Live pathogens: Rapid detection technique developed

Jan 25, 2013
Colorized scanning electron micrograph of E. coli. Photo credit: US Centers for Disease Control and Prevention.

(Phys.org)—Los Alamos researchers have developed a better technique for quick detection of live pathogens in the field. Identification of viable bacteria in a complex environment is scientifically challenging. Current detection and diagnostic techniques are inadequate in major public health emergencies, such as outbreaks of food-borne illness. Detection of live pathogens in the suspected food supply requires days of laboratory culture.

LANL's new method eliminates the need for and greatly speeds the process. The technique relies on bacteria being critically dependent upon the key nutrient iron. The bacteria synthesize and release sequestering agents, called siderophores, into their environment to bind iron tightly for subsequent uptake. This process occurs only in live, intact bacteria. The LANL team created a simple method to use bacterial siderophores for selective, rapid identification of viable bacteria in their surroundings.

Research achievements

Bacteria secrete siderophores to sequester and incorporate the iron they need. The scientists used bacterial siderophores to identify bacteria selectively and rapidly in complex matrices and to discriminate viable bacteria from their dead counterparts.

The team developed strategies to tether siderophores to glass slides. Surface functionalization chemistry, which was developed at LANL for self-assembled monolayers, tethers siderophores and minimizes non-specific interactions associated with complex , such as culture filtrate, serum and urine. The tethered siderophores captured viable bacteria from a mixture of viable and dead Escherichia coli. The team also used a software analysis tool that was originally developed for to conduct quantitative measurement of fluorescence staining in . This tool enables accurate and fast quantitation of the data.

Significance of the research

Rapid and selective determination of bacterial viability is critical for food safety. This simple analytical technique has applications for other situations, such as the rapid determination of the efficiency of a decontamination process, efficacy assessment after initial medical intervention to infection, and detection of exposure to a biological threat agent. The siderophore approach could be universally applicable to all bacteria, making it extremely useful for detection in complex backgrounds.

The journal Advances in Biological Chemistry published the research.

Explore further: Breakthrough understanding of biomolecules could lead to new and better drugs

Related Stories

Hunting for deadly bacteria

Apr 12, 2011

(PhysOrg.com) -- You can't see them, or smell them or taste them. They can be in our water and in our food, multiplying so rapidly that conventional testing methods for detecting pathogens such as E.coli, ...

Engineered bacteria mop up mercury spills

Aug 12, 2011

Thousands of tonnes of toxic mercury are released into the environment every year. Much of this collects in sediment where it is converted into toxic methyl mercury, and enters the food chain ending up in the fish we eat. ...

Enzyme discovery may lead to better tests for tuberculosis

Jan 08, 2013

(Medical Xpress)—Researchers at the University of Pittsburgh Graduate School of Public Health have identified an enzyme that will trigger the rapid breakdown of several mycobacteria species, including the bacteria known ...

Recommended for you

Breaking benzene

18 hours ago

Aromatic compounds are found widely in natural resources such as petroleum and biomass, and breaking the carbon-carbon bonds in these compounds plays an important role in the production of fuels and valuable ...

How to prevent organic food fraud

20 hours ago

A growing number of consumers are willing to pay a premium for fruits, vegetables and other foods labelled "organic", but whether they're getting what the label claims is another matter. Now scientists studying ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Telekinetic
1 / 5 (1) Jan 25, 2013
A pocket version of this tool would be handy before eating roadkill.