Skip to main content
Applied and Environmental Microbiology logoLink to Applied and Environmental Microbiology
. 1988 Apr;54(4):910–916. doi: 10.1128/aem.54.4.910-916.1988

A model for analyzing growth kinetics of a slowly growing Mycobacterium sp.

R S Lambrecht 1, J F Carriere 1, M T Collins 1
PMCID: PMC202572  PMID: 3377502

Abstract

This report describes a simple method for quantifying viable mycobacteria and for determining generation time. We used statistical models and computer analysis of growth curves generated for the slowly growing mycobacterium Mycobacterium paratuberculosis under controlled conditions to derive a mathematical formula relating the dependent variable, growth, to the independent variables, log10 number of organisms in the inoculum (inoculum size) and incubation time. Growth was measured by a radiometric method which detects 14CO2 release during metabolism of a 14C-labeled substrate. The radiometric method allowed for early detection of growth and detected as few as three viable bacteria. The coefficient of variation between culture vials inoculated with the same number of M. paratuberculosis was 0.083. Radiometric measurements were highly correlated to spectrophotometric and plate count methods for measuring growth (r = 0.962 and 0.992, respectively). The proportion of the total variability explained by the model in a goodness of fit test was 0.9994. Application of the model to broth cultures provided accurate estimates of the number of M. paratuberculosis (standard error = 0.21, log10 scale) and the growth rate (coefficient of variation, 0.03). Generation time was observed to be dependent upon the number of organisms in the inoculum. The model accurately described all phases of growth of M. paratuberculosis and can likely be applied to other slowly growing microorganisms.

Full text

PDF
910

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Boonkitticharoen V., Ehrhardt J. C., Kirchner P. T. Radiometric assay of bacterial growth: analysis of factors determining system performance and optimization of assay technique. J Nucl Med. 1987 Feb;28(2):209–217. [PubMed] [Google Scholar]
  2. Buddemeyer E. U. Liquid scintillation vial for cumulative and continuous radiometric measurement of in vitro metabolism. Appl Microbiol. 1974 Aug;28(2):177–180. doi: 10.1128/am.28.2.177-180.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Buddemeyer E. U., Wells G. M., Hutchinson R., Cooper M. D., Johnston G. S. Radiometric estimation of the replication time of bacteria in culture: an objective and precise approach to quantitative microbiology. J Nucl Med. 1978 Jun;19(6):619–625. [PubMed] [Google Scholar]
  4. Camargo E. E., Larson S. M., Tepper B. S., Wagner H. N., Jr Radiometric studies of Mycobacterium lepraemurium. Int J Lepr Other Mycobact Dis. 1976 Jul-Sep;44(3):294–300. [PubMed] [Google Scholar]
  5. Chiodini R. J., Van Kruiningen H. J., Merkal R. S. Ruminant paratuberculosis (Johne's disease): the current status and future prospects. Cornell Vet. 1984 Jul;74(3):218–262. [PubMed] [Google Scholar]
  6. Chiodini R. J., Van Kruiningen H. J., Merkal R. S., Thayer W. R., Jr, Coutu J. A. Characteristics of an unclassified Mycobacterium species isolated from patients with Crohn's disease. J Clin Microbiol. 1984 Nov;20(5):966–971. doi: 10.1128/jcm.20.5.966-971.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cummings D. M., Ristroph D., Camargo E. E., Larson S. M., Wagner H. N., Jr Radiometric detection of the metabolic activity of Mycobacterium tuberculosis. J Nucl Med. 1975 Dec;16(12):1189–1191. [PubMed] [Google Scholar]
  8. Damato J. J., Collins M. T., McClatchy J. K. Urease testing of mycobacteria with BACTEC radiometric instrumentation. J Clin Microbiol. 1982 Mar;15(3):478–480. doi: 10.1128/jcm.15.3.478-480.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Damato J. J., Collins M. T., Rothlauf M. V., McClatchy J. K. Detection of mycobacteria by radiometric and standard plate procedures. J Clin Microbiol. 1983 Jun;17(6):1066–1073. doi: 10.1128/jcm.17.6.1066-1073.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. DeLand F. H., Wagner H. N., Jr Early detection of bacterial growth, with carbon-14-labeled glucose. Radiology. 1969 Jan;92(1):154–155. doi: 10.1148/92.1.154. [DOI] [PubMed] [Google Scholar]
  11. FENNER F. The enumeration of viable tubercle bacilli by surface plate counts. Am Rev Tuberc. 1951 Oct;64(4):353–380. doi: 10.1164/art.1951.64.4.353. [DOI] [PubMed] [Google Scholar]
  12. Gross W. M., Hawkins J. E. Radiometric selective inhibition tests for differentiation of Mycobacterium tuberculosis, Mycobacterium bovis, and other mycobacteria. J Clin Microbiol. 1985 Apr;21(4):565–568. doi: 10.1128/jcm.21.4.565-568.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Grover A. A., Kim H. K., Wiegeshaus E. H., Smith D. W. Host-parasite relationships in experimental airborne tuberculosis. II. Reproducible infection by means of an inoculum preserved at -70 C. J Bacteriol. 1967 Oct;94(4):832–835. doi: 10.1128/jb.94.4.832-835.1967. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Kertcher J. A., Chen M. F., Charache P., Hwangbo C. C., Camargo E. E., McIntyre P. A., Wagner H. N., Jr Rapid radiometric susceptibility testing of Mycobacterium tuberculosis. Am Rev Respir Dis. 1978 Apr;117(4):631–637. doi: 10.1164/arrd.1978.117.4.631. [DOI] [PubMed] [Google Scholar]
  15. Kirihara J. M., Hillier S. L., Coyle M. B. Improved detection times for Mycobacterium avium complex and Mycobacterium tuberculosis with the BACTEC radiometric system. J Clin Microbiol. 1985 Nov;22(5):841–845. doi: 10.1128/jcm.22.5.841-845.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. McFadden J. J., Butcher P. D., Chiodini R., Hermon-Taylor J. Crohn's disease-isolated mycobacteria are identical to Mycobacterium paratuberculosis, as determined by DNA probes that distinguish between mycobacterial species. J Clin Microbiol. 1987 May;25(5):796–801. doi: 10.1128/jcm.25.5.796-801.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Middlebrook G., Reggiardo Z., Tigertt W. D. Automatable radiometric detection of growth of Mycobacterium tuberculosis in selective media. Am Rev Respir Dis. 1977 Jun;115(6):1066–1069. doi: 10.1164/arrd.1977.115.6.1066. [DOI] [PubMed] [Google Scholar]
  18. Siddiqi S. H., Libonati J. P., Middlebrook G. Evaluation of rapid radiometric method for drug susceptibility testing of Mycobacterium tuberculosis. J Clin Microbiol. 1981 May;13(5):908–912. doi: 10.1128/jcm.13.5.908-912.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Applied and Environmental Microbiology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES