A review of the microbiological hazards of dairy products made from raw milk

Abstract

a b s t r a c tThis review concentrates on information concerning microbiological hazards possibly present in raw milk dairy products, in particular cheese, butter, cream and buttermilk. The main microbiological hazards of raw milk cheeses (especially soft and fresh cheeses) are linked to Listeria monocytogenes, verocytotoxin-producing Escherichia coli (VTEC), Staphylococcus aureus, Salmonella and Campylobacter. L. monocytogenes, VTEC and S. aureus have been identified as microbiological hazards in raw milk butter and cream albeit to a lesser extent because of a reduced growth potential compared with cheese. In endemic areas, raw milk dairy products may also be contaminated with Brucella spp., Mycobacterium bovis and the tick-borne encephalitis virus (TBEV). Potential risks due to Coxiella burnetii and Mycobacterium avium subsp. paratuberculosis (MAP) are discussed. Pasteurisation ensures inactivation of vegetative pathogenic microorganisms, which increases the safety of products made thereof compared with dairy products made from raw milk. Several control measures from farm to fork are discussed.

Uncovering Consumer Mindsets Regarding Raw Beverages

“…It is important to note that even dairy products made from raw milk can cause severe health effects due to the unwanted microorganisms [6]. In addition to Listeria, a wide variety of other organisms occasionally found in raw milk make people sick.…”

Foodborne bacteria in dairy products: Detection by molecular techniques

“…In their study, Bianchi et al (2013) concluded that unpasteurized milk can be a vehicle for a variety of microorganisms (Listeria spp., Salmonella, and Campylobacter) and that outbreaks related to cheeses made with unpasteurized milk are also common (Gould et al, 2014). The development of a disease after consumption of contaminated dairy products made from raw milk depends on several factors, such as the pathogenicity of the bacteria strain, the number of ingested microorganisms, the physiological state of the microorganism, and the health condition of the consumer at the moment of ingestion (Verraes et al, 2015).…”

“…Staphylococcus aureus, Salmonella spp., Listeria monocytogenes and Escherichia coli O157:H7 are the most frequent potential pathogens associated with milk or dairy products in industrialized countries (Jakobsen et al, 2011) and are therefore the main microbiological hazards linked to raw milk (Kousta et al, 2010;Yang et al, 2012;Claeys et al, 2013) and raw cheese (Verraes et al, 2015). Raw milk provides a potential growth medium for the development of bacteria that can be controlled or destroyed through the pasteurization process (Arqués et al, 2015).…”

“…This bacterium is commonly found in a wide variety of mammals and birds and can be transferred to food mainly by dairy animals that have mastitis and by human carriers during food processing (Hennekinne et al, 2012). Contamination of Staphylococcus aureus can have a broad occurrence in raw dairy products, with frequencies between 5 and 100% in cheeses (Verraes et al, 2015). The number of Staphylococcus aureus in raw milk or other dairy products needs to be less than 10 4 CFU g -1 , according to the US FDA regulations (Yu et al, 2016).…”

“…Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Escherichia coli O157:H7 and Campylobacter are the most frequent potential pathogens associated with milk or dairy products in industrialized countries (Jakobsen et al, 2011) and are the main microbiological hazards linked to raw milk (Kousta et al, 2010;Yang et al, 2012;Claeys et al, 2013) and raw cheese (Verraes et al, 2015). In addition, as with any food matrix, dairy foods present their own inherent source of inhibitors, such as fat or lipid content, calcium concentration, and the presence of indigenous enzymes, e.g., potential inhibitors, that may have a detrimental influence on the overall integrity of an accurate and sensitive assay (Ozer and Akdemir-Evrendilek, 2014).…”