From Bioweapons to Bacteria Killers

Building effective links with overseas researchers is a matter of perseverance and resources—but the rewards can be substantial. The experience of Dr. William Petri, the newly appointed chief of the Division of Infectious Diseases, is a case in point. Petri originally became involved with scientists in the former Soviet republic of Georgia when in 1998 the Centers for Disease Control asked his help in investigating a suspected outbreak of amoebic liver abscesses in Tbilisi, the republic's capital. Petri's research group was the logical choice because it had devised many of the modern tests used to identify the parasite.

Susan Lareau, a researcher in Petri's laboratory, traveled to Georgia with Dr. Rachel Barwick of the CDC, and together they confirmed a number of cases and identified polluted municipal drinking water as the probable source of the infection. "Making the diagnosis was extremely difficult," Petri notes. "There was no heating in the lab in Tbilisi and the electric power was erratic. Susan, who is now a second-year medical student, did a terrific job."

The particular strain of Entamoeba histolytica that attacked the citizens of Tbilisi was unusual in causing abscesses, rather than the more benign colitis. With a grant from the Biotechnology Engagement Program, Petri himself traveled to Georgia to work with Drs. Shota Tsaverna and Nino Trapaidze to begin to understand why this strain was exceptionally virulent. The program, sponsored by the Department of Health and Human Services, was created to help former Soviet bioweapons scientists apply their expertise to public health problems.

These contacts led to ties with another group of Georgian researchers who are specialists in the use of bacteriophages to treat infections. A bacteriophage is a virus that has evolved in tandem with a specific strain of bacteria and that is capable of destroying it. In general, bacteriophages are highly specific, environmentally safe, and produce few side effects.

Petri traveled to Tbilisi to meet with researchers at the former Eliava Bacteriophage Institute. He found that the physicians in Georgia had been using bacteriophages to treat disease for 50 years. "We learned that they had the capacity to produce bacteriophages on a large scale, to purify them, and prepare them in capsules," he says. "There is a lot of valuable experience and intellectual capital there." The only problem is that Soviet scientists had never conducted the kind of controlled clinical trials needed to ensure their acceptance in Western Europe and the United States.

Petri has formed an alliance with Dr. Lela Kalandarishvili of Tbilisi and Dr. Tony Smithyman, managing director of Cellabs, an Australian company specializing in diagnostics for infectious diseases, to do precisely that. They are currently looking for funding for this project. For Petri, who sees patients suffering from infectious diseases every day, bacteriophages offer a possible alternative to antibiotics, which can actually cause some infections by altering the normal bacterial flora. "Bacteriophages offer a way to selectively kill just the infecting bacterium," he says. "They may offer a safe alternative to antibiotics for treatment of some infectious diseases."