Salmonella contamination in raw foods

Sometimes Salmonella bacteria are found in raw foods. If these foods are not processed or cooked well, the bacteria stay alive in the food and can infect someone who eats it.

Factors which help an outbreak of food borne Salmonella gastro-intestinal infection are contamination of food with the Salmonella pathogen, the Salmonella pathogen should be in adequate numbers with highest viability.

Salmonellae is not known to release toxins into the contaminated food in which they are multiplying, but the ingested bacteria is responsible for the disease by multiplying in the intestine of the host and invading the gastro-intestinal tract.

Human carriers are generally less important than animals in transmission of Salmonella strains. Salmonella present on raw meat and poultry could survive if the product is not cooked to a safe minimum internal temperature, as measured with a food thermometer.

Meat, poultry, egg, dairy products, and fruits and vegetables are primary transmission vehicles; they may be undercooked, allowing the Salmonella strains to survive, or they may cross-contaminate other foods consumed without further cooking.

During the past few years, outbreaks of Salmonella illness have been linked to contaminated cucumbers, pre-cut melon, chicken, eggs, pistachios, raw tuna, sprouts, and many other foods.

The association between poultry and Salmonella genus has long since been recognized. During processing, certain stages including scalding, plucking (defeathering), evisceration, and chilling of carcasses have been recognized as likely cross-contamination pathways.

Salmonella spp. is able to survive for weeks in water and for years in soil if environmental conditions such as temperature, humidity, and pH are favorable. Low water activity (aw) represents a barrier to growth for many vegetative pathogens, including Salmonella spp. Processed foods such as powdered milk, chocolate, peanut butter, infant food, and bakery products are characteristically low-aw food products.
Salmonella contamination in raw foods