Risk evaluation for staphylococcal food poisoning in processed milk produced with skim milk powder

The formation ofStaphylococcus aureusenterotoxin in food environments and advances in risk assessment

“…A summary of different models is provided by van Gerwen and Zwietering. relation between toxin production and cell numbers under the conditions they evaluated based on an equation developed from milk data by Soejima et al 130 : (2) where Tox is the toxin production (log ng ml -1 ) and C is the number of cells (log cfu ml -1 ). Exposure assessments have described initial contamination of the starting ingredients and their changes, mostly growth but also inactivation, due to cooking and during production, holding and storage.…”

“…Sensitivity and scenario analyses in these studies have identified the initial contamination levels together with temperatures and storage/holding times 127,130,131,133 and pH 131 as having the greatest impact on the assessment endpoints. In one study, the assumption concerning the threshold level for the number of S. aureus cells required for hazardous levels of enterotoxin to be produced contributed most to the uncertainty in the risk estimate.…”

“…Risk assessments of S. aureus encompass a range of approaches from illustrative examples 125 and partial risk assessments, 126 to quantitative microbial risk assessments (QMRA) based on probabilistic modeling. 127 Food products assessed include milk, 128,129 skim milk, 130 unripened raw-milk cheese, 131 pork-based Korean food, 127 kimbab, 132,133 home-cooked foods 126 and cream-filled baked goods. 10 The results of risk assessments are equally varied.…”

Nucleic Acid-Based Methods to Identify, Detect and Type Pathogenic Bacteria Occurring in Milk and Dairy Products

“…S. aureus harbouring the enterotoxin gene cluster). In addition, given the well recognised role of S. aureus as one of the commonest aetiological agent of clinical and sub-clinical mastitis [114][115][116] and considering that milk and milk-based products contaminated with this pathogen are some of the food matrices more often involved in staphylococcal food poisoning [117][118][119][120][121][122], they evaluated the effectiveness of these novel assays in artificially and naturally contaminated raw milk [101]. To achieve these goals, standard curves were constructed using ten-fold dilutions of target pre-purified DNA, or DNA extracted from ten-fold dilutions of a egc + S. aureus strain in broth and in raw milk [101].…”

Staphylococcal Enterotoxins, Stayphylococcal Enterotoxin B and Bioterrorism

“…With the proper medium, most toxin production occurs in late log or stationary phase (Otero et al, 1990;Rahkovic et al, 2006;Soejima et al, 2007). S. aureus produces regulatory proteins and small RNAs that control toxin production, probably so that in harsh conditions, the bacterium can conserve energy (Horsburg, 2008;Fournier, 2008).…”