Milk and dairy products provide many essential nutrients for consumers of all ages. They are high sources of easily digestible proteins, carbohydrates, vitamins A, D, E, C, and B group, minerals (i.e., calcium, potassium, zinc, phosphorus, and magnesium), and saturated fatty acids. In particular, the individual consumption of such foods can give health benefits by decreasing fractures rate, blood pressure, and cholesterol and contributing to reducing cardiovascular diseases, diabetes, body weight, and colon cancer risk. Further advantages are the prevention of tooth decay, arthritis, and good functioning of the digestive apparatus. Yogurt and other fermented dairy products may be vehicles of different probiotic bacteria. Dairy products are highly nutritious for humans and a wide range of microorganisms, providing the ideal environment for their growth. The production process, type, and treatment of milk, milking practices, storage conditions, air, water, soil, and feeding management can affect the quality, shelf-life, and safety characteristics of such foods. Therefore, undesirable microorganisms belonging to different genera, such as Pseudomonas, Acinetobacter, Enterobacter, Streptococcus, and Bacillus, are relatively common in raw milk, sometimes reaching amounts of 106-107 cfu/g in cheeses and contributing consequently to a worsening of their sensorial attributes or constituting a health risk in case of pathogenic species occurrence. Among pathogens, Staphylococcus aureus is frequently isolated from the raw milk used for cheese production the dairy managing equipment and environment, and food handlers. Such microorganism produces different potent enterotoxins remaining stable even after milk pasteurization. Their ingestion can result in a staphylococcal food poisoning outbreak, the most common foodborne disease in the European Union (EU) due to the consumption of raw milk and artisanal cheeses. The onset of illness is rapid, with symptoms such as nausea, vomiting, and stomach cramps, generally enduring less than 24 hours. According to the Commission Regulation (EC), No 2073/2005 and further amendments, the coagulase-positive staphylococci (CPS) must be checked in cheeses made from raw milk or pasteurized, ripened, or unripened cheeses. If their values exceed 105 cfu/g, the cheese batch should be tested for staphylococcal enterotoxins. In the year 2020, 16 outbreaks described in 8 EU Member States (Austria, Denmark, Finland, Germany, Italy, the Netherlands, and Slovakia) were linked to the consumption of contaminated milk, cheeses, and dairy products. S. aureus toxins were also involved in 3 outbreaks. This chapter will highlight the occurrence and the sources of CPS in dairy products and the factors that influence the formation of staphylococcal enterotoxins. At the primary production level and in the dairy environments, the food business operators, the lack of proper hygiene measures during cheese-making, an inadequate thermal treatment, and/or post-pasteurization contamination may lead to intoxication caused by the growth of S. aureus and the production of staphylococcal enterotoxins in milk and cheese. Moreover, some preventive measures to avoid their presence will be recommended.
Staphylococcus Aureus in the dairy production chain
Schirone M.
;Visciano P.
2023-01-01
Abstract
Milk and dairy products provide many essential nutrients for consumers of all ages. They are high sources of easily digestible proteins, carbohydrates, vitamins A, D, E, C, and B group, minerals (i.e., calcium, potassium, zinc, phosphorus, and magnesium), and saturated fatty acids. In particular, the individual consumption of such foods can give health benefits by decreasing fractures rate, blood pressure, and cholesterol and contributing to reducing cardiovascular diseases, diabetes, body weight, and colon cancer risk. Further advantages are the prevention of tooth decay, arthritis, and good functioning of the digestive apparatus. Yogurt and other fermented dairy products may be vehicles of different probiotic bacteria. Dairy products are highly nutritious for humans and a wide range of microorganisms, providing the ideal environment for their growth. The production process, type, and treatment of milk, milking practices, storage conditions, air, water, soil, and feeding management can affect the quality, shelf-life, and safety characteristics of such foods. Therefore, undesirable microorganisms belonging to different genera, such as Pseudomonas, Acinetobacter, Enterobacter, Streptococcus, and Bacillus, are relatively common in raw milk, sometimes reaching amounts of 106-107 cfu/g in cheeses and contributing consequently to a worsening of their sensorial attributes or constituting a health risk in case of pathogenic species occurrence. Among pathogens, Staphylococcus aureus is frequently isolated from the raw milk used for cheese production the dairy managing equipment and environment, and food handlers. Such microorganism produces different potent enterotoxins remaining stable even after milk pasteurization. Their ingestion can result in a staphylococcal food poisoning outbreak, the most common foodborne disease in the European Union (EU) due to the consumption of raw milk and artisanal cheeses. The onset of illness is rapid, with symptoms such as nausea, vomiting, and stomach cramps, generally enduring less than 24 hours. According to the Commission Regulation (EC), No 2073/2005 and further amendments, the coagulase-positive staphylococci (CPS) must be checked in cheeses made from raw milk or pasteurized, ripened, or unripened cheeses. If their values exceed 105 cfu/g, the cheese batch should be tested for staphylococcal enterotoxins. In the year 2020, 16 outbreaks described in 8 EU Member States (Austria, Denmark, Finland, Germany, Italy, the Netherlands, and Slovakia) were linked to the consumption of contaminated milk, cheeses, and dairy products. S. aureus toxins were also involved in 3 outbreaks. This chapter will highlight the occurrence and the sources of CPS in dairy products and the factors that influence the formation of staphylococcal enterotoxins. At the primary production level and in the dairy environments, the food business operators, the lack of proper hygiene measures during cheese-making, an inadequate thermal treatment, and/or post-pasteurization contamination may lead to intoxication caused by the growth of S. aureus and the production of staphylococcal enterotoxins in milk and cheese. Moreover, some preventive measures to avoid their presence will be recommended.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
