• New research presented by Ondine shows that Steriwave photodisinfection reduces antibiotic-resistant bacteria by more than 99.9% without generating resistance.
• The research suggests that photodisinfection is a viable alternative to antibiotics.

Canadian life sciences company Ondine Biomedical Inc. (LON: OBI) is today presenting new research showing that Steriwave® photodisinfection reduced antibiotic-resistant bacteria by more than 99.9%. The in vitro study, which is being presented today at the IP2023 Annual conference taking place in Liverpool 17-19 October 2023, indicates that photodisinfection is likely to play an important role in strategies for combatting antimicrobial resistance (AMR).

The controlled study evaluated the efficacy of Ondine’s Steriwave® photodisinfection against Gram-negative and Gram-positive multidrug-resistant (MDR) and extensively drug-resistant (XDR) bacteria with novel antibiotic resistance factors. All of the bacterial strains used in the study exhibited resistance against some of the most commonly prescribed antibiotic classes, including penicillin, tetracyclines, quinolones and carbapenems.

The results of the study showed that treatment with photodisinfection resulted in >99.9% reduction of viable bacteria compared to the control, regardless of the antibiotic susceptibility of the bacteria. The authors concluded that photodisinfection is likely an important adjunct to AMR strategies in the future and that further clinical studies are warranted.

Antimicrobial resistance (AMR) remains a major public health concern, causing 33,000 deaths in Europe annually[i] which is projected to rise to over 10 million globally by 2050.[ii] There are widespread multidrug-resistant (MDR) and extensively drug-resistant (XDR) infections across the world which are mainly caused by Gram-negative bacteria including Enterobacteriaceae and P. aeruginosa AMR bacteria[iii]^,[iv] and Gram-positive bacteria such as Staphylococcus spp.[v] Steriwave has been found to be highly effective against all these pathogens.

Photodisinfection uses a photosensitizer and a specific wavelength of light to trigger photochemical reactions that produce reactive oxygen species. These reactive oxygen species are lethal to a broad spectrum of microbes, including bacteria, fungi, and viruses. Importantly, photodisinfection does not induce antimicrobial resistance formation.

Carolyn Cross, CEO of Ondine, commented:

“We continue to demonstrate, both clinically in hospitals across Canada and in the lab, that photodisinfection can provide a real alternative to topical antimicrobials which are no longer effective against an increasing number of pathogens. The evidence continues to show that photodisinfection destroys all types of pathogens including viruses, bacteria and fungi even those in biofilm, and we believe this technology can save millions of lives. The results of this study are particularly welcome as we prepare for our US Phase 3 trial in partnership with HCA Healthcare who are providing invaluable guidance and support.”

The poster presentation, “Antimicrobial Photodynamic Therapy Against Extensively Drug-Resistant (XDR) Gram Negative Isolates With Novel Antibiotic Resistance Factors”, is being presented at IP2023 between 1:10pm and 2:40pm (BST) on 18 October 2023. The full poster is available to download here.

[i] WHO Regional Office for Europe/European Centre for Disease Prevention and Control. Antimicrobial resistance surveillance in Europe 2022 – 2020 data. Copenhagen: WHO Regional Office for Europe; 2022.

[ii] “O’Neill Review into Antibiotic Resistance” https://researchbriefings.files.parliament.uk/documents/CDP-2017-0074/CDP-2017-0074.pdf

[iii] Cassini A, Högberg LD, Plachouras D, et al. Attributable deaths and disability-adjusted life-years caused by infections with antibiotic-resistant bacteria in the EU and the European Economic Area in 2015: a population-level modelling analysis. Lancet Infect Dis. 2019;19(1):56-66. doi:10.1016/S1473-3099(18)30605-4

[iv] Karakonstantis S, Kritsotakis EI, Gikas A. Pandrug-resistant Gram-negative bacteria: a systematic review of current epidemiology, prognosis and treatment options. J Antimicrob Chemother. 2020;75(2):271-282. doi:10.1093/jac/dkz401

[v]UK Health Security Agency. MRSA, MSSA, Gram-negative bacteraemia and CDI: 30-day all-cause fatality, London: UK Health Security Agency, March 2023.