Download Proteus mirabilis

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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
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Swarming proteus mirabilis
• „bulls-eye“ swarming on solid surfaces & self identity
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Boundary between P. mirabilis strain BB2000
and HI4320
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Aim of study
• Identification and characterization of the
genetic mechanism that is responsible for
bacterial self identity
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Construction of p. mirabilis mutant
library
• randomized Tn5-transposon mutagenesis of rifampicin
resistent p. miarabilis BB2000
Tn5-cat
Shuttle vector
cat
• conjugal transfer by mating of E.coli [pUTminiTn5-Cm]
and BB2000
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tnp: Transposase; mobRP4: conjugal transfer domain
Loss of self recognition I
• Screening of 3600 transposon BB2000 mutants revealed
one mutant with phenotypic loss of self recognition
„identification of self“ (Ids)
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Loss of self recognition II
• six gene cluster idsABCDEF carries information for
„identification of self“
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Phenotyping of individual
idsABCDEF knock outs
idsB – idsF are required for self recognition !
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Phenotyping of individual
idsABCDEF knock outs in HI4320
background
idsD and
idsB,
idsCidsE
and idsF
are essential
can be complemented
for self recognition
by allels
! of different strains
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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
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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
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Additional putative idsE genes in
genome of P. mirabilis HI4320
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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
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Summary
• gene locus idsABCDEF of P. mirabilis is important for selfnonself 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
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Thank you for your attention
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P. mirabilis boundaries
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Transposition and pBBR-MCS2
shuttle vector for mutagenesis
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