Listeria monocytogenes in aquatic food products: Spotlight on epidemiological information, bio-based mitigation strategies and predictive approaches.

ABSTRACT

Listeria monocytogenes is the foodborne pathogen responsible for listeriosis in humans. Its ability to grow at refrigeration temperatures, particularly in products that support its growth and have a long-refrigerated shelf-life, poses a significant health risk, especially for vulnerable consumer groups such as pregnant woman and immunocompromised individuals. A comprehensive analysis of L. monocytogenes in aquatic food products (AFPs) was conducted, examining the prevalence of the bacterium, the associated outbreaks, and the resulting deaths. Data from 66 studies, comprising a total of 19,373 samples, were analysed from the scientific literature to determine prevalence of the pathogen. The mean pooled prevalence of L. monocytogenes was 11% (95% CI 8-14%) among different AFPs categories. Additionally, an overview of worldwide listeriosis outbreaks associated with contaminated AFPs between 1980 and 2023 was provided, totalling 1,824 cases, including 41 deaths. Furthermore, a compilation of bio-based mitigation strategies was presented, including the use of lactic acid bacteria (LAB) and bacteriophages as bio-protective cultures to inhibit L. monocytogenes in AFPs. A variety of predictive microbiology models, based on growth prediction and interaction for Listeria, were reviewed to assess the effectiveness of control strategies in different types of AFPs, offering insights into pathogen behaviour throughout the production chain. The reported growth models described the impact of product storage temperature on pathogen growth parameters, while interaction models, based on the inhibitory effect of LAB presence against Listeria, were described using the Jameson-effect approach and Lotka-Volterra model (i.e., predator-prey model). Both models can be used to describe the simultaneous growth of two bacterial populations and their interactions. Several Quantitative Risk assessment studies have been conducted for AFP, identifying the food category as a relevant contributor in Listeriosis risk, and providing predictive insight into how storage temperature, food microbiota, product shelf-life and population aging influence the risk by L. monocytogenes. More importantly, this quantitative approach can serve as a key tool to assess the effectiveness of specific mitigation and intervention strategies to control the pathogen, such as sampling schemes or bio-preservation techniques.