Risk factors for severe sepsis in community-onset bacteraemic urinary tract infection: impact of antimicrobial resistance in a large hospitalised cohort

Development and validation of artificial intelligence models to predict urinary tract infections and secondary bloodstream infections in adult patients

BACKGROUND

Traditional culture methods are time-consuming, making it difficult to utilize the results in the early stage of urinary tract infection (UTI) management, and automated urinalyses alone show insufficient performance for diagnosing UTIs. Several models have been proposed to predict urine culture positivity based on urinalysis. However, most of them have not been externally validated or consisted solely of urinalysis data obtained using one specific commercial analyzer.

METHODS

A total of 259,187 patients were enrolled to develop artificial intelligence (AI) models. AI models were developed and validated for the diagnosis of UTI and urinary tract related-bloodstream infection (UT-BSI). The predictive performance of conventional urinalysis and AI algorithms were assessed by the areas under the receiver operating characteristic curve (AUROC). We also visualized feature importance rankings as Shapley additive explanation bar plots.

RESULTS

In the two cohorts, the positive rates of urine culture tests were 25.2% and 30.4%, and the proportions of cases classified as UT-BSI were 1.8% and 1.6%. As a result of predicting UTI from the automated urinalysis, the AUROC were 0.745 (0.743-0.746) and 0.740 (0.737-0.743), and most AI algorithms presented excellent discriminant performance (AUROC > 0.9). In the external validation dataset, the XGBoost model achieved the best values in predicting both UTI (AUROC 0.967 [0.966-0.968]) and UT-BSI (AUROC 0.955 [0.951-0.959]). A reduced model using ten parameters was also derived.

CONCLUSIONS

We found that AI models can improve the early prediction of urine culture positivity and UT-BSI by combining automated urinalysis with other clinical information. Clinical utilization of the model can reduce the risk of delayed antimicrobial therapy in patients with nonspecific symptoms of UTI and classify patients with UT-BSI who require further treatment and close monitoring.

Exploring the Dynamic Role of Bacterial Etiology in Complicated Urinary Tract Infections

Background and Objectives. Numerous studies have been conducted to explore the epidemiological characteristics of urinary tract infections (UTI) and sepsis. However, there is still a lack of relevant bacteriological features and prognostic information regarding urosepsis based on bacteriological etiology. The current study aims to evaluate the bacterial etiology of complicated UTI (cUTI) and bacterial resistance to antibiotics and whether they present an intrinsic risk of developing urosepsis. Materials and Methods. A retrospective study was performed that included 102 patients who were diagnosed with cUTI and admitted to the urology department of the "Sfântul Apostol Andrei" County Emergency Clinical Hospital (GCH) from September 2019 to May 2022. Results. A considerable number of patients, n = 41 (40.2%), were diagnosed with multi drug-resistant (MDR) infection. Escherichia coli (E. coli) was identified as the prevailing pathogen, accounting for 51 patients. Klebsiella manifested itself as the subsequent causative agent in 27 instances. The presence of Enterococcus spp. infection was documented in 13 patients, whereas Pseudomonas emerged as the etiological perpetrator in the clinical context of 8 patients. The current study found a substantial prevalence of resistance to first-line antibiotics. The overall resistance rate was 74.5% for penicillin, 58.82% for trimethoprim-sulfamethoxazole and 49% for fluoroquinolones; cephalosporin resistance displayed an inverse correlation with antibiotic generation with fourth-generation cephalosporins exhibiting a resistance rate of 24.5%, and first-generation cephalosporins demonstrating a resistance rate of 35.29%. Conclusions. Age, comorbidities and indwelling urinary catheters are risk factors for developing MDR infections. While the intrinsic characteristics of the causative bacterial agent in cUTI may not be a risk factor for developing urosepsis, they can contribute to increased mortality risk. For empiric antibiotic treatment in patients with cUTI who are at a high risk of developing urosepsis and experiencing a potentially unfavorable clinical course, broad-spectrum antibiotic therapy is recommended. This may include antibiotics, such as amikacin, tigecycline, carbapenems and piperacillin-tazobactam.

Impact of urinary tract infection-causative microorganisms on the progression to bloodstream infection: A propensity score-matched analysis

OBJECTIVES

We aimed to determine the risk factors for the progression of urinary tract infection (UTI) to bloodstream infection (BSI) and to evaluate the mortality-associated factors in patients with urinary tract-related BSI (UT-BSI).

METHODS

A propensity score-matched study was conducted using clinical data from all adult patients with UTIs in two South Korean hospitals.

RESULTS

A total of 84,406 patients with UTIs were enrolled. The relative incidence of UTIs caused by Escherichia coli decreased along with an increase in the incidence of Candida species infections during the study period. UTI caused by E. coli, Klebsiella pneumoniae, Staphylococcus aureus, and Candida species had a relatively high rate of progression to BSI. UT-BSI caused by Candida species (adjusted odd ratio 5.67; 95% confidence interval 3.97-8.11; p < 0.001) was significantly associated with high 30-day mortality.

CONCLUSIONS

UTI-causative microorganisms were associated with both progression to UT-BSI and 30-day mortality in patients with UT-BSI. Considering the trend of increasing age of patients and more frequent use of indwelling urologic devices, UT-BSIs caused by other microorganisms than E. coli could be a more serious medical burden in the future.

A Large Multicenter Prospective Study of Community-Onset Healthcare Associated Bacteremic Urinary Tract Infections in the Era of Multidrug Resistance: Even Worse than Hospital Acquired Infections?

INTRODUCTION

Healthcare-associated (HCA) infections represent a growing public health problem. The aim of this study was to compare community-onset healthcare associated (CO-HCA) bacteremic urinary tract infections (BUTI) and hospital-acquired (HA)-BUTI with special focus on multidrug resistances (MDR) and outcomes.

METHODS

ITUBRAS-project is a prospective multicenter cohort study of patients with HCA-BUTI. All consecutive hospitalized adult patients with CO-HCA-BUTI or HA-BUTI episode were included in the study. Exclusion criteria were: patients < 18 years old, non-hospitalized patients, bacteremia from another source or primary bacteremia, non-healthcare-related infections and infections caused by unusual pathogens of the urinary tract. The main outcome variable was 30-day all-cause mortality with day 1 as the first day of positive blood culture. Logistic regression was used to analyze factors associated with clinical cure at hospital discharge and with receiving inappropriate initial antibiotic treatment. Cox regression was used to evaluate 30-day all-cause mortality.

RESULTS

Four hundred forty-three episodes were included, 223 CO-HCA-BUTI. Patients with CO-HCA-BUTI were older (p < 0.001) and had more underlying diseases (p = 0.029) than those with HA-BUTI. The severity of the acute illness (Pitt score) was also higher in CO-HCA-BUTI (p = 0.026). Overall, a very high rate of MDR profiles (271/443, 61.2%) was observed, with no statistical differences between groups. In multivariable analysis, inadequate empirical treatment was associated with MDR profile (aOR 3.35; 95% CI 1.77-6.35), Pseudomonas aeruginosa (aOR 2.86; 95% CI 1.27-6.44) and Charlson index (aOR 1.11; 95% CI 1.01-1.23). Mortality was not associated with the site of acquisition of the infection or the presence of MDR profile. However, in the logistic regression analyses patients with CO-HCA-BUTI (aOR 0.61; 95% CI 0.40-0.93) were less likely to present clinical cure.

CONCLUSION

The rate of MDR infections was worryingly high in our study. No differences in MDR rates were found between CO-HCA-BUTI and HA-BUTI, in the probability of receiving inappropriate empirical treatment or in 30-day mortality. However, CO-HCA-BUTIs were associated with worse clinical cure.

Burden of illness in US hospitals due to carbapenem-resistant Gram-negative urinary tract infections in patients with or without bacteraemia

Background

Urinary tract infections (UTIs) are the most common infections caused by Gram-negative bacteria and represent a major healthcare burden. Carbapenem-resistant (CR) strains of Enterobacterales and non-lactose fermenting pathogens further complicate treatment approaches.

Methods

We conducted a retrospective analysis of the US Premier Healthcare Database (2014–2019) in hospitalised adults with a UTI to estimate the healthcare burden of Gram-negative CR UTIs among patients with or without concurrent bacteraemia.

Results

Among the 47,496 patients with UTI analysed, CR infections were present in 2076 (4.4%). Bacteraemia was present in 24.5% of all UTI patients, and 1.7% of these were caused by a CR pathogen. The most frequent CR pathogens were Pseudomonas aeruginosa (49.4%) and Klebsiella pneumoniae (14.2%). Patients with CR infections had a significantly longer hospital length of stay (LOS) (median [range] 8 [5–12] days vs 6 [4–10] days, P < 0.001), were less likely to be discharged home (38.4% vs 51.0%, P < 0.001), had a higher readmission rate (22.6% vs 13.5%, P < 0.001), and had greater LOS-associated charges (mean US$ 91,752 vs US$ 66,011, P < 0.001) than patients with carbapenem-susceptible (CS) infections, respectively. The impact of CR pathogens was greater in patients with bacteraemia (or urosepsis) and these CR urosepsis patients had a significantly higher rate of mortality than those with CS urosepsis (10.5% vs 6.0%, P < 0.001).

Conclusions

Among hospitalised patients with UTIs, the presence of a CR organism and bacteraemia increased the burden of disease, with worse outcomes and higher hospitalisation charges than disease associated with CS pathogens and those without bacteraemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06229-x.

Glycated Hemoglobin < 6.5% Is Associated With Uroseptic Shock in Diabetic Patients With Urinary Tract Infection

This study aimed to compare the clinical characteristics and treatment outcomes of diabetic and non-diabetic individuals with urinary tract infection (UTI) and determine whether glycated hemoglobin (HbA1c) levels <6. 5% leads to uroseptic shock in diabetic individuals. We retrospectively collected and analyzed the clinical data of 1,363 individuals with UTIs in Taiwan from January 2006 to January 2018. Of the 345 diabetic individuals, 61 (17.7%) developed uroseptic shock. Diabetic patients who developed uroseptic shock tended to be older and males and, had a history of congestive heart failure, urolithiasis, higher serum creatinine level during hospitalization, lower serum HbA1c level, bacteremia, and acute kidney injury. Backward stepwise multivariate logistic regression analysis showed that male gender [odds ratio (OR), 1.861; 95% confidence interval (CI), 1.009–3.433; P = 0.047], congestive heart failure (OR, 4.036; 95% CI, 1.542–10.565; P = 0.004), bacteremia (OR, 2.875; 95% CI, 1.539–5.370; P = 0.001), and HbA1c level <6.5% (OR, 2.923; 95% CI, 1.580–5.406; P = 0.001) were associated with an increased risk of developing uroseptic shock among diabetic patients during hospitalization due to UTI. HbA1c level <6.5% is independently associated with uroseptic shock in diabetic patients with UTI.

Rapid identification of uropathogens by combining Alfred 60 system with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry technology

Rapid identification of uropathogens is needed to determine appropriate antimicrobial therapy. This study evaluated performance of the Alfred 60 system combined with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) technology for rapid identification of uropathogens. The Alfred 60 system was used to screen urine cultures, followed by identifying the microbial pathogen in positive cultures using MALDI-TOF MS. The Alfred 60 detected positive cultures by measuring the turbidity of urine samples, which were transferred automatically to vials containing liquid medium and incubated for 3.5 h at 35 °C in the Alfred 60 system. Vials that showed growth were removed and centrifuged. The pellet was subjected to MALDI-TOF MS identification. In parallel, positive urine samples were inoculated onto agar plates for identification by conventional culture. The time required to detect positive urine cultures with Alfred 60 and identify the uropathogens with MALDI-TOF MS ranged from 15 min to 3.5 h. Among 146 positive urine samples tested, conventional cultures showed three culture groups: group 1 included 101 samples with growth of a single type of microorganism; group 2 included 34 samples with 2 types of microorganisms; and group 3 included 11 samples with ≥ 3 types of microorganisms. Direct identification by MALDI-TOF MS was concordant with 95% of the samples in group 1, 100% of the principal microorganism in group 2, but could not identify microorganisms in group 3. This combination of methods provides rapid, reliable microbial identification for most positive urine cultures.

Preventing sepsis development in complicated urinary tract infections

Introduction: Urinary tract infections (UTIs) are the most prevalent infections in the community and the most common reason for antimicrobial prescribing in ambulatory care. A UTI is defined as complicated when urinary tract anatomical abnormalities or urinary devices are present, when it is recurrent and when associated with immunodeficiency. Complicated UTIs (cUTIs) have a higher risk of treatment failure and often require longer antimicrobial treatment courses. cUTIs, especially those which are healthcare-associated, are often due to multidrug resistant organisms (MDROs).Areas covered: This article will review the available evidence in relation to prevention of sepsis in cUTI, evaluating the risk factors associated with sepsis development. Published articles from January 2005 to September 2019 on UTIs and sepsis prevention in complicated UTIs were identified by using MEDLINE (National Library of Medicine Bethesda MD) and by reviewing the references of retrieved articles.Expert opinion: Prevention of sepsis relies on prompt and timely diagnosis of cUTI, early identification of the causative organism, removal of obstructions and source control, proper and adequate empirical/targeted antimicrobial treatment. In particular, source control, i.e. removal of urinary obstructions, infected stents, urinary catheters, nephrostomies, and drainage of hydronephrosis/abscess, is essential for preventing the development and progression of sepsis.

Urinary tract infection-related hospitalization among older adults receiving home health care

BACKGROUND

Urinary tract infection (UTI)- related hospitalizations are a poor patient outcome in the rapidly growing home health care (HHC) arena that serves a predominantly elderly population. We examined the association between activities of daily living (ADL) and risk of UTI-related hospitalization among this population.

METHODS

Using a retrospective cohort design, we conducted a secondary data analysis of a 5% random sample of a national HHC dataset, the Outcome and Assessment Information Set for the year 2013. Andersen's Behavioral Model of Health Service Utilization was used as a guiding framework for statistical modeling. We used logistic regression to examine the association between UTI-related hospitalization and predisposing, enabling, or need factors.

RESULTS

Among beneficiaries (n = 24,887) hospitalized in 2013, 1,133 had UTI-related hospitalizations. HHC patients with a UTI-related hospitalization were more likely to have severe ADL dependency, impaired decision making, and lower Charlson Comorbidity Index, than those with a non UTI-related hospitalization (P < .001). Risk factors for UTI-related hospitalization included female sex, (adjusted odds ratio [AOR], 1.44; 95% confidence interval [CI], 1.25-1.66), Medicaid recipient (AOR, 1.99; 95% CI, 1.09-3.64), severe ADL dependency (AOR, 1.50; 95% CI, 1.16-1.94), the presence of a caregiver to assist with supervision and safety (AOR, 1.26; 95% CI, 1.06-1.49), treatment for UTI in the previous 14 days (AOR, 2.85; 95% CI, 2.46-3.29), presence of a urinary catheter (AOR, 3.77; 95% CI, 2.98-4.77), and prior history of indwelling or suprapubic catheter (AOR, 1.44; 95% CI, 1.06-1.94).

CONCLUSIONS

ADL dependency levels are a potentially modifiable risk factor for UTI-related hospitalization on admission to HHC. ADL dependency levels can inform clinical interventions to ameliorate ADL dependency in HHC settings and identify groups of patients at high risk for UTI-related hospitalization.

A multicentre study investigating parameters which influence direct bacterial identification from urine

Rapid diagnosis is one of the best ways to improve patient management and prognosis as well as to combat the development of bacterial resistance. The aim of this study was to study parameters that impact the achievement of reliable identification using a combination of flow cytometry and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF-MS).The study was carried out in nine hospitals in Spain and included 1,050 urine samples with bacterial counts of 5x10⁶ bacteria/ml. MALDI-ToF-MS-based identification was performed according to a previously described protocol. Valid identification by direct MALDI-ToF-MS was obtained in 72.8% of samples, in 80.3% of samples found to be positive by culture, 32.2% of contaminated samples, and 19.7% of negative samples. Among the positives samples with a valid identification the concordance at the species level was 97.2%. The parameters related to success of direct identification were: high bacterial count, the presence of Escherichia coli as a pathogen and rod-bacteria morphology provided by flow cytometry. The parameters related to failure were a high epithelial cell (EC) count, a high white blood cell (WBC) count and urine samples obtained from in-patients. In summary, this multicentre study confirms previously published data on the usefulness and accuracy of direct MALDI-ToF-MS-based identification of bacteria from urine samples. It seems important to evaluate not only the bacterial count, but also other parameters, such as EC and WBC counts, bacterial species and morphology, and the health care setting, to decide whether the sample is suitable for direct identification.

Prospective cohort study of risk factors for extended-spectrum ß-lactamase-producing Escherichia coli urinary tract infections in elderly patients admitted to hospital

BACKGROUND

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli are currently common in community-onset infections, limiting therapeutic options. In this work we aim to identify the prevalence of and risk factors for ESBL-producing E. coli in elderly patients with urinary tract infections (UTI) admitted to hospital.

METHODS

Prospective cohort study on elderly patients with E. coli UTI admitted to a university hospital in Spain, from January 2013 to December 2015. Clinical features, microbiology and outcomes were recorded from the electronic medical records and reviewed by two researchers. Cases were segregated according to ESBL-producing E. coli. Risk factors for ESBL-producing E. coli were analysed by multivariate analysis.

RESULTS

The prevalence of ESBL-producing E. coli was 27.4% (85/310). Healthcare-associated UTI was the only risk factor for ESBL-producing E. coli (OR 6.79; 95% CI 3.22-14.31, P < .001) by multivariate analysis. ESBL-producing E. coli was 43.9% in the healthcare-associated UTI group and 8.9% in the community-acquired UTI group (P < .001). Inadequate empirical antibiotic therapy and length of stay in hospital were higher in the ESBL-producing E. coli group than in the non-ESBL-producing E. coli group (62.3% vs 5.3% and 6.60 ± 3.69 days vs 5.61 ± 3.16 days, respectively). Mortality was not significantly different between groups (13% in ESBL-producing E. coli group vs 7.5% in non-ESBL-producing E. coli group, P = .140).

SUMMARY

Healthcare-associated UTI was a risk factor for ESBL-producing E. coli in elderly patients with UTI admitted to hospital. Our results might help clinicians in choosing empirical antibiotics in an overall high rate setting of ESBL-producing E. coli.

Bacteremic Urinary Tract Infection Caused by Multidrug-Resistant Enterobacteriaceae Are Associated With Severe Sepsis at Admission: Implication for Empirical Therapy

The purpose of this study is to compare the clinical features and treatment outcomes among patients with bacteremic urinary tract infection (UTI) caused by multidrug-resistant (MDR) and non-MDR Enterobacteriaceae and to identify whether MDR pathogens were independently associated with severe sepsis or septic shock at presentation.The clinical data of adult patients visiting and being treated at Chia-Yi Christian Hospital due to bacteremic UTI caused by Enterobacteriaceae from January 2006 to August 2015 were retrospectively analyzed.A total of 585 patients were enrolled. Among them, 220 (37.6%) were caused by the MDR Enterobacteriaceae. A total of 206 patients (35.2%) developed severe sepsis or septic shock at presentation. Patients in the MDR group tend to be male and have a past history of gout, recurrent UTI, prior hospitalization, hydronephrosis, renal stone, ureteral stone, indwelling urinary catheter, newly development of renal dysfunction, severe sepsis or septic shock, intensive care unit (ICU) admission, receipt of ineffective empirical therapy, longer hospital stay, and higher in-hospital mortality (2.7% vs 1.9%, P = 0.569). Using multivariate logistic regression analysis, it is revealed that independent predictors associated with severe sepsis or septic shock at presentation were liver cirrhosis (OR 2.868; 95% CI 1.439-5.716; P = 0.003), indwelling urinary catheter (OR 1.936; 95% CI 1.238-3.027; P = 0.004), and MDR Enterobacteriaceae (OR 1.447; 95% CI 1.002-2.090; P = 0.049).Multidrug resistance was associated with the development of severe sepsis or septic shock upon presentation among patients with bacteremic UTI caused by Enterobacteriaceae. Therefore, empirical antibiotics therapy for patients with UTI presented with severe sepsis and/or septic shock should be more broad-spectrum to effectively cover MDR Enterobacteriaceae.

Differential characteristics of healthcare-associated compared to community-acquired febrile urinary tract infections in males

The objective of this study was to analyse the characteristics of healthcare-associated febrile urinary tract infection (HCA-FUTI) compared to community-acquired FUTI (CA-FUTI) in men. An ambispective cross-sectional study in which we recorded clinical and microbiology data and outcomes from males with FUTI attended in the Emergency Department was carried out. A total of 479 males with FUTI, 162 (33.8%) HCA-FUTI and 317 (66.2%) CA-FUTI, were included. HCA-FUTI patients were older (p < 0.001), had higher Charlson scores (p < 0.001) and received previous antimicrobial treatment more frequently (p < 0.001) compared to CA-FUTI patients. HCA-FUTI was less likely caused by Escherichia coli (p < 0.001) and more frequently by Klebsiella spp. (p = 0.02), Enterobacter spp. (p < 0.001) and Pseudomonas aeruginosa (p < 0.001). Resistance to ceftriaxone (p = 0.006), gentamicin (p < 0.001), quinolones (p < 0.001), co-trimoxazole (p = 0.001) and fosfomycin (p = 0.009) was higher among E. coli strains isolated from males with HCA-FUTI and so was the prevalence of extended-spectrum beta-lactamase and AmpC E. coli and Klebsiella spp.-producing strains (p = 0.012). Inadequate antimicrobial treatment and all-cause in-hospital mortality was associated with HCA-FUTI (p < 0.001 and p = 0.004, respectively). Independent factors for mortality were severe sepsis or septic shock [odds ratio (OR) 29; 95% confidence interval (CI): 3.9-214] and cirrhosis (OR 23.7; 95% CI: 1.6-350.6). Male patients with HCA-FUTI have different clinical characteristics, outcomes and microbiological features compared to CA-FUTI patients. Previous contact with the healthcare system has to be taken into consideration when deciding the optimal antimicrobial treatment in males with FUTI.