A long-sought test for direct detection of disease-causing E. coli bacteria

Feb 18, 2008
E. coli
Researchers have developed a test for direct detection of disease-causing E. coli bacteria. This photo shows an electron micrograph of a bacteria cluster. Credit: Courtesy of USDA-Agricultural Research Service

Biochemists in Japan are reporting development of a long-sought direct test for identifying the presence E. coli bacteria that get into water and food as a result of fecal contamination. That contamination causes millions of cases of food poisoning and other gastrointestinal illness around the world each year. Their study is scheduled for the April 4 issue of ACS’ Biotechnology Progress.

In the report, Yasunori Tanji and colleagues point out that tests now in use do not directly identify E. coli. Instead, these tests detect “coliform” bacteria that health officials use as indicators for fecal contamination. Coliforms, however, can originate from natural sources, and are not always reliable indicators of fecal contamination. Direct tests for E. coli do exist, but are too time-consuming and complex for general use.

The new study describes successful use of genetically engineered viruses that infect E. coli to identify a wide range of E. coli strains found in sewage. Researchers first engineered the viruses to be harmless to E. coli. Then they gave the viruses genes to produce green fluorescent proteins. The resulting viruses reveal the presence of E. coli by lighting up and glowing after infecting the bacteria. The test uses a fluorescent microscope to detect the glow and the presence of disease-causing bacteria, and takes only a few hours.

Source: ACS

Explore further: Towards controlled dislocations

add to favorites email to friend print save as pdf

Related Stories

Plants prepackage beneficial microbes in their seeds

Sep 29, 2014

Plants have a symbiotic relationship with certain bacteria. These 'commensal' bacteria help the pants extract nutrients and defend against invaders – an important step in preventing pathogens from contaminating fruits and ...

Quick ID for water pathogens

Oct 30, 2013

Drinking water flowing from your tap can contain harmful bacteria, viruses and single-cell animals. And most countries do not routinely test for all these bugs. Instead, scientists usually take a water sample ...

Recommended for you

Towards controlled dislocations

15 hours ago

Crystallographic defects or irregularities (known as dislocations) are often found within crystalline materials. Two main types of dislocation exist: edge and screw type. However, dislocations found in real ...

Chemists tackle battery overcharge problem

Oct 17, 2014

Research from the University of Kentucky Department of Chemistry will help batteries resist overcharging, improving the safety of electronics from cell phones to airplanes.

Surface properties command attention

Oct 17, 2014

Whether working on preventing corrosion for undersea oil fields and nuclear power plants, or for producing electricity from fuel cells or oxygen from electrolyzers for travel to Mars, associate professor ...

User comments : 0