Reuben was a 37 year-old Mexican veteran and the youngest patient on the dermatology ward. I will never forget the look in his tormented eyes as he implored us to save him from the horrors of his relentless disease.
Scleroderma comes from Greek words meaning “hard skin.” In scleroderma the body’s fibrous tissue thickens and the skin toughens and constricts. It becomes difficult for patients to walk, use their hands, open their mouth, or even smile. The internal organs suffer as well. Reuben was becoming slowly encased in skin as hard as stone.
His suffering was made more severe by sores of the fingers and toes. Deep and painful ulcers pierced the flesh of his back and shoulders. Reuben was a pitiful sight, and with each passing month the skin ulcerations became larger and more numerous. There was little we could do to help him. None of us knew what caused scleroderma or how to cure it.
Scleroderma is closely related to two other diseases: rheumatoid arthritis and lupus erythematosus. All three diseases have similar immunologic abnormalities which link them together as so-called “connective tissue” diseases. It is believed that people with these three diseases are “allergic” and “autoimmune” to their own body tissue.
We all knew what would happen to Reuben. His internal organs would become more and more scarred, and when they could no longer function, Reuben’s agony would end. Until that time, the nurses tried to make him as comfortable as possible.
Reuben agreed to let me take a piece of skin to test for germs. I chose a hard, stonelike area of skin next to a large ulcer on his back. The skin was deadened with an anaesthetic and the area was carefully cleansed to minimize contamination from surface skin bacteria. The biopsy was over in moments. Half the tissue was sent to Eugenia Craggs in the TB lab; the other half to the pathologist.
By choosing Reuben’s scleroderma skin tissue as a “control,” I was set on a path of scientific study from which I could never veer, no matter how hard I tried. It was a path of destiny that led me into the secrets of scleroderma, cancer and AIDS, and finally into the origin of life itself.
When Eugenia received Reuben’s tissue she added a little sterile saline water and mashed the specimen in a tissue grinder. Placing a tiny amount of the mashed tissue onto a glass slide, she then colored the tissue with the acid-fast stain. The stained material on the slide was covered with a thin glass coverslip. Eugenia put the slide onto her microscope and focused the oil-immersion lens that magnified Reuben’s tissue preparation one thousand times.
After studying Reuben’s tissue carefully, Eugenia phoned me at the dermatology clinic. “This is Eugenia in TB. The specimen on Reuben Gomez is positive for acid-fast bacteria.”
“That’s impossible,” I said. “The skin is from a patient with scleroderma. There aren’t any acid-fast bacteria in scleroderma!”
Eugenia was emphatic. “Well, I don’t know anything about scleroderma, but I’ve been working in TB for years. And I know acid-fast rods when I see them. If you don’t believe me, you can come over to the lab and look for yourself.”
As I peered into Eugenia’s microscope, I saw the red-stained acid-fast rods in Reuben’s preliminary smear preparation. The red rods looked just like the mycobacteria that cause tuberculosis and leprosy. Eugenia had made a tremendous discovery. These microbes had to be important in Reuben’s disease because it is never normal to find acid-fast bacteria in tissue.
What kind of mycobacteria were they? There was no way of telling until the microbes were grown in culture. All the acid-fast rods of the various species of mycobacteria can look the same. In order to determine the precise identification of Reuben’s microbe we would have to wait until the culture was tested biochemically.
Eugenia had already planted Reuben’s tissue on TB media but it could take weeks to grow. We had to be patient. In the meantime, I was confident the pathologist would see acid-fast bacteria in Reuben’s tissue sections, just as Eugenia had seen them in Reuben’s smear preparation. I was sure we had discovered the hidden cause of scleroderma.
My pipe dream was quickly burst by the pathologist who couldn’t find acid-fast bacteria in Reuben’s slides. I rechecked to be sure; there was none. Why were numerous acid-fast bacteria present in Eugenia’s preparation, but not in the pathologist’s tissue sections? Did the histologic process of chemically “fixing” the tissue somehow destroy Reuben’s microbes or make them unstainable with the acid-fast dye?
There was another complication. A review of Reuben’s old medical records showed he was diagnosed with a mild case of lung tuberculosis seven years before his scleroderma began. As proof, there was a lab report stating that Mycobacterium tuberculosis had been cultured from his sputum. Were the acid-fast bacteria in Reuben’s scleroderma related to his old lung TB infection? If so, I was confident Eugenia would be able to grow Mycobacterium tuberculosis in her lab.
After several weeks of incubation, a microbe grew from Reuben’s tissue but it was not Mycobacterium tuberculosis. Some of the bacteria were typical rod-shaped acid-fast bacteria; but most of the forms were round and “coccus-like” and not acid-fast. In addition, some of Reuben’s microbes were fungus-like and produced long chains and filaments. Exactly what kind of germ was growing? I had never seen such a peculiar microbe with so many different forms! Eugenia suspected Reuben’s microbe might be an acid-fast fungus called “Nocardia.”
In the classification system of bacteria, the acid-fast mycobacteria are closely related to fungi. “Myco” is the Greek word for fungus. For the first half of this century, microbiologists believed that only a few species of mycobacteria were important in human and animal disease. The two most common diseases caused by acid-faxt mycobacteria are tuberculosis (caused by Mycobacterium tuberculosis), and leprosy (caused by Mycobacterium leprae). In the textbooks it is always stated that the germ of leprosy has never been cultured, but I later learned that this “fact” is not true.
In the 1960s, mycobacteriologists began to recognize other species of mycobacteria that cause disease in human beings. These newly discovered species are termed “atypical,” “anonymous,” or “unclassified” mycobacteria. This was confusing to me because I was not well-trained in microbiology in medical school. However, in my scleroderma research, I soon discovered that most physicians are not well-versed in bacteriology. They simply do not have the necessary laboratory training and expertise to be knowledgeable in this field.
When the pathologist could not find acid-fast bacteria in Reuben’s tissue, I wondered if Reuben’s germ might be the leprosy germ. Leprosy mycobacteria are more difficult to stain than TB mycobacteria. And there are certain forms of leprosy in which acid-fast bacilli are extremely difficult to detect. Special acid-fast staining techniques have been devised to detect leprosy mycobacteria in tissue sections. I asked the technicians in the histology lab to try some of these special acid-fast stains on Reuben’s sections.
One of the special leprosy stains proved successful. After many hours of microscopic examination, I found a few acid-fast rods in Reuben’s skin. The red rods looked just like TB and leprosy bacilli.
Eugenia and other microbiologists could not precisely identify Reuben’s microbe. They classified it as a possible “atypical” mycobacterium, or perhaps a fungus. I was learning that microbiology is not the exact science that I thought it was.
[…] Several months later I received a report from Richard E. Mansfield MD, Chief of the Laboratory Branch at Carville. He wrote: “The reason it took so long to get the final report was that a rapid-growing, acid-fast bacterium was cultured from the tissue you sent. We have found this to be Mycobacterium fortuitum. We have just received confirmation from the National Centers for Communicable Disease in Atlanta, Georgia. Acid-fast bacteria were found on rare slides. Further recuts are being made and I will send you a marked slide where definite acid-fast rods can be identified.” Doctor Mansfield expressed some concern as to whether the tissue might be contaminated, or whether the acid-fast bacteria might have developed after the scleroderma process took hold. I decided not to tell him how I got the samples. Ruth Gordon wrote that she also had cultured Mycobacterium fortuitum and remarked, “We had better luck in recognizing it than some cultures you have sent us.”
Mycobacterium fortuitum is an “atypical” species of mycobacteria that can cause TB in humans. There was no way it could have been a contaminant. I was confident it was the same acid-fast microbe that Eugenia had detected a year and a half earlier. Why was it so difficult to recognize it at that time? Eugenia frequently cultured Mycobacterium fortuitum in her TB lab. Perhaps Reuben’s acid-fast microbe had changed as he neared death, so that the identity and classification of the microbe were now more obvious.
From my work at the VA with Eugenia I learned one important thing: microbes change form. Sometimes they appear one way, sometimes another. And they could fool the experts. The appearance of the microbe depended on what it was fed in the laboratory. In the textbooks of microbiology the classification of organisms was simple and straightforward. But in reality, it was not that way at all.
