Article Figures & Data
Figures
- FIG. 1.
Distribution of biofilm formation in static media. Diagrams illustrate A590 values obtained after dissolution of biofilm-bound CV for four E. coli strain collections of different origin and relevant control strains after growth in LB medium (A), ABTG (B), ABTCAA (C), and diluted mucus (D). Distribution of biofilm formation of each of the four strain collections is shown in a box and whisker format. Boxes range from the 25th to 75th percentile and are intersected by the median line. Whiskers extending below and above the box range from the 10th to the 90th percentile, respectively. Outliers are indicated as individual data points. Means of A590 values obtained for K-12 and prototypic pathogen control strains are shown.
- FIG. 2.
Correlation of biofilm formation in different media. A590 values obtained after dissolution of biofilm-bound CV for all 331 E. coli isolates of the four strain collections in each medium are plotted against A590 values obtained in each of the other three media (LB versus ABTG [A], LB versus ABTCAA [B], LB versus mucus [C], ABTG versus ABTCAA [D], ABTG versus mucus [E], and ABTCAA versus mucus [F]). Both axes are log scaled. The calculated Pearson correlation coefficient r is indicated in each plot. Asterisks demonstrate significance of positive correlation (P < 0.001).
- FIG. 3.
Dependence of biofilm formation on growth medium composition. Distribution of log-transformed A590 values obtained after dissolution of biofilm-bound CV for all 331 E. coli isolates in four growth media is illustrated as a box-and-whisker diagram. Features of the box and whisker format are described in the legend Fig. 1. The mean value (MlnA) of each distribution is indicated by a dotted line in the box and is listed below the diagram together with the corresponding standard error. For easier comparison, MlnA values were retransformed to the linear scale and resulted in the listed geometric means (Mg, A) of the original data. Asterisks indicate significant difference between the given MlnA value and the MlnA values obtained in all other growth media (P < 0.05). SE, standard error.
- FIG. 4.
Comparison of biofilm formation of strains that carry or lack genes specific for F-like conjugative plasmids or EAggEC. E. coli isolates were grouped based on positive PCR amplification of F-like tra genes finO and traA (A) or the EAggEC-specific gene probe AA (B). Distributions of log-transformed A590 values obtained after dissolution of biofilm-bound CV for these strain groups are illustrated as box-and-whisker diagrams. Features of the box-and-whisker format are described in the legend to Fig. 1. The mean value (MlnA) of each distribution is indicated by a dotted line in the box.
- FIG. 5.
Biofilm formation in a flow chamber model system. Micrographs represent horizontal sections of biofilms monitored by SCLM 72 h to 96 h after inoculation with the following strains: E. coli MG1655 (A), MG1655(R1drd19) (B), MG1655ompR234 (C), EAggEC 042 (D), and E. coli isolated from humans suffering from diarrhea (I), bacteremia (E, G, H, and L), and UTI (F, J, and K). The horizontal sections correspond to a surface area spanning 230 μm by 230 μm and were collected at the substratum or within the biofilm as indicated by the blue lines in the vertical sections to the right and above. The positions of the vertical sections are indicated by the red lines in the horizontal sections.
Tables
- TABLE 1.
Prevalence of F-like conjugative transfer genes among E. coli isolate collections
Strain origin No. of strains tested No. of strainsa with the following genes detected: traA finO traA finO None Feces—healthy 105 39 (37) 4 5 57 Feces—diarrhea 68 28 (41) 3 14 23 Bacteremia 90 45 (50) 4 0 41 UTI in men 68 21 (31) 4 2 41 Total 331 133 (40) 15 21 162 ↵a Percentages of strains relative to the number of tested strains are shown in parentheses.
- TABLE 2.
Prevalence of EAggEC-associated genes among E. coli isolates
Strain origin No. of strains tested No. of strainsa with the following genes detected: AA aggR aap AA aap None Feces—healthy 105 9 (8.6%) 1 1 94 Feces—diarrhea 68 7 (10.3%) 2 0 59 Bacteremia 90 3 (3.3%) 0 0 87 UTI in men 68 0 (0.0%) 0 0 68 Total 331 19 (5.7%) 3 1 308 ↵a Percentages of strains relative to the number of tested strains are shown in parentheses.
