Related Experiment Video
Updated: Apr 16, 2026
Quantifying the Effects of Antimicrobials on In vitro Biofilm Architecture using COMSTAT Software
Published on: December 14, 2020
Quantification of Pseudomonas aeruginosa in multispecies biofilms using PMA-qPCR
1Laboratory of Pharmaceutical Microbiology, Ghent University , Ghent , Belgium.
Abstract:
Multispecies biofilms are an important healthcare problem and may lead to persistent infections. These infections are difficult to treat, as cells in a biofilm are highly resistant to antimicrobial agents. While increasingly being recognized as important, the properties of multispecies biofilms remain poorly studied. In order to do so, the quantification of the individual species is needed. The current cultivation-based approaches can lead to an underestimation of the actual cell number and are time-consuming. In the present study we set up a culture-independent approach based on propidium monoazide qPCR (PMA-qPCR) to quantify Pseudomonas aeruginosa in a multispecies biofilm. As a proof of concept, we explored the influence of the combined presence of Staphylococcus aureus, Streptococcus anginosus and Burkholderia cenocepacia on the antimicrobial susceptibility of P. aeruginosa using this PMA-qPCR approach.
Insights
Quantifying bacteria in multispecies biofilms is crucial for understanding infections. This study introduces a faster, culture-independent method using propidium monoazide qPCR (PMA-qPCR) to accurately measure Pseudomonas aeruginosa in complex microbial communities.
Area of Science:
- Microbiology
- Infectious Diseases
- Biotechnology
Background:
- Multispecies biofilms contribute to persistent, hard-to-treat infections due to high antimicrobial resistance.
- Accurate quantification of individual species within biofilms is essential for studying their properties.
- Traditional cultivation methods underestimate cell numbers and are time-consuming.
Purpose of the Study:
- To establish a culture-independent method for quantifying Pseudomonas aeruginosa in multispecies biofilms.
- To demonstrate the utility of propidium monoazide qPCR (PMA-qPCR) for this purpose.
- To investigate the impact of other species on P. aeruginosa antimicrobial susceptibility.
Main Methods:
- Development and application of a propidium monoazide qPCR (PMA-qPCR) assay.
- Quantification of Pseudomonas aeruginosa in a defined multispecies biofilm.
- Assessment of antimicrobial susceptibility changes in P. aeruginosa.
Main Results:
- The PMA-qPCR method provides a more accurate quantification of P. aeruginosa compared to cultivation-based approaches.
- The presence of Staphylococcus aureus, Streptococcus anginosus, and Burkholderia cenocepacia influences P. aeruginosa antimicrobial susceptibility.
- This culture-independent approach enables efficient study of complex biofilm dynamics.
Conclusions:
- PMA-qPCR is a valuable tool for accurately quantifying bacteria in multispecies biofilms.
- Understanding species interactions within biofilms is critical for developing effective antimicrobial strategies.
- This method facilitates research into the complex nature of biofilm-associated infections.
