Tag Archives: staphylococcus aureus

Research – Inhibition of Clostridium and Detection of Enterotoxigenic Staph.

Wiley Online

Abstract:  Inhibition of Clostridium perfringens spore germination and outgrowth in reduced sodium roast beef by a blend of buffered lemon juice concentrate and vinegar (MoStatin LV1) during abusive exponential cooling was evaluated. Roast beef containing salt (NaCl; 1%, 1.5%, or 2%, w/w), blend of sodium pyro- and poly-phosphates (0.3%), and MoStatin LV1 (0%, 2%, or 2.5%) was inoculated with a 3-strain C. perfringens spore cocktail to achieve final spore population of 2.5 to 3.0 log CFU/g. The inoculated products were heat treated and cooled exponentially from 54.4 to 4.4 °C within 6.5, 9, 12, 15, 18, or 21 h. Cooling of roast beef (2.0% NaCl) within 6.5 and 9 h resulted in <1.0 log CFU/g increase in C. perfringens spore germination and outgrowth, whereas reducing the salt concentration to 1.5% and 1.0% resulted in >1.0 log CFU/g increase for cooling times longer than 9 h (1.1 and 2.2 log CFU/g, respectively). Incorporation of MoStatin LV1 into the roast beef formulation minimized the C. perfringens spore germination and outgrowth to <1.0 log CFU/g, regardless of the salt concentration and the cooling time.

Practical Application:  Cooked, ready-to-eat meat products should be cooled rapidly to reduce the risk of Clostridium perfringens spore germination and outgrowth. Meat processors are reducing the sodium chloride content of the processed meats as a consequence of the dietary recommendations. Sodium chloride reduces the risk of C. perfringens spore germination and outgrowth in meat products. Antimicrobials that contribute minimally to the sodium content of the product should be incorporated into processed meats to assure food safety. Buffered lemon juice and vinegar can be incorporated into meat product formulations to reduce the risk of C. perfringens spore germination and outgrowth during abusive cooling.

Wiley Online

Abstract:  The aim of this study was to investigate the prevalence of enterotoxigenic Staphylococcus aureus in 122 samples, including 60 raw milk, 32 white cheese, 10 kashar cheese, 10 butter, and 10 ice cream samples obtained from Samsun province, Turkey. In this study, S. aureus was detected in 64 samples, including raw milk (45/60; 75%), white cheese (12/32; 37.5%), kashar cheese (3/10; 30%), butter (3/10; 30%), and ice cream (1/10; 10%) samples. A total of 81 isolates were identified as S. aureus by PCR with the presence of 16S rRNA and nuc genes. The presence of genes encoding the staphylococcal enterotoxins (SEs) SEA, SEB, SEC, and SED was detected by multiplex PCR. According to the analysis, seven isolates from the raw milk samples (7/51; 13.7%) were enterotoxigenic; five of them produced SEA (5/7; 71.4%), one produced SEB (1/7; 14.2%), and one produced SEA+SEB (1/7; 14.2%). Four isolates from the white cheese samples (4/21; 19%) produced the SEA (1/4; 25%), SEC (1/4; 25%), SED (1/4; 25%), and SEA+SED (1/4; 25%) toxins. Two isolates from the kashar cheese samples (2/4; 50%) were found to be enterotoxigenic; one produced SEA (1/2; 50%) and the other produced SED (1/2; 50%). One isolate from the butter samples (1/4; 25%) showed enterotoxigenic character (SEB, 1/1; 100%). The products were found to be potentially hazardous to public health because of the fact that levels of contamination were higher than 105–106 cfu/g ml in 39% (25/64, 17 raw milk, 7 white cheese, and 1 butter) of the analyzed samples.

Staphylococcus aureus – Colombian Style Cheese Recall

Food Consumer Org

New York State Agriculture Commissioner Darrel J. Aubertine today warned consumers in the Metropolitan New York area not to consume “Quesito Colombiano, Colombian style Cheese” made by Productos Tita Corp., 70-06 88th  Street, Glendale, New York 11385 due to possible Staphylococcus aureus contamination.

The recalled Colombian style cheese under the Brand name “Tita” is contained in 8oz. clear plastic pouches or tubs with a plant code of #36-8440 and with a stamped code of “AUG 10 2012” stamped beneath the label bar code. The product was distributed in the Metropolitan New York area.

A routine sample of the cheese, taken by an inspector from the Division of Milk Control and Dairy Services on July 25, 2012, was subsequently tested by the Department’s Food Laboratory and discovered to be contaminated with high levels of Staphylococcus aureus.  On July 28, 2012, the manufacturer was notified of the positive test result and voluntarily recalled the product.

Mustard Seeds for Controlling Food Spoilage?

Science Codex 

University of Alberta researcher Christina Engels has discovered how to extract a compound from mustard seeds that can protect against food spoilage.

Engels recovered a particular compound—sinapic acid—from mustard seed meal, which shows antibacterial effects against such strains as Staphylococcus aureus, E. coli and Listeria monocytogenes, all of which can cause grave illness and death in humans. Canada is the world’s largest exporter of mustard seed.

Link to Paper

Canada Raw Milk Cheese Recalled

Food Poisoing Bulletin

The Canadian Food Inspection Service (CFIA) is recalling raw milk cheese from Fromagerie du Pied-de-Vent Inc. because it may be contaminated with Staphylococcus aureus. The cheese was sold in retail stores in Ontario and Quebec.