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An Investigagtion on Influenza
- F. W. Twort, D. N. Twort
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- Journal:
- Journal of Hygiene / Volume 20 / Issue 1 / July 1921
- Published online by Cambridge University Press:
- 15 May 2009, pp. 85-98
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(1) Our experiments support the view that influenza is casued by B. influenzae, and that pneumococci and certain streptococci are the most important agents of secondary infections. No new type of bacterium was discovered, and no evidence was obtained of the presence of an ultra-micrascopic virus.
(2) B. influenzae appears more toxic for rabbits and mice when grown on fresh liver or kidney media than when grown on blood agar or in blood broth, and this is especially so when the kidney or liver is obtained from an animal of t he same species that has previously been inoculated with a culture of the influenza bacillus.
(3) Three fairly distinct special forms have been isolated from cultures of B. dysenteriae. They are probably not sexual units or stages in a true life cycle. Special large forms have also been obtained from cultures of B. influenzae, but these reverted back to the normal small type after several sub-cultures.
(4) A filter-passing material has been found associated with certain micro- cocci from vaccinia and in pure cultures of members of the dysentery-typhoid- coli group of bacteria. This material breaks down and dissolves the bacteria of the cultures, and the “infection” can be carried to fresh normal cultures. The evidence is against its being a living ultra-microscopic virus infecting the bacteria, but it may have some connection with the special forms. No definite evidence of a similar dissolving material has been found associated with cultures of the influenza bacillus.
(5) There is some indication that one or more of the forms isolated from pure cultures of dysentery bacilli may be special toxin-producing units, also that this function is at its maximum when the bacilli are first produced by the normal small forms or by sexual units of a normal culture. This may possibly be the case also with special forms that have been found in cultures of the influenza bacillus.
(6) It is believed that non-pathogenic wild varieties of ultra-microscopic viruses must exist in nature, and that they should present less difficulty in cultivation than the pathogenic varieties. Cultivations were made from filtrates of soil, faeces and water on various special media, and the tubes incubated in various gases. The chief gases tested either alone or mixed were oxygen, nitrogen, carbon dioxide and sulphuretted hydrogen. All the results were negative, but some interesting deposit colonies were obtained on media con taining a small quantity of sodium sulphide.
(7) The influenza bacillus grows in symbiosis with amoebae on blood agar, and in such cultures the bacillus lives considerably longer.
(8) The influenza bacillus grows in symbiosis with a small spirillum that was isolated from a grass emulsion, and in symbiosis with an extremely minute and delicate bacterium isolated from garden soil; after passing the emulsions through a Berkefeld filter. With these delicate bacteria the influenza bacillus will grow on media containing no blood, and if an egg medium is used the mixed growth is dense, heaped up and brownish in colour. In such cultures the in fluenza bacillus may live for months.
(9) The influenza and other bacilli will grow in an atmosphere of pure oxygen or pure carbon dioxide under diminished pressure.
The anaerobic cocci: gas formation, fermentation reactions, sensitivity to antibiotics and sulphonamides. Classification
- Ronald Hare, Peter Wildy, F. S. Billett, D. N. Twort
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- Journal:
- Journal of Hygiene / Volume 50 / Issue 3 / September 1952
- Published online by Cambridge University Press:
- 15 May 2009, pp. 295-319
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1. A total of ninety-nine strains of anaerobic cocci from human beings have been studied and six groups demarcated on the basis of gas formation and fermentation reactions.
2.Gas formation by strains of group I is due to fermentation of glucose, laevu-lose or maltose, with a sulphur compound as an activator and with the production of gas rich in CO2.
3.Gas formation by strains of groups II, III and V is due to fermentation of different organic acids, sulphur not being required, and accompanied by the production of gases containing a high proportion of H2.
4.Two groups, IV and VI, do not from gas, but the latter has marked fermentation abilities.
There is correlation between microscopic apperances, probable pathogenicity, sensitivity to antibiotics and sulphonamides and the groups demarcated.
Ninety-two out of ninety-nine strains isolated from human beings could be placed in one or other group.
We are greatly indebted to Dr H. J. Parish of the Wellcome Research Laboratories for a sample of Polymyxin E, to Prof. L. Young for much assistance and advice and to those colleagues, particularly Dr R. M. Caiman of Queen Charlotte's Hospital, who sent us strains.