Hour One: Phage Therapy / Tau Neutrino.

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Science Friday > Archives > 2000 > July > July 21, 2000:

Hour One: Phage Therapy / Tau Neutrino

When you think about treating a bacterial infection, you probably think of using an antibiotic such as penicillin, vancomycin, or erythromycin. But before use of Alexander Fleming's penicillin became widespread in the 1940's, the medical community was focussing its attention on a different line of bacteria-killing research -- the bacteriophage.

First named in 1917 by researcher Felix d'Herelle at France's Pasteur Institute, bacteriophages (or just phages for short) are viruses that prey upon bacteria. They have a simple structure - a DNA-filled head attached by a shaft to spidery "legs" that are used to grip onto the surface of a bacterium. Once a phage latches onto a bacterium, it injects its payload of genetic material into the bacterium's innards. The bacterium then begins to rapidly produce "daughter" copies of the phage -- until the bacterium becomes too full and ruptures, sending hundreds of new phage particles into the open world.

Electron micrograph of phage courtesy
the Australian National University.

Doctors used phages as medical treatment for illnesses ranging from cholera to typhoid fevers. In some cases, a liquid containing the phage was poured into an open wound. In others, they were given orally, via aerosol, or injected. In some cases, the treatments worked well - in others, they did not. When antibiotics came into the mainstream, phage therapy largely faded in the west.

However, researchers in eastern Europe, including the former Soviet Union, continued their studies of the potential healing properties of phages. And now that strains of bacteria resistant to standard antibiotics are on the rise, the idea of phage therapy has been getting more attention in the worldwide medical community. Several biotechnology companies have been formed in the U.S. to develop bacteriophage-based treatments -- many of them drawing on the expertise of researchers from eastern Europe. On this hour of Science Friday, we'll take a look at the current state of phage research, talk about what progress has been made in phage therapy, and about whether it may be a viable medical option in the near future.

Plus - an international team of physicists working at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, reported today that after 25 years of looking, they had finally snapped the photograph of the tau neutrino, an elusive inhabitant of the sub-atomic particle zoo.

The tau neutrino is one of three types of neutrinos predicted by the Standard Model of particle physics, The other two types, the electron neutrino and the muon neutrino, are easier to produce and observe, and were first detected in 1956 and 1962, respectively. Stanford physicist Martin Perl discovered the tau lepton 25 years ago and won the Nobel Prize for his discovery. The existence of the tau neutrino follows from the existence of the tau lepton -- but the Fermilab experiment is the first to actually see the new neutrino.

The experiment itself was done in 1997. By firing a beam of high-energy photons through a tungsten plate, the researchers created a beam of subatomic particles. After filtering those particles, they were left with a stream of only neutrinos. That beam was directed through alternating layers of an iron solution and a photographic medium. When 4 of the neutrinos collided with iron nuclei, they became tau leptons, whose images were captured on the film. in tiny streaks. It took the researchers three years of examining the film and analyzing the streaks to reach the conclusion that their experiment had succeeded.

We'll talk to one of the Fermilab team researchers... followed by a phage tutorial. Call in - our number is 1-800-989-8255.

Listen to this program in RealAudio!

Guests:
Regina Rameika
Staff Scientist Member, DONUT (Direct Observation of the Nu Tau) Collaboration Fermi National Accelerator Laboratory
Batavia, Illinois

Elizabeth Kutter
Member of the Faculty in Scientific Inquiry
Head of the Laboratory of Phage Biology
The Evergreen State College
Olympia, Washington

Alexander Sulakvelidze
Founder, Intralytix, Inc.
Assistant Professor, Epidemiology
Assistant Professor, Medicine
University of Maryland School of Medicine
Baltimore, Maryland

Books/Articles Discussed:

New York Times Magazine: A Stalinist Antibiotic Alternative U.S. News: Phages may once again fight tough bacterial infections (11/2/98) BBC broadcast on phage therapy Evergreen University: Bacteriophage Home Page The Bacteriophage Ecology Group Phage Therapeutics International Inc. - PhageTx Exponential Biotherapies, Inc. Intralytix, Inc. G.Eliava Institute of Bacteriophage, Microbiology and Virology Tbilisi Institute for Bacteriophage Therapy ClinicalTrials.gov

Produced By: Karin Vergoth
Web Producer: Charles Bergquist