Urethral meatal colonization in the pathogenesis of catheter-associated bacteriuria

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 and 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 per cent). Urethral meatal colonization with the organism responsible for bacteriuria, that is Escherichia coli (5 episodes), Staphylococcus aureus (2), Streptococcus faecalis (2) and Staphylococcus epidermidis (2), was persistent and present from 2 to 5 days before bacteriuria. In each ward 81 per cent or more of the cultures obtained on day 1 of catheterization showed no gram-negative colonization. Subsequently, the gram-negative colonization density increased in both groups but the increase was significant (p less than 0.001) only for patients on the open ward. Similar trends were observed for gram-positive colonization. The prevalence 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 but the specific urethral meatal flora was not always predictive of the species responsible for bacteriuria.     

Urinary tract infection in oliguric patients with chronic renal failure

We studied 182 patients with chronic renal failure by urinalysis and urine cultures. Of the patients 27 per cent had significant bacteriuria (more than 10(5) per ml.), 38 per cent had significant pyuria (more than 10 white blood cells per high power field), 19 per cent had urinary tract infection and 7 per cent had symptomatic urinary tract infection. All 12 patients with symptomatic urinary tract infection had significant bacteriuria and 11 had significant pyuria, while 1 had 5 to 10 white blood cells per high power field. Incidences of urinary tract infection differed depending on the primary renal disease (12, 13, 41 and 67 per cent for chronic glomerulonephritis, diabetic nephropathy, polycystic kidney and chronic pyelonephritis, respectively). Among the patients with chronic glomerulonephritis no significant differences were seen in frequencies of bacteriuria and urinary tract infection between male and female patients or between those who did and did not undergo hemodialysis. Also, no significant correlation was seen between bacteriuria and daily urine output but pyuria was significantly more frequent in oliguric patients or those on hemodialysis.     

Anaerobic bacterium in renal transplantation

Renal allograft recipients were studied prospectively utilizing improved culture techniques to investigate anaerobic bacteriuria. The study population was compared with a population of patients with chronic renal insufficiency and end stage renal disease. The over-all incidence of anaerobic urinary tract infection was 7.5 per cent while the over-all incidence of aerobic urinary tract infection was 23.5 per cent. Patients with cadaver renal transplants during the early postoperative period had the highest incidence of both anaerobic (42.9 per cent) and aerobic (71.4 per cent) urinary tract infection of all groups. The potential association between significant anaerobic bacteriuria during the first postoperative month and poor prognosis for cadaver renal allografts merits further investigation.     

Anaerobic bacteriuria in renal transplantation.

Renal allograft recipients were studied prospectively utilizing improved culture techniques to investigate anaerobic bacteriuria. The study population was compared with a population of patients with chronic renal insufficiency and end stage renal disease. The over-all incidence of anaerobic urinary tract infection was 7.5 per cent while the over-all incidence of aerobic urinary tract infection was 23.5 per cent. Patients with cadaver renal transplants during the early postoperative period had the highest incidnece of both anaerobic (42.9 per cent) and aerobic (71.4 per cent) urinary tract infection of all groups. The potential association between significant anaerobic bacteriuria during the first postoperative month and poor prognosis for cadaver renal allografts merits further investigation.     

Bacteriuria during closed urinary drainage: an evaluation of top-vented versus bag-vented systems.

For a 10-month period a top-vented closed urinary drainage system was evaluted and compared to a conventional bag-vented drainage system. The study involved random assignment of either system to all adult patients who required urinary catheterization. Criteria for exclusion included acute or chronic genitourinary tract infection and surgical interference with bladder function. The end point of the study was removal of any part of the system after at least 24 hours or a positive urine culture (greater than 10,000 colonies per ml. urine). The series included 236 patients. Distributions of patient age, sex and hospital service assignment (medical or surgical), antibiotic usage and duration of catheterization were similar in both study groups. Of 113 patients with the top-vented system 16 (14.2 per cent) acquired bacteriuria, whereas 13 of 123 (10.6 per cent) with the bag-drainage system acquired bacteriuria. No significant difference was noted. Antibiotics were used in 202 of 236 patients (86 per cent). Although usage delayed the appearance of bacteriuria in both groups isolates were more frequently yeasts and gram-negative organisms other than Escherichia coli.     

Indwelling urinary catheter infections in small community hospital. Role of urinary drainage bag

Ninety cases of closed drainage urinary catheterization were studied by daily bacteriologic monitoring with Microstix. In 23 per cent of the patients bacteriuria developed, and 92.6 per cent of all catheter infections occurred within three days. These infections occurred primarily in postsurgical patients, and were probably related to initial contamination during catheter insertion. Only 1 patient had a positive drainage bag urine culture prior to the development of bladder bacteriuria. At our institution poor catheter technique was much more important as a risk factor of nosocomial urinary tract infection than an antiseptic drainage bag system.     

Urinary tract infection in pediatric renal transplantation

Urinary tract infection is a frequent complication following renal transplantation and represents a potential focus for systemic infection in the immunosuppressed transplant recipient. The incidence, etiologic factors, temporal pattern, bacteriology, and prognostic significance of urinary tract infection were determined by analysis of 85 renal allografts in 69 patients. Significant bacteriuria occurred after 49 of 85 transplants (58 per cent). The incidence of infection was not related to success or source of the allograft, but was related to patient gender. Urinary tract infections developed in 68 per cent of females, while only 43 per cent of males became infected (p < 0.05). Escherichia coli caused most first infections (30 per cent), while Pseudomonas aeruginosa and E. coli were equally responsible for recurrent infections (25 per cent each). Children with previous reconstructive urologic surgery had similar allograf success (63 per cent) and infection rates (53 per cent) as our other children (61 per cent and 58 per cent, respectively). No apparent correlation was noted between episodes of infection and graft rejection. Thorough preoperative assessment and preparation and prompt, specific treatment minimize the adverse influences of urinary tract infection.     

Symptomatic recurrent urinary tract infections in patients with renal scarring in relation to fecal colonization with P-fimbriated Escherichia coli

We evaluated prospectively 49 women with renal scarring and a history of febrile urinary tract infections in regard to the incidence of recurrent symptomatic urinary tract infection and fecal colonization with P-fimbriated Escherichia coli. During a 3-year followup 26 patients (53 per cent) had symptomatic urinary tract infection (0.036 infections per patient-month), including 8 (16 per cent) who had 9 new episodes of febrile urinary tract infection, while 33 (67 per cent) had Escherichia coli bacteriuria (10(5) bacteria per ml. urine in pure culture). Thus, patients with previous febrile urinary tract infections and renal scarring have a high risk for recurrent infections. For comparison, the incidence of symptomatic urinary tract infection also was determined in 35 women with a recent episode of acute nonobstructive pyelonephritis and with normal kidneys on excretory urography. These patients had 0.031 symptomatic infections per patient-month. The fecal flora were examined twice a year for P-fimbriated Escherichia coli in 48 patients with renal scarring. Of these patients 21 (44 per cent) had at least 1 fecal colonization with a P-fimbriated Escherichia coli strain. However, in only 1 instance was a relationship detected between the presence of P-fimbriated Escherichia coli in the fecal flora and the development of subsequent febrile urinary tract infection. The findings indicate that fecal sampling twice a year is not of value to predict future urinary tract infections in adults with renal scarring.     

India ink immune method for the study of antibody-coated urinary bacteria

The sediments of 373 urines were studied for antibody-coated bacteria by the India ink immune method. Positive results were obtained in 14.7 per cent of upper urinary tract infections, 18.9 per c nt of lower urinary tract infections, 29 per cent of bacteriuria, and 15.2 per cent in healthy girls. Since antibody-coated bacteria could find their way into negative urines only by contamination, 296 vulvar secretions were also examined. Positive results were obtained in 15.5 per cent of girls with urinary tract infections, 63.9 per cent of those with vulvitis and 24.1 per cent in girls with no infection. It is concluded from the results that the presence or absence of antibody-coated bacteria in the urine is unrelated to the site of urinary infection.     

Cinoxacin: new antimicrobial agent for urinary tract infections.

One hundred forty-six patients with recurrent urinary tract infections were treated with 500 mg. of cinoxacin twice daily for seven to fourteen days. Satisfactory clinical response occurred in 94 per cent. Of the 100 patients with significant pretherapy bacteriuria (greater than or equal to 10(4) organisms/ml. of urine), 65 had complicated infections. Approximately the same per cent of patients with (90 per cent) as without (94 per cent) complicating conditions had a satisfactory clinical response to treatment. The pathogen was eliminated in a higher percentage of patients without underlying disease (90 versus 80 per cent), and infections recurred less frequently in this group (3 versus 14 per cent). Emergence of resistance by initially susceptible organisms during the course of therapy occurred in 4 of 76 patients (5 per cent). A satisfactory clinical response occurred in all 46 patients with an initial colony count of less than 10(4) organisms/ml. urine. Only 1 patient in this group was a bacteriologic failure. Adverse effects of a relatively wild nature were seen in 4 of 146 patients (2.7 per cent). Successful eradication of 12 of 23 urinary infections in patients whose pathogens were resistant to the 30-microgram. cinoxacin disk suggests that the 100-microgram. disk may be more realistic for determining bacterial susceptibility by the disk diffusion method in view of the very high urinary concentration of the drug.     

Correlation of antibody-coated bacteria with intravenous pyelogram in children with refluxing and nonrefluxing units

A fluorescent technique for detecting immune globulins on the surface of urinary bacteria has been used to differentiate upper from lower urinary tract infections. In an attempt to correlate positive fluorescence with deteriorative changes on the intravenous pyelogram, a total of 79 pediatric patients was studied. Twenty-three had ileal conduits with freely refluxing urine. The remaining 56 children had intact urinary tracts. Thirty of these had vesicoureteral reflux. Urine cultures were studied in conjunction with fluorescent antibody determinations. In patients with significant bacteriuria good correlation was seen with the presence of bacterial fluorescence and positive renal changes. This correlation was 88 per cent in patients with bowel conduits, 71 per cent in patients with vesicoureteral reflux, and 38 per cent in patients without reflux. Possible false positive and false negative results were relatively low, each occurred in 10 per cent of the specimens examined. It is concluded that the combination of urinary tract infection and positive bacterial fluorescence is seen when upper tract deterioration has occurred and is seen most frequently in association with urinary reflux. In these instances aggressive therapy is often indicated.     

Urinary tract infection in percutaneous surgery for renal calculi

Percutaneous extraction of renal stones is associated with a risk of infection, which sometimes can be severe as a result of the intraoperative introduction of a ureteral catheter, the nephroscopy itself and the fact that a nephrostomy tube sometimes is left in place. It generally is accepted that patients with a preoperative urinary tract infection should be covered during the operation by an appropriate antibiotic. However, the need for routine prophylactic antibiotic treatment in patients with sterile urine preoperatively still is a subject of debate. We report the bacteriological results of 126 cases of percutaneous extraction of renal stones. Of the patients 107 had sterile urine preoperatively and deliberately did not receive prophylactic antibiotics so that the mechanisms of urinary tract infection after percutaneous nephrolithotomy could be studied. Of these patients 37 (35 per cent) suffered a postoperative urinary tract infection, usually owing to Escherichia coli, streptococcus or staphylococcus. The responsible organism was isolated in the bladder urine only in 22 cases, in the nephrostomy tube in 2 and in both sites in 13. Eleven patients (10 per cent) presented with a fever of 38.5C or more. All of the infected patients received appropriate antibiotic therapy and there were only 2 bacteriological failures on long-term followup (5 per cent). A total of 19 patients had a urinary tract infection preoperatively. All 19 patients received appropriate antibiotic therapy starting at least 24 hours preoperatively and continuing for a minimum of 3 weeks. Five patients (26 per cent) presented with a fewer but there were no serious septic complications. All of the patients were discharged from the hospital with sterile urine and there was only 1 long-term bacteriological failure (5 per cent). Both patients with Pseudomonas infection were cured. The risk of clinical infection following percutaneous nephrolithotomy is low despite the fact that 35 per cent of the patients have bacteriuria postoperatively, provided a careful bacteriological examination is performed preoperatively and the patients with urinary tract infection are treated appropriately. These results are in favor of short-term prophylactic antibiotics adapted to the bacterial ecology.     

Is antibiotic administration indicated after outpatient cystoscopy

The incidence of urinary tract infection was examined in 138 patients who underwent diagnostic cystoscopy in an outpatient clinical setting with preoperatively sterile urine. A prospective randomized trial was conducted to compare the incidence of infection in patients who received no antibiotic (controls, group 1) and those who received a postoperative course of oral antibiotics (group 2). The incidence of bacteriuria after cystoscopy was 2.8 per cent in group 1 (control) and 1.5 per cent in group 2, with an over-all incidence of 2.2 per cent. Only 1 patient presented with a symptomatic infection (0.7 per cent). This study has confirmed the safety of outpatient cystoscopy and has demonstrated that routine administration of postoperative antibiotics is not indicated.     

Effect of silver oxide/trichloroisocyanuric acid antimicrobial urinary drainage system on catheter-associated bacteriuria

We assessed the efficacy of silver oxide coating of the indwelling urethral catheter and catheter adapter, and instillation of trichloroisocyanuric acid into the urinary drainage bag in the prevention of catheter-associated bacteriuria in a prospective and randomized study of 74 patients. Bacteriuria was documented in 29 of the 74 patients (39 per cent). There was a significant difference between the attack rates, with 11 of 41 patients (27 per cent) in the test group and 18 of 33 (55 per cent) in the control group having bacteriuria (p equals 0.02) after a median time to bacteriuria of 36 and 8 days, respectively (p equals 0.01). Urethral meatal colonization was implicated as the source of bladder bacteriuria in 12 of 18 patients (67 per cent) in the control group and 5 of 11 (45 per cent) in the test group. Trichloroisocyanuric acid significantly reduced drainage bag contamination but bag contamination with the same microorganism responsible for bacteriuria preceded infection in only 2 of the 29 patients (7 per cent), 1 in each group. Patients who received systemic antimicrobial agents acquired bacteriuria less frequently than those who did not. The apparent protective effect of systemic antimicrobials was strongest during the first 4 days of catheterization. The data indicate that episodes of bacteriuria arising from the urethral meatus are common among catheterized patients and that the antimicrobial catheter is effective in reducing the incidence of catheter-associated bacteriuria.     

Lower urinary tract dysfunction in girls with untreated asymptomatic or covert bacteriuria

A total of 50 to 80% of all girls with asymptomatic or covert bacteriuria will have recurrences after antibacterial treatment. Deficient bladder emptying is an important factor predisposing to urinary infections. We investigated lower urinary tract function in 57 girls with untreated so-called asymptomatic bacteriuria. Detailed questioning revealed a high frequency of symptoms, such as urgency and incontinence. The symptoms were not acute and no patient had dysuria. The urinary flow curve pattern indicated bladder emptying problems in 42% of the girls and residual urine of greater than 5 ml. was seen in 71%. Cystometry revealed consistent detrusor instability in 75% of the patients. Lower urinary tract dysfunction may explain the marked tendency for recurrent infection after treatment of asymptomatic bacteriuria. With a detailed history, and noninvasive determination of urinary flow and residual urine, these abnormalities are easily detected. Bladder rehabilitation may offer a new method of treatment for these patients.     

Follicular cystitis in girls with untreated asymptomatic or covert bacteriuria

Nodular changes of the bladder mucosa, that is cystitis follicularis or cystitis cystica, are found in 2 to 9% of all children with urinary tract infections. The nodules are composed of lymphoid aggregates, resembling Peyer's patches in the intestine. Children with this finding are considered to have a poor short-term prognosis with a marked tendency for recurrent infections. Screening programs for bacteriuria have revealed that a few per cent of the female population are bacteriuric without symptoms of overt disease. Of 59 girls followed with untreated asymptomatic bacteriuria 52 had nodular changes of the bladder mucosa at cystoscopy. Biopsy was performed in 22 girls, and revealed lymphocytic infiltration in 19 and follicular formation in 11. The nodular changes persisted when bacteriuria continued but disappeared in patients who became abacteriuric. This finding demonstrates the reversibility of the changes, and supports the assumption that they are secondary to the presence of bacteria and not a primary lesion.     

Microbiology of the urethra and perineum and its relationship to bacteriuria in community-residing men with spinal cord injury

OBJECTIVE: Reasons why some persons with spinal cord injury (SCI) experience recurrent urinary tract infections more than others are poorly understood. We performed a prospective study of bacterial flora of the urethra and perineum in men with and without bacteriuria to understand more completely the relationship between bacterial colonization and invasion of the urinary tract. METHODS: Urine, urethra, and perineum cultures were obtained from 70 men. Microbial flora of these sites was compared for men with and without bacteriuria. RESULTS: Urine colony count was 0 in 16 (22.9%) men. Perinea in 2 men (12.5%) and urethras in 6 men (37.5%) were colonized with various gram-negative bacilli, enterococci, and/or Staphylococcus aureus. Among 54 (77.1%) men with bacteriuria, uropathogens were shown in the perineum in 31 (57.4%) and in the urethra in 46 (85.2%). In 40 (74.1%) of men with bacteriuria, at least one bacterial species present in the urine was also found in the urethra and/or perineum. Differences in the occurrence of uropathogens in men with and without bacteriuria were statistically significant, and organisms were present in higher numbers in men with bacteriuria. CONCLUSION: Men with SCI who have bacteriuria are significantly more likely to be colonized in the distal urethra and perineum with uropathogens that are often present in the urine in comparison with men without bacteriuria.     

Biochemical risk factors in patients with renal staghorn stone disease

Thirty-three patients operated on for renal staghorn calculous disease were studied retrospectively with respect to urine and stone composition, bacteriuria, and abnormalities of the urinary tract. Calcium phosphate was the most common stone constituent, present in 30 of 31 concrements. Twenty-one of these stones also contained magnesium ammonium phosphate, despite the fact that only 10 patients had presented evidence of urinary tract infection during the initial period of the disease. Twenty-four-hour urine composition was normal in only 3 patients. In 59 per cent an increased CaOx risk index was observed suggesting that CaOx risk factors might contribute to the development of staghorn concrements. A metabolic evaluation of staghorn stone formers appears to be of importance for design of the postoperative treatment.     

Detrusor-sphincter dyssynergia.

We followed 62 patients with complete suprasacral spinal cord injuries and detrusor-sphincter dyssynergia for at least 2 years. The patients were evaluated urodynamically at regular intervals and 50 per cent were subjected to external sphincterotomy, after which they were compared for the presence of bacteriuria and upper urinary tract changes. Patients on prolonged intermittent catheterization did as well as those who achieved balanced bladder function as a result of sphincterotomy.     

Bacteriuria in young women. Effect of estrogen, progestogen, and estrogen-progestogen combination

Eighty-two women were assigned at random to either an estrogen, progestogen, estrogen-progestogen combination, or to a placebo taken orally three of four weeks for 12 cycles. All patients were fitted with an intrauterine device to prevent pregnancy. Urine cultures were obtained prior to study and at monthly intervals thereafter, and the cumulative incidence of acquired infection was calculated for all patients who stayed in the study for at least three months. The acquired bacteriuria incidence was: placebo 14.3 per cent, estrogen 15.8 per cent, estrogen-progestogen 18.7 per cent, and progestogen 35.7 per cent. The increased incidence with progestogen may be secondary to the production of a menopausal hormonal milieu, a common time for bacteriuria to occur in the female.