Medicine: Life Without Germs

When Louis Pasteur found that some germs are always present in the healthiest animals and men, he concluded that no animal or man could live without them.

But last week hundreds of lowly mice, rats, chickens and quail, and even a few grunting pigs, gave the lie to the great man by leading near-normal lives without a germ anywhere in them or on them. The fact that such animals can now be raised in quantity lets researchers, for the first time, study a “pure” infectious disease with only one kind of germ present. And truly germfree surgery on human patients, fulfilling a century-old dream, will soon be possible.

“The use of germfree animals as a tool in biological and medical research will be as natural in the future as the use of the microscope and carbon 14,” says Bacteriologist James A. Reyniers. It was Reyniers, 53, who pioneered in germfree animal work for 30 years at the University of Notre Dame. Virtually all the germfree colonies now multiplying in a dozen medical centers on four continents are either descended from Reyniers’ stock or were developed by his methods. Reyniers left Notre Dame two years ago to set up the Germfree Life Research Center in Tampa, Fla., where he is concentrating on the mysterious role of viruses as causes of cancer.

Remote-Control Surgery. If it is to live germfree, an animal must be born germfree. This is relatively easy with birds such as chickens. The fertilized egg is germfree on the inside, and its shell can easily be sterilized in a germicidal bath. The “tank” in which the birds are to live can be heated to serve as an in cubator; when the chicks hatch, they can feed and fend for themselves at once. The Japanese quail is even better than the chicken because the birds begin to lay when about seven weeks old (as against seven months for chickens).

The difficulties are far greater with mammals. To get a germfree line started, researchers have to deliver germfree young by Caesarean section. Just before the pregnant animal would normally deliver, it is anesthetized, strapped to a miniature operating table, and its abdomen shaved and sterilized. Two sterilized tanks are prepared and connected by a sterile tunnel. The animal is slipped into the operating tank. A surgeon puts his hands in the rubber gauntlets that are sealed into portholes in the tank’s sides. A set of sterile instruments is already in place. He delivers the young, drops them into a sterile tray, and passes them as fast as possible through the connecting tunnel into the rearing tank.

Sterile air passes constantly through the rearing tank. A milk formula is slipped in through a sterile lock. Already inside are sterile eye droppers with rubber nipples. Every hour, 24 hours a day, the young animals must be fed by hand, always by the tedious process of working through a rubber gauntlet. Monkeys, with the longest “nursing” time, are the costliest animals to raise. Pigs are better: born with their eyes open, they are not a feeding problem, and when only six weeks old they are the right size for experimental surgery which may later be adapted to man. Small animals such as rats, mice and guinea pigs will breed in the germfree tanks, so that once the line has been established, generation after generation is born germfree.

Death in 48 Hours. Using germfree animals to study human ills at the National Institute of Allergy and Infectious Diseases, a research team headed by Dr. Walter L. Newton has found that the organisms that cause amoebic dysentery cannot survive in the bowel unless bacteria are present. The Walter Reed Army Institute of Research has found that if germfree guinea pigs are taken out of their sterile environment and put in an ordinary animal room, all die of overwhelming infection within 48 hours. But, mysteriously, only 50% of mice die, and rats or chickens can be brought into the open with no ill effects. Experiments with these animals may show why some soldiers, exposed to unfamiliar diseases in a foreign country, get sick and die, while others have a mild illness and some escape.

The most promising application of germfree research direct to man is in surgery. Despite all precautions, it has been impossible to protect a patient’s wound completely against infection, which is still a common fatal complication of surgery. At Notre Dame, Bacteriologist Philip C. Trexler devised a plastic isolator, which has been modified at Walter Reed, and used at the University of Arkansas to deliver pigs.

The isolator is a sausage-shaped, flexible, transparent plastic bubble, slightly inflated to about five feet in diameter with germ-free air and glued to the skin around the place where the surgeon will make his incision. Inside the bubble are surgical instruments, lying on a part of the plastic that is supported by stands next to the operating table. Half-jackets, with sleeves, gloves and a sort of helmet are molded into the sides of the bubble for the surgeons, letting them see and work inside while standing outside. The technique has been tested extensively in animals, is ready for its first trial with humans.