New Independent Study Supports Photodisinfection

Ondine Biomedical Provides Biological Context for Nasal Decolonization Strategies Following Landmark Nasal Microbiome Study

Ondine Biomedical Inc. (AIM: OBI), a leader in light-activated antimicrobial therapies, highlights new biological evidence supporting its photodisinfection technology in a newly published study in Nature Communications (Aggarwal et al., 2025). The research titled “Large-scale characterisation of the nasal microbiome redefines Staphylococcus aureus colonisation status”   maps the nasal microbiome in detail and helps explain why conventional screening and traditional antibiotic based nasal decolonisation treatments have important clinical limitations.

The multicenter CARRIAGE study analyzed the nasal microbiomes of approximately 1,180 healthy adults and identified seven distinct Community State Types (CSTs). A primary finding of the study is that Staphylococcus aureus (S. aureus) colonization—a leading cause of hospital-acquired infections (HAIs)—is characterized by a low-diversity microbial state (CST-1) that actively inhibits “Good Neighbor” commensal bacteria.

The research redefined the biological understanding of “intermittent” carriers. Previously considered a distinct group, these individuals were shown to be persistent carriers with fluctuating bacterial loads. This finding suggests that traditional single-point-in-time culture swabs may be an unreliable metric for risk stratification, as they often fail to detect pathogens in patients with transiently low microbial levels at the time of screening.

Emeritus Professor of Microbiology at University College London, Michael Wilson, stated:

“The CARRIAGE study provides biological context for the limitations of selective screening. By demonstrating that S. aureus colonization is a stable community state that can fluctuate in density, the research highlights the potential value of proactive, broad spectrum universal decolonization strategies. Photodisinfection was developed to address these biological challenges by providing a rapid, non-antibiotic method to eliminate a broad spectrum of pathogens across the adult patient population.”

While many hospitals utilize the topical antibiotic mupirocin for decolonization, the CARRIAGE study identifies specific beneficial bacteria, such as Corynebacterium species and Dolosigranulum pigrum, that naturally inhibit S. aureus. Conventional antibiotics can result in prolonged dysbiosis (microbial imbalance) affecting these beneficial microbes. In contrast, photodisinfection utilizes a brief oxidative burst to eliminate pathogens. This physical mode of action does not exert the selection pressure associated with chemical antibiotics and may facilitate a “microbiome reset,” allowing protective species to repopulate the nasal passage more effectively.

Healthcare workers frequently act as transient vectors for S. aureus. As a rapid and repeatable tool, photodisinfection may serve as an adjunct to traditional personal protective equipment (PPE), potentially reducing transmission without the resistance risks associated with topical pharmaceuticals.

Carolyn Cross, CEO of Ondine Biomedical:

“The CARRIAGE study provides further evidence that we need to move beyond selective screening toward universal, effective nasal decolonization. Steriwave was designed precisely for this purpose: to safely and rapidly eliminate pathogens in the nasal passages—a major source of infection—without contributing to antibiotic resistance.”

Separate clinical evaluations and health economic modeling presented at the 2025 International Conference on Prevention & Infection Control (ICPIC) have reported up to a 70% reduction in surgical site infections (SSIs) in facilities utilizing universal photodisinfection protocols. These evaluations suggest that the approach can lead to significant cost savings per procedure by reducing hospital readmissions and length of stay.

Photodisinfection technology is currently deployed in hospitals across Canada and within the UK’s National Health Service (NHS). In the United States, the technology is advancing through a Phase 3 clinical trial as part of the FDA regulatory process. Ondine Biomedical remains focused on expanding the application of photodisinfection into intensive care units, dialysis centers, oncology, and long-term care facilities to support global antimicrobial stewardship goals.