Evaluation of the adhesive characteristics of uropathogenic Escherichia coli strains in patients with spinal cord injuries

The adhesion characteristics of 9 clinical E.coli strains, isolated from the urine of 9 patients with spinal cord injuries in late period were evaluated. Patient age was 21 to 54 years. Neurogenic urination disordes observed in patients were the result of a spinal injury in the cervical (5 patients), thoracic (2 patients) and thoracolumbar (2 patients) spine. The duration of disease ranged from 2 to 12 years. Despite primarily a low adhesion activity of tested strains, the formation of biofilm occurs on the surfaces having both hydrophobic (polystyrene) and hydrophilic (cover glass) properties. After 24 h, according to the photometric evaluation, 7 of 9 strains had weak, 1 - medium, and 1 - high ability to form biofilms. After 48 hours, only 4 strains had low ability to form biofilms, of whom 2 had an increase ability compared to the previous period of observation. Other strains possess the medium ability to form biofilm. When quantifying the ability of bacteria to form biofilms on the surface of the cover glass, it was revealed that a large fraction of the area of the field of view was accounted for microcolonies with size 10 μm 2 at 24 hours, and microcolony with size from 100 to 1000 μm 2 at 48 h. There were number of significant correlations between parameters studied. After 24 h, the correlation coefficient between the optical density (OD630) and the number, OD630 and proportion of microcolonies with size 10 to 10000 pm 2 varied from 0.79 to 0.9. After 48 hours, there was a direct correlation between the OD630 and the number (r = 0.73, P = 0.025), OD630 and proportion (r = 0.81, P = 0.009) of microcolonies with size 1,000 to 10,000 mkm 2.

E. coli, neurogenic bladder, spinal cord injury, biofilms, E. coli, surface colonization