Researchers at Rensselaer Polytechnic Institute (RPI) in Troy, N.Y., have developed a new method to eliminate deadly pathogenic bacteria in food products and packaging, without the need for antibiotics or chemicals, RPI has announced. The method can kill various types of pathogenic bacteria, including Listeria, which is among the most common causes of foodborne illnesses, causing an average of 500 deaths in the United States each year.
The team of engineers managed to successfully attach cell lytic enzymes to silica nanoparticles, which are entirely safe to be used with food products, and created a coating that could selectively kill Listeria, when it gets in contact with the bacteria, without affecting other chemicals or bacteria present. The process takes only a few minutes and can effectively tackle Listeria even in high concentrations. In addition, the lytic enzymes could be attached to starch nanoparticles that are typically used for food packaging.
The method can be modified so that other types of bacteria are targeted and eliminated by altering the type of lytic enzymes used in the process, so that selective bacteria can be killed, including anthrax, commented co-author of the study Jonathan Dordick, vice president for research and the Howard P Isermann Professor at Rensselaer.
Researchers at the Rensselaer Center for Biotechnology and Interdisciplinary Studies and the Rensselaer Nanoscale Science and Engineering Center for the Directed Assembly of Nanostructures took part in developing the method. Ravi Kane, the PK Lashmet Professor of Chemical and Biological Engineering, who contributed to the research, added that the success of the study could be attributed to the fact that a new strategy for killing specific types of bacteria was identified. Stable enzyme-based coatings or sprays could be utilized at various stages of food manufacture and the food supply chain, including picking, packaging and preparation, so that bacteria are removed long before they have the chance to cause foodborne illnesses, he explained.
The researchers based their work on a previous study dating back to 2010, in which they managed to create a coating that could kill methicillin-resistant Staphylococcus aureus (MRSA), the bacteria responsible for antibiotic-resistant infections. This method was intended to be used for sanitizing surgical equipment and hospital walls.
Dordick and his colleagues found that lytic enzymes could be the answer to food safety. They stated that the silica nanoparticles used in the process were approved by the U.S. Food and Drug Administration. The team of researchers now plans to continue working on new methods to use lytic enzymes for selective elimination of bacteria from other products, RPI said.