1 / 18

_________________________________________________________

_________________________________________________________. _________________________________________________________________________. Proteus mirabilis. gram negative, facultative anaerobe rod causes infections in human urinary tract (pyelonephritis, kidney stones) followed by septicaemia

lester
Download Presentation

_________________________________________________________

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. _________________________________________________________ _________________________________________________________________________

  2. Proteus mirabilis • gram negative, facultative anaerobe rod • causes infections in human urinary tract (pyelonephritis, kidney stones) followed by septicaemia • motile bacterium with peritrichous flagella • Morphology change in swarming process

  3. Swarming proteus mirabilis • „bulls-eye“ swarming on solid surfaces & self identity

  4. Boundary between P. mirabilis strain BB2000 and HI4320

  5. Aim of study • Identification and characterization of the genetic mechanism that is responsible for bacterial self identity

  6. Construction of p. mirabilis mutant library • randomized Tn5-transposon mutagenesis of rifampicin resistent p. miarabilis BB2000 Tn5-cat Shuttle vector • conjugal transfer by mating of E.coli [pUTminiTn5-Cm] and BB2000 cat tnp: Transposase; mobRP4: conjugal transfer domain

  7. Loss of self recognition I • Screening of 3600 transposon BB2000 mutants revealed one mutant with phenotypic loss of self recognition „identification of self“ (Ids)

  8. Loss of self recognition II • six gene cluster idsABCDEF carries information for „identification of self“

  9. Phenotyping of individual idsABCDEF knock outs idsB – idsF are required for self recognition !

  10. Phenotyping of individual idsABCDEF knock outs in HI4320 background idsD and idsE are essential for self recognition ! idsB, idsC and idsF can be complemented by allels of different strains

  11. idsD and idsE encode identity determinants ….but the ids gene cluster is not the sole determinant of boundary formation ! boundary between BB2000+pidsHI4320 and HI4320+pidsBB2000

  12. Conserved organization of ids gene cluster in other P. mirabilis isolates idsABCDEF with nearly identical length and ~96% identity to homolog idsD and idsE have variable domains in protein sequences

  13. Additional putative idsE genes in genome of P. mirabilis HI4320

  14. Model of self recognitation idsA is not required for self identity; idsF overtakes function distinct from idsB and idsC in self-nonself recognition; idsD and idsE are molecular self identifiers

  15. Summary • gene locus idsABCDEF of P. mirabilis is important for self-nonself discrimination and boundary formation • Conserved ids gene cluster has been found in other proteus mirabilis strains • idsA is not required for parental recognition • idsB, idsC and idsF are interchangeable between strains • idsD and idsE are specific molecular identifiers that possess strain dependent variable domains • other ids homologs in bacterial genome may contribute to the self recognition process

  16. Thank you for your attention

  17. P. mirabilis boundaries

  18. Transposition and pBBR-MCS2 shuttle vector for mutagenesis

More Related