TWORT, FREDERICK WILLIAM

b. Camberely, London, England, 22 October 1877; d. Camberely, 20 March 1950)

microbiology.

Twort was the eldest of the eleven children of William Henry Twort, a medical practitioner in Camberly. He attended St. Thomas’ Hospital Medical School in London, where he qualified in 1900 as member of the Royal College of Surgeons of England and licentiate of the Royal College of Physicians of London. He caried out no clinical practice and in 1901 was appointed assistant to Louis Jenner, the superintendent of the Clinical Laboratory (1902), Twort entered the field of microbilofy, in which discipline he remained for the rest of his professional career, as assistant to William Bulloch, bacteriologist to the London Hospital. He stayed three fo seven years, during which time he gained wide experience in hospital bacteriology while beginning hiw own investigations. By 1907 the latter had become of primary importance to him, and he obtained the position of superintendent of the Brown Animal Sanatory Institution, a veterinary dispensary in London where Charles Sherrington and Victor Horsley had worked. Here Twort isolated himself from his colleagues in bacteriology and engaged only in research. Being by nature a recluse and an outstanding example of the independent research worker, he remained in this post for thirty-five years, except for a period of military service during World War I, He was appointed professor of bacteriology in the University of London in 1919 and was elected a fellow of the Royal Society in 1929.

Twort possessed great industry and powers of concentration as well as unusual ability; his remarkable technical skills were of the utmost advantage in his work. his aloofness and his inability to commit himself in his scientific writings militated against dissemination of his undoubtedly outstanding and original contributions to bacteriology. He was a kind and gentle person with a simple, uncomplicated nature; but he was also shy, naïve, slightly paranoid, and without much humor. Nevertheless, he could be aggressive and obstinate in defense of a principle, as for example the financial support of research. Biographers vaguely mention controversies and a“combative personality”(lancet, 1950), but do not elaborate. He has also been styled“an erratic genius” (British Medical Journal, 1950).

Twort married Dorothy Nony Banister, daughter of F. J. Banister, an architect, and she helped him in his work. They had three daughters and a son who also entered the medical profession.

Twort’s work in bacteriology was based on the premise that pathogenic bacteria must have evolved from wild, free-living organisms, an original theme at a time when bacteriologists were studying pathogens per se almost exclusively. Among several of his original contributions the most important was the discovery of the lytic phenomena now known to be caused by bacteriophage. Twort was working on the purification of vaccinia virus in an attempt to discover nonpathogenic ultramicroscopic viruses when he encountered a substance that could dissolve the bacterium Staphylococcus aureus in culture. He isolated it by ultrafiltration, and was able to transmit it indefinitely to further generations of micrococci. It is now known that this substance is a virus that attacks bacteria. Although Twort made this suggestion, he also advanced other suggestions, and, as usual, did not commit himself to any one. His classic paper on ultramicroscopic viruses, published in Lancet in 1915, was in the form of a preliminary communication, but the expected sequel appreared during World War I and excited little interest. Moreover, in 1915 Twort joined the army, and on his return to his investigations in 1919 he did not continue what eventually became a most fruitful field of research. In 1917 Félix d’Hérelle discovered the same phenonmenon and named it bacteriophage. The attempts he made to establish his own priority only served to reaffirm that of Twort.

In his other researches Twort also made original contributions that led eventually to fundamental advances in bacteriology. His first important paper, published in 1907, established the essentials of the adaptation and mutation of bacteria, showing, for example, that a nonpathogenic microorganism could become pathogenic. Once again his work gained little recognition at the time. It was the same with his paper published in 1909 on the factors that affect the growth of bacteria; the significance of these factors was not recognized until twenty years later. Twort’s studies of Johne’s bacillus, a mycobacterium responsible for a chronic intestinal disease of cattle, carried out with G. L. Y. Ingram in 1912, revealed an essential growth factor that. when present, allowed the organism to be cultured and a protective vaccine to be prepared. It opened up the whole field of the nutritional needs of bacteria, a field that could only be developed as biochemistry advanced. During World War I Twort investigated dysentery in the Middle East and discovered special forms of the causative bacillus; but his speculations on them were vague (1920) and the only result was his demonstration that these bizarre forms could be induced.

After World War I, Twort’s researches became increasingly insignificant as he struggled to prove his thesis that pathogens derive from wild ancestors, that bacteria evolve from viruses, and that viruses come from even more primitive forms of life. The outcome of all these studies seems of little importance; they were terminated abruptly in 1944 by the destruction of his laboratory and equipment by enemy action.

BIBLIOGRAPHY

I. Original Works. Twort’s classic paper, on what is now termed bacteriophage, is“An Investigation of the Nature of Ultra-Microsscoic Viruses,”in Lancet (1915), 2 , 1241–1243. It is reprinted in full in N. Hayon, ed., Selected Papers on Virology (Englewood Cliffs, N.J., 1964), 97–102, and extracts appear in H. A. Lechevalier and M. Solotrorovsky, Three Centuries of Microbiology (New York, 1955). 303-306.

A list of Twort’s papers, containing twenty-two items, is in P. Fildes’ obituary (see below), 517. Those of importance are “The Fermentation of Glucosides by Bacteria of the Typhoid-coli Group and the Acquisition of New Fermenting Powers by Bacillus dysenteriae and other Micro-organisms. Preliminary Communication,” in Proceedings of the Royal Society, series B, 79 (1907), 329-336;“The Influence of Glucosides on the Growth of Acid-fast Bacteria,” ibid., 81 (1909), 248; “A Method for Isolating and Cultivating the Mycobacterium enteritidis chronicle pseudo-tuberculosae bovis, Johne,...,” with G. L. Y. Ingram, ibid., 84 (1912). 517-542; and“Researches on Dysentery.”in British Journal of Experimental Pathology, 1 (1920). 237-243.

II. Secondary Literature. The only extended discussion of Twort and his work is by P. Fildes, Obituary Notices of Fellows of the Royal Society, 7 (1951), 505-517. Obituaries are in British Medical Journal (1950), 1 , 788-789, with a portrait; Lancet (1950), 1 , 648–649; and Nature, 165 (1950), 874. There is a portrait of Twort when working with W. Bulloch in C. E. Dolman. “Paul Ehrlich and William Bulloch: a Correspondence and Friendship (1896–1914).” in Clio Medica, 3 (1968). 65-84, fig. 9.

Edwin Clarke