The Vitek 2 Compact is diagnostic test software used for biochemical identification and antimicrobial susceptibility testing of organisms. Using the Vitek, we are able to obtain rapid results for identification of Gram positive bacteria, including Bacillus, and Gram negative bacteria as well as yeast identification.

Vitek 2 Compact

bioMérieux launches VITEK® 2 Compact to complete its VITEK 2 range

Focus on Thermopilic Spores
Thermophilic spore forming bacteria are of special concern to those involved in food processing.  Spores and bacteria are present almost everywhere in the environment and food processing facilities are no exception.  When spore forming bacteria encounter nutrient deprivation and dense population conditions, they undergo a developmental process called sporulation,  which results in the production of resistant, metabolically inactive spores.

The spores are highly resistant to environmental stresses such as high temperatures, acids, and disinfectants.  Normal pasteurization will kill pathogens and most vegetative cells, however, it will not destroy bacterial spores. The spores may then reside dormant in the product or if conditions are met, such as when milk powder is reconstituted, they can germinate and through enzymatic activity, cause spoilage of the product.

Three categories of thermophilic spore forming bacteria cause food spoilage:

• Those that produce flat sour spoilage such as Bacillus stearothermophilus and Bacillus coagulus.
• Those that produce gas but not hydrogen sulfide such as the thermophilic anaerobe Clostridium thermosaccharolyticum.
• Those that produce hydrogen sulfide spoilage such as Desulfotomaculum nigrificans.

Enumeration of the spores cannot be accomplished by the same procedure used to determine the number of vegetative cells in the product.  Heat shock, or sub-lethal heating,  is required.   The heat breaks the dormancy of the spores and helps them to germinate so the sample can then be plated to determine the number of thermophilic spores in the product.      

Spores can be destroyed,  the most effective means appear to be sterilization and UHT (Ultra high temperatures).  Also occasionally used is an initial heat shock to activate the spores followed by a second heat treatment which kills them.   However,  due to the heat sensitivity of many components of dairy products, treatments such as this can have negative effects on product quality. Please visit the following sites for interesting articles on endospores.

• Reduction of Spore Loads in Milk and Powder Milk by Control of Processing
• Heat Resistance of Bacillus spp. Spores Isolated from Cow's Milk and Farm Environment
• Bacterial Spores and Chemical Sporicidal Agents

Now Available!  

	Did you know that the Chestnut Labs can help you with your environmental sampling program?  Find out more about this service and...  Get into the ZONE with your environmental sampling!

PCR testing for Salmonella,  Listeria, Enterobacter sakazakii, and E. coli 0157.  Get fast results! E.coli 0157 same day, next day for Salmonella and E. sakazakii.

In addition to the BAX detection system, now we also have the Riboprinter microbial characterization system. The riboprinter allows for DNA genus and species identification of over 6000 different Gram negative and Gram positive organisms in only 8 hours.