Skip to main content
. 2023 Mar 22;11(2):e05179-22. doi: 10.1128/spectrum.05179-22

FIG 2.

FIG 2

Planktonic-derived P. aeruginosa PAO9505 OMVs transfer plasmid DNA to recipient bacteria more efficiently than transformation with plasmid DNA alone. (A) Schematic diagram illustrating transformation of bacteria with 500 ng of total DNA associated with either non-treated control OMVs, which included extravesicular chromosomal and plasmid DNA (control OMVs), DNase-treated OMVs, which contained plasmid and chromosomal DNA (OMVs +DNase), or 500 ng of plasmid alone (plasmid alone). (B) The presence of pBBR1MCS-5 within PAO9503 transformants resulting from transformation using either control PAO9505 OMVs or pBBR1MCS-5 plasmid DNA alone as a positive control was confirmed by colony PCR using primers specific for the detection of the pBBR1MCS-5 gentamicin resistance cassette (Gmr). A positive plasmid control PAO9503 transformant (pos. control col.) and pBBR1MCS-5 DNA (PCR + control) were used as positive controls for the PCR. H2O (PCR − control) and PAO9503 recipient colonies (recipient col) were used as negative controls for the PCR. Arrow indicates the gentamicin cassette amplicon (Gmr; 500 bp). Data are representative of images from n = 4 biological replicates. (C) The transformation efficiency of control PAO9505 pBBR1MCS-5 OMVs (circles) and plasmid DNA alone (triangles) was calculated as the number of PAO9503 transformants per 108 plasmid DNA copies. Data are means ± SEM of n = 4 biological replicates. *, P < 0.05 (Mann-Whitney test). (D) The number of transformants resulting from transformation of P. aeruginosa PAO9503 or PAO9505 with 1 μg of pBBR1MCS-5. Data are means ± SEM of n = 3 biological replicates. *, P < 0.05 (Student's t test).