Urinary tract infections (UTI) are among most common bacterial diseases both in community and hospital settings. Due to their high rate of frequency, recurrence, complications as well as increasing antimicrobial resistance, they pose a real challenge to medical professionals. Older people are more susceptible to UTI because their immune system is weaker, and comorbidities are often present (Aplay et al. 2018).
Of all hospital-associated UTI, 70–80% result from an indwelling urinary catheter, especially in older people, after surgical procedures and among patients staying in intensive care units (Temiz et al. 2012; Wójkowska-Mach et al. 2013; Piechota 2016). Catheter use is also associated with noninfectious outcomes, including mechanical trauma, mobility impairment as well as urethral strictures (Esposito et al. 2011; Hollingsworth et al. 2013). Additionally, prolonged catheterization increases the risk of biofilm formation in which uropathogens are difficult to treat with anti microbial agents (Zalewska-Piatek et al. 2009). Therefore, before deciding to catheterize the bladder it is important to estimate indications individually.
An optimal empirical therapy for UTI requires understanding of local epidemiology and antimicrobial susceptibility profiles. Uropathogens have developed resistance mechanisms to commonly prescribed anti biotics what limits treatment options of effective therapies. So, we conducted a study to describe clinical characteristics of patients with UTI, including CAUTI, as well as to determine etiology and susceptibility profiles of most common urinary isolates in different age groups.
A retrospective study was conducted on hospitalized adults from 1st January 2013 to 31st December 2015 in a Department of Internal Medicine and Nephrology with Dialysis Centre of Regional Hospital in southern Poland. During this period 4512 patients (2452 women and 2060 men) were hospitalized in our department in whom we diagnosed 498 cases of UTI. Among these cases, a group with CAUTI was distinguished. In the study, we made a systematic analysis of medical records of patients with diagnosed UTI.
UTI was diagnosed based on a positive result of a urine culture test with significant bacterial growth ≥ 105 CFU/ml and a presence of at least one of the following symptoms: body temperature ≥ 37.5°C, dysuria, perineal pain, suprapubic pain or flank pain. Laboratory tests usually showed the elevated level of inflammatory markers and leucocyturia in urinalysis. According to the European Centre for Disease Prevention and Control (ECDC 2015), diagnostic criteria for CAUTI included the maintenance of a catheter in the bladder for at least 7 days. The patients were also categorized by age as follows: 19–74 years (young old), 75–85 years (old old) and > 85 years (longevity).
Urine for bacteriological examination was obtained from the middle stream but in catheterized patients after a catheter replacement with the hygiene and sterility principles preserved. All urine samples were inoculated in a Microbiology Department on Columbia agar with 5% sheep blood, Sabouarud agar and Chromogenic media. Inoculated agar plates were incubated aerobically at 35–37°C for 18–24 hours. Colonies were counted on the inoculated medium and multiplied by the loop volume to determine bacterial count. Bacterial identification was done by standard biochemical procedures, including Vitek 2 Compact system.
Antibiotic susceptibility testing (AST) as an
Because of
We accepted
Among 4512 hospitalized patients, we recognized 498 cases of UTI (11.0%), of which 60 were CAUTI (1.3%). The mean age was 74.8 ± 14.6 years (ranging from 19 to 101 years) without differences between CAUTI and non-CAUTI population (76.2 ± 10.4 vs. 74.6 ± 15.0 years;
Table I presents the demographic and clinical characteristics of the studied population. Females showed much higher prevalence of the total UTI as 319 (64.1%), and in the non-CAUTI group than in the CAUTI group (67.6% vs. 38.3%;
Characteristic of patients with UTI enrolled in the study.
Characteristic | Total UTI n = 498 (100%) | CAUTI n = 60 (100%) | non-CAUTI n = 438 (100%) | OR (95% CI) | |||||
---|---|---|---|---|---|---|---|---|---|
n | % | n | % | n | % | ||||
Gender: | Male | 179 | 35.9% | 37 | 61.7% | 142 | 32.4% | 3.35 (1.92–5.86) | < 0.001 |
Female | 319 | 64.1% | 23 | 38.3% | 296 | 67.6% | 0.30 (0.17–0.52) | < 0.001 | |
Hypertension | 263 | 52.8% | 37 | 61.7% | 226 | 51.6% | 1.51 (0.87–2.62) | 0.145 | |
Heart failure | 174 | 34.9% | 23 | 38.3% | 141 | 32.2% | 1.31 (0.75–2.29) | 0.344 | |
Diabetes mellitus | 190 | 38.2% | 18 | 30.0% | 172 | 39.3% | 0.72 (0.40–1.28) | 0.258 | |
Urolithiasis | 22 | 4.4% | 1 | 1.7% | 21 | 4.8% | 0.34 (0.04–2.55) | 0.292 | |
Bronchopneumonia | 9 | 1.8% | 1 | 1.7% | 8 | 1.8% | 0.91 (0.11–7.41) | 0.931 | |
Malignancy (total) | 80 | 16.1% | 11 | 18.3% | 69 | 15.8% | 1.34 (0.68–2.65) | 0.405 | |
Genitourinary malignancy | 41 | 8.2% | 9 | 15.0% | 32 | 7.3% | 2.24 (1.01–4.96) | 0.047 | |
Prostatic hyperplasia | 57 | 11.4% | 10 | 16.7% | 47 | 10.7% | 1.66 (0.79–3.50) | 0.180 | |
Urine stasis in kidneys | 23 | 4.6% | 5 | 8.3% | 18 | 4.1% | 4.34 (1.76–10.73) | 0.001 | |
Percutaneous nephrostomy | 8 | 1.6% | 1 | 1.7% | 7 | 1.6 % | 1.04 (0.13–8.63) | 0.968 | |
Hemodialysis | 20 | 4.0% | 2 | 3.3% | 18 | 4.1% | 0.80 (0.18–3.56) | 0.774 | |
Immunotherapy | 26 | 5.2% | 4 | 6.7% | 22 | 5.0% | 1.35 (0.45–4.06) | 0.593 |
Data are expressed as number and percentage.
One patient may have several co-existing diseases
Microbial uropathogens isolated from the urine samples.
Pathogen | Total UTI | CAUTI | non-CAUTI | OR (95% CI) | ||||
---|---|---|---|---|---|---|---|---|
n | % | n | % | n | % | |||
363 | 72.9% | 37 | 61.7% | 326 | 74.4% | 0.55 (0.31–0.97) | 0.039 | |
30 | 6.0% | 6 | 10.0% | 24 | 5.5% | 1.92 (0.75–4.90) | 0.174 | |
12 | 2.4% | 5 | 8.3% | 7 | 1.6% | 5.60 (1.72–18.24) | 0.004 | |
20 | 4.0% | 4 | 6.7% | 16 | 3.7% | 1.88 (0.61–5.84) | 0.272 | |
40 | 8.0% | 2 | 3.3% | 38 | 8.7% | 0.36 (0.09–1.54) | 0.170 | |
11 | 2.2% | 2 | 3.3% | 9 | 2.0% | 1.64 (0.35–7.80) | 0.532 | |
Other | 22 | 4.4% | 4 | 6.7% | 18 | 4.1% | 1.67 (0.54–5.10) | 0.371 |
Total | 498 | 100.0% | 60 | 100.0% | 438 | 100.0% | – | – |
Other pathogens:
Production of extended-spectrum β-lactamases (ESBL) was found in 11.8% of total strains with the prevalence as follows: in the CAUTI (9/60; 15.0%) group and in the non-CAUTI (50/438; 11.4%) group.
Table III presents susceptibility profile of
Susceptibility profile of
Antibiotics | Total UTI (n = 363) | CAUTI (n = 37) | non-CAUTI (n = 326) | OR (95% CI) | ||||
---|---|---|---|---|---|---|---|---|
n’ | % susc. | n’ | % susc. | n’ | % susc. | |||
Beta-lactam antibacterials, penicylinns | ||||||||
Ampicillin | 354 | 30.2% | 36 | 19.4% | 318 | 31.4% | 0.53 (0.22–1.24) | 0.143 |
AM/CL | 361 | 49.9% | 37 | 43.2% | 324 | 50.6% | 0.74 (0.37–1.48) | 0.397 |
PIP/TZ | 207 | 87.0% | 19 | 68.4% | 188 | 88.8% | 0.27 (0.09–0.79) | 0.017 |
Aminoglycosides | ||||||||
Amikacin | 211 | 88.2% | 18 | 61.1% | 193 | 90.7% | 0.16 (0.06–0.47) | 0.001 |
Gentamicin | 211 | 91.0% | 20 | 70.0% | 191 | 93.2% | 0.17 (0.06–0.52) | 0.002 |
Cephalosporins | ||||||||
Cefalexin | 197 | 79.7% | 17 | 41.2% | 180 | 83.3% | 0.14 (0.05–0.40) | < 0.001 |
Cefuroxime | 358 | 85.8% | 36 | 75.0% | 322 | 87.0% | 0.45 (0.20–1.02) | 0.057 |
Cefotaxime | 238 | 87.0% | 22 | 63.6% | 216 | 89.4% | 0.21 (0.08–0.55) | 0.002 |
Ceftazidime | 237 | 83.5% | 21 | 61.9% | 216 | 85.6% | 0.27 (0.10–0.71) | 0.008 |
Cefepime | 210 | 89.5% | 19 | 73.7% | 191 | 91.1% | 0.27 (0.09–0.85) | 0.025 |
Antipseudomonal fluoroquinolones | ||||||||
Ciprofloxacin | 361 | 70.4% | 37 | 54.1% | 324 | 72.2% | 0.45 (0.23–0.90) | 0.024 |
Norfloxacin | 360 | 60.3% | 37 | 40.5% | 323 | 62.5% | 0.41 (0.20–0.82) | 0.011 |
Folate pathway inhibitors | ||||||||
Cotrimoxazole | 358 | 72.3% | 36 | 72.2% | 322 | 72.4% | 0.99 (0.46–2.14) | 0.986 |
Antipseudomonal carbapenems | ||||||||
Imipenem | 179 | 100.0% | 18 | 100.0% | 161 | 100.0% | – | – |
Nitrofuran derivatives | ||||||||
Nitrofurantoin | 357 | 89.4% | 37 | 83.8% | 320 | 90.0% | 0.57 (0.22–1.48) | 0.251 |
Abbrevations: Amoxicillin/clavulanic acid = AM/CL, Piperacillin/Tazobactam = PIP/TZ
n’ – number of all determinations for a given antibiotic; % susc. – % susceptibility
An antimicrobial susceptibility profile of
Susceptibility profile of
Antibiotics | 19–74 years (n = 133) | 75–85 years (n = 134) | > 85 years (n = 96) | 75–85 years vs. 19–74 years | > 85 years vs. 19–74 years | |||||
---|---|---|---|---|---|---|---|---|---|---|
n’ | % susc. | n’ | % susc. | n’ | % susc. | OR (95% CI) | OR (95% CI) | |||
Ampicillin | 132 | 31.1% | 130 | 26.9% | 92 | 33.7% | 0.82 (0.48–1.40) | 0.461 | 1.13 (0.64–1.99) | 0.678 |
AM/CL | 133 | 49.6% | 133 | 51.1% | 95 | 48.4% | 1.06 (0.66–1.72) | 0.806 | 0.95 (0.56–1.61) | 0.858 |
PIP/TZ | 73 | 86.3% | 80 | 85.0% | 54 | 90.7% | 0.90 (0.36–2.23) | 0.819 | 1.56 (0.50–4.85) | 0.446 |
Amikacin | 74 | 90.5% | 83 | 81.9% | 54 | 94.4% | 0.47 (0.18–1.24) | 0.127 | 1.78 (0.44–7.21) | 0.422 |
Gentamicin | 72 | 88.9% | 85 | 89.4% | 54 | 96.3% | 1.06 (0.38–2.89) | 0.916 | 3.25 (0.66–15.97) | 0.147 |
Cefalexin | 70 | 74.3% | 78 | 75.6% | 49 | 93.9% | 1.07 (0.51–2.26) | 0.849 | 5.31 (1.47–19.19) | 0.011 |
Cefuroxime | 132 | 85.6% | 133 | 82.0% | 93 | 91.4% | 0.76 (0.40–1.47) | 0.421 | 1.79 (0.75–4.28) | 0.193 |
Cefotaxime | 83 | 81.9% | 95 | 85.3% | 60 | 96.7% | 1.28 (0.58–2.83) | 0.548 | 6.40 (1.40–29.14) | 0.017 |
Ceftazidime | 83 | 80.7% | 94 | 81.9% | 60 | 90.0% | 1.08 (0.51–2.31) | 0.839 | 2.15 (0.79–5.87) | 0.136 |
Cefepime | 73 | 84.9% | 82 | 87.8% | 55 | 98.2% | 1.28 (0.51–3.21) | 0.602 | 9.58 (1.20–76.64) | 0.033 |
Ciprofloxacin | 132 | 72.0% | 134 | 67.9% | 95 | 71.6% | 0.82 (0.49–1.39) | 0.471 | 0.98 (0.55–1.76) | 0.949 |
Norfloxacin | 133 | 62.4% | 132 | 59.1% | 95 | 58.9% | 0.87 (0.53–1.43) | 0.581 | 0.86 (0.50–1.48) | 0.598 |
Cotrimoxazole | 130 | 74.6% | 133 | 67.7% | 95 | 75.8% | 0.71 (0.42–1.22) | 0.215 | 1.06 (0.58–1.97) | 0.841 |
Imipenem | 57 | 100.0% | 74 | 100.0% | 48 | 100.0% | – | – | – | – |
Nitrofurantoin | 132 | 91.7% | 131 | 87.8% | 94 | 88.3% | 0.65 (0.29–1.47) | 0.303 | 0.69 (0.28–1.66) | 0.402 |
Abbrevations: Amoxicillin/clavulanic acid = AM/CL, Piperacillin/Tazobactam = PIP/TZ
n’ – number of all determinations for a given antibiotic; % susc. – % susceptibility
Furthermore, we also carried out an analysis concerning
Urinary tract infection is emerging as an important community-acquired and nosocomial bacterial infection what was also confirmed by our 3-year analysis. It occurs on average in 1 per 10 of hospitalized patients and that was also presented in our previous study (Michno et al. 2016).
In our study, UTI mainly concerned older people who constituted the majority, as evidenced by average age of the studied population. The proportion of older people is rising constantly from 11% in 2012 and it is supposed to reach 22% by 2050 (UN 2012). Thus, challenges associated with infections in older population require specific assessment.
Urinary tract catheterization is one of the most common reason of bacteriuria caused by tendency of bacteria to adhere to artificial materials. It is believed that CAUTI occurs at a rate of 3–7% per day of catheterization and the incidences approach 100% within 30 days (Lo et al. 2014). Among patients hospitalized in our department, CAUTI were diagnosed in 1.3% cases that was a slightly higher than in the study carried out in Australia – 0.9% (Gardner et al. 2014). In another study, CAUTI were reported in 2.2% of hospitalized patients of the urological and orthopedic department (Giles et al. 2015).
In the current study, CAUTI was significantly more frequent in men that was similar to the Korean report (Kim et al. 2017). The authors, like in our study, analyzed the characteristics of CAUTI and non-CAUTI patients. They observed that CAUTI occurred significantly more often in patients with hypertension, those who used ventilators and after operations. In our analysis, CAUTI was more frequent in patients with genitourinary malignancy and urine stasis in kidneys. Patients with cancer have a greater tendency to acquire infections than general population due to cellular and humoral immune dysfunction, as well as complications of cancer therapy, including neutropenia or disruption of natural physical barriers (Thirumala et al. 2010). Urinary tract obstruction provides an opportunity for bacteria to adhere to urothelium and infect patients. In such case, effective antibiotic therapy as well as an appropriate urological intervention is necessary to prevent recurrent UTI and septic complications.
The predominant uropathogen responsible for CAUTI in our study was
In the current study,
Antimicrobial resistance is now accepted as a major problem in public health and patient care. It is mainly associated with an abuse of antimicrobial agents and makes it difficult to choose a proper empirical treatment by medical practitioners, especially in cases of multidrug resistant strains (Pobiega et al. 2015). Uropathogens developed resistance mechanisms of which the most common is ESBL. Organisms producing ESBL are clinically relevant and remain an important cause of failure of cephalosporins (Bradford 2001). In this study,
Susceptibility of
It is important to point out that the minimum susceptibility rate to support empirical treatment of UTI is 80% of all the strains of a specific uropathogen in a given region. According to these guidelines, the European Association of Urology (EAU) recommend cotrimoxazole as a first-line drug for empirical therapy in UTI (Grabe et al. 2009). In our study, 74.6% of
Patients with CAUTI are a specific group in which treatment of the infection may by difficult due to a high resistance rate of uropathogens. In such a case, it is necessary to administer an adequate initial antimicrobial therapy according to local antimicrobial susceptibility situation (Saurel et al. 2006). Inadequate empirical antimicrobial therapy extends treatment contributing to various complications and transformation into a chronic illness. Our analysis confirmed that
Regardless of the age groups among the population analyzed in this study,
The results of this study can be used to construct a hospital formulary and internal procedure for antibiotics usage in case of UTI in a specific department. Our results can also be helpful for comparison between departments and hospitals interested in this issue.
There are some limitations to this study. First, we retrospectively collected data through electronic medical records. It was difficult to obtain all characteristics for analyzing risk factors such as previous antibiotics use and history of recurrent UTI due to unrecorded information. Second, this study was conducted only in a single center. Therefore, it is difficult to reflect the overall characteristics of our region. The current report suggests the need for further large-scale monitoring of epidemiology and susceptibility profiles of most common uropathogens causing UTI, including CAUTI, to improve the effectiveness of empirical treatment.
The presented study showed considerable bacterial resistance to common empirically used antibiotics in case of CAUTI.