Related Experiment Videos
Synergism within polyhexamethylene biguanide biocide formulations
P Gilbert1, D Pemberton, D E Wilkinson
1Department of Pharmacy, University of Manchester, UK.
The Journal of Applied Bacteriology
|October 1, 1990
Summary
Polyhexamethylene biguanides (PHMB) show increased antimicrobial activity with longer polymer chains. Combining different molecular weights of PHMB creates a synergistic effect, enhancing their effectiveness against bacteria.
Area of Science:
- Polymer Chemistry
- Microbiology
- Antimicrobial Agents
Background:
- Polyhexamethylene biguanides (PHMB) are polymeric biguanides with varying molecular weights.
- Antimicrobial activity of PHMB is known to correlate with polymer length.
- Cell preparation methods can influence observed antimicrobial efficacy.
Purpose of the Study:
- To investigate the relationship between PHMB molecular weight and antimicrobial activity.
- To determine the impact of cell preparation (centrifugation/washing) on PHMB efficacy.
- To explore synergistic effects of combining different PHMB molecular weight fractions.
Main Methods:
- Testing discrete molecular weight fractions of PHMB against microbial cells.
- Comparing PHMB activity with untreated and washed cell suspensions.
- Evaluating combinations of low and high molecular weight PHMB fractions.
Main Results:
- Antimicrobial activity generally increased with PHMB polymer length, with diminishing returns above n=6.
- Centrifugation and washing significantly enhanced the activity of high molecular weight PHMB by removing lipopolysaccharide (LPS).
- A strong synergistic antimicrobial effect was observed when combining low and high molecular weight PHMB fractions against washed cells.
Conclusions:
- PHMB's antimicrobial efficacy is dependent on polymer length and cell surface properties.
- Removal of bacterial LPS enhances the activity of higher molecular weight PHMB.
- Combinatorial use of varied molecular weight PHMB fractions offers a potent synergistic antimicrobial strategy.