Research Insight No. (21)
Femtosecond Lasers Against MRSA Biofilms: From Inhibiting Formation to Disintegrating Mature Biofilms
In a recent research study conducted at Beni-Suef University, in collaboration with the Laser Research Centre at the Faculty of Health Sciences, University of Johannesburg (South Africa), researcher Esraa Ahmed Mohamed Hassan—an assistant lecturer in the Department of Biological Laser Applications at the Institute of Laser Research and Applications—investigated the potential use of femtosecond lasers to combat one of the most complex forms of bacterial resistance: the biofilm formed by *Methicillin-resistant Staphylococcus aureus* (MRSA). Biofilms pose a significant challenge because bacteria do not always exist as individual, free-floating cells; instead, they can form highly organized structures known as biofilms. Within these structures, bacterial cells adhere to one another and become embedded in an extracellular matrix that provides protection and stability, making them exceptionally difficult to eradicate. Consequently, the study sought to address a critical question:
Can a sub-lethal dose of a femtosecond laser prevent the formation of a biofilm, and can it also affect a biofilm that has already fully developed?
The study examined the impact of exposure to a 400 nm femtosecond laser on the ability of MRSA bacteria to form biofilms. The results demonstrated that femtosecond laser treatment can inhibit the ability of MRSA to form biofilms. Specifically, biofilm viability decreased by 75.3%, biomass by 44.5%, and metabolic activity by 60–85%. Furthermore, there was a notable reduction in biofilm coverage (59.4%), extracellular matrix content (46.0%), and bacterial cell density (38.1%), reflecting a significant impact on the biofilm’s structure and natural organization.
The study went beyond preventing biofilm formation; it also examined the laser's effect on pre-established, mature biofilms (grown for 24 hours). The results showed a 69% reduction in biofilm viability, along with a 27.7% decrease in biomass and a 55.7% decline in metabolic activity. Microscopic examinations further revealed distinct alterations in the biofilm's microstructure following laser treatment.
A key strength of this study is that it did not stop at demonstrating the anti-biofilm effect; it also sought to elucidate the underlying molecular mechanisms. By analyzing a set of genes associated with biofilm formation and virulence factors—and by investigating the "quorum sensing" network—the researchers uncovered a disruption in the regulatory network that enables MRSA to form and maintain biofilms. These findings support a proposed model suggesting that exposure to femtosecond lasers can disrupt the regulatory systems of bacteria, thereby affecting the formation of the biofilm matrix and weakening its overall structure.
This work represents a significant research milestone in applying laser science and biophotonics to address a global medical challenge. The results lay a foundation for the future development of a light-based therapeutic modality—an adjunctive treatment—that could be applied in clinical settings, pending further studies on safety, efficacy, and evaluation through biological models and clinical trials. Furthermore, these findings open avenues for additional research into the potential of phototherapy as a future supportive tool for combating biofilm-associated infections and antibiotic-resistant bacteria. Through this project, Beni-Suef University underscores the importance of fostering interdisciplinary research that leverages laser science and biophotonics to tackle medical challenges. It also encourages the translation of fundamental scientific knowledge and research outcomes into pathways for developing innovative solutions that benefit both the scientific community and society at large.
The study was conducted under the supervision of:
Professor Tarek Ali, Professor of Laser Physics and President of Beni-Suef University.
Professor Ahmed Osama El-Gendy, Professor of Microbiology and Immunology and Dean of the Medical Sciences Sector at Beni-Suef National University. Michael R. Hamblin, Professor Harvard Medical School, Laser Research Center, Faculty of Health Sciences, University of Johannesburg
The study was published under the title:
“400 nm Femtosecond Laser Irradiation Eradicates Mature MRSA Biofilms and Inhibits Their Formation via Quorum Sensing Dysregulation”
In Scientific Reports in 2026, one of Springer Nature's Nature Portfolio journals, classified as Category 1 (Q1) with an impact factor of 4.9 according to the Web of Science database.
Research link and DOI: https://doi.org/10.1038/s41598-026-64350-w
English Brief
400 nm femtosecond laser irradiation eradicates mature MRSA biofilms and inhibits their formation via quorum sensing dysregulation
A recent study from Beni-Suef University investigated the potential of 400 nm femtosecond laser irradiation as an anti-virulence approach against biofilms formed by methicillin-resistant Staphylococcus aureus (MRSA). The study examined both the prevention of biofilm formation and the effect of femtosecond laser irradiation on pre-formed 24-hour mature biofilms. The findings demonstrated a significant inhibition of biofilm formation with a 75.3% decrease in biofilm viability, reduction in biomass by 44.5%, metabolic activity by 60–85%, 59.4% reduction in biofilm area coverage, together with reductions in extracellular matrix fraction and bacterial cell density. In mature biofilms, laser treatment reduced biofilm viability by 69%, biomass by 27.7%, and metabolic activity by 55.7%, accompanied by clear microscopic structural changes. Importantly, the study also investigated the molecular mechanisms underlying these effects. Gene-expression analysis and examination of the quorum-sensing regulatory network revealer