Food-Borne Pathogens and Contaminants in Raw Milk – A Review

Abstract

the aim of the present review is to highlight the threats to human health posed by consumption of milk and dairy products. the interest in drinking raw milk has been growing in some societies as many people believe it has health benefits. Raw milk is promoted as 'health food' despite the fact that it poses a realistic microbiological hazard for the consumers' health or life. Food-borne disease outbreaks associated with Campylobacter spp., Salmonella spp., shigatoxin-producing Escherichia coli, Brucella melitensis, Mycobacterium bovis and tick-borne encephalitis virus have been traced to the consumption of raw milk, however, many other microorganisms that can be present in milk are considered as potential food-borne pathogens to humans. the other common causative agents in food-borne disease outbreaks are bacterial toxins produced by Bacillus, Clostridium and Staphylococcus spp. some of the milk pathogens harbour antimicrobial resistant genes, which can be transferred to commensal bacteria. most dangerous are methicillin-resistant Staphylococcus aureus and extended spectrum beta lactamase/Ampc gene-carrying bacteria from the family of Enterobacteriaceae, which might negatively affect the treatment of infections in humans. Fungi are not considered as food-borne pathogens for humans, however their secondary metabolites, mycotoxins, constitute a potential threat to public health. mycotoxins or their metabolites detected so far in milk samples include aflatoxins, ochratoxin A, zearalenone and its metabolites, fumonisins, de-epoxy-deoxynivalenol and cyclopiazonic acid. key words: public health, milk, food-borne pathogens, enterotoxins, mycotoxins Milk and dairy products are important in the diet of humans, because they are a source of numerous essential nutrients such as proteins, fats, carbohydrates, vitamins and minerals (van Hooijdonk and Hettinga, 2015). A significant share in worldwide milk production is represented by milk from ruminants such as cattle (85.4%), buffalo (11.1%), goat (2.1%), sheep (1.4%) and camel (0.2%) (Gerosa and Skoet, 2012). Milk production by yak (ruminant), horse and donkey (equids) is estimated as less *This study was funded from statutory funds related to the project entitled "Research on the occurence and toxity of secondary metabolites of moulds and identification of organisms by molecular biology methods". Unauthenticated Download Date | 5/8/18 7:22 AM

Harmonized Collaborative Validation of Aflatoxins and Sterigmatocystin in White Rice and Sorghum by Liquid Chromatography Coupled to Tandem Mass Spectrometry

“…In summarizing information on analytical methods for STC in foodstuffs, Veršilovskis and de Saeger [19] concluded that LC/MS/MS should be used in efforts to develop sensitive methods and that sample preparation should be improved. This was realized in some new methods developed for the determination of STC in various grains and cheese by Veršilovskis et al (LOD 0.03–0.15 μg/kg) [20,35] and in the multi-mycotoxin method reported by Sulyok et al (LOD 0.4 μg/kg) [29].…”

“…STC exhibits various toxicological, mutagenic, and carcinogenic effects in animals, and it has been recognized as a 2B carcinogen (possible human carcinogen) by the International Agency for Research on Cancer [17]. Recent reviews described the occurrence of STC in a variety of foodstuffs [18,19,20]. The European Food Safety Authority (EFSA) Panel on Contaminants in the Food Chain (CONTAM Panel) analyzed a total of 1259 samples of cereal grains, cereal products, and nuts, collected between August 2013 and November 2014 in nine European countries (and originating from 45 countries), for the presence of STC.…”

Contaminants in Animal Products

“…There are less yeast and mold in raw milk than LAB [64]. In a study conducted in Slovenia, 95.0% of raw milk that was collected during winter and summer contains yeast and 63.3% contains molds.…”

“…In general, it is not expected that milk has microorganisms and toxins unless there is a systemic or local infection. But clinical and subclinical mastitis, which are associated with local or systemic infections are common problems for animals [64,65]. The milk flora of dairy animals consists of lactic acid bacteria (LAB; Lactococcus, Lactobacillus, Leuconostoc, Streptococcus, Enterococcus spp.)…”

“…The milk flora of dairy animals consists of lactic acid bacteria (LAB; Lactococcus, Lactobacillus, Leuconostoc, Streptococcus, Enterococcus spp.) [64]. Staphylococcus aureus, which produces toxins like Staphylococcal enterotoxins (SEs), SE-like toxins (SEI) and toxic shock syndrome toxin (TSST-1) and is primarily responsible for foodborne poisonings, mostly exists in milks of animals with mastitis [65].…”