Skip to main content
NCBI home page
Infection and Immunity logoLink to Infection and Immunity
. 1994 Oct;62(10):4167–4175. doi: 10.1128/iai.62.10.4167-4175.1994

Survival and replication of Rhodococcus equi in macrophages.

M K Hondalus 1, D M Mosser 1
PMCID: PMC303092  PMID: 7927672

Abstract

Rhodococcus equi is a facultative intracellular bacterium of macrophages that can cause serious pneumonia in both young horses and immunocompromised people. Essential to understanding rhodococcus pathogenesis is a quantitative documentation of the intracellular events that follow macrophage phagocytosis of the organism. By using a bacterial immunofluorescence staining assay, we verified the intracellular survival and replicative potential of R. equi in both murine peritoneal macrophages and equine alveolar macrophages in vitro. Following an initial lag period of 6 to 12 h, the intracellular numbers of R. equi begin to rise, often reaching macrophage-compromising levels by 48 h. A quantitative determination of bacterial growth by a novel image analysis cytometry technique confirmed our fluorescence microscopic results. By 48 h postinfection, bacterial numbers had increased by more than fivefold, and the majority of infected macrophages in the monolayer contained 10 or more bacteria per cell. The intracellular organisms were viable, as evidenced by the ability to incorporate radiolabeled uracil. The use of these techniques has identified differences in the in vitro replicative capacities of a virulent strain and an avirulent strain of R. equi. A clinical isolate of R. equi expressing a 17-kDa virulence-associated plasmid-encoded antigen was able to survive and replicate within macrophages, whereas an avirulent, non-plasmid-containing strain replicated poorly. These results suggest that plasmid-encoded bacterial virulence factors may contribute to the ability of R. equi to replicate within its host cell, the macrophage.

Full text

PDF
4167

Images in this article

4170Image
on p.4170
4171Image
on p.4171
4172Image
on p.4172

Selected References

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

  1. Armstrong J. A., Hart P. D. Response of cultured macrophages to Mycobacterium tuberculosis, with observations on fusion of lysosomes with phagosomes. J Exp Med. 1971 Sep 1;134(3 Pt 1):713–740. doi: 10.1084/jem.134.3.713. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Desomer J., Crespi M., Van Montagu M. Illegitimate integration of non-replicative vectors in the genome of Rhodococcus fascians upon electrotransformation as an insertional mutagenesis system. Mol Microbiol. 1991 Sep;5(9):2115–2124. doi: 10.1111/j.1365-2958.1991.tb02141.x. [DOI] [PubMed] [Google Scholar]
  3. Emmons W., Reichwein B., Winslow D. L. Rhodococcus equi infection in the patient with AIDS: literature review and report of an unusual case. Rev Infect Dis. 1991 Jan-Feb;13(1):91–96. doi: 10.1093/clinids/13.1.91. [DOI] [PubMed] [Google Scholar]
  4. Frehel C., de Chastellier C., Offredo C., Berche P. Intramacrophage growth of Mycobacterium avium during infection of mice. Infect Immun. 1991 Jun;59(6):2207–2214. doi: 10.1128/iai.59.6.2207-2214.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Goodfellow M., Collins M. D., Minnikin D. E. Thin-layer chromatographic analysis of mycolic acid and other long-chain components in whole-organism methanolysates of coryneform and related taxa. J Gen Microbiol. 1976 Oct;96(2):351–358. doi: 10.1099/00221287-96-2-351. [DOI] [PubMed] [Google Scholar]
  6. Goodfellow M. The taxonomic status of Rhodococcus equi. Vet Microbiol. 1987 Aug;14(3):205–209. doi: 10.1016/0378-1135(87)90106-4. [DOI] [PubMed] [Google Scholar]
  7. Gotoh K., Mitsuyama M., Imaizumi S., Kawamura I., Yano I. Mycolic acid-containing glycolipid as a possible virulence factor of Rhodococcus equi for mice. Microbiol Immunol. 1991;35(3):175–185. doi: 10.1111/j.1348-0421.1991.tb01546.x. [DOI] [PubMed] [Google Scholar]
  8. Gulig P. A., Curtiss R., 3rd Plasmid-associated virulence of Salmonella typhimurium. Infect Immun. 1987 Dec;55(12):2891–2901. doi: 10.1128/iai.55.12.2891-2901.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Harvey R. L., Sunstrum J. C. Rhodococcus equi infection in patients with and without human immunodeficiency virus infection. Rev Infect Dis. 1991 Jan-Feb;13(1):139–145. doi: 10.1093/clinids/13.1.139. [DOI] [PubMed] [Google Scholar]
  10. Hietala S. K., Ardans A. A. Interaction of Rhodococcus equi with phagocytic cells from R. equi-exposed and non-exposed foals. Vet Microbiol. 1987 Aug;14(3):307–320. doi: 10.1016/0378-1135(87)90118-0. [DOI] [PubMed] [Google Scholar]
  11. Hondalus M. K., Diamond M. S., Rosenthal L. A., Springer T. A., Mosser D. M. The intracellular bacterium Rhodococcus equi requires Mac-1 to bind to mammalian cells. Infect Immun. 1993 Jul;61(7):2919–2929. doi: 10.1128/iai.61.7.2919-2929.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hondalus M. K., Sweeney C. R., Mosser D. M. An assay to quantitate the binding of Rhodococcus equi to macrophages. Vet Immunol Immunopathol. 1992 May;32(3-4):339–350. doi: 10.1016/0165-2427(92)90055-u. [DOI] [PubMed] [Google Scholar]
  13. Johnson J. A., Prescott J. F., Markham R. J. The pathology of experimental Corynebacterium equi infection in foals following intrabronchial challenge. Vet Pathol. 1983 Jul;20(4):440–449. doi: 10.1177/030098588302000407. [DOI] [PubMed] [Google Scholar]
  14. Kalpana G. V., Bloom B. R., Jacobs W. R., Jr Insertional mutagenesis and illegitimate recombination in mycobacteria. Proc Natl Acad Sci U S A. 1991 Jun 15;88(12):5433–5437. doi: 10.1073/pnas.88.12.5433. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Martens R. J., Fiske R. A., Renshaw H. W. Experimental subacute foal pneumonia induced by aerosol administration of Corynebacterium equi. Equine Vet J. 1982 Apr;14(2):111–116. doi: 10.1111/j.2042-3306.1982.tb02359.x. [DOI] [PubMed] [Google Scholar]
  16. Nakazawa M., Haritani M., Sugimoto C., Isayama Y. Virulence of Rhodococcus equi for mice. Nihon Juigaku Zasshi. 1983 Oct;45(5):679–682. doi: 10.1292/jvms1939.45.679. [DOI] [PubMed] [Google Scholar]
  17. Noel G. J., Mosser D. M., Edelson P. J. Role of complement in mouse macrophage binding of Haemophilus influenzae type b. J Clin Invest. 1990 Jan;85(1):208–218. doi: 10.1172/JCI114414. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Pearlman E., Jiwa A. H., Engleberg N. C., Eisenstein B. I. Growth of Legionella pneumophila in a human macrophage-like (U937) cell line. Microb Pathog. 1988 Aug;5(2):87–95. doi: 10.1016/0882-4010(88)90011-3. [DOI] [PubMed] [Google Scholar]
  19. Portnoy D. A., Jacks P. S., Hinrichs D. J. Role of hemolysin for the intracellular growth of Listeria monocytogenes. J Exp Med. 1988 Apr 1;167(4):1459–1471. doi: 10.1084/jem.167.4.1459. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Portnoy D. A., Martinez R. J. Role of a plasmid in the pathogenicity of Yersinia species. Curr Top Microbiol Immunol. 1985;118:29–51. doi: 10.1007/978-3-642-70586-1_3. [DOI] [PubMed] [Google Scholar]
  21. Prescott J. F. Rhodococcus equi: an animal and human pathogen. Clin Microbiol Rev. 1991 Jan;4(1):20–34. doi: 10.1128/cmr.4.1.20. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Sansonetti P. J., Ryter A., Clerc P., Maurelli A. T., Mounier J. Multiplication of Shigella flexneri within HeLa cells: lysis of the phagocytic vacuole and plasmid-mediated contact hemolysis. Infect Immun. 1986 Feb;51(2):461–469. doi: 10.1128/iai.51.2.461-469.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Takai S., Kawazu S., Tsubaki S. Humoral immune response of foals to experimental infection with Rhodococcus equi. Vet Microbiol. 1987 Aug;14(3):321–327. doi: 10.1016/0378-1135(87)90119-2. [DOI] [PubMed] [Google Scholar]
  24. Takai S., Koike K., Ohbushi S., Izumi C., Tsubaki S. Identification of 15- to 17-kilodalton antigens associated with virulent Rhodococcus equi. J Clin Microbiol. 1991 Mar;29(3):439–443. doi: 10.1128/jcm.29.3.439-443.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Takai S., Sekizaki T., Ozawa T., Sugawara T., Watanabe Y., Tsubaki S. Association between a large plasmid and 15- to 17-kilodalton antigens in virulent Rhodococcus equi. Infect Immun. 1991 Nov;59(11):4056–4060. doi: 10.1128/iai.59.11.4056-4060.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Tkachuk-Saad O., Prescott J. Rhodococcus equi plasmids: isolation and partial characterization. J Clin Microbiol. 1991 Dec;29(12):2696–2700. doi: 10.1128/jcm.29.12.2696-2700.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Van Etta L. L., Filice G. A., Ferguson R. M., Gerding D. N. Corynebacterium equi: a review of 12 cases of human infection. Rev Infect Dis. 1983 Nov-Dec;5(6):1012–1018. doi: 10.1093/clinids/5.6.1012. [DOI] [PubMed] [Google Scholar]
  28. Zink M. C., Yager J. A., Prescott J. F., Fernando M. A. Electron microscopic investigation of intracellular events after ingestion of Rhodococcus equi by foal alveolar macrophages. Vet Microbiol. 1987 Aug;14(3):295–305. doi: 10.1016/0378-1135(87)90117-9. [DOI] [PubMed] [Google Scholar]
  29. Zink M. C., Yager J. A., Prescott J. F., Wilkie B. N. In vitro phagocytosis and killing of Corynebacterium equi by alveolar macrophages of foals. Am J Vet Res. 1985 Oct;46(10):2171–2174. [PubMed] [Google Scholar]
  30. Zink M. C., Yager J. A., Smart N. L. Corynebacterium equi Infections in Horses, 1958-1984: A Review of 131 Cases. Can Vet J. 1986 May;27(5):213–217. [PMC free article] [PubMed] [Google Scholar]
  31. Zychlinsky A., Prevost M. C., Sansonetti P. J. Shigella flexneri induces apoptosis in infected macrophages. Nature. 1992 Jul 9;358(6382):167–169. doi: 10.1038/358167a0. [DOI] [PubMed] [Google Scholar]

Articles from Infection and Immunity are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES