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. 1997 Sep;65(9):3606–3614. doi: 10.1128/iai.65.9.3606-3614.1997

Analysis of expression of the alpha-toxin gene (hla) of Staphylococcus aureus by using a chromosomally encoded hla::lacZ gene fusion.

K Ohlsen 1, K P Koller 1, J Hacker 1
PMCID: PMC175513  PMID: 9284126

Abstract

The staphylococcal alpha-toxin (Hla) is a major virulence factor contributing to Staphylococcus aureus pathogenesis. To elucidate the conditions influencing hla expression, the determinant was fused to lacZ, the reporter gene coding for beta-galactosidase. The hla::lacZ fusion was integrated into the chromosome of the wild-type S. aureus strain Wood 46, leading to the variant Wood 46-3. Alpha-toxin expression was found to be dependent on temperature, showing a maximum at 42 degrees C. Furthermore, the indicator strain showed a growth phase-dependent hla regulation which was influenced by temperature. At 37 degrees C, induction of hla::lacZ expression occurred in the late exponential phase of growth, whereas at 42 degrees C, a strong induction was observed as early as the mid-exponential phase. These observations were verified by Northern blot analysis of hla mRNA and by Western blot (immunoblot) analysis of culture supernatants of strain Wood 46. It was additionally found that the induction of hla transcription at 42 degrees C was not coupled with higher concentrations of agr RNAIII, the effector molecule of the global regulator agr. Furthermore, expression of the alpha-toxin was repressed at a high osmolarity. It was also shown that oxygen is essential for hla expression and that cultivation of the S. aureus strain Wood 46-3 on solid medium and in the presence of carbon dioxide stimulated hla transcriptional activity.

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Selected References

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  1. Bhakdi S., Muhly M., Korom S., Hugo F. Release of interleukin-1 beta associated with potent cytocidal action of staphylococcal alpha-toxin on human monocytes. Infect Immun. 1989 Nov;57(11):3512–3519. doi: 10.1128/iai.57.11.3512-3519.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bhakdi S., Muhly M., Mannhardt U., Hugo F., Klapettek K., Mueller-Eckhardt C., Roka L. Staphylococcal alpha toxin promotes blood coagulation via attack on human platelets. J Exp Med. 1988 Aug 1;168(2):527–542. doi: 10.1084/jem.168.2.527. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bhakdi S., Tranum-Jensen J. Alpha-toxin of Staphylococcus aureus. Microbiol Rev. 1991 Dec;55(4):733–751. doi: 10.1128/mr.55.4.733-751.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Birnboim H. C., Doly J. A rapid alkaline extraction procedure for screening recombinant plasmid DNA. Nucleic Acids Res. 1979 Nov 24;7(6):1513–1523. doi: 10.1093/nar/7.6.1513. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bramley A. J., Patel A. H., O'Reilly M., Foster R., Foster T. J. Roles of alpha-toxin and beta-toxin in virulence of Staphylococcus aureus for the mouse mammary gland. Infect Immun. 1989 Aug;57(8):2489–2494. doi: 10.1128/iai.57.8.2489-2494.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Casadaban M. J., Chou J., Cohen S. N. In vitro gene fusions that join an enzymatically active beta-galactosidase segment to amino-terminal fragments of exogenous proteins: Escherichia coli plasmid vectors for the detection and cloning of translational initiation signals. J Bacteriol. 1980 Aug;143(2):971–980. doi: 10.1128/jb.143.2.971-980.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cheung A. L., Koomey J. M., Butler C. A., Projan S. J., Fischetti V. A. Regulation of exoprotein expression in Staphylococcus aureus by a locus (sar) distinct from agr. Proc Natl Acad Sci U S A. 1992 Jul 15;89(14):6462–6466. doi: 10.1073/pnas.89.14.6462. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Cheung A. L., Projan S. J. Cloning and sequencing of sarA of Staphylococcus aureus, a gene required for the expression of agr. J Bacteriol. 1994 Jul;176(13):4168–4172. doi: 10.1128/jb.176.13.4168-4172.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Csonka L. N. Physiological and genetic responses of bacteria to osmotic stress. Microbiol Rev. 1989 Mar;53(1):121–147. doi: 10.1128/mr.53.1.121-147.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Duncan J. L., Cho G. J. Production of staphylococcal alpha toxin. II. Glucose repression of toxin formation. Infect Immun. 1972 Nov;6(5):689–694. doi: 10.1128/iai.6.5.689-694.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Gardel C. L., Mekalanos J. J. Regulation of cholera toxin by temperature, pH, and osmolarity. Methods Enzymol. 1994;235:517–526. doi: 10.1016/0076-6879(94)35167-8. [DOI] [PubMed] [Google Scholar]
  12. Genigeorgis C., Foda M. S., Mantis A., Sadler W. W. Effect of sodium chloride and pH on enterotoxin C production. Appl Microbiol. 1971 May;21(5):862–866. doi: 10.1128/am.21.5.862-866.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Genigeorgis C., Sadler W. W. Effect of sodium chloride and pH on enterotoxin B production. J Bacteriol. 1966 Nov;92(5):1383–1387. doi: 10.1128/jb.92.5.1383-1387.1966. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Graham J. E., Wilkinson B. J. Staphylococcus aureus osmoregulation: roles for choline, glycine betaine, proline, and taurine. J Bacteriol. 1992 Apr;174(8):2711–2716. doi: 10.1128/jb.174.8.2711-2716.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Gray G. S., Kehoe M. Primary sequence of the alpha-toxin gene from Staphylococcus aureus wood 46. Infect Immun. 1984 Nov;46(2):615–618. doi: 10.1128/iai.46.2.615-618.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Göransson M., Uhlin B. E. Environmental temperature regulates transcription of a virulence pili operon in E. coli. EMBO J. 1984 Dec 1;3(12):2885–2888. doi: 10.1002/j.1460-2075.1984.tb02225.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Hromockyj A. E., Tucker S. C., Maurelli A. T. Temperature regulation of Shigella virulence: identification of the repressor gene virR, an analogue of hns, and partial complementation by tyrosyl transfer RNA (tRNA1(Tyr)). Mol Microbiol. 1992 Aug;6(15):2113–2124. doi: 10.1111/j.1365-2958.1992.tb01385.x. [DOI] [PubMed] [Google Scholar]
  18. Kass E. H., Kendrick M. I., Tsai Y. C., Parsonnet J. Interaction of magnesium ion, oxygen tension, and temperature in the production of toxic-shock-syndrome toxin-1 by Staphylococcus aureus. J Infect Dis. 1987 Apr;155(4):812–815. doi: 10.1093/infdis/155.4.812. [DOI] [PubMed] [Google Scholar]
  19. Kernodle D. S., Voladri R. K., Menzies B. E., Hager C. C., Edwards K. M. Expression of an antisense hla fragment in Staphylococcus aureus reduces alpha-toxin production in vitro and attenuates lethal activity in a murine model. Infect Immun. 1997 Jan;65(1):179–184. doi: 10.1128/iai.65.1.179-184.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Kraus A., Hueck C., Gärtner D., Hillen W. Catabolite repression of the Bacillus subtilis xyl operon involves a cis element functional in the context of an unrelated sequence, and glucose exerts additional xylR-dependent repression. J Bacteriol. 1994 Mar;176(6):1738–1745. doi: 10.1128/jb.176.6.1738-1745.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Kreiswirth B. N., Löfdahl S., Betley M. J., O'Reilly M., Schlievert P. M., Bergdoll M. S., Novick R. P. The toxic shock syndrome exotoxin structural gene is not detectably transmitted by a prophage. Nature. 1983 Oct 20;305(5936):709–712. doi: 10.1038/305709a0. [DOI] [PubMed] [Google Scholar]
  22. Kyhse-Andersen J. Electroblotting of multiple gels: a simple apparatus without buffer tank for rapid transfer of proteins from polyacrylamide to nitrocellulose. J Biochem Biophys Methods. 1984 Dec;10(3-4):203–209. doi: 10.1016/0165-022x(84)90040-x. [DOI] [PubMed] [Google Scholar]
  23. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  24. Mekalanos J. J. Environmental signals controlling expression of virulence determinants in bacteria. J Bacteriol. 1992 Jan;174(1):1–7. doi: 10.1128/jb.174.1.1-7.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Mikulskis A. V., Delor I., Thi V. H., Cornelis G. R. Regulation of the Yersinia enterocolitica enterotoxin Yst gene. Influence of growth phase, temperature, osmolarity, pH and bacterial host factors. Mol Microbiol. 1994 Dec;14(5):905–915. doi: 10.1111/j.1365-2958.1994.tb01326.x. [DOI] [PubMed] [Google Scholar]
  26. Morfeldt E., Taylor D., von Gabain A., Arvidson S. Activation of alpha-toxin translation in Staphylococcus aureus by the trans-encoded antisense RNA, RNAIII. EMBO J. 1995 Sep 15;14(18):4569–4577. doi: 10.1002/j.1460-2075.1995.tb00136.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Morfeldt E., Tegmark K., Arvidson S. Transcriptional control of the agr-dependent virulence gene regulator, RNAIII, in Staphylococcus aureus. Mol Microbiol. 1996 Sep;21(6):1227–1237. doi: 10.1046/j.1365-2958.1996.751447.x. [DOI] [PubMed] [Google Scholar]
  28. Novick R. P., Ross H. F., Projan S. J., Kornblum J., Kreiswirth B., Moghazeh S. Synthesis of staphylococcal virulence factors is controlled by a regulatory RNA molecule. EMBO J. 1993 Oct;12(10):3967–3975. doi: 10.1002/j.1460-2075.1993.tb06074.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. O'Reilly M., de Azavedo J. C., Kennedy S., Foster T. J. Inactivation of the alpha-haemolysin gene of Staphylococcus aureus 8325-4 by site-directed mutagenesis and studies on the expression of its haemolysins. Microb Pathog. 1986 Apr;1(2):125–138. doi: 10.1016/0882-4010(86)90015-x. [DOI] [PubMed] [Google Scholar]
  30. Ott M., Messner P., Heesemann J., Marre R., Hacker J. Temperature-dependent expression of flagella in Legionella. J Gen Microbiol. 1991 Aug;137(8):1955–1961. doi: 10.1099/00221287-137-8-1955. [DOI] [PubMed] [Google Scholar]
  31. Patel A. H., Nowlan P., Weavers E. D., Foster T. Virulence of protein A-deficient and alpha-toxin-deficient mutants of Staphylococcus aureus isolated by allele replacement. Infect Immun. 1987 Dec;55(12):3103–3110. doi: 10.1128/iai.55.12.3103-3110.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Pospiech A., Neumann B. A versatile quick-prep of genomic DNA from gram-positive bacteria. Trends Genet. 1995 Jun;11(6):217–218. doi: 10.1016/s0168-9525(00)89052-6. [DOI] [PubMed] [Google Scholar]
  33. Prugnola A., Aricò B., Manetti R., Rappuoli R., Scarlato V. Response of the bvg regulon of Bordetella pertussis to different temperatures and short-term temperature shifts. Microbiology. 1995 Oct;141(Pt 10):2529–2534. doi: 10.1099/13500872-141-10-2529. [DOI] [PubMed] [Google Scholar]
  34. Regassa L. B., Novick R. P., Betley M. J. Glucose and nonmaintained pH decrease expression of the accessory gene regulator (agr) in Staphylococcus aureus. Infect Immun. 1992 Aug;60(8):3381–3388. doi: 10.1128/iai.60.8.3381-3388.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Schenk S., Laddaga R. A. Improved method for electroporation of Staphylococcus aureus. FEMS Microbiol Lett. 1992 Jul 1;73(1-2):133–138. doi: 10.1016/0378-1097(92)90596-g. [DOI] [PubMed] [Google Scholar]
  36. Schmoll T., Ott M., Oudega B., Hacker J. Use of a wild-type gene fusion to determine the influence of environmental conditions on expression of the S fimbrial adhesin in an Escherichia coli pathogen. J Bacteriol. 1990 Sep;172(9):5103–5111. doi: 10.1128/jb.172.9.5103-5111.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Sheehan B. J., Foster T. J., Dorman C. J., Park S., Stewart G. S. Osmotic and growth-phase dependent regulation of the eta gene of Staphylococcus aureus: a role for DNA supercoiling. Mol Gen Genet. 1992 Mar;232(1):49–57. doi: 10.1007/BF00299136. [DOI] [PubMed] [Google Scholar]
  38. Smeltzer M. S., Hart M. E., Iandolo J. J. Phenotypic characterization of xpr, a global regulator of extracellular virulence factors in Staphylococcus aureus. Infect Immun. 1993 Mar;61(3):919–925. doi: 10.1128/iai.61.3.919-925.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Song L., Hobaugh M. R., Shustak C., Cheley S., Bayley H., Gouaux J. E. Structure of staphylococcal alpha-hemolysin, a heptameric transmembrane pore. Science. 1996 Dec 13;274(5294):1859–1866. doi: 10.1126/science.274.5294.1859. [DOI] [PubMed] [Google Scholar]
  40. Vandenesch F., Kornblum J., Novick R. P. A temporal signal, independent of agr, is required for hla but not spa transcription in Staphylococcus aureus. J Bacteriol. 1991 Oct;173(20):6313–6320. doi: 10.1128/jb.173.20.6313-6320.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Walev I., Martin E., Jonas D., Mohamadzadeh M., Müller-Klieser W., Kunz L., Bhakdi S. Staphylococcal alpha-toxin kills human keratinocytes by permeabilizing the plasma membrane for monovalent ions. Infect Immun. 1993 Dec;61(12):4972–4979. doi: 10.1128/iai.61.12.4972-4979.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Wiseman G. M. The hemolysins of Staphylococcus aureus. Bacteriol Rev. 1975 Dec;39(4):317–344. doi: 10.1128/br.39.4.317-344.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]

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