and recalcitrance to resistance. We hypothesize that the lack of resistance to MH may occur from the induction of fewer VBNCs. To test this hypothesis, we will compare VBNCs induced by treatment of the wound causing bacterium Escherichia coli with the minimum inhibitory concentration (MIC) of MH and the conventional antibiotic, ampicillin. We will first determine the MIC, the lowest concentration required to inhibit bacterial growth, for MH and ampicillin against E. coli. VBNCs will be calculated in these treated E. coli cultures as the number of viable cells, determined using live/dead staining and microscopy, minus the number of culturable cells, determined using a viable plate count. By comparing the induction of VBNCs by MH and ampicillin, this study may suggest a mechanism for the low antibiotic resistance to MH and support its widespread use as a topical antimicrobial over conventional antibiotics.
Recommended Citation
Nunez, Isaac; Castillo, Andrea; and Nutting, Haven, "Viable But Not Culturable Bacteria Induced by Manuka Honey Compared to Conventional Antibiotics" (2025). 2025 Symposium. 23.
https://dc.ewu.edu/srcw_2025/ps_2025/p1_2025/23
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Viable But Not Culturable Bacteria Induced by Manuka Honey Compared to Conventional Antibiotics
PUB NCR
Development of novel antimicrobials is critical to treat the large number of recurring infections due to antibiotic resistant bacteria. Bacteria can develop antibiotic resistance by entry into the metabolically inactive Viable But Not Culturable state (VBNC), where the bacteria are alive but not culturable on standard growth media. This state is triggered by environmental stressors including antibiotic exposure. Since most antibiotics target metabolic processes, metabolically inactive bacteria will be resistant to their effects. A promising antimicrobial, Manuka Honey (MH), is being investigated due to its broad-spectrum antimicrobial activity and recalcitrance to resistance. We hypothesize that the lack of resistance to MH may occur from the induction of fewer VBNCs. To test this hypothesis, we will compare VBNCs induced by treatment of the wound causing bacterium Escherichia coli with the minimum inhibitory concentration (MIC) of MH and the conventional antibiotic, ampicillin. We will first determine the MIC, the lowest concentration required to inhibit bacterial growth, for MH and ampicillin against E. coli. VBNCs will be calculated in these treated E. coli cultures as the number of viable cells, determined using live/dead staining and microscopy, minus the number of culturable cells, determined using a viable plate count. By comparing the induction of VBNCs by MH and ampicillin, this study may suggest a mechanism for the low antibiotic resistance to MH and support its widespread use as a topical antimicrobial over conventional antibiotics.
