• Photodisinfection achieved complete elimination (>99.999% kill) against Salmonella enterica and 99.999% reduction of MRSA biofilm – exceeding food safety requirements
• Successful program made possible by Government of Canada and Canadian Agricultural Partnership's AgriScience Program.

Ondine Biomedical (OBI:LON), a Canadian life sciences company, reported that photodisinfection being developed for food processing demonstrated high efficacy against key food-borne pathogens. Results of the proof-of-concept study, presented on 12 April, 2023,[1] confirmed 4-5 log (up to 99.999%) elimination of pathogens commonly found on hard surfaces in meat processing facilities, as well as those directly located on fresh-cut chicken, beef, and pork meat – paving the way for Canadian leadership in food safety innovations. On the basis of these findings, Ondine intends to apply for additional non-dilutive funding to continue the development of food-safe photodisinfection technology.

Bacterial contamination in the meat industry significantly impacts consumers, workers, animals, community well-being, and industry profitability. Consuming meat contaminated with harmful bacteria can cause illness and death, with over 400,000 people globally dying each year from eating contaminated food.[2] This damages public health and leads to loss of consumer confidence in meat products which can significantly impact profitability across the meat industry.

Conducted in collaboration with Chinook Contract Research, the Ondine Biomedical program identified four food-safe photosensitizers – compounds which eliminate pathogens when exposed to a specific wavelength of light. The photosensitizers were screened against the bacterial organisms Salmonella enterica (Salmonella) and MRSA (Methicillin-resistant Staphylococcus aureus), grown and tested as biofilms. Biofilms are known to tolerate up to 1000 times higher concentrations of antibiotics and disinfectants than planktonic (free-floating) cells, which are typically used in food safety studies.[3] Results showed that the photodisinfection process was able to achieve complete elimination of all Salmonella enterica biofilms (>99.999%), and a 99.999% (5-log) reduction of MRSA biofilms in several different food safety models.[4]

This research was funded in part by the Government of Canada under the Canadian Agricultural Partnership's AgriScience Program, a federal, provincial, territorial initiative.[5] The AgriScience Program aims to accelerate the pace of innovation by providing funding and support for pre-commercial science activities and cutting-edge research that benefits consumers and the agriculture and agri-food sector.

Dr. Joe Ross, Senior Scientist at Chinook Contract Research, said:

"For our optimized photosensitized light combinations against MRSA we were seeing upwards of 5-log10 reduction, 99.999% order reduction, as well as maximum kill of Salmonella enterica, meaning that we could not detect any of the biofilm after photodisinfection. These results show that photodisinfection is already in the same ballpark for efficacy as chemical disinfectants like bleach or hydrogen peroxide, and it is meeting the minimum reduction thresholds for both food and non-food contact surfaces."

There is a significant need in the food-processing industry for new technologies to reduce the incidence of food-borne pathogens – bacteria, fungi, viruses, and protozoa. Eradicating these invasive microbes will help protect the consumers, workers and animals within the $9.4 billion (2021) Canadian meat export industry, as well as reduce the incidence of food-borne illnesses. Photodisinfection is particularly suitable for the food processing industry because it is non-antibiotic and broad-spectrum, meaning that it could be widely adopted without risking increased antimicrobial resistance.

S. enterica, a subspecies of Salmonella, is a leading cause of human infections from the consumption of contaminated food. Globally, it is estimated to cause 93.8 million human infections and 155,000 deaths annually, and accounts for 38% of foodborne illnesses, 35% of hospitalizations and 28% of deaths due to foodborne illnesses worldwide.[6] A Centers for Disease Control and Prevention (CDC) study published in 2021 showed an estimated 40% increase in antibiotic-resistant Salmonella infections across the US from 2004 to 2016.[7]

Dr. Richard Rusk (DVM, MD, CCFP, MPH, DipZBPV, FRSPH), Prevention Medicine Specialist and former Manitoba Medical Officer of Health, said:

"I believe that photodisinfection is an innovative and very important technology when it comes to food safety. We have around 10% wastage of meat in Canada each year due to contamination, so we need to continue to improve food safety and reduce meat contamination. This new approach to eradicating pathogens is also increasingly vital in light of growing concerns over antibiotic use, antimicrobial stewardship and resistance. By 2050, antimicrobial resistance will have more of an impact on human life expectancy than cancer, so improving the interaction between food safety, workers' health, and animals in the food chain is key."

Dr. Nicolas Loebel, Ondine Biomedical's President and Chief Technology Officer, said:

"We intend to revolutionise infection control without using antibiotics, and deploy this critical technology worldwide. Photodisinfection has the potential to be used to sanitize food and surfaces in manufacturing facilities, grocery stores, and homes, as well as extending shelf life and reducing waste without the need for harsh chemicals or antibiotics.

Improving food safety in meat processing plants represents a significant new commercial opportunity for Ondine. The outcomes from this study suggest that photodisinfection has a role to play in helping reduce food spoilage and improve food, animal, and worker safety in meat processing plants. We would like to thank the Government of Canada and its AgriScience Program for their support of this important work."