Skip to main content
PMC home page
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1981 Feb;145(2):1010–1017. doi: 10.1128/jb.145.2.1010-1017.1981

Genetic regulation of variable Vi antigen expression in a strain of Citrobacter freundii.

N J Snellings, E M Johnson, D J Kopecko, H H Collins, L S Baron
PMCID: PMC217211  PMID: 6161917

Abstract

Certain strains of the genus Citrobacter exhibit a variable expression of the Vi surface antigen that appears to involve a special mechanism for regulation of gene expression. Two nonlinked chromosomal loci, viaA and viaB, are known to determine nonvariable Vi antigen expression in strains of Salmonella. To confirm the presence of analogous loci in Citrobacter and to ascertain whether either of them is involved in variable Vi antigen expression in this organism, donor strains were constructed from Citrobacter freundii WR7004 and used to transfer their Vi antigen-determining genes to ViaA- and ViaB- Salmonella typhi recipient strains. Vi antigen expression in C. freundii was found to be controlled by loci analogous to the Salmonella via genes. S. typhi recipients of the C. freundii viaA+ genes were restored to the full, continuous expression of the Vi antigen normally seen in S. typhi. Thus, the C. freundii viaA genes appeared to play no role in the variable expression of the Vi antigen. In contrast, S. typhi recipients of the C. freundii viaB+ genes exhibited the rapid, reversible alternation between full Vi antigen expression and markedly reduced Vi antigen expression that was seen to occur in the C. freundii parent. The C. freundii viaB locus was thus identified as the one whose genes are regulated so as to produce variable Vi antigen expression. Genes determining another C. freundii surface antigen, the synthesis of which is not affected by the mechanism regulating Vi expression, were coinherited with the C. freundii viaB+ genes. An invertible, insertion sequence element located within the C. freundii viaB locus is proposed to account for the regulation of variable Vi antigen expression.

Full text

PDF
1010

Images in this article

1012Image
on p.1012

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BRINTON C. C., Jr Non-flagellar appendages of bacteria. Nature. 1959 Mar 21;183(4664):782–786. doi: 10.1038/183782a0. [DOI] [PubMed] [Google Scholar]
  2. Fujita H., Yamaguchi S., Iino T. Studies on H-O variants in Salmonella in relation to phase variation. J Gen Microbiol. 1973 May;76(1):127–134. doi: 10.1099/00221287-76-1-127. [DOI] [PubMed] [Google Scholar]
  3. JOHNSON E. M., KRAUSKOPF B., BARON L. S. GENETIC MAPPING OF VI AND SOMATIC ANTIGENIC DETERMINANTS IN SALMONELLA. J Bacteriol. 1965 Aug;90:302–308. doi: 10.1128/jb.90.2.302-308.1965. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Johnson E. M., Baron L. S. Genetic transfer of the Vi antigen from Salmonella typhosa to Escherichia coli. J Bacteriol. 1969 Jul;99(1):358–359. doi: 10.1128/jb.99.1.358-359.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Johnson E. M., Krauskopf B., Baron L. S. Genetic analysis of the ViA-his chromosomal region in Salmonella. J Bacteriol. 1966 Nov;92(5):1457–1463. doi: 10.1128/jb.92.5.1457-1463.1966. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Lederberg J, Iino T. Phase Variation in Salmonella. Genetics. 1956 Sep;41(5):743–757. doi: 10.1093/genetics/41.5.743. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Miyake T. Exchange of Genetic Material between Salmonella Typhimurium and Escherichia Coli K-12. Genetics. 1962 Aug;47(8):1043–1052. doi: 10.1093/genetics/47.8.1043. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Old D. C., Corneil I., Gibson L. F., Thomson A. D., Duguid J. P. Fimbriation, pellicle formation and the amount of growth of salmonellas in broth. J Gen Microbiol. 1968 Apr;51(1):1–16. doi: 10.1099/00221287-51-1-1. [DOI] [PubMed] [Google Scholar]
  9. Pearce U. B., Stocker B. A. Phase variation of flagellar antigens in Salmonella: abortive transduction studies. J Gen Microbiol. 1967 Nov;49(2):335–349. doi: 10.1099/00221287-49-2-335. [DOI] [PubMed] [Google Scholar]
  10. Silverman M., Simon M. Phase variation: genetic analysis of switching mutants. Cell. 1980 Apr;19(4):845–854. doi: 10.1016/0092-8674(80)90075-6. [DOI] [PubMed] [Google Scholar]
  11. Snellings N. J., Johnson E. M., Baron L. S. Genetic basis of Vi antigen expression in Salmonella paratyphi C. J Bacteriol. 1977 Jul;131(1):57–62. doi: 10.1128/jb.131.1.57-62.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Swaney L. M., Liu Y. P., To C. M., To C. C., Ippen-Ihler K., Brinton C. C., Jr Isolation and characterization of Escherichia coli phase variants and mutants deficient in type 1 pilus production. J Bacteriol. 1977 Apr;130(1):495–505. doi: 10.1128/jb.130.1.495-505.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Zieg J., Simon M. Analysis of the nucleotide sequence of an invertible controlling element. Proc Natl Acad Sci U S A. 1980 Jul;77(7):4196–4200. doi: 10.1073/pnas.77.7.4196. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES