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Assessing the effect of micafungin on Pseudomonas aeruginosa biofilm formation using confocal microscopy and gene
Sari S Rasheed1, Kohar Annie Kissoyan2, Usamah Hadi3
1Department of Experimental Pathology Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon. sari.s.rasheed@gmail.com.
Introduction:
1,3-β-D-glucan of the fungal cell wall and extracellular matrix (ECM) of Candida biofilm is also present as a periplasmic glucan and within the ECM of P. aeruginosa biofilm. Micafungin inhibits the synthesis of β-D-glucans. This project evaluates the effect of micafungin on P. aeruginosa biofilm formation, by determining transcription levels of biofilm formation encoding genes and measuring the thickness of biofilms in treated and untreated samples from BALB/c mice.
Methodology:
Relative gene transcription levels of P. aeruginosa biofilm-encoding pelC, algC, and ndvB genes were assessed by RT-qPCR on treated and untreated samples. Thickness calculation by Z-stacking of treated and untreated biofilms obtained from in vitro and in vivo samples was determined by confocal scanning laser microscopy (CSLM).
Results:
Samples from micafungin-treated mice showed decreased pelC, ndvB, and algC transcription levels with values of 260, 74, and 2-fold decreases, respectively. Reduction in biofilms thickness was confirmed with Z-stacking using CSLM that revealed a 16.8% drop in the thickness of biofilms after treatment with micafungin in vitro, and a 64% reduction in thickness post treatment with micafungin in vivo.
Conclusion:
Micafungin inhibits biofilm formation as measured by decrease in transcription levels of biofilm encoding genes and confocal microscopy. This reflects the events occurring in the course of an acute infection with P. aeruginosa, whereby the administration of micafungin would inhibit subsequent slime production, thus eliminating such barrier that could prevent antibacterial delivery to the core planktonic cells in biofilms.
Insights
Micafungin effectively inhibits Pseudomonas aeruginosa biofilm formation by reducing key gene transcription and biofilm thickness. This antifungal agent shows promise in treating infections by preventing slime production and improving antibiotic delivery.
Area of Science:
- Microbiology
- Antifungal Research
- Biofilm Dynamics
Background:
- 1,3-β-D-glucan is a component of fungal cell walls and the extracellular matrix (ECM) of *Candida* and *Pseudomonas aeruginosa* biofilms.
- Micafungin is an antifungal agent known to inhibit β-D-glucan synthesis.
Purpose of the Study:
- To evaluate the impact of micafungin on *P. aeruginosa* biofilm formation.
- To assess the effect of micafungin on the transcription of biofilm formation genes.
- To measure the thickness of *P. aeruginosa* biofilms after micafungin treatment.
Main Methods:
- Gene transcription levels of *pelC*, *algC*, and *ndvB* were quantified using RT-qPCR.
- Biofilm thickness was determined via Z-stacking with confocal scanning laser microscopy (CSLM).
- Experiments were conducted on both in vitro and in vivo samples from BALB/c mice.
Main Results:
- Micafungin treatment led to significant decreases in *pelC* (260-fold), *ndvB* (74-fold), and *algC* (2-fold) transcription.
- In vitro biofilms showed a 16.8% reduction in thickness after micafungin treatment.
- In vivo biofilms exhibited a substantial 64% decrease in thickness following micafungin administration.
Conclusions:
- Micafungin effectively inhibits *P. aeruginosa* biofilm formation, evidenced by reduced gene transcription and biofilm thickness.
- This suggests micafungin can impede slime production during acute infections, potentially enhancing antibiotic penetration to biofilm-embedded bacteria.
