From Yahoo Headlines:
Friday December 13 1:15 PM EST
Ecoli Sensor Could Detect Bacteria
BERKELEY, California (Reuter) -- Researchers have developed a
sensor that they say for the first time can instantly detect toxic E. coli
bacteria.
One child died and 50 other people were sickened in the western United
States and Canada recently by an outbreak of E. coli linked to
unpasteurized apple juice produced by Odwalla, a California company.
It was one of a number of serious E. coli outbreaks recently around the
world.
Raymond Stevens, a chemist at the Ernest Orlando Lawrence Berkeley
National Laboratory in Berkeley, Calif., said his team has developed
sensors capable of providing an extremely inexpensive, on-the-spot
litmus test for E. coli strain 0157:H7, the virulent strain responsible for
the outbreaks of illness.
"These sensors have been designed so that the presence of this strain of
E. coli causes a color change, from blue to red. The greater the color
change in the sensor, the higher the concentration of 0157:H7. The color
change is instantaneous," Stevens said.
"We can make an inexpensive sensor that can be placed on a number of
different materials such as plastic, paper or glass. The cost of the sensor
is so nominal that it could be part of a bottle cap or container lid. If you
open the product and the sensor has turned from blue to red, then you
have a contaminated food product," he said.
Until now, no technology existed to allow food companies, health
inspectors, or consumers to find out immediately whether E. coli was
present, according to the lab.
Currently, the best detection method requires taking a sample which
must be cultured for 24 hours before technicians can test whether the
bacteria are present, it said.
Another technique under development, which uses polymerase chain
reaction technology, takes several hours to give results, it said.
E. coli thrives in animal fecal material. Pasteurization of milk and
juices can kill the organism as can thorough cooking of meats. |
