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.     

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.     

Catheter-associated bacteriuria in patients in reverse isolation

We determined the incidence and source of bacterial colonization of the bladder in 18 consecutive renal transplant recipients who required postoperative indwelling urethral catheterization and who were in reverse isolation. The patients were catheterized for an average of 6 days. Bladder bacteriuria occurred in 5 patients (27 per cent): 2 owing to urethral organisms, 2 after breaks in the drainage system and 1 owing to an unidentified source. The drainage bag urine was contaminated rarely and never was a source of bladder bacteriuria. The data suggest that bacterial contamination of the drainage bag may be an infrequent source of bladder bacteriuria in patients with limited contact with a hospital environment.     

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.     

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.     

Catheter-associated bacteriuria

Catheter-associated urinary tract infections are the most common nosocomial infection and a frequent cause of significant morbidity, sepsis, and death. The pathogenesis is multifaceted. Most frequently, bacteria from the urethral meatus ascend to the bladder between the mucosal and catheter surfaces. Alternatively, bacteria may ascend within the drainage system following contamination of the drainage bag or disruption of the catheter tubing junction. The incidence of infection is approximately 5 to 7 per cent for each day of catheterization and closely linked to unalterable host factors such as age, female sex, and debilitating disease. Efforts to reduce the incidence of infection must begin with reduction of the frequency and duration of catheterization. Aseptic insertion of the catheter and careful maintenance of the drainage system are mandatory to prevent incidental bacterial contamination. Prophylactic, systemic, or topical antimicrobial agents and modifications of the catheter drainage system that are designed to reduce contamination are expensive and have not been shown to be efficacious for the majority of patients. Furthermore, antimicrobial prophylaxis frequently leads to outgrowth of resistant bacterial strains that are difficult to eradicate. However, antimicrobial prophylaxis warrants consideration for high-risk patients who are catheterized for a short time. If bacteriuria occurs prior to removal of the catheter, the patient should be treated with appropriate antimicrobial therapy. Urinalysis or urine cultures should be obtained following removal of the catheter to assure sterility of the urinary tract. If these guidelines are followed, the incidence and sequelae of catheter-associated urinary tract infections can be reduced.     

Incidence and importance of bacteriuria in postoperative, short-term urinary catheterization

The frequency and importance of bacteriuria in patients requiring short-term postoperative catheterization (24 to 48 hours) is unknown. From a prospective, controlled study of 100 patients requiring catheterization postoperatively, the authors determined that there was a definite risk (6%) of bacteriuria; however, a symptomatic urinary tract infection developed in only 1% of the patients. There was no advantage to using either a latex or silicone catheter. It appears that the risk of symptomatic bacteriuria in this group of patients is very low when a closed urinary drainage system is used under strict, sterile conditions of catheter insertion and with meticulous ongoing catheter care.     

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.     

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.     

Nosocomial urinary tract infections

Convenience to the hospital staff is certainly not an acceptable reason for the use of a potentially dangerous drainage tube. An indwelling urinary drainage catheter should be used only in patients who need multiple straight urinary catheterizations, develop urinary obstruction or incontinence, or are comatose and require frequent urinary output measurements. An indwelling catheter may also be needed for drainage or stenting during or following genitourinary surgery. Once it has been determined that urinary catheterization is necessary, a closed urinary drainage system catheter must be carefully and aseptically inserted by experienced hospital personnel after careful preparation. The closed drainage system must be meticulously maintained throughout the patient's hospitalization and catheterization. After the catheter is removed, a urinary culture should be performed to identify any postcatheter infection. If there is infection, the patient must be treated with antibiotics. If symptoms of a urinary tract infection, bacteremia, or sepsis ensue, treatment must be rapidly begun with antibiotics as appropriate on the basis of drug sensitivity testing. These techniques will not eliminate bacteriuria associated with urinary drainage catheters. However, they will reduce the incidence, morbidity, and mortality associated with urinary catheterization.     

New apparatus to reduce urinary drainage associated with urinary tract infections

The automatic release of povidone iodine (PVP-I) into the outlet tube of a urinary collecting bag significantly reduced urinary tract infections (UTIs) and provided a more practical bacterial barrier than manual instillation of PVP-I into the bag as used previously. In 52 patients using a new urinary drainage system with a cartridge that released PVP-I into the outlet tube of the collection bag UTIs developed in 3, compared with 57 patients using a standard closed drainage system and in whom 13 UTIs developed (p less than 0.005). The PVP-I group had 92 percent of the accumulative catheter-days free of bladder infection, compared with 77 percent in the standard group. The main route of bacterial contamination leading to urinary drainage UTIs was through the collection bag.     

Efficacy of a latex Foley catheter with sustained release of chlorhexidine: 1st report: Clinical trials for the prevention of urinary tract infection

Seventy five patients requiring urethral catheterization for over 24 hours were treated with a latex Foley catheter with sustained release of chlorhexidine in a closed drainage system. While the catheter was indwelling, urinary concentrations of chlorhexidine were maintained at the level of 1 to 2 micrograms/ml in average in almost all patients. The catheter was highly effective in preventing the acquisition of catheter-associated bacteriuria in patients with initially sterile urine without systemic antimicrobial therapy. The acquisition rate of bacteriuria was 8, 16, 23, 35 and 74% on day 3, 4, 5, 6 and 7 with the catheter indwelling, respectively. The catheter was not effective in eradicating preexisting bacteriuria. Complications of the catheter were minimal.     

Long-term prophylaxis of urinary infections in women: comparative trial of trimethoprim, methenamine hippurate and topical povidone-iodine

We randomized 64 patients with a history of recurrent urinary tract infections among 3 regimens of long-term (1 year) prophylactic treatment: 20 were given 100 mg. trimethoprim at night, 25 received 1,000 mg. methenamine hippurate every 12 hours and 19 were asked to cleanse the perineum (especially the periurethral area) twice daily with povidone-iodine solution. The progress of patients in terms of urinary symptoms and/or bacteriuria, changes in periurethral flora, side effects, and hematological and biochemical profiles was followed at regular intervals. All treatments were effective in reducing the incidence of symptomatic attacks when compared to the 12 months immediately before therapy and there was little to choose between the individual regimens on this account. However, trimethoprim was tolerated better than were the other 2 treatment regimens. In the group given trimethoprim most of the breakthrough infections (71.4 per cent) that occurred were caused by trimethoprim-resistant organisms (usually Escherichia coli), while in the other 2 groups the incidence of trimethoprim-resistant organisms causing infection was low (2.7 per cent). Treatment with trimethoprim reduced significantly the periurethral colonization of Escherichia coli.     

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.     

Prospective study of urinary tract infections and urinary antibodies after radical prostatectomy and cystoprostatectomy

The authors have prospectively documented that men who undergo orthotopic bladder substitution more frequently experience bacteriuria than do normal men [19] or men with carcinoma of the prostate scheduled to have radical prostatectomy (see Table 1). Because the frequency of bacteriuria in men after prostatectomy was also lower than that after orthotopic bladder substitution (see Table 1), removal of the prostate and any of its presumed antibacterial properties probably does not account for this difference. Furthermore, the authors' data (see Table 5 ) and that of Woodside and associates [23] demonstrate that intestine incorporated into the genitourinary tract generates a local antibody response against urinary bacteria. Although others have suggested that the incorporation of bowel in the urinary tract may be associated with increased bacteriuria, this effect has never been documented prospectively. The mechanism of this increased frequency of bacteriuria is unknown. Because the anatomy of the male secretory genitourinary system may be altered after radical prostatectomy and orthotopic bladder substitution, the authors evaluated local antibody production before and after these operations. More than 20 years ago, Burdon [5] found that the initial portion of the VB1 sample in men had significantly higher levels of IgA compared with the VB2 specimen, whereas the levels of IgG were similar in the two portions. This latter finding was confirmed by Shorliffe and co-workers [22] when they examined prostatic secretion. Other investigators have found high levels of IgA in human prostatic tissue and fluid. [24,25]. On the basis of these findings, it was believed that, in men, the prostate produces most of the urinary IgA, whereas the bladder or upper urinary tracts make most of the urinary IgG. Although the authors' study confirms that most local urinary tract IgG is produced by the bladder or upper urinary tracts, this study documents that the prostate is not the only source of urethral IgA in men. Despite almost complete removal or prostate secretory epithelium by radical prostatectomy, as evidenced by a dramatic fall in postoperative VB1 and VB2 PSA compared with preoperative levels (Table 3). men who had this operation had only slightly decreased IgA levels after the operation (Table 4, Fig I). The source of this IgA must be urethral because the VB1 urinary stream contains more IgA than the VB2 urine even after radical prostatectomy. The authors have not determined whether the urinary IgA concentrations observed after radical prostatectomy are the true baseline values for a man without a prostate, or whether they actually reflect abnormal production of local IgA stimulated by radical prostatectomy. Because post-prostatectomy bacteriuris occurred frequently during urethral catheter drainage, the authors screened for postoperative IgA titers to mix 1 and mix 2 to determine whether specific production of antibody against gram-negative organisms might account for some of the postoperative IgA measured. Postradical prostatectomy mix 1 and mix 2 titers were not elevated, compared with preoperative measurements. Because urethral glandular tissue other than prostatic tissue is present in the male urethra, these glands also might be responsible for significant local antibody production. The high levels of urinary IgA and IgG after cystoprostatectomy with ileal orthotopic bladder substitution document that intestine incorporated into the urinary tract is still capable of producing local antibody. This observation corresponds with the findings of Mansson and associated [26] of elevated IgA and IgG in ileal reservoir urine compared with normal urinary tracts. It has been estimated that 1 m of intestine may secrete up to 780 mg/d of IgA [27], indicating that normal intestine production of antibody alone can account for the high IgA and IgG levels found in the patients who underwent bladder substitution. Interestingly, the ratio of IgA to IgG concentration in smal intestine fluid is 2:129, similar to the ratio of IgA to IgG in bladder substitution urine (2.92.1:52, Table 4). Because mix 1 and mix 2 IgA concentrations were elevated in VB1 and VB2 urine after ileal bladder substitution (see Table 5), some of this antibody was produced by the ileal bladder substitution in response to the inevitable bacteriuria that occurs during the prolonged postoperative catheter drainage. The findings is absent after radical prostatectomy alone. In addition, some of this increased antibody might be a result of the increased bacteriuria noted in the patients who underwent ileal bladder substitution after the initial postoperative period. The significance of the increased bacteriuria and elevated antibody levels after ileal bladder substitution is unclear. Because most of these episodes of bacteriuria were asymptomatic, whether they represent clinical infections that should be treated is not known. Bishop and associates [28] found that the bacterial flora of ileal conduits with asymptomatic bacteriuria had bacterial counts of 1000 or fewer colonies, and they noted that the healthy ileum in situ may contain more than 10,000 organisms per milliliter [29]. Because the normal urinary tract is usually sterile, it is possible that the bacteriuria found by the authors after ileal bladder substitution represents some form of bowel colonization more commonly associated with the bowel rather than clinical urinary tract infection and has limited clinial importance. Trinchieri and associated [30] found that urinary from patients with ileocystoplasty prevented attachment of E. coli to human uroepithelial cells more effectively that urine from patients with recurrent urinary infections. This observation suggests that the relatively large quantities of Iga produced by the ileal bladder substitution may, in fact, prevent clinical infection by preventing tissue invasion by the bacteria. Only long-term follow-up of patients with ileocystoplasty or ileal bladder substitution will determine the clinical significance of the bacteriuria. The authors' study had documented an increased incidence of bacteriuria in men after ileal bladder substitution and no such increase after radical prostatectomy. Analysis of the data shows that male sources other than the prostate--probably urethral glands-- must produce significant quantities of local urinary tract IgA. After ileal bladder substitution, the incorporated ileum may produce volumes of local antibody that may exceed the amounts ordinarily produce by the normal urinary tract. The clinical significance of the increased incidence of bacteriuria and elevated antibody levels in patients after illeal bladder substitution is unclear.     

Evaluation of a vented drainage system in prevention of bacteriuria.

A vented urinary drainage system was compared to an otherwise identical non-vented system in a prospective, randomized, double-blind study. Among the 316 female patients evaluated there was a significant reduction in the rate of bacteriuria after 10 days using the vented system (66 per cent in the non-vented group versus 26 per cent in the vented group, p less than 0.05), while no significant difference could be demonstrated among the 190 male patients. We used urine hemoglobin as an indicator of mucosal trauma that might predispose to bacteriuria and no significant difference could be shown between the 2 drainage systems.     

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.     

The clinical significance of Staphylococcus aureus bacteriuria

To investigate the rate of occurrence, clinical presentation, predisposing factors and frequency of secondary bacteremia 132 patients with significant Staphylococcus aureus bacteriuria were reviewed retrospectively. Staphylococcus aureus accounted for 3.3 per cent of all positive urine cultures. Most patients were elderly men. The most important predisposing factors in the urinary tract were indwelling catheters (63 per cent), obstruction (56 per cent) and instrumentation or surgery (43 per cent). Bacteremia developed secondary to bacteriuria in all 11 patients (8.3 per cent). For that reason Staphylococcus aureus bacteriuria should be regarded as a hazardous condition, especially in patients with predisposing factors in the urinary tract.     

Catheter-associated bacteriuria. An experimental study

A bacteriologically-stressed catheterized animal model was developed to evaluate the comparative importance of the intraluminal versus the extraluminal route of catheter-acquired urinary tract infections. This study indicated that in short-term catheterization (less than 7 days), contamination of the drainage spout or accidental disconnection of the drainage tube resulted in bacteriuria within a short time (32-48 hours). If a strict sterile closed drainage system was maintained, the extraluminal route assumed more importance in the development of bacteriuria, however this pathway was considerably slower (72-168 hours). It appeared that catheter-associated bacteriuria results from ascending bacterial colonization within glycocalyx-enclosed biofilm on the inside and/or outside surfaces of the catheter and drainage systems. Development of a biomaterial that inhibits bacterial adherence and does not allow upstream colonization of bacteria on the catheter drainage system would significantly influence the rate of catheter-acquired urinary tract infection.     

Effects of contraceptive pills and intrauterine devices on urinary bladder

The incidence of bacteriuria and cystoscopic changes in women on oral contraceptives or users of IUD (intrauterine devices) were evaluated compared with a control group. Subjects with bacteriuria accounted for 40.5 per cent of pill users, 20 per cent of women fitted with IUD, and 16 per cent of the control group. Bladder trabeculations were found in 50.5 per cent of the pill group, 8.7 per cent of the IUD group, and 8 per cent of the controls. Congested bladder trigone was observed in 24.6 per cent of women fitted with an IUD. The mode of action of ovarian hormones and their possible side effects on the bladder are discussed. The relation of IUD to pelvic inflammatory disease and its effect on the urinary bladder are evaluated.