1887

Abstract

A low-molecular-mass cytotoxin produced by isolated previously from patients with antibiotic-associated haemorrhagic enterocolitis was purified, and its biological and chemical properties were elucidated. The toxin inhibited the syntheses of DNA and RNA by HEp-2 cells dose-dependently, whereas protein synthesis was only slightly inhibited, as measured by the incorporation of radioactive precursors. When synchronously cultured HEp-2 cells were examined in the presence of cytotoxin, inhibition of DNA synthesis occurred promptly within 5 h, but cell-rounding, the earliest visible morphological change, was not observed until 6 h after exposure. The intracellular levels of ATP decreased with an approximately similar time course. These results suggest that cytotoxicity toward HEp-2 cells is primarily due to the inhibitory effect of the cytotoxin on nucleic acid synthesis, possibly on DNA synthesis. Cell rounding and cell death were induced even in the absence of the cytotoxin after incubation with the cytotoxin for 6 h. The cytotoxin was heat-labile, cytotoxic activity decreasing to 50% of the initial level on heating at 70°C for 20 min. Plasmids were extracted from three strains of producing the cytotoxin and analysed by agarose gel electrophoresis. Two strains possessed plasmids of different sizes, but one strain possessed no plasmid, indicating that the cytotoxin is probably chromosomally encoded. Analysis by NMR and FAB-mass-spectrometry revealed that the molecular mass of the cytotoxin should be 217.1062 Da (exact mass), its molecular formula being CHON.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-138-9-1921
1992-09-01
2021-04-20
Loading full text...

Full text loading...

/deliver/fulltext/micro/138/9/mic-138-9-1921.html?itemId=/content/journal/micro/10.1099/00221287-138-9-1921&mimeType=html&fmt=ahah

References

  1. Ashkenazi S., Cleary T. G., Murray B. E., Wanger A., Pickering L. K. 1988; Quantitative analysis and partial character-ization of cytotoxin production by Salmonella strains. Infection and Immunity 56:3089–3094
    [Google Scholar]
  2. Baloda S. B., Faris A., Krovacek K., Wadstrom T. 1983; Cytotoxic enterotoxins and cytotoxic factors produced by S. enteritidis and S. typhimurium. Toxicon 21:785–790
    [Google Scholar]
  3. Cookson B. T., Cho H.-L., Herwaldt L. A., Goldman W. E. 1989; Biological activities and chemical composition of purified tracheal cytotoxin of Bordetella pertussis. Infection and Immunity 57:2223–2229
    [Google Scholar]
  4. Donta S. T., Shaffer S. J. 1980; Effects of Clostridium difficile toxin on tissue-cultured cells. Journal of Infectious Diseases 141:218–222
    [Google Scholar]
  5. Guerrant R. L., Wanke C. A., Pennie R. A., Barrett L. J., Lima A. A. M., O’Brien A. D. 1987; Production of a unique cytotoxin by Campylobacter jejuni. Infection and Immunity 55:2526–2530
    [Google Scholar]
  6. Kado C. I., Liu S.-T. 1981; Rapid procedure for detection and isolation of large and small plasmids. Journal of Bacteriology 145:1365–1373
    [Google Scholar]
  7. Katayama S., Ninomiya M., Minami J., Okabe A., Hayashi H. 1990; Transcriptional control plays an important role for the production of heat-labile enterotoxin in enterotoxigenic Escherichia coli of human origin. Microbiology and Immunology 34:11–24
    [Google Scholar]
  8. Ketyi I., Pacsa S., Emody L., Vertenyi A., Kocsis B., Kuch B. 1979; Shigella dysenteriae 1-like cytotoxic enterotoxins produced by Salmonella strains. Acta Microbiologica Hungarica 26:217–223
    [Google Scholar]
  9. Koo F. C. W., Peterson J. W. 1983; Cell-free extracts of Salmonella inhibit protein synthesis and cause cytotoxity in eukaryotic cells. Toxicon 21:309–320
    [Google Scholar]
  10. Lima A. A. M., Lyerly D. M., Wilkins T. D., Innes D. J., Guerrant R. L. 1988; Effects of Clostridium difficile toxins A andB in rabbit small and large intestine in vivo and on cultured cells in vitro. Infection and Immunity 56:582–588
    [Google Scholar]
  11. Minami J., Okabe A., Shiode J., Hayashi H. 1989; Production of a unique cytotoxin by Klebsiella oxytoca. Microbial Pathogenesis 7:203–211
    [Google Scholar]
  12. O’Brien A. D., Holmes R. K. 1987; Shiga and Shiga-like toxins. Microbiological Reviews 51:206–220
    [Google Scholar]
  13. O’Brien A. D., La Beck G. D., Thompson M. R., Formal S. B. 1982; Production of Shigella dysenteriae type 1-like cytotoxin by Escherichia coli. Journal of Infectious Diseases 146:763–769
    [Google Scholar]
  14. Rosenthal R. S., Nogami W., Cookson B. T., Goldman W. E., Folkening W. J. 1987; Major fragment of soluble peptidoglycan released from growing Bordetella pertussis is tracheal cytotoxin. Infection and Immunity 55:2117–2120
    [Google Scholar]
  15. Watanabe F., Hashimoto T., Tagawa K. 1985; Energy-independent protection of the oxidative phosphorylation capacity of mitochondria against anoxic damage by ATP and its non-metabolizable analogs. Journal of Biochemistry 97:1229–1234
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-138-9-1921
Loading
/content/journal/micro/10.1099/00221287-138-9-1921
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error