Urethral Meatal Colonization in the Pathogenesis of Catheter-Associated Bacteriuria

Publisher Website
Google Scholar
Abstract
Urethral meatal colonization with potential urinary tract pathogens was studied before bacteriuria in 31 consecutive acute spinal cord injury patients on an open ward (137 cultures) and 18 renal homotransplant patients in reverse isolation (80 cultures). All patients required indwelling urethral catheterization; no antimicrobials were given. Daily quantitative cultures of the urethral meatus, and bladder and drainage bag urine were obtained. The urethra was the source for 11 of 31 episodes of bacteriuria (35%). Urethral meatal colonization with the organism responsible for bacteriuria, i.e., Escherichia coli (5 episodes), Staphylococcus aureus (2), Streptococcus faecalis (2) and S. epidermidis (2), was persistent and present from 2 to 5 days before bacteriuria. In each ward .gtoreq. 81% of the cultures obtained on day 1 of catheterization showed no gram-negative colonization. Subsequently, the gram-negative colonization density increased in both groups; the increase was significant (P < 0.001) only for patients on the open ward. Similar trends were observed for gram-positive colonization. The prevalance of potential pathogens was similar for patients whether or not they suffered bacteriuria. An increased density of bacterial colonization was associated with increased susceptibility to bacteriuria; the specific urethral meatal flora was not always predictive of the species responsible for bacteriuria.