Reduction of Listeria monocytogenes in Meat Products Through a Combination of High Pressure and Bacteriophages

Although foodborne infections caused by the ubiquitous bacterium Listeria ( L.) monocytogenes are relatively rare, they are of great significance due to the severity of the disease and the high case-fatality rate. In 2020, 575 cases of infection were reported in Germany, resulting in 31 deaths (RKI, 2021). During an outbreak in 2018 involving 109 cases of listeriosis, a meat product was identified as the most likely cause (RKI, 2019).

With regard to contamination with L. monocytogenes , both heated meat products—such as boiled sausages or cooked ham— can be affected by secondary contamination, e.g., during slicing, as well as meat products intended for raw consumption, such as raw sausages, through primary and/or secondary contamination. In addition to the wide range of established measures for reducing L. monocytogenes during the production of meat products, new methods for microbial reduction—such as non-thermal high-pressure treatment and bioconservation with bacteriophages— offer a way to further reduce the risk of L. monocytogenes in meat products.