Performance comparison of the BioSys optical assay and the violet red bile agar method for detecting coliforms in food products.

Coliform counts in a variety of foods, including dairy products (raw milk, pasteurized milk, yogurt, butter, and ice cream), meats (pork sausage, ground beef, and raw chicken), raw eggs, and chocolate, were performed by the rapid automated BioSys optical assay and the conventional method with violet red bile agar (VRBA). The standard deviation (SD) among five replicate counts for the optical assay was similar to or better than that obtained with VRBA plates for all foods tested. The average SD for all foods tested was 0.

EZ Coli Rapid Detection System: A Rapid Method for the Detection of Escherichia coli O157 in Meat and Other Foods.

The EZ Coli™ Rapid Detection System consists of a selective enrichment medium and a rapid immunological detection kit. After being incubated for 15 to 24 h at 40 to 42°C, an Escherichia coli O157 culture was at a sufficient cell concentration (> 10 CFU/ml) to be tested with the EZ Coli Detection Kit. In studies of foods seeded with E.

Evaluation of Stabilized Bismuth Sulfite Agar for Detection of Salmonella in Foods.

The combination of a new manufacturing process, packaging, and media engineering has all contributed to the development of extended shelf-life (stabilized)-plated media (DuraPak). One of the first products stabilized by this process was bismuth sulfite agar plates (BSA). Stabilized BSA were stored 3-4 months at 35°C and then were inoculated in parallel with lab-prepared BSA following overnight aging at room temperature.

Biosensors in the Food Industry: Present and Future.

Food microbiologists are not yet able to monitor food and beverage production on-line with a device as simple and straight-forward as a pH meter. Most microbiological evaluations are limited by traditional labor intensive and time-consuming plating techniques. Test results are usually obtained after the product has left the manufacturer.

Effects of Yeasts on Survival of Staphylococcus aureus in Pickled Cheese Brine.

The interactions between staphylococci and yeasts in pickled cheese brine were investigated. Above pH 5, Staphylococcus aureus grew in pickled cheese brine. Acid-consuming yeasts increased the pH of the brine to a level which enabled development of staphylococci.

Competitive Growth of Chicken Skin Microflora and Clostridium botulinum Type E after an Irradiation Dose of 0.3 Mrad.

Chicken skins with chicken exudate were used as a model system to determine if low dose irradiation might cause a health hazard by eliminating the natural flora and allowing Clostridium botulinum type E spores, if present, to produce toxin in the absence of typical spoilage. Irradiation (0.3 Mrad, 5°C) reduced the natural flora from 10 to 10 to 10 to 500 cells/7 cm, whereas C.

Attachment of Bacteria to Meat Surfaces: A Review.

The mechanism of attachment of bacteria to meat surfaces involves two consecutive stages. During the primary stage, bacterial attachment is probably due to physical forces, and the number of bacteria becoming attached is proportional to the number in the water film over the surface. The second stage is initially characterized by an increased strength of attachment due to polysaccharide formation, which is a time-dependent process.

Seasonal and Processing Influences on Bacterial Count of Raw and Processed Milk.

An increase in total counts of raw milk was detected during summer in comparison to winter. The higher summer temperature did not affect the numbers of coliforms and staphylococci. The microbial contamination of pasteurized milk did not change significantly during the year.

Electron Microscopic Investigations into Attachment of Bacteria to Teats of Cows.

Scanning electron microscopy was used to examine microorganisms on the skin of cows' teats which were artificially contaminated and subsequently stored for different times. From the results it seems that bacteria were not spread uniformly on the surface of the teats. No extra-cellular polymers were observed before storage of the teats, but during storage polymers, in the form of thin fibers, were produced.

Attachment of Bacteria to Teats of Cows.

The mechanism of attachment of bacteria to meat skin is of great importance in slaughter hygiene and sampling methods. In this study teats of cows were chosen as the meat surface for attachment experiments. Both the attachment rate and strength of attachment were determined.