Logo of iaiPermissionsJournals.ASM.orgJournalIAI ArticleJournal InfoAuthorsReviewers
Infect Immun. Aug 1993; 61(8): 3164–3174.
PMCID: PMC280984

Enhancement of extracapsular polysaccharide synthesis in Klebsiella pneumoniae by RmpA2, which shows homology to NtrC and FixJ.


We determined the complete nucleotide sequence of a 2.1-kb HindIII-EcoRI fragment that was cloned from a resident large plasmid of Klebsiella pneumoniae Chedid, a highly virulent and mucoviscous strain of the O1:K2 serotype. This fragment encoded an ability to enhance K2 capsular polysaccharide synthesis in K. pneumoniae, and a 636-bp open reading frame (rmpA2) was found. The 411-bp rmpA reported to be involved in the virulence and mucoid phenotypes of K. pneumoniae by Nassif et al. (Mol. Microbiol. 3:1349-1359, 1989) was a part of rmpA2. Eighty percent homology in nucleotide sequence was found between rmpA2 and rmpA in the corresponding regions. The central domain of the deduced amino acid sequence of RmpA2 showed considerable homology to the central domains of NtrC of K. pneumoniae and Escherichia coli, to which the sigma factor of RNA polymerase binds. The C-terminal domain of RmpA2 also demonstrated considerable homology with the putative helix-turn-helix motifs of LuxR of Vibrio fischeri and FixJ of Rhizobium meliloti. Moreover, RmpA2 also showed some homology in its N- and C-terminal regions to those of RcsA, a transcriptional activator for colanic acid synthesis in E. coli. On the other hand, a sequence upstream of rmpA2 was found to be highly homologous to insertion sequence 3 of members of the family Enterobacteriaceae. Southern hybridization analysis suggested that rmpA2 exists on the large plasmids of all mucoviscous virulent K2 strains but not on those of the slightly mucoviscous avirulent strains. Freeze substitution electron microscopy and fluorescent-antibody staining with anti-K2 serum revealed that K. pneumoniae Chedid has a dense and thick capsule (180 nm) with dense extracapsular substance, whereas K. pneumoniae K2-215, one of the slightly mucoviscous and avirulent strains, has a capsule which is looser and thinner (120 nm) than that of strain Chedid and no extracapsular substance. Introduction of rmpA2 into K2-215 as well as reference strains K. pneumoniae K9 and K72 resulted in a change of the colony phenotype to highly mucoviscous through abundant production of extracapsular substance which reacted with anti-K2, -K9, or -K72, respectively, as did their parental strains. From these results, it is suggested that RmpA2 belongs to the family of transcriptional regulators and confers a highly mucoviscous phenotype on cells of various serotypes of K. pneumoniae by enhancing extracapsular polysaccharide synthesis.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (3.8M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Arakawa Y, Ohta M, Kido N, Mori M, Ito H, Komatsu T, Fujii Y, Kato N. Chromosomal beta-lactamase of Klebsiella oxytoca, a new class A enzyme that hydrolyzes broad-spectrum beta-lactam antibiotics. Antimicrob Agents Chemother. 1989 Jan;33(1):63–70. [PMC free article] [PubMed]
  • Arakawa Y, Ohta M, Wacharotayankun R, Mori M, Kido N, Ito H, Komatsu T, Sugiyama T, Kato N. Biosynthesis of Klebsiella K2 capsular polysaccharide in Escherichia coli HB101 requires the functions of rmpA and the chromosomal cps gene cluster of the virulent strain Klebsiella pneumoniae Chedid (O1:K2). Infect Immun. 1991 Jun;59(6):2043–2050. [PMC free article] [PubMed]
  • BATSHON BA, BAER H, SHAFFER MF. Immunologic paralysis produced in mice by Klebsiella pneumoniae type 2 polysaccharide. J Immunol. 1963 Jan;90:121–126. [PubMed]
  • Beveridge TJ, Graham LL. Surface layers of bacteria. Microbiol Rev. 1991 Dec;55(4):684–705. [PMC free article] [PubMed]
  • Bolivar F, Backman K. Plasmids of Escherichia coli as cloning vectors. Methods Enzymol. 1979;68:245–267. [PubMed]
  • Boyer HW, Roulland-Dussoix D. A complementation analysis of the restriction and modification of DNA in Escherichia coli. J Mol Biol. 1969 May 14;41(3):459–472. [PubMed]
  • Cryz SJ, Jr, Mortimer PM, Mansfield V, Germanier R. Seroepidemiology of Klebsiella bacteremic isolates and implications for vaccine development. J Clin Microbiol. 1986 Apr;23(4):687–690. [PMC free article] [PubMed]
  • Domenico P, Diedrich DL, Straus DC. Extracellular polysaccharide production by Klebsiella pneumoniae and its relationship to virulence. Can J Microbiol. 1985 May;31(5):472–478. [PubMed]
  • Edmondson AS, Cooke EM. The production of antisera to the Klebsiella capsular antigens. J Appl Bacteriol. 1979 Jun;46(3):579–584. [PubMed]
  • Kado CI, Liu ST. Rapid procedure for detection and isolation of large and small plasmids. J Bacteriol. 1981 Mar;145(3):1365–1373. [PMC free article] [PubMed]
  • Kiseleva BS, Krasnogolovets VN. Rol' Klebsiella pneumoniae v étiologii bakterial'nogo sepsisa. Zh Mikrobiol Epidemiol Immunobiol. 1983 Feb;(2):20–25. [PubMed]
  • Lawrence JG, Ochman H, Hartl DL. The evolution of insertion sequences within enteric bacteria. Genetics. 1992 May;131(1):9–20. [PMC free article] [PubMed]
  • McCallum KL, Whitfield C. The rcsA gene of Klebsiella pneumoniae O1:K20 is involved in expression of the serotype-specific K (capsular) antigen. Infect Immun. 1991 Feb;59(2):494–502. [PMC free article] [PubMed]
  • Meno Y, Amako K. Morphological evidence for penetration of anti-O antibody through the capsule of Klebsiella pneumoniae. Infect Immun. 1990 May;58(5):1421–1428. [PMC free article] [PubMed]
  • Mizuta K, Ohta M, Mori M, Hasegawa T, Nakashima I, Kato N. Virulence for mice of Klebsiella strains belonging to the O1 group: relationship to their capsular (K) types. Infect Immun. 1983 Apr;40(1):56–61. [PMC free article] [PubMed]
  • Mori M, Ohta M, Agata N, Kido N, Arakawa Y, Ito H, Komatsu T, Kato N. Identification of species and capsular types of Klebsiella clinical isolates, with special reference to Klebsiella planticola. Microbiol Immunol. 1989;33(11):887–895. [PubMed]
  • Nassif X, Honoré N, Vasselon T, Cole ST, Sansonetti PJ. Positive control of colanic acid synthesis in Escherichia coli by rmpA and rmpB, two virulence-plasmid genes of Klebsiella pneumoniae. Mol Microbiol. 1989 Oct;3(10):1349–1359. [PubMed]
  • Sanger F, Nicklen S, Coulson AR. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. [PMC free article] [PubMed]
  • Simoons-Smit AM, Verweij-van Vught AM, MacLaren DM. The role of K antigens as virulence factors in Klebsiella. J Med Microbiol. 1986 Mar;21(2):133–137. [PubMed]
  • Springer EL, Roth IL. Ultrastructure of the capsule of Klebsiella pneumoniae and slime of Enterobacter aerogenes revealed by freeze etching. Arch Mikrobiol. 1973 Nov 19;93(4):277–286. [PubMed]
  • Stout V, Torres-Cabassa A, Maurizi MR, Gutnick D, Gottesman S. RcsA, an unstable positive regulator of capsular polysaccharide synthesis. J Bacteriol. 1991 Mar;173(5):1738–1747. [PMC free article] [PubMed]
  • Sugiyama T, Kido N, Arakawa Y, Mori M, Naito S, Ohta M, Kato N. Rapid small-scale preparation method of cell surface polysaccharides. Microbiol Immunol. 1990;34(7):635–641. [PubMed]
  • Wacharotayankun R, Arakawa Y, Ohta M, Hasegawa T, Mori M, Horii T, Kato N. Involvement of rcsB in Klebsiella K2 capsule synthesis in Escherichia coli K-12. J Bacteriol. 1992 Feb;174(3):1063–1067. [PMC free article] [PubMed]
  • Whitfield C. Bacterial extracellular polysaccharides. Can J Microbiol. 1988 Apr;34(4):415–420. [PubMed]
  • WILKINSON JF, DUDMAN WF, ASPINALL GO. The extracellular polysaccharide of Aerobacter aerogenes A3 (S1) (Klebsiella type 54). Biochem J. 1955 Mar;59(3):446–451. [PMC free article] [PubMed]
  • Williams P, Lambert PA, Haigh CG, Brown MR. The influence of the O and K antigens of Klebsiella aerogenes on surface hydrophobicity and susceptibility to phagocytosis and antimicrobial agents. J Med Microbiol. 1986 Mar;21(2):125–132. [PubMed]
  • Yanisch-Perron C, Vieira J, Messing J. Improved M13 phage cloning vectors and host strains: nucleotide sequences of the M13mp18 and pUC19 vectors. Gene. 1985;33(1):103–119. [PubMed]

Articles from Infection and Immunity are provided here courtesy of American Society for Microbiology (ASM)


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...