CHALLENGED TO PROVE HIS GERM THEORY OF DISEASE, LOUIS PASTEUR SHAPED THE TERRAIN ON WHICH THE BATTLE AGAINST ANTHRAX IS BEING FOUGHT

THE FAMOUS VETERINARIAN MONSIEUR H. Rossignol had had it with chemist Louis Pasteur and his outrageous theory that germs caused disease. The final straw came in 1881 when Pasteur announced that vaccinating livestock-in effect giving them the very disease then decimating pigs, sheep and cattle across southern Europe-would protect them. So Rossignol called Pasteur's bluff, challenging him to a public test of his vaccine. For the venue of his experiment, Rossignol would even offer his farm in Pouilly-Le-Fort, a small village 30 miles southeast of Paris.

Louis Pasteur was not easily intimidated. He shared with many brilliant scientists that particular blend of brashness and impatience so often characterized as arrogance. Attending a lecture at the Paris Academy of Medicine two years before, in 1879, he had listened with growing anger as a learned physician spoke about a vague "miasm" that caused women to die of childbed fever. Finally, Pasteur could take it no longer. He rose to his feet. "The cause of the epidemic is nothing of the kind," he shouted. "It is the doctor and his staff who carry the microbe from a sick woman to a healthy woman!" When the physician responded indignantly that no one would ever find this microbe, Pasteur sprang to the speaker's blackboard and drew a string of beads, representing the germ now known as streptococcus. "There it is!" he declared.

Pasteur's legendary self-confidence-many called it conceit-aside, Rossignol's challenge constituted both a gamble for Pasteur and an opportunity for the veterinarian and other critics to ridicule him and his germ theory. Many were certain that Pasteur's vaccine would fail in the bright daylight of a working farm. After all, he hadn't perfected it yet; in fact, he hadn't tried it outside the laboratory. Even his assistants feared that the experiment could go wrong. But Pasteur put on a brave face. "What succeeded with 14 sheep in the laboratory," he insisted, "will succeed with 50 in Melun."

In early May, Pasteur ordered 25 animals at Rossignol's farm tagged and inoculated with the vaccine. Another 25 received none. Then, on May 31, all 50 were injected with a culture of highly virulent anthrax. Within two days, Pasteur declared, the results would be known. On the appointed day, a group of farmers, veterinarians, pharmacists, agricultural officials and even a local baron crowded into Rossignol's pasture. Never one to miss a good story, the foppish Paris correspondent of the London Times, Henri de Blowitz, focused world attention on this tiny town. "M. Pasteur, one of the scientific glories of France, made to-day experiments in connexion with his latest researches on that malady dreaded by agriculturists, called 'charbon,'" de Blowitz wrote.

The day before the verdict, Pasteur received word that some of the vaccinated sheep had fallen ill, and his optimism flagging, he berated his assistant Emile Roux for making a mistake in preparing the vaccines. He then ordered Roux to go alone to the trial to face the public humiliation for which Roux was responsible. But a telegram that night brought news that the vaccinated sheep were recovering. Pasteur decided he would go after all.

When Pasteur's party arrived at the railroad station the next morning, the cheers of the crowd told of his success. Without missing a beat, he turned to them and announced theatrically, "Well, then! Men of little faith!"

Indeed, the test had proved a complete triumph. "At 2 o'clock, 23 of the sheep which had not been inoculated were dead," de Blowitz recorded. "At 3 o'clock died the 24th and the 25th an hour later. The 25 inoculated animals were sound, and frolicked and gave signs of perfect health." There, in that modest field, the French chemist had vanquished a foe far more wily and destructive than a skeptical veterinarian. For charbon, as the scourge was then known, has another name: anthrax.

TO RID THE WORLD OF ITS DEADLY SCOURGES

SINCE CLASSICAL TIMES, OBSERVERS SUCH AS HOMER AND HIPpocrates have noted anthrax's exceptional lethality. Every year for centuries, it killed many thousands of livestock. Pasteur's anthrax vaccine not only provided the first effective protection against an infectious disease in human history, it provided proof for his germ theory, the seminal idea that individual microorganisms cause particular diseases. The conquest of anthrax would open the door to fighting other scourges, such as smallpox, tuberculosis and cholera. From Pasteur's work, the disciplines of immunology and bacteriology emerged, which eventually led to vaccinations that would save millions, even billions, of lives.

Yet, more than a century ago, Pasteur understood that his research and the advances it ushered in were a double-edged sword. "Two contrary laws," said Pasteur in 1888, "seem to be wrestling with each other nowadays: the one, a law of blood and of death, ever imagining new means of destruction and forcing nations to be constantly ready for the battlefield-the other, a law of peace, work and health, ever evolving new means for delivering man from the scourges which beset him." Pasteur's prophetic words have only added to his luster.

In the wake of the anthrax devastation that spread through the U.S. mail last fall, Nobel laureate and CalTech president David Baltimore says that today's microbiologists "are all the children of Pasteur." But, he adds, we've neglected some of Pasteur's legacy. "Microbiology has certainly taken on a new urgency since the anthrax deliveries started. It has shown that one important heritage from Pasteur has been allowed to wither-our public health preparedness."

In his own day, Pasteur knew how high the stakes were. During the years when his experiments slowly showed how living yeasts and bacteria could ferment beer, turn grapes into wine, spoil milk, decompose meat and spread epidemics among sheep, swine and other livestock, the Pasteurs lost three of their five young children to the rampant diseases of the day. "My dearest Marie," he wrote his wife in despair, "so they will all die one by one, our dear children. . . ."

"There's a picture of Louis Pasteur on my desk," says Col. Arthur Friedlander, science adviser and senior military scientist at the U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick, in Maryland, where Army scientists are following in Pasteur's footsteps as they battle to protect the public's health, as well as that of U.S. soldiers. "Pasteur and the other pioneers of his day introduced the general scientific methods we still use," says Friedlander. "I work on trying to understand the same disease, anthrax, that Pasteur first studied over a hundred years ago."

FROM BEET JUICE TO MICROBES

BORN IN 1822 IN THE SMALL VILLAGE OF DÔLE, PASTEUR showed early talent as an artist but was soon drawn to the enigmas of chemistry. As a freshly minted professor of chemistry at Strasbourg, at age 26 he married Marie Laurent, the daughter of the university's rector. When they moved to the university at Lille in the mid-1850s, Pasteur took his first step into the world of microbes. "Louis," Marie wrote to his father, "is now up to his neck in beet juice. He spends all his days in the distillery." Fermenting beet sugar into alcohol was a major industry in the region, but the distillers were afflicted by mysterious failures in the process. Pasteur investigated and identified the essential role of yeasts in fermentation, as well as spotting the rodlike bacteria that infested the "sick" vats. In doing so, he developed a new technique: growing the culprit bacteria in a pure broth, in flasks that he incubated in an oven. Once he identified a microbe under the microscope, he could grow it in his flask, then remove a drop and prove it had the power to spoil a good flask of fermenting beet sugar. Pasteur's cultures turned the study of germs into a science. He could now show that the same germ would have the same effect every time he repeated an experiment.

By 1870, Pasteur had discovered germs that live without oxygen and found others that were blighting French vineyards. He taught growers to heat their wines to kill the bacteria that spoiled them-a process soon known as pasteurization-and he proved that microbes cause the decay of plants and animals after death. He demolished the widespread belief in spontaneous generation of life and ended an epidemic that was destroying the silkworm industry. And when he discovered that grapes would not ferment in a sterile environment, he foresaw a day "when easily applied preventive measures will stop the scourges whose sudden appearance devastates and terrifies entire populations." Among many other academic honors, Pasteur was elected to the Paris Academy of Sciences.

Still, most physicians scoffed at his ideas. They insisted that any bacteria seen in diseased tissues were spontaneous products of the disease, not the cause of it. Pasteur's laboratory became a beehive of experiments designed to prove that germs could not arise on their own. Using all kinds of microbes, broths, temperatures and filters, he showed again and again that once a broth was sterilized and sealed, no microbes would grow in it. In such sealed flasks, meat did not decompose, milk did not spoil, sugars did not ferment. But as soon as the flasks were opened to the air, germs entered and their growth set nature in motion again. He even demonstrated that, using a heated flask whose neck was bent to one side like a swan's, he could leave the flask unsealed and repeat his results-because the moisture on the sides of the swan neck trapped all dust and germs. It was a great triumph of experimental technique over mere speculation. Yet, still some Academy scientists contested the results.

Pasteur was not the only scientist to isolate the anthrax germ. Others had noticed the strange proliferation of tiny rodlike objects in the blood of sheep killed by the disease. And in 1876, unbeknownst to Pasteur then growing Bacillus anthracis in his flasks, an obscure country physician in Germany was also experimenting with it. In April, this doctor, Robert Koch, set the scientific world abuzz with his detailed description of the germ and its life cycle from rods to tangled skeins of filaments and, at last, to spores that could survive for long periods after a host animal was killed.

In village pastures and in a makeshift laboratory at his home, Koch had been studying this process for years, and it took him several days of lectures and demonstrations at the Botanical Institute, in Breslau, to present his story. It was riveting science, and from then on Koch and Pasteur were widely seen as rivals. It's true that both men were pioneers whose experiments changed medicine forever. But as Koch went on to discover the germs that cause tuberculosis and cholera, he stuck largely to the laboratory and the microscope. Pasteur was searching for the great principles of contagion, more interested in preventing than curing diseases, and he extracted his principles by studying the epidemics that struck down chickens, pigs, cattle and sheep, as well as people.

HEROIC-BUT DANGEROUS-EXPERIMENTS

PASTEUR PROVED TO HIMSELF THAT INJECTING GERMS INTO healthy animals caused anthrax. His trusted assistant Emile Roux described Pasteur walking in a field at Saint-Germain, through the stubble left after a harvest. Pasteur asked a farmer about a place where the earth had a different color. The man explained he'd buried sheep killed by anthrax there the year before. Pasteur took a closer look and saw the ground dotted with the little casts of soil left by earthworms. He guessed that worms ate the decaying material underground, then came up to the surface and excreted spore-laden humus, which discolored the soil. "Pasteur never stopped at ideas," Roux later recalled, "but immediately proceeded to the experiment. . . . The earth extracted from the intestine of one of the worms, injected into guinea pigs, forthwith gave them anthrax." This brilliant experiment proved conclusively that the spores had remained infectious despite their long passage up to the surface inside earthworms.

A VACATION WAS JUST WHAT PASTEUR NEEDED

AS HE CONTINUED HIS EXPERIMENTS WITH ANTHRAX, PASTEUR also began investigating outbreaks of chicken cholera. But in the summer of 1879, some flasks of the germ were left on the laboratory shelf while he went off on vacation. When he started the experiments again, a group of chickens injected with cholera from these flasks did not get sick. Somehow, the germs had lost their virulence. A fresh batch of germs was collected from a farm and injected into the lab's chickens as well as some new chickens bought at a market. The new chickens all got cholera, but the older birds did not. His method had failed, it seemed. But as he pondered the results, Pasteur thought of the work of an English doctor, Edward Jenner, 83 years earlier. Learning that milkmaids who got cowpox never seemed to contract smallpox afterward, Jenner created a crude vaccination by inoculating patients with a weak form of virus that caused cowpox in livestock. It worked, but seemed more of a folk remedy than a proven medical procedure. Pasteur now intuited, without any proof, that using weakened cholera germs, he had "vaccinated" his chickens with the first injections. It was an accident, but as Pasteur himself once said, "chance only favors the prepared mind."

In a flurry of new experiments, Pasteur discovered a method for weakening the cholera germs and soon developed a vaccine to protect chickens from the disease. He next extended these techniques to anthrax. It was at this time that Pasteur accepted Rossignol's challenge and, in so doing, illuminated the true possibilities of germ theory and vaccination.

Seven years later, ill health would force Pasteur to abandon his research. By then, reports microbiologist and Pasteur biographer René Dubos, "medical bacteriology and the sister sciences of immunology, public health and epidemiology had reached maturity, largely through his genius and devotion." And at the same time that Pasteur was advancing his theories over several decades, a growing movement in Europe and America prompted a new approach to public health, what social historian Paul Starr calls the "filth theory" of disease. From the 1850s on, passionate hygienists and social reformers campaigned to clean up water supplies and raw sewage in cities. One report from New York City in 1865 told of pedestrians paying broom-wielding youngsters to sweep a path through garbage so they could cross Broadway. The city established its Board of Health a year later. In 1892, the New York City Health Department opened a bacteriological laboratory where doctors could get diagnostic tests for their patients. And in 1894, the lab began producing a diphtheria antitoxin serum, a new treatment developed in Paris by Pasteur's assistant Emile Roux.

The success of public health institutions over the past century and a half-from stationing a nurse at every school to establishing the Centers for Disease Control, to vaccinating masses of people, to the widespread use of antibiotics-prompted the U.S. Surgeon General to declare in 1967: "We have basically wiped out infection in the United States." Ten years later the World Health Organization accomplished its extraordinary worldwide campaign to eradicate smallpox. As for anthrax, it was just a minor, treatable irritation to cattlemen, who still catch it from a cow now and then but worry more about rattlesnakes.

Yet even before the deadly envelopes with anthrax spores made bioterrorism a new reality, the return of infectious disease was a growing problem, becoming the third leading cause of death in the United States in recent years. Take tuberculosis, for example. By 1968, it had been essentially eradicated from New York City, in part through a $40 million annual budget to fight the disease. By 1988, a skin-and-bones budget of $4 million could do little against a mini-epidemic resulting, in part, from the influx of new immigrants to the city who brought tuberculosis with them. Today, after a costly eight-year effort to reverse the trend, the number of TB cases has steadily declined, but budget cuts are again being considered.

A FEW RESISTANT BACTERIA TAKE OVER

EVEN MORE INSIDIOUS PROBLEMS HAVE EMERGED: ANTIBIOTICS, overprescribed by doctors and taken improperly by some patients for colds and other viruses on which antibiotics have no effect, have lost efficacy against many strains of bacteria. One strain of the tuberculosis bacteria, for instance, has grown resistant to every antibiotic and kills half the people it infects.

When resistance to antibiotics was first recognized in the 1940s, scientists explained it in relatively benign terms. Random mutations and natural selection created these few resistant bacteria. But as Laurie Garrett, author of The Coming Plague, points out, "More recently scientists have witnessed an alarming mechanism of microbial adaptation and change." When threatened, the germs can scour their landscape for genetic material that lets them fight back. They can freely exchange bits of DNA and RNA, called plasmids or transposons, that jump between species of bacteria, fungi and parasites. These fragments of genetic code carry genes for resistance to antibiotics, for increased virulence and for all sorts of devious survival tactics, such as thriving on soap or even in bleach. So while our public health officials were proclaiming the end of infectious diseases, the microbes were taking collective action to outwit our efforts to eradicate them. In fact, since 1976 some 30 new diseases have appeared and 20 previously common ones have reemerged. A recent CDC report on infectious diseases concludes that "as long as microbes can evolve, new diseases will appear."

For all its promise of designing new drugs, vaccines and diagnostic techniques, genetic engineering, many scientists worry, also has a potential for producing new "designer diseases" and making old microbes more dangerous. Molecular biologists caution that "biomedical science inevitably has its dark side." Two concerned scientists warned in a recent issue of the professional journal Nature Genetics that "the ever-expanding microbial genome databases now provide a parts-list of all potential genes involved in pathogenicity and virulence." It is conceivable, they point out, that a scientist with evil intentions could mix together a cocktail of the world's most deadly pathogens and release it.

Frightening new scenarios involving infectious diseases have also emerged from military research on biological warfare. As anthrax was infecting postal workers here, the U.S. government was arranging to help Uzbekistan, on the Afghan border, remove thousands of tons of deadly anthrax spores dumped into burial pits on an island used by the Soviet germ warfare program. And a report last March in the Bulletin of the Atomic Scientists, the journal written by the keepers of the doomsday clock, described the fallout from past research at Utah's Dugway Proving Ground: "In open-air germ warfare tests from 1951 to 1969, human volunteers and animals were exposed to the aerosol dispersal of many germs not native to the area, including encephalomyelitis, Rocky Mountain spotted fever, psittacosis, Q fever, anthrax, brucellosis, plague, tularemia, and hydratid disease."

At Fort Detrick, with that picture of Pasteur staring across the desk at him, Arthur Friedlander is working to develop new and more effective vaccines against anthrax. In one approach, he and his colleagues are studying weakened germs, as Pasteur did. "We are using modern molecular techniques to create a genetically defined microbe," he says, "but the concept is the same." And taking a different approach, they are also working with a single purified component of the bacterium, rather than the whole microbe, to induce protection against infection. They have already demonstrated in the lab that such a vaccine offers protection. "It will shortly be tested for safety in the first human trials," he reports.

Friedlander pauses for just a moment to reflect on the future we all face. "The relation of my work to Pasteur is not just scientific," he says. "Pasteur was applying science to solve problems of society. For many years I studied the mechanisms that microbes use to damage the host and cause disease. But in recent years, I've worked on using this information to develop new vaccines for the armed forces. The specter of the use of biology to produce harm, previously only dimly anticipated, has now been realized."

Friedlander notes that there have been only about 25 human generations from the time of the plague pandemic of the Middle Ages, which decimated parts of Europe and Asia, to today, and less than a century since the influenza pandemic that killed more than 20 million people in just six months. "In Pasteur's time," he says, "the best scientific minds developed a means to prevent anthrax because of its economic impact on livestock. We now need to engage the best scientists of this generation to overcome the threat of biological terrorism to our civilization."

It is just over a century since Pasteur's death. Three years before he died, on December 27, 1892, as he was honored on his 70th birthday at the Sorbonne, the words he used to urge students to persevere still resonate: "Young men have faith in those powerful and safe methods of which we do not yet know all the secrets. And, whatever your career may be, do not let yourselves be discouraged by the sadness of certain hours which pass over nations."

PHOTO (COLOR): Anthrax bacteria

PHOTO (COLOR): The chemist's dogged work saved millions, but few believed that Louis Pasteur (at age 64 in a portrait by Nadar) could thwart the deadly anthrax bacteria.

PHOTO (COLOR): Pasteur, a master showman, silenced his most bitter opponents when the sheep he had vaccinated in a French pasture all survived.

PHOTO (COLOR): "Things turned out as M. Pasteur had foretold," wrote the London Times' Henri de Blowitz in 1881.

PHOTO (COLOR): "My own work with anthrax," says researcher Col. Friedlander at Fort Detrick, "has taken on a previously unimagined urgency."

PHOTO (COLOR): Somewhat rivalrously, German bacteriologist Robert Koch, who first described the anthrax microbe, attacked Pasteur's work.

PHOTO (COLOR): "Is this a time for sleep?" asks an 1883 Life magazine cartoon, reflecting U.S. fears of a raging cholera epidemic in Europe.

PHOTO (COLOR): Today's specter is the increasingly familiar figure in a HAZMAT suit. Pasteur predicted his legacy would be a double-edged sword.

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By Paul Trachtman

Paul Trachtman, a former Smithsonian editor, learned of Pasteur from his father, a doctor who passed on his lifelong passion for science.