1887

Abstract

is a common intestinal-dwelling protozoan and causes diarrhoea in humans and animals worldwide. For several years, a small number of drugs such as the 5-nitroimidazole metronidazole (MET) or the thiazolide nitazoxanide (NTZ) have been used for chemotherapy against giardiasis. However, various pre-clinical and clinical investigations revealed that antigiardial chemotherapy may be complicated by emergence of giardial resistance to these drugs. The present study addressed the question if isoflavones with antigiardial activity, such as daidzein (DAI) or formononetin (FOR), may serve as alternative compounds for treatment of giardiasis. For this purpose, the potential of clone WB C6 to form resistance to FOR and related isoflavones was tested . In the line of these experiments, a clone (C3) resistant to isoflavones, but sensitive to MET and NTZ, was generated. Affinity chromatography on DAI-agarose using cell-free extracts of trophozoites resulted in the isolation of a polypeptide of approximately 40 kDa, which was identified by mass spectrometry as a nucleoside hydrolase (NH) homologue (EAA37551.1). In a nucleoside hydrolase assay, recombinant NH hydrolysed all nucleosides with a preference for purine nucleosides and was inhibited by isoflavones. Using quantitative RT-PCR, the expression of genes that are potentially involved in resistance formation was analysed, namely NH and genes encoding variant surface proteins (VSPs, TSA417). The transcript level of the potential target NH was found to be significantly reduced in C3. Moreover, drastic changes were observed in VSP gene expression. This may indicate that resistance formation in against isoflavones is linked to, and possibly mediated by, altered gene expression. Taken together, our results suggest FOR or related isoflavones as an alternative antigiardial agent to overcome potential problems of resistance to drugs like MET or NTZ. However, the capacity of to develop resistance to isoflavones can potentially interfere with this alternative treatment of the disease.

Loading

Article metrics loading...

/content/journal/micro/10.1099/mic.0.2007/010041-0
2007-12-01
2019-10-22
Loading full text...

Full text loading...

/deliver/fulltext/micro/153/12/4150.html?itemId=/content/journal/micro/10.1099/mic.0.2007/010041-0&mimeType=html&fmt=ahah

References

  1. Aldritt, S. M. & Wang, C. C. ( 1986; ). Purification and characterization of guanine phosphoribosyltransferase from Giardia lamblia. J Biol Chem 261, 8528–8533.
    [Google Scholar]
  2. Aldritt, S. M., Tien, P. & Wang, C. C. ( 1985; ). Pyrimidine salvage in Giardia lamblia. J Exp Med 161, 437–445.[CrossRef]
    [Google Scholar]
  3. Altschul, S. F., Madden, T. L., Schäffer, A. A., Zhang, J., Zhang, Z., Miller, W. & Lipman, D. L. ( 1997; ). Gapped blast and psi-blast: a new generation of protein database search programs. Nucleic Acids Res 25, 3389–3402.[CrossRef]
    [Google Scholar]
  4. Blum, H., Beier, H. & Gross, H. J. ( 1987; ). Improved silver staining of plant proteins, RNA and DNA in polyacrylamide gels. Electrophoresis 8, 93–99.[CrossRef]
    [Google Scholar]
  5. Dakora, F. D. & Phillips, D. A. ( 1996; ). Diverse functions of isoflavonoids in legumes transcend anti-microbial definitions of phytoalexins. Physiol Mol Plant Pathol 49, 1–20.[CrossRef]
    [Google Scholar]
  6. Dixon, R. A. & Steele, C. L. ( 1999; ). Flavonoids and isoflavonoids – a good mine for metabolic engineering. Trends Plant Sci 4, 394–400.[CrossRef]
    [Google Scholar]
  7. Ey, P. L., Davey, R. A. & Duffield, G. A. ( 1992; ). A low-affinity nucleobase transporter in the protozoan parasite Giardia intestinalis. Biochim Biophys Acta 1109, 179–186.[CrossRef]
    [Google Scholar]
  8. Gardner, T. B. & Hill, D. R. ( 2001; ). Treatment of giardiasis. Clin Microbiol Rev 14, 114–128.[CrossRef]
    [Google Scholar]
  9. Gero, A. M., Kang, E. W., Harvey, J. E., Schofield, P. J., Clinch, K. & Furneaux, R. H. ( 2000; ). Trichomonas vaginalis: detection of nucleoside hydrolase activity as a potential screening procedure. Exp Parasitol 94, 125–128.[CrossRef]
    [Google Scholar]
  10. Huang, X. & Miller, W. ( 1991; ). A time-efficient, linear-space local similarity algorithm. Adv Appl Math 12, 337–357.[CrossRef]
    [Google Scholar]
  11. Jarroll, E. L., Manning, P., Berrada, A., Hare, D. & Lindmark, D. G. ( 1989; ). Biochemistry and metabolism of Giardia. J Protozool 36, 190–197.[CrossRef]
    [Google Scholar]
  12. Keister, D. B. ( 1983; ). Axenic culture of Giardia lamblia in TYI-S-33 medium supplemented with bile. Trans R Soc Trop Med Hyg 77, 487–488.[CrossRef]
    [Google Scholar]
  13. Khan, I. A., Avery, M. A., Burandt, C. L., Goins, D. K., Mikell, J. R., Nash, T. E., Azadegan, A. & Walker, L. A. ( 2000; ). Antigiardial activity of isoflavones from Dalbergia frutescens bark. J Nat Prod 63, 1414–1416.[CrossRef]
    [Google Scholar]
  14. Kulakova, L., Singer, S. M., Conrad, J. & Nash, T. E. ( 2006; ). Epigenetic mechanisms are involved in the control of Giardia lamblia antigenic variation. Mol Microbiol 61, 1533–1542.[CrossRef]
    [Google Scholar]
  15. Laemmli, U. K. ( 1970; ). Cleavage of structural proteins during the assembly of the head of the bacteriophage T4. Nature 227, 680–685.[CrossRef]
    [Google Scholar]
  16. Megraud, F., Occhialini, A. & Rossignol, J.-F. ( 1998; ). Nitazoxanide: a potential drug for eradication of Helicobacter pylori with no cross-resistance to metronidazole. Antimicrob Agents Chemother 42, 2836–2840.
    [Google Scholar]
  17. Müller, N. & Gottstein, B. ( 1998; ). Antigenic variation and the murine immune response to Giardia lamblia. Int J Parasitol 28, 1829–1839.[CrossRef]
    [Google Scholar]
  18. Müller, N. & von Allmen, N. ( 2005; ). Recent insights into the mucosal reactions associated with Giardia lamblia infections. Int J Parasitol 35, 1339–1347.[CrossRef]
    [Google Scholar]
  19. Müller, J., Rühle, G., Müller, N., Rossignol, J. F. & Hemphill, A. ( 2006; ). In vitro effects of thiazolides on Giardia lamblia WB clone C6 cultured axenically and in coculture with CaCo2 cells. Antimicrob Agents Chemother 50, 162–170.[CrossRef]
    [Google Scholar]
  20. Müller, J., Sterk, M., Hemphill, A. & Müller, N. ( 2007; ). Characterization of Giardia lamblia WB C6 clones resistant to nitazoxanide and to metronidazole. J Antimicrob Chemother 60, 280–287.[CrossRef]
    [Google Scholar]
  21. Nash, T. E., Merritt, J. W., Jr & Conrad, J. T. ( 1991; ). Isolate and epitope variability in susceptibility of Giardia lamblia to intestinal proteases. Infect Immun 59, 1334–1340.
    [Google Scholar]
  22. Parkin, D. W. ( 1996; ). Purine-specific nucleoside N-ribohydrolase from Trypanosoma brucei brucei. J Biol Chem 271, 21713–21719.
    [Google Scholar]
  23. Parkin, D. W., Horenstein, B. A., Abdulah, D. A., Estupiñán, B. & Schramm, V. L. ( 1991; ). Nucleoside hydrolase from Crithidia fasciculata. Metabolic role, purification, specificity, and kinetic mechanism. J Biol Chem 266, 20658–20665.
    [Google Scholar]
  24. Savioli, L., Smith, H. & Thompson, A. ( 2006; ). Giardia and Cryptosporidium join the ‘Neglected Diseases Initiative’. Trends Parasitol 22, 203–208.[CrossRef]
    [Google Scholar]
  25. Shi, W., Schramm, V. L. & Almo, S. C. ( 1999; ). Nucleoside hydrolase from Leishmania major. J Biol Chem 274, 21114–21120.[CrossRef]
    [Google Scholar]
  26. Thompson, R. C. A. ( 2000; ). Giardiasis as a re-emerging infectious disease and its zoonotic potential. Int J Parasitol 30, 1259–1267.[CrossRef]
    [Google Scholar]
  27. Townson, S. M., Boreham, P. F., Upcroft, P. & Upcroft, J. A. ( 1994; ). Resistance to the nitroheterocyclic drugs. Acta Trop 56, 173–194.[CrossRef]
    [Google Scholar]
  28. Upcroft, P. & Upcroft, J. A. ( 2001; ). Drug targets and mechanisms of resistance in the anaerobic protozoa. Clin Microbiol Rev 14, 150–164.[CrossRef]
    [Google Scholar]
  29. Upcroft, J. A., Campbell, R. W., Benakli, K., Upcroft, P. & Vanelle, P. ( 1999; ). Efficacy of new 5-nitroimidazoles against metronidazole-susceptible and -resistant Giardia, Trichomonas, and Entamoeba spp. Antimicrob Agents Chemother 43, 73–76.
    [Google Scholar]
  30. Upcroft, J. A., Dunn, L. A., Wright, J. M., Benakli, K., Upcroft, P. & Vanelle, P. ( 2006; ). 5-nitroimidazole drugs effective against metronidazole-resistant Trichomonas vaginalis and Giardia duodenalis. Antimicrob Agents Chemother 50, 344–347.[CrossRef]
    [Google Scholar]
  31. von Allmen, N., Bienz, M., Hemphill, A. & Müller, N. ( 2004; ). Experimental infections of neonatal mice with cysts of Giardia lamblia clone GS/M-83–H7 are associated with an antigenic reset of the parasite. Infect Immun 72, 4763–4771.[CrossRef]
    [Google Scholar]
  32. Wang, C. C. & Aldritt, S. ( 1983; ). Purine salvage networks in Giardia lamblia. J Exp Med 158, 1703–1712.[CrossRef]
    [Google Scholar]
  33. Wright, J. M., Dunn, L. A., Upcroft, P. & Upcroft, J. A. ( 2003; ). Efficacy of antigiardial drugs. Expert Opin Drug Saf 2, 529–541.[CrossRef]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/mic.0.2007/010041-0
Loading
/content/journal/micro/10.1099/mic.0.2007/010041-0
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