Tech Researchers Test Novel Methods of Detecting Pathogens

by George Zamora

SOCORRO, N.M., November 12, 2001 -- New Mexico Tech researchers currently are working on developing ultra-sensitive technologies for detecting certain bacteria in the environment before the pathogenic microorganisms become abundant enough to cause outbreaks of infectious diseases.

Although the university's Pathogen Detection Program was initiated by the Office of Naval Research over a year-and-a-half before anthrax-laden letters started making headlines across the United States, Tom Kieft and Snezna Rogelj of the New Mexico Tech Department of Biology now realize that the processes and technologies they are developing may soon have important implications in the nation's war against terrorism.

"Although we aren't working on specific bioterrorism agents like anthrax or smallpox, we are certainly making progress with some very real killers, especially those typically found in closed environments such as submarines," says Rogelj.

The New Mexico Tech biologists are teaming up with researchers at Yale University, the BioStar Corporation in Washington, D.C., and Battelle's Pacific Northwest and Oakridge national laboratories to develop a small, self-contained device which can be used by almost anyone to detect the presence of pathogens, even in the minuscule amounts that are found well before full-blown infections set in.

"This easy-to-operate, hand-held detection system could be used either aboard ship or at a remote location," says Kieft, "and, ideally, could be easily operated by someone who has been given minimal manual training, and could quickly provide the operator with a 'yes' or 'no' answer as to whether or not a pathogen is present."

Some of the pathogens detected by such a device could include a variety of airborne, waterborne, and foodborne microorganisms such as Legionella, which causes "Legionaire's Disease," Streptococcus, E. coli, Campylobacter, and antibiotic- resistant strains of the common bacteria Staphylococcus.

"Whether you're stationed in a submarine, or eating in a restaurant, it doesn't really matter," Rogelj points out. "Regardless of where they are encountered, these types of microorganisms are a real threat."

Kieft and Rogelj are using a two-pronged approach to finding methods which can be employed in such a small system: Kieft, a microbiologist, is adapting established biological procedures, such as the polymerase chain reaction (PCR) to detect and identify the DNA sequences specific to pathogens; while Rogelj, a cell biologist and immunologist, is combining PCR with antibody- based detection methods in a new technique call "immuno-PCR."

"We're not looking at the genes, but at the products these genes encode," she says. "And the real beauty of it is that we don't have to find the whole organism, we just have to find parts of it."

Researchers at Yale University Medical School are working concurrently on developing strategies that will allow the pathogen detection device to differentiate between microorganisms that are pathogenic and those that are not.

Pacific Northwest National Laboratory, meanwhile, is tasked with miniaturizing these emerging bio-technologies through nanotechnology and packaging them into a detection system which will be smaller than an average briefcase.

A working prototype of the instrument already has been developed at the national lab, but is of limited use because it currently targets only a few pathogens.

The next phase of the Pathogen Detection Program will concentrate on enhancing the sensitivity of the pathogen detection system, increasing the number of pathogens it is capable of detecting, and improving the differentiation of specific toxins which are characteristic of each pathogen, thus allowing researchers, and ultimately, the end users of the detector, to positively identify what microorganism they may be dealing with.

The Pathogen Detection Program is a coordinated effort to attack a very timely problem, says Kieft, the principal investigator of the research project, and by employing these novel approaches, several practical applications may be found for many different pathogens.

"This research project has taken on a whole different focus since September 11," Rogelj adds. "Now it's not only the soldier in a closed environment that we're concerned about, but also the innocent child who might become exposed to these pathogens. . . . For those of us working on this project, the entire picture has changed."