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. 1997 Apr;65(4):1327–1334. doi: 10.1128/iai.65.4.1327-1334.1997

Proteus mirabilis mannose-resistant, Proteus-like fimbriae: MrpG is located at the fimbrial tip and is required for fimbrial assembly.

X Li 1, H Zhao 1, L Geymonat 1, F Bahrani 1, D E Johnson 1, H L Mobley 1
PMCID: PMC175136  PMID: 9119470

Abstract

The mannose-resistant, Proteus-like (MR/P) fimbria, responsible for mannose-resistant hemagglutination, is a virulence factor for uropathogenic Proteus mirabilis. Based on known fimbrial gene organization, we postulated that MrpG, a putative minor subunit of the MR/P fimbria, functions as an adhesin responsible for hemagglutination, while MrpA serves as the major structural subunit for the filamentous structure. To test this hypothesis, an mrpG mutant was constructed by allelic-exchange mutagenesis and verified by PCR and Southern blotting. The mrpG mutant was found to be negative for hemagglutination, while wild-type strain H14320 and the complemented mutant were positive. Western blots with antiserum raised against an overexpressed MrpG'-His6 fusion protein showed that MrpG was present in the fimbrial preparations of both the wild-type strain and the complemented mutant but absent in that of the mrpG mutant. The mrpG mutant was significantly less virulent in a CBA mouse model of ascending urinary tract infection. Western blots with antiserum to whole MR/P fimbriae showed that MrpA protein was also missing from the fimbrial preparation of the mrpG mutant. Using immunogold electron microscopy, we found that the normal MR/P-fimbrial structure was absent in the mrpG mutant, suggesting that MrpG is essential for initiation of normal fimbrial formation. In the wild-type strain, MrpG protein was localized to the tips of the fimbriae or at the surface of the cell when antiserum raised against overexpressed MrpG was used. Given the tip localization, MrpG may be required for initiation of assembly of MR/P fimbriae but does not appear to be the fimbrial adhesin.

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Selected References

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  1. Bahrani F. K., Cook S., Hull R. A., Massad G., Mobley H. L. Proteus mirabilis fimbriae: N-terminal amino acid sequence of a major fimbrial subunit and nucleotide sequences of the genes from two strains. Infect Immun. 1993 Mar;61(3):884–891. doi: 10.1128/iai.61.3.884-891.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bahrani F. K., Johnson D. E., Robbins D., Mobley H. L. Proteus mirabilis flagella and MR/P fimbriae: isolation, purification, N-terminal analysis, and serum antibody response following experimental urinary tract infection. Infect Immun. 1991 Oct;59(10):3574–3580. doi: 10.1128/iai.59.10.3574-3580.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bahrani F. K., Massad G., Lockatell C. V., Johnson D. E., Russell R. G., Warren J. W., Mobley H. L. Construction of an MR/P fimbrial mutant of Proteus mirabilis: role in virulence in a mouse model of ascending urinary tract infection. Infect Immun. 1994 Aug;62(8):3363–3371. doi: 10.1128/iai.62.8.3363-3371.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bahrani F. K., Mobley H. L. Proteus mirabilis MR/P fimbrial operon: genetic organization, nucleotide sequence, and conditions for expression. J Bacteriol. 1994 Jun;176(11):3412–3419. doi: 10.1128/jb.176.11.3412-3419.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bijlsma I. G., van Dijk L., Kusters J. G., Gaastra W. Nucleotide sequences of two fimbrial major subunit genes, pmpA and ucaA, from canine-uropathogenic Proteus mirabilis strains. Microbiology. 1995 Jun;141(Pt 6):1349–1357. doi: 10.1099/13500872-141-6-1349. [DOI] [PubMed] [Google Scholar]
  6. Cook S. W., Mody N., Valle J., Hull R. Molecular cloning of Proteus mirabilis uroepithelial cell adherence (uca) genes. Infect Immun. 1995 May;63(5):2082–2086. doi: 10.1128/iai.63.5.2082-2086.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Donnenberg M. S., Kaper J. B. Construction of an eae deletion mutant of enteropathogenic Escherichia coli by using a positive-selection suicide vector. Infect Immun. 1991 Dec;59(12):4310–4317. doi: 10.1128/iai.59.12.4310-4317.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Faulk W. P., Taylor G. M. An immunocolloid method for the electron microscope. Immunochemistry. 1971 Nov;8(11):1081–1083. doi: 10.1016/0019-2791(71)90496-4. [DOI] [PubMed] [Google Scholar]
  9. Hagberg L., Engberg I., Freter R., Lam J., Olling S., Svanborg Edén C. Ascending, unobstructed urinary tract infection in mice caused by pyelonephritogenic Escherichia coli of human origin. Infect Immun. 1983 Apr;40(1):273–283. doi: 10.1128/iai.40.1.273-283.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Hultgren S. J., Normark S., Abraham S. N. Chaperone-assisted assembly and molecular architecture of adhesive pili. Annu Rev Microbiol. 1991;45:383–415. doi: 10.1146/annurev.mi.45.100191.002123. [DOI] [PubMed] [Google Scholar]
  11. Johnson D. E., Russell R. G., Lockatell C. V., Zulty J. C., Warren J. W., Mobley H. L. Contribution of Proteus mirabilis urease to persistence, urolithiasis, and acute pyelonephritis in a mouse model of ascending urinary tract infection. Infect Immun. 1993 Jul;61(7):2748–2754. doi: 10.1128/iai.61.7.2748-2754.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Klemm P., Christiansen G. Three fim genes required for the regulation of length and mediation of adhesion of Escherichia coli type 1 fimbriae. Mol Gen Genet. 1987 Jul;208(3):439–445. doi: 10.1007/BF00328136. [DOI] [PubMed] [Google Scholar]
  13. Legnani-Fajardo C., Zunino P., Algorta G., Laborde H. F. Antigenic and immunogenic activity of flagella and fimbriae preparations from uropathogenic Proteus mirabilis. Can J Microbiol. 1991 Apr;37(4):325–328. doi: 10.1139/m91-052. [DOI] [PubMed] [Google Scholar]
  14. Lindberg F., Lund B., Johansson L., Normark S. Localization of the receptor-binding protein adhesin at the tip of the bacterial pilus. Nature. 1987 Jul 2;328(6125):84–87. doi: 10.1038/328084a0. [DOI] [PubMed] [Google Scholar]
  15. Massad G., Bahrani F. K., Mobley H. L. Proteus mirabilis fimbriae: identification, isolation, and characterization of a new ambient-temperature fimbria. Infect Immun. 1994 May;62(5):1989–1994. doi: 10.1128/iai.62.5.1989-1994.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Massad G., Fulkerson J. F., Jr, Watson D. C., Mobley H. L. Proteus mirabilis ambient-temperature fimbriae: cloning and nucleotide sequence of the aft gene cluster. Infect Immun. 1996 Oct;64(10):4390–4395. doi: 10.1128/iai.64.10.4390-4395.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Massad G., Mobley H. L. Genetic organization and complete sequence of the Proteus mirabilis pmf fimbrial operon. Gene. 1994 Dec 2;150(1):101–104. doi: 10.1016/0378-1119(94)90866-4. [DOI] [PubMed] [Google Scholar]
  18. McCrea K. W., Watson W. J., Gilsdorf J. R., Marrs C. F. Identification of hifD and hifE in the pilus gene cluster of Haemophilus influenzae type b strain Eagan. Infect Immun. 1994 Nov;62(11):4922–4928. doi: 10.1128/iai.62.11.4922-4928.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Miller V. L., Mekalanos J. J. A novel suicide vector and its use in construction of insertion mutations: osmoregulation of outer membrane proteins and virulence determinants in Vibrio cholerae requires toxR. J Bacteriol. 1988 Jun;170(6):2575–2583. doi: 10.1128/jb.170.6.2575-2583.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Mobley H. L., Belas R. Swarming and pathogenicity of Proteus mirabilis in the urinary tract. Trends Microbiol. 1995 Jul;3(7):280–284. doi: 10.1016/s0966-842x(00)88945-3. [DOI] [PubMed] [Google Scholar]
  21. Mobley H. L., Warren J. W. Urease-positive bacteriuria and obstruction of long-term urinary catheters. J Clin Microbiol. 1987 Nov;25(11):2216–2217. doi: 10.1128/jcm.25.11.2216-2217.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Old D. C., Adegbola R. A. Haemagglutinins and fimbriae of Morganella, Proteus and Providencia. J Med Microbiol. 1982 Nov;15(4):551–564. doi: 10.1099/00222615-15-4-551. [DOI] [PubMed] [Google Scholar]
  23. Willems R. J., Geuijen C., van der Heide H. G., Matheson M., Robinson A., Versluis L. F., Ebberink R., Theelen J., Mooi F. R. Isolation of a putative fimbrial adhesin from Bordetella pertussis and the identification of its gene. Mol Microbiol. 1993 Aug;9(3):623–634. doi: 10.1111/j.1365-2958.1993.tb01722.x. [DOI] [PubMed] [Google Scholar]
  24. Wray S. K., Hull S. I., Cook R. G., Barrish J., Hull R. A. Identification and characterization of a uroepithelial cell adhesin from a uropathogenic isolate of Proteus mirabilis. Infect Immun. 1986 Oct;54(1):43–49. doi: 10.1128/iai.54.1.43-49.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]

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