Figure 1.
Capture of IncX-replicon plasmids.
Agarose gel electrophoresis of (a) plasmid purification of strains Shigella sp. MO17, MO440 and LN126, respectively, followed by (b) plasmid purifications of IncX-replicon positive transformants of Entranceposon derivatives of the same strains. The leftmost three lanes are EcoRI digests of the three first lanes. Based on the sequence analysis, the plasmids of MO17 and MO440 were identified as being identical, only differing by the position of the Entranceposon. This difference in Entranceposon insertion site accounts for the dissimilar band pattern observed within the digested versions of these two plasmids (see text for more details).
Figure 2.
Graphical representation of the annotated IncX-type plasmids, pLN126_33, pMO17/440_54 and R485. The central diagrams represent the %GC content. Black pins represent the insertion points of the Entranceposon derivatives.
Table 1.
Reported occurrences of type 3 biofilm promoting IncX-plasmids.
Figure 3.
Fimbriae encoding gene cassettes.
(top) The different versions of the mrkABCDF cassette and their flanking IS elements as they are arranged on plasmids pOLA52, R485, pMAS2027 & pLN126_33, compared to the corresponding chromosomal region of K. pneumoniae MGH 78578. (bottom) A similar comparison between the inserted region of plasmids pMO17/440_54 and the corresponding E. coli region that contains a putative type 1 fimbrial biogenesis cassette.
Figure 4.
Biofilm induction by IncX-plasmids containing fimbrial gene cassettes.
Biofilm formation measured via a crystal violet retention assay in E. coli Genehogs (GH) carrying pOLA52 compared with that of plasmids pMO17_54, pMO440_54, pLN126_33 and R485, respectively. The mrkC mutant of pOLA52 has a disrupted Usher protein-encoding gene and can therefore not produce biofilm. Error bars are standard deviations (n = 4).