How resilient are different strains of listeria monocytogenes in cooking salt at 20 ºc over time?

Introduction: Listeria monocytogenes is a gram-positive pathogenic bacterium responsible for listeriosis in humans and other animals. Human listeriosis is primarily caused by the consumption of foods contaminated with L. monocytogenes. Although rare, this severe foodborne infection leads to high rates of hospitalization and mortality, particularly among vulnerable groups such as the elderly, immunocompromised individuals, and pregnant women. L. monocytogenes is known for its widespread distribution in hostile environments and its remarkable resilience in high-salinity conditions, surviving and even growing in up to 10% NaCl. This resilience facilitates its persistence in food processing environments and allows it to multiply in various food products. Purpose: The aim of this study was to evaluate the survival dynamics of different Listeria monocytogenes strains in cooking salt at 20 ºC over time. By comprehensively analyzing the resilience of these bacterial strains, we aim to generate valuable insights into microbial persistence. This knowledge is crucial for developing enhanced food safety strategies, particularly in understanding and mitigating the survival of pathogens in high-salinity environments. Conclusion: Under controlled conditions, L. monocytogenes strains have demonstrated the ability to survive under osmotic stress. Compared to the persistent and non-persistent strains of food origin, the clinical strains showed higher viability rate over time, highlighting the interest for a genetic study of these strains. Understanding these dynamics is essential for developing effective food safety strategies, given the ongoing challenge of L. monocytogenes contamination in the food industry. The variation observed between strains suggests the need for a more controlled and specific assessment in the food industry.