Journal: bioRxiv

Article Title: Within-host evolution of Klebsiella spp. from intestinal carriage to bacteremia

doi: 10.64898/2026.01.05.697662

Figure Lengend Snippet: (A.) Biofilm biomass produced after 4h of culture in M63B1 medium by the paired strains of Klebsiella isolated from rectal carriage (stool) or bacteriemia (blood), stained by crystal violet (Absorbance 570nm). Specific biofilm structure for concordant paired strains isolated from patient #5, CH1669 isolated from blood sample and CH1670 isolated from rectal swabbing alone (B.) and co-cultured (C.) Strains were followed in the BioFlux microfluidic system at 37°C under a shear force of 0.5 dyn/cm² using epifluorescence microscope (Axio observer 7, Zeiss) at a magnification of 20×. Images were acquired in real time at T = 5 h, 12 and 18h. CH1669, isolated from blood, competitiveness against CH1670 isolated from rectal swabbing (D.) ; K. pneumoniae CH1157 (E .) and E. coli TG1 (F.) . Each value is the mean ± SEM of at least three separate experiments. Statistical analysis: nonparametric Mann-Whitney test between paired strains: *p < 0.05, **p < 0.01.

Article Snippet: After a 15 min adhesion step at 37 °C without flow, biofilm growth was monitored at 37 °C under a shear force of 0.5 dyn/cm2 (63 μL/h) using an Axio Observer 7 inverted epifluorescence microscope (Zeiss, 20×).

Techniques: Produced, Isolation, Staining, Cell Culture, Shear, Microscopy, MANN-WHITNEY