Listeriosis of plants

Plant listeriosis involves the interaction between plant tissues and the bacterium Listeria monocytogenes. Although historically categorized as a human and animal pathogen, modern agronomic research highlights its ability to persist within plants as an endophyte, utilizing the plant's resources to survive and replicate.

The causal agents are non-spore-forming rods of the Listeria genus. These bacteria are characterized by significant environmental resilience, allowing them to remain viable in agricultural soils, compost, and irrigation water for extended periods, even under fluctuating climate conditions.

Susceptible crops primarily include leafy greens, such as lettuce, spinach, and various herbs, as well as root vegetables. The entry points for the pathogen include natural stomatal openings, as well as mechanical injuries caused by insects, equipment during harvesting, or cultivation practices that damage the root system.

Symptoms of infection are often subtle or asymptomatic, making field diagnosis challenging. Infected plants may exhibit minor growth retardation or reduced vitality, but the primary concern is the internal colonization of tissues, which does not always produce visible lesions or decay, complicating traditional diagnostic efforts.

Management and prevention focus on minimizing environmental contamination. Key practices include using fully decomposed organic amendments, ensuring water quality for irrigation, and sanitizing harvesting machinery. Implementing strict hygienic standards in the field remains the most effective strategy for managing the presence of Listeria in agricultural production systems.