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. 1994 Jun;62(6):2478–2482. doi: 10.1128/iai.62.6.2478-2482.1994

Corneal virulence of Staphylococcus aureus: roles of alpha-toxin and protein A in pathogenesis.

M C Callegan 1, L S Engel 1, J M Hill 1, R J O'Callaghan 1
PMCID: PMC186534  PMID: 8188373

Abstract

Staphylococcus aureus produces a variety of proteins, including alpha-toxin and protein A, that could contribute to corneal tissue damage during keratitis. We examined corneal infections produced by intrastromal injection of four S. aureus strains--three isogenic mutants, one lacking alpha-toxin (Hly- Spa+), one lacking protein A (Hly+ Spa-), and one lacking both alpha-toxin and protein A (Hly- Spa-), and the wild type (Hly+ Spa+)--in a rabbit model of experimental keratitis. Rabbit corneas were injected intrastromally with 100 CFU of one of the four strains, and the eyes were examined by slit lamp biomicroscopy over a 25-h period. Corneal homogenates were used for determination of CFU and neutrophil myeloperoxidase activity at 5-h intervals. All strains had the same logarithmic growth curve from 0 to 10 h postinfection, after which CFU remained constant at 10(7) CFU per cornea. By 15 h postinfection, slit lamp examination scores were significantly higher for eyes infected with Hly+ strains than for Hly(-)-infected eyes. At this time, distinct epithelial erosions were seen in Hly(+)-infected eyes but not in Hly(-)-infected eyes. Myeloperoxidase activity was significantly greater for Hly(+)-infected corneas than for Hly(-)-infected corneas at both 20 and 25 h postinfection. Spa(+)- and Spa(-)-infected eyes showed no differences in slit lamp examination scores or myeloperoxidase activities. These results suggest that alpha-toxin, but not protein A, is a major virulence factor in staphylococcal keratitis, mediating the destruction of corneal tissue in eyes infected with this bacterial pathogen.

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Selected References

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  1. Bhakdi S., Tranum-Jensen J. Damage to mammalian cells by proteins that form transmembrane pores. Rev Physiol Biochem Pharmacol. 1987;107:147–223. doi: 10.1007/BFb0027646. [DOI] [PubMed] [Google Scholar]
  2. Bradley P. P., Priebat D. A., Christensen R. D., Rothstein G. Measurement of cutaneous inflammation: estimation of neutrophil content with an enzyme marker. J Invest Dermatol. 1982 Mar;78(3):206–209. doi: 10.1111/1523-1747.ep12506462. [DOI] [PubMed] [Google Scholar]
  3. 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]
  4. Callegan M. C., Engel L. S., Hill J. M., O'Callaghan R. J. Ciprofloxacin versus tobramycin for the treatment of staphylococcal keratitis. Invest Ophthalmol Vis Sci. 1994 Mar;35(3):1033–1037. [PubMed] [Google Scholar]
  5. Callegan M. C., Hill J. M., Insler M. S., Hobden J. A., O'Callaghan R. J. Methicillin-resistant Staphylococcus aureus keratitis in the rabbit: therapy with ciprofloxacin, vancomycin and cefazolin. Curr Eye Res. 1992 Nov;11(11):1111–1119. doi: 10.3109/02713689209015083. [DOI] [PubMed] [Google Scholar]
  6. Callegan M. C., Hobden J. A., Hill J. M., Insler M. S., O'Callaghan R. J. Topical antibiotic therapy for the treatment of experimental Staphylococcus aureus keratitis. Invest Ophthalmol Vis Sci. 1992 Oct;33(11):3017–3023. [PubMed] [Google Scholar]
  7. Chusid M. J., Davis S. D. Polymorphonuclear leukocyte kinetics in experimentally induced keratitis. Arch Ophthalmol. 1985 Feb;103(2):270–274. doi: 10.1001/archopht.1985.01050020122034. [DOI] [PubMed] [Google Scholar]
  8. Forsgren A., Sjöquist J. "Protein A" from S. aureus. I. Pseudo-immune reaction with human gamma-globulin. J Immunol. 1966 Dec;97(6):822–827. [PubMed] [Google Scholar]
  9. Gustafson G. T., Stålenheim G., Forsgren A., Sjöquist J. "Protein A" from Staphylococcus aureus. IV. Production of anaphylaxis-like cutaneous and systemic reactions in non-immunized guinea-pigs. J Immunol. 1968 Mar;100(3):530–534. [PubMed] [Google Scholar]
  10. Haraldsson I., Jonsson P. Histopathology and pathogenesis of mouse mastitis induced with Staphylococcus aureus mutants. J Comp Pathol. 1984 Apr;94(2):183–196. doi: 10.1016/0021-9975(84)90039-2. [DOI] [PubMed] [Google Scholar]
  11. Harshman S., Boquet P., Duflot E., Alouf J. E., Montecucco C., Papini E. Staphylococcal alpha-toxin: a study of membrane penetration and pore formation. J Biol Chem. 1989 Sep 5;264(25):14978–14984. [PubMed] [Google Scholar]
  12. Hazlett L. D., Zucker M., Berk R. S. Distribution and kinetics of the inflammatory cell response to ocular challenge with Pseudomonas aeruginosa in susceptible versus resistant mice. Ophthalmic Res. 1992;24(1):32–39. doi: 10.1159/000267142. [DOI] [PubMed] [Google Scholar]
  13. Heczko P. B., Grov A., Oeding P. In vivo reactions of staphylococcal antigens. 1. Hypersensitivity to protein A. Acta Pathol Microbiol Scand B Microbiol Immunol. 1973 Dec;81(6):731–740. doi: 10.1111/j.1699-0463.1973.tb02268.x. [DOI] [PubMed] [Google Scholar]
  14. Johnson M. K., Hobden J. A., Hagenah M., O'Callaghan R. J., Hill J. M., Chen S. The role of pneumolysin in ocular infections with Streptococcus pneumoniae. Curr Eye Res. 1990 Nov;9(11):1107–1114. doi: 10.3109/02713689008997584. [DOI] [PubMed] [Google Scholar]
  15. Jonsson P., Lindberg M., Haraldsson I., Wadström T. Virulence of Staphylococcus aureus in a mouse mastitis model: studies of alpha hemolysin, coagulase, and protein A as possible virulence determinants with protoplast fusion and gene cloning. Infect Immun. 1985 Sep;49(3):765–769. doi: 10.1128/iai.49.3.765-769.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Kupferman A., Leibowitz H. M. Quantitation of bacterial infection and antibiotic effect in the cornea. Arch Ophthalmol. 1976 Nov;94(11):1981–1984. doi: 10.1001/archopht.1976.03910040687017. [DOI] [PubMed] [Google Scholar]
  17. Kupferman A., Leibowitz H. M. Topical antibiotic therapy of staphylococcal keratitis. Arch Ophthalmol. 1977 Sep;95(9):1634–1637. doi: 10.1001/archopht.1977.04450090156015. [DOI] [PubMed] [Google Scholar]
  18. Limberg M. B. A review of bacterial keratitis and bacterial conjunctivitis. Am J Ophthalmol. 1991 Oct;112(4 Suppl):2S–9S. [PubMed] [Google Scholar]
  19. Novick R. Properties of a cryptic high-frequency transducing phage in Staphylococcus aureus. Virology. 1967 Sep;33(1):155–166. doi: 10.1016/0042-6822(67)90105-5. [DOI] [PubMed] [Google Scholar]
  20. 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]
  21. 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]
  22. Thelestam M., Blomqvist L. Staphylococcal alpha toxin--recent advances. Toxicon. 1988;26(1):55–65. doi: 10.1016/0041-0101(88)90137-7. [DOI] [PubMed] [Google Scholar]
  23. Williams R. N., Paterson C. A., Eakins K. E., Bhattacherjee P. Quantification of ocular inflammation: evaluation of polymorphonuclear leucocyte infiltration by measuring myeloperoxidase activity. Curr Eye Res. 1982;2(7):465–470. doi: 10.3109/02713688208996350. [DOI] [PubMed] [Google Scholar]

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