Seattle - In the world of microbiology it is the stealthiest of offenders.
It's neither discriminating nor particularly forgiving. The most notorious of its crimes occurred in 1993: hundreds of Washington residents were poisoned with the E.coli O157:H7 bacteria after eating tainted hamburger at a chain of fast-food restaurants.
“A one-day E.coli laboratory test, as part of a disease tracking system, could have prevented a lot of those illnesses and may have even prevented the deaths,” said Romesh Gautom, Ph.D., molecular epidemiologist with the Washington state Department of Health's Public Health Laboratory in Shoreline.
Gautom developed just such a test. Until his innovation, identifying the fingerprints of an E.coli organism in public health labs took a full three to five days.
Now, it takes a mere 24 hours to identify a particular strain of E.coli. Once an outbreak strain is detected, disease investigators are able to more rapidly pin-point the contaminated food source.
“What Dr. Gautom accomplished is a major enhancement to the original three-day lab test,” said the Centers for Disease Control and Prevention's Dr. Bala Swaminathan. “He refined it to a level that it had not been refined before.”
Indeed, Gautom's fine-tuning of the rapid pulsed field gel electrophoresis test will strengthen the CDC's foodborne disease tracking.
PulseNet: A National Network of Public Health Labs
The CDC's Swaminathan and Jon Counts, director of the state Public Health Laboratories in Washington, will be on hand for the debut of PulseNet, a national network of public health laboratories that performs DNA fingerprinting on bacteria. The network will provide for the rapid comparison of these fingerprint patterns through an electronic database.
“PulseNet is an early warning system for potential outbreaks; it will allow public health laboratories in Washington and other states to share information,” Counts said. “The one-day test will make the PulseNet that much more successful.”
Gautom's test currently is being used at the state's Public Health Laboratory in Shoreline to test all E.coli O157:H7 cultures and several other disease-causing bacteria from Washington state. Very soon, the CDC will release a one-day pulsed field gel electrophoresis typing test based on Gautom's method. This test will be used by all PulseNet participating labs across the nation.
“Rapid and accurate DNA fingerprinting of E.coli and other organisms is essential to conducting a disease outbreak investigation,” Gautom said. “It will prove invaluable in the prevention of foodborne illness epidemics in the first place.”
“With a one-day turn around time, we're able to identify the strains on a fast track. If we're able to more quickly identify the source of contamination, ultimately, we can prevent or lessen the severity of an outbreak,” Gautom said.
When it comes to E.coli O157:H7 or Salmonella, “Three days is a lot of time to wait around for test results when we could be reacting -- namely, pulling contaminated product off the shelf,” said Swaminathan, the CDC's chief of foodborne and diarrheal illnesses. “The CDC has long felt that a 24-hour test is optimal to making the nationwide foodborne tracking system successful.”
“Whenever we can reduce the time it takes to detect where a bacterial organism originated, we're playing a role in the quick recovery of people who suffer from foodborne illness while protecting people at large,” Gautom said.
The Big Outbreak of `93
Five years ago, the nation's largest E.coli outbreak occurred in Washington and other Western states. The O157:H7 strain caused more than 500 people to become ill. They became infected after eating contaminated, undercooked hamburger at a chain of fast-food restaurants. Three of the infected individuals were children who died.
Gautom stressed that one disease-causing bacteria is no more serious than another. However, the E.coli O157:H7 outbreaks of January 1993 and October 1996 (associated with unpasteurized apple juice) heightened public concern about this dangerous strain sometimes found in ground beef and, on rare occasions, in raw milk, unpasteurized apple cider and alfalfa sprouts.
Most E.coli O157:H7 infections occur as single cases and do not result in outbreaks. The number of reported cases in Washington peaked in 1993, and have dropped since. The state Department of Health currently reports approximately 150 E.coli O157:H7 cases a year.
Meat Industry Insights News Service
P.O. Box 553
Northport, NY 11768
Phone: 631-757-4010
Fax: 631-757-4060
E-mail: sflanagan@sprintmail.com
Return to Home Page