Withdrawal of lots of iceberg salad: risk of listeriosis
Alarm issued concerning several lots of iceberg salad, with presence of Listeria monocytogenes
The Ministry of Health recently issued an alert concerning several lots of iceberg salad, urging consumers to return their purchased products. The cause of this measure is the presence of Listeria monocytogenes, a pathogenic bacterium known to contaminate food and cause serious infections in humans.
Listeria monocytogenes: a microbiological profile
Listeria monocytogenes is a gram-positive, psychrotrophic and optional anaerobic bacterium. These characteristics give it a remarkable capacity to adapt to different environments, including refrigerated ones, where many other microorganisms do not survive. Its ability to form biofilms and resist adverse conditions, such as low pH and high salt concentrations, promotes its persistence in food industries.
The pathogenicity of Listeria monocytogenes is linked to its ability to invade and multiply in host cells. Once ingested with contaminated food, the bacterium passes through the epithelial barrier of the intestine and can spread to other organs such as liver, spleen and central nervous system.
Listeriosis: an insidious disease
Listeriosis, the infection caused by Listeria monocytogenes, can manifest with nonspecific gastrointestinal symptoms such as diarrhea, nausea and fever. However, in immunocompromised individuals, infants and pregnant women, the infection may develop into more severe forms, characterized by meningitis, encephalitis or septicaemia.
Women at particular risk during pregnancy
Pregnant women are particularly at risk, as the infection can cause miscarriage, premature birth or severe neonatal infection. In infants, listeriosis can manifest as a systemic disease, with symptoms ranging from subacute to fulminant.
Why the iceberg salad?
Lettuce, especially the iceberg-wide leaf lettuce, is an ideal vehicle for the proliferation of Listeria monocytogenes. The presence of micro-lesions on the surface of the leaves may encourage bacterial colonization, while low storage temperatures, if not appropriate, may slow down but not stop the growth of the pathogen.
Preventive measures
To reduce the risk of getting listeriosis, it is essential to take some simple precautions:
- Proper food handling: Wash fruits and vegetables, especially leafy vegetables, thoroughly before consumption
- Proper cooking: Ensure that food, especially meat and poultry, is cooked at sufficient temperatures
- Proper storage: Keep food refrigerated at appropriate temperatures and avoid cross-contamination between raw and cooked foods
- Attention to people at risk: Elderly people, infants, pregnant women and immunocompromised individuals should pay particular attention to food safety
The recall of lots of iceberg salad underlines the importance of adequate food surveillance and proper application of health and hygiene standards throughout the production chain. Collaboration between producers, distributors and consumers is essential to ensure food safety and prevent food-borne diseases.
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