**2.2. Vesicoureteral reflux**

Under normal circumstances, the ureterovesical junction allows urine to enter the bladder but prevents urine from regurgitating into the ureter and the kidney. This results in the kidney being protected from high pressure in the bladder and from contamination by vesical bacteria. In this way, vesicoureteral reflux is considered to be an important factor in urinary tract infection [20]. It occurs in 10% of patients over 4 years of SCI [21]. Although the reflux is the result of high intravesical pressure, it must be controlled by another neurological mechanism since patients with a T10- L2 lesion exhibit more regressive effects than patients who have a level of damage above or below this level [22]. The damage at this level is probably related to the ureteral peristaltic mechanisms.

#### **2.3. Intermittent catheterization**

Intermittent catheterization (IC) during the recovery period appears to reduce the rate of urinary tract infections and substantially eliminate many of the complications associated with the use of an indwelling catheter [23, 24]. However, IC may also present certain complications, such as traumatic urethral injury (immediate) or urethral restenosis and recurrent epididymitis (late). In one study, SCI patients, using pure intermittent catheterization for more than 5 years, showed urine stasis at 19% and epididymitis at 28.5% [23]. The appearance of the above complications appears to be increased according to the number of years of pure IC performed [23]. Research supports the use of sterile IC technique in the acute phase of the neurogenic bladder [25] and agrees with a study in which few cases of bacteriuria and urinary tract infection were observed using sterile intermittent catheterization as compared to using a non-sterile procedure [26]. On the other hand, Shekelle et al. reported contradictory results in the value of sterile techniques or techniques without direct catheter contact compared to pure intermittent catheterization, as there is insufficient evidence of risk associated with psychological, behavioral and hygienic factors [27]. Hydrophilic catheters for clean intermittent catheterization are associated with lower rates of long-term complications (urethral stenosis) and may cause a lower degree of bacteriuria [28]. Another type of catheter, with an insertion sheath, which bypasses the first 1.5 cm of the urethra, appears to reduce the incidence of urinary tract infections in hospitalized men with SC damage [29].

**2.6. Condom catheter drainage**

**2.7. Biofilm (biomembranes)**

treatment infections.

Condom catheters are used in male patients to manage incontinence but not bladder emptying. Their application is accompanied by the same degree of urinary tract infection as in the use of intermittent catheterization. However, condom catheters do not ensure complete bladder drainage and can (in cases of poor application) be considered a cause of occlusion [43]. It is recommended that the condom catheter is applied daily, although no increase in infections has been reported in non-daily applications [44]. In addition, although condom catheters are external, they appear to be related to colonization of the urethra by pathogenic microbes. They are accompanied by Pseudomonas [45] and Klebsiella [46] infections due to the colonization of the regions of the urethra, perineum, penis, and rectum by the above microorganisms. In addition, the urine trap is a very good reservoir of microorganisms. In male patients using condom catheter, urine culture was 73% positive for Pseudomonas, although the degree of bacteriuria was much lower [47, 48]. Also, the colonization of the urethra with Pseudomonas is combined with the presence of the condom catheter [49]. From the above, it can be seen that the chronic use of a condom catheter drainage and urine collector predisposes to the colonization of the patient and the upward introduction of microorganisms into the anterior urethra.

Urinary Tract Infections in Neuro-Patients http://dx.doi.org/10.5772/intechopen.79690 65

According to their initial description, microorganisms are referred to as non-adherent "planktonic" cells [50] based on their developmental characteristics in enriched liquids and solids. Today, it is now known that bacteria in their natural environment are typically attached to some biological or non-surface area. It is also known that adhering microorganisms under suitable conditions form complex structures, biofilms (bio-membranes). These structures are formed as the microorganisms are surrounded by an extracellular exopolysaccharide (EPS) layer which themselves produce [50, 51]. Bacteria are the best-studied microorganisms

Fungi, protozoa, viruses, and algae have also been isolated from corresponding extracellular material in direct contact with organic or inorganic surfaces [52]. Stable microbial attachment to the underlying surfaces and the formation of biofilms creates significant and often insoluble problems both in the medical community and in the industry [53]. *Staphylococcus aureus*, *Staphylococcus epidermidis*, *Enterococcus faecalis* and *Pseudomonas aeruginosa* often colonize implanted medical devices [54] (such as pacemakers, intravenous catheters, urinary catheters, prosthetic implants, and heart valves) as well as pathological tissue structures (such as respiratory epithelium in patients with cystic fibrosis or cystic fibrosis mucosal in patients with neurogenic bladder) and create biofilms, thus causing chronic and often resistant to

Bacterial biomembranes are observed in 73% [55] patients with SCI using IC, and no relationship has been found between the presence of bio-membrane and symptoms [56]. However, the presence of at least 20 bacterial adherence in each bladder cell appears to be related to the symptomatology of the infection [57]. Bacterial cells are detached individually or in groups

regarding surface colonization and subsequent biofilm formation.

#### **2.4. Permanent indwelling catheters**

Permanent indwelling catheters are the greatest risk factor for complicated UTIs [30]. They are responsible for most in-hospital UTIs, 3–10% per day and with 100% bacteriuria in their long-term use [31]. Silver-coated catheters are more effective in preventing urinary tract infections in patients who require short-term catheterization and reduce the incidence of symptomatic urinary tract infection and bacteriemia compared to simple catheters [32, 33]. For short-term catheters not exceeding 2–3 weeks, the use of nitrofurazone, minocycline, and rifampin-impeded catheters reduce the risk of urinary tract infection [34, 35] due to antibiotic overlap.

#### **2.5. Suprapubic catheters**

The use of a permanent suprapubic catheter is an effective way of draining the bladder in SCI patients with a low rate of urinary tract infection [36, 37]. Suprapubic catheterization may be an alternative drainage method for female patients who cannot perform self-IC [38]. The disadvantage is the continuous presence of the catheter (foreign material) within the bladder associated with the formation of urinary lithiasis as compared to intermittent catheterization at rates of 9 and 4%, respectively, over a period of more than 9 years [39]. On the other hand, this chronic irritation from the catheter is accompanied by an increased incidence of bladder cancer as compared to intermittent catheterization [40]. Nomura et al. [41] reported that 25% of patients with long-term use of suprapubic catheter showed bladder stone formation, which was accompanied by a 7.24 urine pH. Suprapubic drainage in patients with neurogenic urinary disorders is preferred (against urethral catheterization) as it appears to reduce the risk of urethritis, orchiepididymitis, testicular abscess and urethral erosion as compared to permanent catheterization [42].

### **2.6. Condom catheter drainage**

complications, such as traumatic urethral injury (immediate) or urethral restenosis and recurrent epididymitis (late). In one study, SCI patients, using pure intermittent catheterization for more than 5 years, showed urine stasis at 19% and epididymitis at 28.5% [23]. The appearance of the above complications appears to be increased according to the number of years of pure IC performed [23]. Research supports the use of sterile IC technique in the acute phase of the neurogenic bladder [25] and agrees with a study in which few cases of bacteriuria and urinary tract infection were observed using sterile intermittent catheterization as compared to using a non-sterile procedure [26]. On the other hand, Shekelle et al. reported contradictory results in the value of sterile techniques or techniques without direct catheter contact compared to pure intermittent catheterization, as there is insufficient evidence of risk associated with psychological, behavioral and hygienic factors [27]. Hydrophilic catheters for clean intermittent catheterization are associated with lower rates of long-term complications (urethral stenosis) and may cause a lower degree of bacteriuria [28]. Another type of catheter, with an insertion sheath, which bypasses the first 1.5 cm of the urethra, appears to reduce the incidence of urinary tract infections in hospitalized men

64 Microbiology of Urinary Tract Infections - Microbial Agents and Predisposing Factors

Permanent indwelling catheters are the greatest risk factor for complicated UTIs [30]. They are responsible for most in-hospital UTIs, 3–10% per day and with 100% bacteriuria in their long-term use [31]. Silver-coated catheters are more effective in preventing urinary tract infections in patients who require short-term catheterization and reduce the incidence of symptomatic urinary tract infection and bacteriemia compared to simple catheters [32, 33]. For short-term catheters not exceeding 2–3 weeks, the use of nitrofurazone, minocycline, and rifampin-impeded catheters reduce the risk of urinary tract infection [34, 35] due to antibiotic

The use of a permanent suprapubic catheter is an effective way of draining the bladder in SCI patients with a low rate of urinary tract infection [36, 37]. Suprapubic catheterization may be an alternative drainage method for female patients who cannot perform self-IC [38]. The disadvantage is the continuous presence of the catheter (foreign material) within the bladder associated with the formation of urinary lithiasis as compared to intermittent catheterization at rates of 9 and 4%, respectively, over a period of more than 9 years [39]. On the other hand, this chronic irritation from the catheter is accompanied by an increased incidence of bladder cancer as compared to intermittent catheterization [40]. Nomura et al. [41] reported that 25% of patients with long-term use of suprapubic catheter showed bladder stone formation, which was accompanied by a 7.24 urine pH. Suprapubic drainage in patients with neurogenic urinary disorders is preferred (against urethral catheterization) as it appears to reduce the risk of urethritis, orchiepididymitis, testicular abscess and urethral erosion as compared to

with SC damage [29].

**2.5. Suprapubic catheters**

permanent catheterization [42].

overlap.

**2.4. Permanent indwelling catheters**

Condom catheters are used in male patients to manage incontinence but not bladder emptying. Their application is accompanied by the same degree of urinary tract infection as in the use of intermittent catheterization. However, condom catheters do not ensure complete bladder drainage and can (in cases of poor application) be considered a cause of occlusion [43]. It is recommended that the condom catheter is applied daily, although no increase in infections has been reported in non-daily applications [44]. In addition, although condom catheters are external, they appear to be related to colonization of the urethra by pathogenic microbes. They are accompanied by Pseudomonas [45] and Klebsiella [46] infections due to the colonization of the regions of the urethra, perineum, penis, and rectum by the above microorganisms. In addition, the urine trap is a very good reservoir of microorganisms. In male patients using condom catheter, urine culture was 73% positive for Pseudomonas, although the degree of bacteriuria was much lower [47, 48]. Also, the colonization of the urethra with Pseudomonas is combined with the presence of the condom catheter [49]. From the above, it can be seen that the chronic use of a condom catheter drainage and urine collector predisposes to the colonization of the patient and the upward introduction of microorganisms into the anterior urethra.

#### **2.7. Biofilm (biomembranes)**

According to their initial description, microorganisms are referred to as non-adherent "planktonic" cells [50] based on their developmental characteristics in enriched liquids and solids. Today, it is now known that bacteria in their natural environment are typically attached to some biological or non-surface area. It is also known that adhering microorganisms under suitable conditions form complex structures, biofilms (bio-membranes). These structures are formed as the microorganisms are surrounded by an extracellular exopolysaccharide (EPS) layer which themselves produce [50, 51]. Bacteria are the best-studied microorganisms regarding surface colonization and subsequent biofilm formation.

Fungi, protozoa, viruses, and algae have also been isolated from corresponding extracellular material in direct contact with organic or inorganic surfaces [52]. Stable microbial attachment to the underlying surfaces and the formation of biofilms creates significant and often insoluble problems both in the medical community and in the industry [53]. *Staphylococcus aureus*, *Staphylococcus epidermidis*, *Enterococcus faecalis* and *Pseudomonas aeruginosa* often colonize implanted medical devices [54] (such as pacemakers, intravenous catheters, urinary catheters, prosthetic implants, and heart valves) as well as pathological tissue structures (such as respiratory epithelium in patients with cystic fibrosis or cystic fibrosis mucosal in patients with neurogenic bladder) and create biofilms, thus causing chronic and often resistant to treatment infections.

Bacterial biomembranes are observed in 73% [55] patients with SCI using IC, and no relationship has been found between the presence of bio-membrane and symptoms [56]. However, the presence of at least 20 bacterial adherence in each bladder cell appears to be related to the symptomatology of the infection [57]. Bacterial cells are detached individually or in groups from the upper layers of the biofilm circulating in the fluid medium, urine in this case, and attempting to adhere to a new substrate which is more conducive to their growth. These detachable bacteria can cause systemic infection [53, 58].

and Klebsiella spp. are less, and have a higher frequency of infections than Pseudomonas, Proteus, and Serratia. Esclarin De Ruz et al. [20] reported that *E. coli*, 36% enterobacteria, 15% *Pseudomonas aeruginosa*, 15% *Acinetobacter* spp., 12% Enterococcus, 6% other microorganisms, and 26% multiple strains were isolated in 45%. In another study in 43 of 50 individuals with SCI, the same types of microorganisms as those from various areas of the skin, including perineal, peripubic, and perinatal regions, were isolated in urine [69]. In 50% of the cases, the same microorganism was isolated from the anterior urethra and from the bladder [70]. Also, the catheter insertion mode is also considered to be significant, which appears to cause an increase of approximately 10 times the number of bladder colonies [70]. The above results demonstrate the important role of bacterial colonization of the skin and urethra as a source of

Urinary Tract Infections in Neuro-Patients http://dx.doi.org/10.5772/intechopen.79690 67

When a UTI is suspected, it is important that the urine specimen is obtained in an appropriate manner in order to prevent contamination and a potential false-positive result. For patients with indwelling catheters (either the urethral catheter or suprapubic), the indwelling catheter should be changed to a new catheter, and the specimen should be obtained from the new catheter after capping the catheter for a few minutes to allow a small amount of urine to collect in the bladder. The urine specimen should then be collected by uncapping the catheter. For patients with external catheters or those who perform IC, the specimen should be col-

The significance of pyuria in neurogenic patients in combination with the use of intermittent catheterization or permanent catheter is often difficult to assess. Changing the Foley catheter in symptomatic patients causes an increase in the leucocytes without affecting the microbial strain or the number of colonies [71]. Positive urine culture (105 CFU/ml colonies), with the presence of >50 leucocytes per field of vision, is associated with an increased risk of fever. In addition, Gram-positive microorganisms such as *Staphylococcus epidermidis* and *Streptococcus faecalis* are accompanied by a small number of leukocytes despite the occurrence of a large number of colonies, while Gram-negative microorganisms are accompanied by significant pyuria [72]. According to the above significant pyuria is associated with the presence of catheters, infection with Gram-negative microorganisms, as well as bacterial tissue filtration.

Comparative studies are difficult to perform in these patient groups due to different definitions of bacteriuria and urinary tract infection, different urinary tract drainage methods, as well as the severity of acute, subacute, chronic, or total and partial lesions. In 1992, according to the National Institute on Disability Rehabilitation Research, severe bacteriuria is defined as the number of colony counts of 10<sup>2</sup> CFU uropathogenic micro granules per ml of urine in samples taken by catheterization, 10<sup>4</sup> CFU/ml urine samples under pure micturition and any

vaccination, through the catheters, of the bladder with microorganisms.

lected by catheterization with a new sterile catheter.

**5. Pyuria**

**6. Bacteriuria**
