The Urea Method for Bacterial Viability Counts with the Electron Microscope and its Relation to other Viability Counting Methods Free

Abstract

SUMMARY: Live rod-shaped bacteria incubated on a medium containing 3 % urea grow but do not divide. They thus become much longer than dead bacteria lying among them, and the numbers of each kind can easily be counted in an electron microscope. This urea method gives accurate results and has several advantages over colony-counting methods. The significance of various interesting differences in the. counts given by the two methods is discussed. Slope cultures at 18 hr. gave live counts of over 95 % by the urea method.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-11-3-349
1954-12-01
2024-03-29
Loading full text...

Full text loading...

/deliver/fulltext/micro/11/3/mic-11-3-349.html?itemId=/content/journal/micro/10.1099/00221287-11-3-349&mimeType=html&fmt=ahah

References

  1. Bergey’s Manual of Determinative Bacteriology, 6th ed.. 1948 p. 486 Breed R.S., Murray E.G.D., Hitchens A.P. Edited by Baltimore: Williams & Wilkins;
  2. Brieger E.M., Cosslett V.E. 1949; Preparation of bacteria for electron microscopy. Nature; Lond.: 164352
    [Google Scholar]
  3. Cosslett V.E. 1951 Practical Electron Microscopy p. 185 London:: Butter-worth’s Scientific Publications.;
    [Google Scholar]
  4. Fry R.M., Greaves R.I.N. 1951; The survival of bacteria during and after drying. J. Hyg., Camb. 49:220
    [Google Scholar]
  5. Heinmets F., Taylor W.W., Lehman J.J. 1954; The use of metabolites in the restoration of the viability of heat and chemically inactivated Escherichia coli. J. Bact. 67:5
    [Google Scholar]
  6. Hillier J., Knaysi G., Baker R.F. 1948; New preparation techniques for the electron microscopy of bacteria. J.Bact. 56:569
    [Google Scholar]
  7. Hinshelwood C.N. 1946 The Chemical Kinetics of the Bacterial Cell p. 64 Oxford:: Clarendon Press.;
    [Google Scholar]
  8. Ishikawa M. 1928; Influence of carbohydrates on bacterial decomposition of urea. J. infect. Dis. 43:67
    [Google Scholar]
  9. Jennison M.W. 1937; Relations between plate counts and direct microscopic counts of Escherichia coli during the logarithmic growth period. J. Bact. 33:461
    [Google Scholar]
  10. Jordan R.C., Jacobs S.E. 1944; The growth of bacteria with a constant food supply. 1. Preliminary observations on Bacterium coli. J. Bact. 48:579
    [Google Scholar]
  11. Kelly C.D., Rahn O. 1932; The growth rate of individual cells. J. Bact. 23:147
    [Google Scholar]
  12. Lea D.E. 1946 Actions of Radiations on Living Cells pp. 78319 Cambridge University Press.;
    [Google Scholar]
  13. Migaki H., Mcculloch E.C. 1949; Survivor curves of bacteria exposed to surface-active agents. J. Bact. 58:161
    [Google Scholar]
  14. Régnier J., David R., Kaplan A. 1932; Contribution a l’etude numerique de la multiplication microbienne. De l’existence de la phase de latence. C.R. Acad. Sci., Paris 194:323
    [Google Scholar]
  15. Topley and wilson’s Principles of Bacteriology and Immunity, 3rd ed.. 1946 p. 88 6th ed. Wilson G.S., Miles A.A. Revised by London:: Edward Arnold.;
  16. Wilson G.S. 1922; The proportion of viable bacteria in young cultures, with special reference to the technique employed in counting. J. Bact. 7:405
    [Google Scholar]
  17. Wilson G.S. 1926; The. proportion of viable bacteria in agar cultures of B. aertrycke (mutton), with special reference to the change in size of the organism during growth, and in the opacity to which they give rise. J. Hyg., Camb. 25:150
    [Google Scholar]
  18. Wilson W.J. 1906; Pleomorphism, as exhibited by bacteria grown on media containing urea. J. Path. Bact. 11:394
    [Google Scholar]
  19. Ziegler N.R., Halvorson H.O. 1935; Application of statistics to problems in bacteriology. IV. Experimental comparison of the dilution method, the plate count, and the direct count for the determination of bacterial populations. J. Bact. 29:609
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-11-3-349
Loading
/content/journal/micro/10.1099/00221287-11-3-349
Loading

Data & Media loading...

Most cited Most Cited RSS feed