Bio-Rad Instruments Used To Identify Bacteria In Odwalla Fruit Juice Investigation.

HERCULES, Calif.--(BUSINESS WIRE)--Nov. 5, 1996--The process of identifying a strain of E. coli bacteria from a common source as the cause of the recent outbreak of intestinal illness reported in several western states has been based in large part on using instruments designed by Bio-Rad Laboratories, the company announced today.

Researchers at the Washington State Dept. of Health (Seattle) used the Bio-Rad GenePath and CHEF Mapper systems, along with a protocol designed by the federal Centers for Disease Control (CDC), to process bacterial isolates from patients and from food sources, to determine that they shared a common source. Odwalla, the producer of the fruit juice in question, immediately pulled the potentially affected products and has been extremely helpful in further testing to identify the original source of the contamination, also with Bio-Rad instruments.

Different strains of a single class of bacteria can contain many subtle variations. Identifying the specific strain of bacteria within the general class is necessary to prove that a wide-spread infection arises from the same source. In this case, tests revealed that a single strain of bacterium (Escherichia coli -- or E. coli -- O157:H7) was responsible for all of the infections, indicating that a common source was likely. Subsequent tests showed that the apple juice products from Odwalla were the likely source of the infections. With full cooperation from the manufacturer, this has been further pinpointed to a single processing tank at the production facility.

The Bio-Rad instruments that were used in this process are the GenePath and CHEF Mapper systems. These employ a sophisticated technology called Pulsed-Field Gel Electrophoresis, to perform genetic fingerprinting of the bacteria samples. The DNA from processed bacteria appear as bands of color against a uniform background. The pattern of these bands is characteristic for each strain of bacteria. If the same band pattern is found in samples from different sources, it indicates that it is the same strain of bacteria, and confirms the point of origin of the infection outbreak.

The Bio-Rad GenePath and CHEF Mapper systems are widely used in controlling infection outbreaks, whether in hospitals or in the general population. The abilities of these products to precisely identify specific microbial strains allows physicians to track the source of an infection outbreak and prevent its further spread.

Bio-Rad Laboratories (AMEX BIO.A and BIO.B) is a multinational manufacturer and distributor of life science research products, clinical diagnostics, and analytical instruments based in Hercules, California.

CONTACT: Bio-Rad Laboratories

Tom Chesterman, 510/741-6006

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