Happy Accidents: Serendipity in Major Medical Breakthroughs in the Twentieth Century (47 page)

10. In the 1880s a fundamental method of differential staining of bacteria was stumbled upon by Christian Gram, a Danish physician working in Berlin. Trying to develop a double stain for kidney sections, he used gentian violet and iodine, then placed the preparations in alcohol. He observed that some bacteria in the sections retained the color and others not. Christian Gram, “Über die isolierte Färbung der Schizomyceten in Schnitt-und Trockenpräparaten,”
Fortschr Med
2 (1884): 1985–89. Henceforth, the world of bacteriology has been divided into gram-positive and gram-negative organisms. In the 1930s, bacteriologists discovered that these two groups react differently to antibiotics, making Gram's stain more useful in diagnosis.

11. Maurois,
Life of Sir Alexander Fleming,
137.

12. Alexander Fleming, “On the Antibacterial Action of Cultures of a Penicillium, with Special Reference to Their Use in the Isolation of
B. influenzae,
”
Brit J Exper Path
10 (1929): 226–36.

13. The continuous subculture of this mold by Fleming and others was the principal source of penicillin for approximately fourteen years until the large-scale commercial production of penicillin during World War II.

14. Nor was its therapeutic importance recognized by others during this period. Indeed, similar observations on the destructive effects of mold on bacteria could be found in the literature dating back to the 1870s. John Tyndall, one of England's most distinguished physicists, inspired by Pasteur's discovery of microorganisms in “fresh air,” wondered if they were evenly distributed through the atmosphere. He set up a series of open test tubes containing broth and found settling on the surface of the broth in some an “exquisitely beautiful” mold, called penicillium. Of the more than three hundred strains of penicillium, some had been used by the French cheese industry for centuries. The blue veins of Roquefort cheese are due to the mold
Penicillium roqueforti,
and the distinctive taste of Camembert is imparted by
Penicillium camemberti.
Tyndall made another interesting observation: “in every case where the mold was thick and coherent, the bacteria died or became dormant, and fell to the bottom as a sediment.” John Tyndall,
Essays on the Floating Matter of the Air, in Relation to Putrefaction and Infection
(New York: D. Appleton, 1882). This effect was noted in a few brief sentences buried in a seventy-four-page article describing his interest as a physicist in the scattering of light by unseen particles floating in air, and furthermore preceded by seven years the proof by Robert Koch in 1882 that bacteria could cause disease. Also about the same time, Lister noted in his laboratory book that in a sample of urine containing bacteria as well as some filaments of mold, the bacteria seemed unable to grow. It's further startling to note that a medical scientist, John Burdon Sanderson, in the early years of St. Mary's Hospital in 1871, had observed that penicillium molds can inhibit the growth of bacteria in culture. Just a year before Fleming's publication, in 1928, a book published in France dealt extensively with bacterial inhibition by molds and by other bacteria, citing in a sixty-page chapter the concept of “antibiosis.” Georges Papacostas and Jean Gaté,
Les associations microbiennes
(Paris: Doin, 1928). The word had been coined in 1889.

15. Lewis Thomas,
The Youngest Science: Notes of a Medicine-Watcher
(New York: Viking, 1983), 29.

16. Gwyn Macfarlane,
Howard Florey: The Making of a Great Scientist
(Oxford: Oxford University Press, 1979).

17. Ronald W. Clark,
The Life of Ernst Chain: Penicillin and Beyond
(New York: St. Martin's Press, 1985), 1.

18. Ibid., 33.

19. David Wilson,
In Search of Penicillin
(New York: Knopf, 1976).

20. The Oxford team had quickly found out that penicillin was not, in fact, an enzyme but a relatively small molecule. This surprised and disappointed Chain, but he assumed that it would be easy to determine its molecular structure and to synthesize it. He was proved wrong on both counts. It was not until 1945, through the X-ray crystallography work of Oxford University's Dorothy Hodgkin, that the molecule was found to contain thirty-nine atoms in an unusual four-membered ring called a beta-lactam structure to which was attached a side chain. X-ray diffraction crystallography involves shining a beam of X-rays through a pure crystal of a substance. The crystal causes the beam to split up into a complex pattern, which can then be analyzed mathematically to show the positions of individual atoms in a molecule. Such a chemical arrangement had never before been found in nature and only rarely in the laboratory.

21. E. B. Chain, “Thirty years of penicillin therapy,”
J R Coll Physicians Lond
6 (1972): 103–31.

22. Clark,
Life of Ernst Chain,
37.

23. E. B. Chain, H. W. Florey, A. D. Gardner, et al., “Penicillin as a chemotherapeutic agent,”
Lancet
2 (1940): 226–28.

24. The paper caught the eye of Alexander Fleming. His visit to the Oxford laboratory was a surprise to some of the staff, especially Chain, who remarked, “Good God! I thought he was dead!” But there he was—a modest man with shaggy eyebrows, pale blue eyes behind wire-rimmed spectacles, and his customary blue suit and bowtie inquiring, “What have you been doing with my old penicillin?” Given a tour by Florey and Chain, Fleming typically said little else. This left Chain with the impression that Fleming had not understood anything that was shown him.

25. Macfarlane,
Howard Florey,
331.

26. E. P. Abraham, E. Chain, C. M. Fletcher, et al., “Further observations on penicillin,”
Lancet
2 (1941): 177–89.

27. Agriculture was the one area of scientific research for which Congress generously appropriated money. From the 1890s to the 1930s the Department of Agriculture was the leading agency of the federal government with scientific interests and health-related scientific work.

28. Lennard Bickel,
Rise Up to Life
(London: Angus and Robertson, 1972), 147.

29. Penicillin functions by inhibiting an enzyme necessary for chemical construction of the bacterium's cell wall. Without the wall, the cell eventually bursts and dies. Variations in the composition of the side chain determine the various characteristics of the different penicillins. Most commercial penicillins today are produced from a strain of
P. chrysogenum.
The main form produced is called penicillin G. Penicillin is effective against most gram-positive bacteria, including those that cause gonorrhea, syphilis, meningococcal meningitis, pneumococcal pneumonia, and some staphylococcal and streptococcal infections. Most gram-negative bacteria are resistant to penicillin. Two synthetic penicillins, ampicillin and amoxicillin, are active against both gram-positive and gram-negative bacteria. Bacterial strains that become penicillin-resistant are mutants that produce a penicillin-destroying enzyme, penicillinase. This acts by opening the beta-lactam ring of the penicillin molecule. Semisynthetically produced penicillins, such as oxacillin and methicillin, that are not degraded by penicillinase have been developed.

30. Penicillin was not successfully synthesized until 1957, but it remains cheaper to produce the drug from the mold. It has been found that exposing the culture to X-rays further raises the yield.

31. Remarkably, the first people to note this phenomenon of microbial antagonism were Pasteur and Joubert in 1877, observing in a famous phrase that “life hinders life.” They speculated on the clinical potential of microbial products as therapeutic agents.

32. Alexander Fleming, “Penicillin, Nobel Lecture, December 11, 1945,” in
Nobel Lectures, Physiology or Medicine, 1942–1962
(Amsterdam: Elsevier, 1964), 83–93.

33. D. C. Balfour, N. M. Keith, J. Cameron, and A. Fleming, “Remarks made at the dinner for Sir Alexander Fleming held at Mayo Foundation House, July 16, 1945, Rochester, MN.” Quoted in J. W. Henderson, “The yellow brick road to penicillin: A story of serendipity,”
Mayo Clinic Proceedings
72 (1997): 683–87.

34. Alexander Fleming, “Réponse.” In “Séance solonnelle et extra-ordinaire du 4 septembre 1945. Séance tenue en l'honnneur de la visite à l'Académie de Sir Alexander Fleming,”
Bull Acad Natl Méd
(1945): 537–44.

35. Macfarlane,
Howard Florey,
364.

36. Clark,
Life of Ernst Chain,
31.

37. Macfarlane,
Howard Florey,
304.

38. E. B. Chain, “The quest for new biodynamic substances,” in
Reflections on Research and the Future of Medicine,
ed. Charles E. Lyght (New York: McGraw-Hill, 1967), 167–68.

C
HAPTER
6: The Next Wonder Drug: Streptomycin

1. Selman A. Waksman,
The Antibiotic Era
(Tokyo: Waksman Foundation of Japan, 1975).

2. Quoted in J. Comroe, “Pay dirt: The story of streptomycin,”
Am Rev Resp Dis
(1978): 778.

3. S. A. Waksman and H. B. Woodruff, “The soil as a source of micro-organisms antagonistic to disease producing bacteria,”
J Bact
40 (1940): 581.

4. Years earlier, researchers in Belgium had used some actinomycetes to dissolve bacterial cultures, but their aim related to immunity. With the antigens released from the bacterial contents, they hoped to induce formation of antibodies against the specific bacterium. A. Gratia and S. Dath, “Moisissures et Microbes Bacteriophages,”
C R Soc Biol Paris
92 (1925): 461–62. Waksman's quest was to find a bacteriolytic substance safe enough to be used as an antibiotic.

5. A strain of actinomycin was later found useful in Hodgkin's disease and thus crossed the line from antibiotic to chemotherapy.

6. Ryan,
Forgotten Plague,
218.

7. The first test tube culture is now in the collection of the Smithsonian Institution.

8. A. Schatz and S. A. Waksman, “Effect of streptomycin and other antibiotic substances upon
Mycobacterium tuberculosis
and related organisms,”
Proc Soc Exp Biol Med
57 (1944): 244–48.

9. Antibiotics work by interfering with a bacterium's reproduction, its metabolic exchange through its cell envelope, or its source of energy. They can interfere with cell-wall synthesis, as penicillin and vancomycin do. Or, like the tetracyclines and erythromycin, they can inhibit the vital process of DNA synthesis, leading to cell death. A class of antibiotics known as polymyxins affect the permeability of the cell membrane, leading to leakage of intracellular components. Finally, an antibiotic may block specific metabolic steps that are essential, as the sulfa drugs do in competing with the vitamin substance PABA.

10. Another bounty of soil and mold research is a useful agent for lowering blood cholesterol. Lovastatin (marketed as Mevacor by Merck) was isolated from a strain of
Aspergillus terreus
and approved for use in the United States by the FDA in 1987. A. W. Alberts, J. S. MacDonald, A. E. Till, and J. A. Tobert, “Lovastatin,”
Cardiol Drug Rev
7 (1989): 89–109.

11. “Streptomycin Suit Is Labeled ‘Baseless,’”
New York Times,
March 13, 1950.

12. Burton Feldman,
The Nobel Prize: A History of Genius, Controversy, and Prestige
(New York: Arcade, 2000), 276.

13. Selman A. Waksman,
My Life with the Microbes
(New York: Simon and Schuster, 1954), 285.

14. Selman A. Waksman,
The Conquest of Tuberculosis
(Berkeley and Los Angeles: University of California Press, 1964), 90.

C
HAPTER
7: The Mysterious Protein from Down Under

1. Baruch S. Blumberg, “Australia antigen and the biology of hepatitis B,”
Nobel Lectures in Physiology or Medicine, 1971–1980,
ed. Jan Lindsten (Singapore: World Scientific Publishing, 1992), 275–96.

2. Baruch S. Blumberg, B. J. S. Gerstley, D. A. Hungerford, W. T. London, and A. I. Sutnick, “A serum antigen (Australia antigen) in Down's syndrome, leukemia and hepatitis,”
Ann Intern Med
66 (1967): 924–31.

3. Baruch S. Blumberg,
Hepatitis B: The Hunt for a Killer Virus
(Princeton: Princeton University Press, 2002), 102.