Defining the Optimal Duration of Therapy for Hospitalized Patients With Complicated Urinary Tract Infections and Associated Bacteremia

Comparison of urinary tract-related and catheter-related bloodstream infections in long-term and acute care wards: A retrospective cohort study

BACKGROUND

The characteristics of bloodstream infections in patients admitted to long-term care wards remain unclear. This study examined differences in nosocomial-onset urinary tract-related bloodstream infections (UTRBSIs) and catheter-related bloodstream infections (CRBSIs) between patients admitted to long-term and acute care wards.

METHODS

This retrospective cohort study was conducted at a mixed-care hospital with long-term and acute care wards from April 2015 to March 2024. Patient backgrounds, causative pathogens, antibiotic resistance, and treatment patterns were compared between the two groups.

RESULTS

Among the 252 patients, 108 (42.9 %) were diagnosed with UTRBSIs and 87 (34.5 %) with CRBSIs. In UTRBSIs, the long-term care group had significantly longer hospitalization (721 vs. 16 days, P < 0.001), more frequent use of indwelling urinary catheters (76.7 % vs. 28.6 %, P < 0.001), and higher isolation rates of extended-spectrum β-lactamase-producing Enterobacterales (41.1 % vs. 8.6 %, P < 0.001). Piperacillin/tazobactam and meropenem were significantly more frequently used empirically in the long-term care group. In CRBSIs, the isolation rates of main causative pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) (9.5 % vs. 6.7 %, P = 0.707) and methicillin-resistant coagulase-negative Staphylococcus spp. (40.5 % vs. 48.9 %, P = 0.519), showed no significant differences between the two groups despite differences in patient backgrounds. Anti-MRSA agents were rarely used empirically in both groups (19.0 % vs. 15.6 %, P = 0.779).

CONCLUSIONS

Patients admitted to long-term care wards may require empirical therapy for UTRBSIs targeting drug-resistant Enterobacterales, while for CRBSIs, empirical use of anti-MRSA agents may be considered, similar to patients admitted to acute care wards.

A Systematic Literature Review of the Epidemiology of Complicated Urinary Tract Infection

INTRODUCTION

Urinary tract infections (UTIs) are common bacterial infections and present with heterogeneous clinical phenotypes. Whereas many uncomplicated UTIs resolve spontaneously or with antibiotic treatment, a complicated UTI (cUTI) presents with greater morbidity and a higher risk of treatment failures. The goal of this study was to estimate the real-world epidemiology of cUTI, including acute pyelonephritis (AP) and catheter-associated UTIs (CAUTIs), and its associated mortality internationally.

METHODS

A systematic literature search was conducted using PubMed, Embase, Cochrane, and EconLit databases for relevant articles published between July 2013 and July 2023 covering Europe and the following countries: France, Italy, Germany, Spain, the UK, China, Japan, and the US (US). Search terms relating to cUTI, AP, CAUTI, outcomes of interest (epidemiology), and real-world research designs were used. There were no language limitations (protocol registry: PROSPERO-CRD42023454794).

RESULTS

Database searches yielded 1014 unique records, of which 91 met the prespecified inclusion criteria; bibliography and conference abstract searches yielded 27 additional records for a total of 118 records for inclusion. Disease presentation and reported outcomes varied widely across studies, and most studies reporting incidence and prevalence of cUTI were from the US (21 of 29). No studies reporting incidence or prevalence rates of cUTI in China, Germany, or the UK were identified. Overall, high antibiotic resistance rates were reported in both inpatient and outpatient settings. The inpatient cohort mortality rates were highly variable (0-50%) depending on the patient population.

CONCLUSIONS

While disease presentation and reported outcomes varied widely across studies, cUTIs represent a considerable burden in terms of incidence, prevalence, drug resistance, and mortality, yet vast knowledge gaps remain in the literature. There is a crucial need to address these gaps to effectively evaluate new treatments and improve future analyses of cUTI burden and outcomes.

Evaluation of shorter versus longer antifungal treatment durations for Candida spp. urinary tract infections among hospitalized adults

Infectious Diseases Society of America guidelines recommend 14 days of treatment for Candida spp. urinary tract infections (UTIs). To our knowledge, no data are available to compare <14 days for Candida spp. UTI. This was a single-center, retrospective cohort study between 01 January 2015 and 01 January 2024. Hospitalized adults with >1 urine culture with Candida spp. and symptoms who initiated >1 antifungal dose within 96 hours were included. Multiple exclusion criteria existed, including but not limited to if Candida spp. were isolated from another site, antifungals were received for another indication, or the participant was asymptomatic. The primary outcome was clinical treatment success. Binary logistic regression was performed to further assess the relationship between fluconazole duration and clinical treatment success. Among 2,400 patients with candiduria, 45 and 58 in the 14-day and <14-day cohorts were assessed after exclusion criteria were applied, respectively. Median (interquartile range) fluconazole duration was 14 (14-14) days in the 14-day cohort and 7 (5-7) in the <14-day cohort. There was no difference in clinical treatment success in patients treated for 14 days vs <14 days (14 days: 93.3% (42/45) vs <14 days: 93.1% (54/58), P = 1.000; between-group difference (95% CI: 0.02 [-9.6 to 10]). Fluconazole duration did not have a significant association with clinical treatment success on binary logistic regression (P = 0.503; odds ratio 0.917 [95% CI: 0.712-1.181]). There was no statistically significant difference in clinical treatment success in patients treated with fluconazole for a median of 14 days vs a median of 7 days for symptomatic Candida spp. UTI. These data support the potential utility of shorter antifungal durations for Candida spp. UTI.

Evaluation of antibiotic de-escalation based on the DASON criteria by pharmacist-led post-prescription review and feedback: A retrospective study in a medium-sized Japanese hospital

INTRODUCTION

Among antimicrobial stewardship team (AST) activities, de-escalation, which is aimed at optimizing antibiotic use, lacks a standardized evaluation method. The Duke Antimicrobial Stewardship Outreach Network (DASON) criteria provide a framework for assessing de-escalation; however, their applicability in small to medium-sized hospitals in Japan has remained unclear. We aimed to evaluate the effectiveness of AST pharmacist-led post-prescription review and feedback (PPRF) using multiple indicators, including de-escalation based on the DASON criteria, to determine whether these indicators are also applicable in medium-sized hospitals.

METHODS

A retrospective study was conducted at a 330-bed hospital, comparing pre-PPRF (April 2021 to March 2022) and post-PPRF (April 2022 to March 2023) periods. The effectiveness of AST pharmacist-led PPRF was evaluated using the de-escalation rate determined by the DASON criteria, inappropriate antibiotic use in definitive therapy, days of therapy (DOT), and days of antibiotic spectrum coverage (DASC) per DOT.

RESULTS

The de-escalation rate significantly increased from 20 % to 45 % (P < 0.01), and inappropriate antibiotic use in definitive therapy decreased from 7 % to 0 % after AST pharmacist-led PPRF. While DOT significantly increased from 11 days to 13 days (P = 0.02), no significant change was observed in the DASC/DOT ratio.

CONCLUSION

This study suggests that de-escalation based on the DASON criteria can be an effective quantitative indicator for evaluating AST pharmacist-led PPRF in medium-sized hospitals. The findings also suggest that incorporating multiple indicators tailored to each hospital's conditions can provide a more comprehensive framework for evaluating AST pharmacist-led PPRF.

A comparison of empiric therapy with cefazolin versus ceftriaxone for patients with complicated urinary tract infections in a tertiary care veterans affairs medical center

BACKGROUND

Data are limited regarding use of narrow-spectrum agents for the treatment of complicated urinary tract infections (cUTIs). We sought to evaluate cefazolin compared with ceftriaxone for the empiric treatment of patients with cUTIs in an inpatient setting.

METHODS

We conducted a retrospective, single-center, cohort study involving patients with cUTI treated with cefazolin or ceftriaxone at a Veterans Affairs (VA) medical center between November 1, 2019 and September 30, 2022. The primary outcome was 30-day clinical success, defined as resolution of signs and symptoms of infection without re-initiation of antibiotics during hospitalization or relapse within 30 days after cUTI diagnosis. Secondary outcomes included hospital length of stay and Clostridioides difficile infection (CDI) within 30 days of the end of antibiotic therapy.

RESULTS

We identified 113 patients with cUTI treated with cefazolin (n = 52) or ceftriaxone (n = 61) meeting study criteria. The study arms had similar demographics, although patients treated with ceftriaxone more frequently had subjective fever on admission or nephrolithiasis while cefazolin-treated patients had more altered mental status as the only UTI symptom reported, urinary catheter, and had a single dose of another antibiotic prior to starting the study medication. Clinical success was achieved in 47/52 (90%) and 53/61 (87%) in the cefazolin and ceftriaxone groups, respectively (P = 0.56). Additionally, there were no statistically significant differences in length of stay and development of CDI.

CONCLUSIONS

In this retrospective cohort study of patients with cUTI at a VA medical center, empiric therapy with cefazolin appears to be a safe and effective treatment option.

Identification of CMY-190, a novel chromosomally encoded AmpC β-lactamase, and plasmid-encoded KPC-2 in a clinical isolate of Citrobacter youngae

This study investigates the antibiotic resistance phenotype and genotype of Citrobacter youngae strain YS01, isolated from a peritoneal effusion sample, focusing on both chromosomal and plasmid-mediated resistance mechanisms to inform clinical antibiotic therapy. Our results reveal the presence of the chromosomally encoded β-lactamase CMY-190 and the plasmid-encoded carbapenemase KPC-2, which confer resistance to cephalosporins and carbapenems, respectively. CMY-190 exhibits substrate and inhibition profiles similar to AmpC β-lactamases and shares 88.05% amino acid identity with the plasmid-encoded enzyme CFE-2 from Citrobacter freundii pJA99. DNA sequence analysis identified the ampR gene upstream of both bla CMY-190 and bla KPC-2. In addition, genes identified surrounding the ampR-ampC regions in C. youngae, including ORF1, the fumarate operon (frdABCD), blc, and lolB, a DNA fragment not present in other Citrobacter species. The ampR-ampC genes were cloned into the PHSG398 vector and expressed in Escherichia coli DH5α, with the transformed strain showing partial resistance to cephalosporins. The bla KPC-2 was carried by Tn1721, previously identified mainly in Asian strains of Klebsiella pneumoniae. The expression of KPC-2 was confirmed by the conjugation of the donor bacterium C. youngae with E. coli J53 and by the transformation of the plasmid containing bla KPC-2 into E. coli DH5α, with all the transformed strains demonstrating resistance to carbapenems and elevated carbapenem MICs. To the best of our knowledge, this is the first report of a novel chromosomally encoded AmpC β-lactamase gene, bla CMY-190, and the emergence of bla KPC-2 in C. youngae.

Acute kidney injury in paediatric kidney transplant recipients

Acute kidney injury (AKI) in paediatric kidney transplant recipients is common. Infection including urinary tract infection (UTI) and rejection are the most common causes in children. Surgical complications often cause AKI early post-transplant, whereas BK polyomavirus nephropathy rarely occurs in the first month post-transplant. Understanding kidney physiology helps to appreciate the sensitivity of the allograft to AKI, more so than native kidneys. Although the cause of AKI is often multi-factorial, there may be an underlying process that is treatable. Eliciting the aetiology, in this regard, is of paramount importance. Pre-renal and post-renal causes of allograft dysfunction are important to distinguish from intrinsic kidney disease. Clinical information and examination of fluid balance, urine dipstick testing, blood tests, bladder and kidney transplant ultrasound, and kidney transplant biopsy remain vital assessment tools in narrowing the differential diagnosis. A careful prescribed and recreational drug history is always warranted as many drugs including supplements are nephrotoxic. Additional causes such as allograft rejection, recurrent disease, and calcineurin inhibitor toxicity need to be considered in cases of allograft dysfunction, which would not affect the native kidneys. Early detection and assessment of AKI is crucial in promoting recovery. Significant progress has been made in specific pathologies over the last 20 years, which has improved kidney allograft survival rates considerably. Research into identifying AKI biomarkers to assist early diagnosis, before the serum creatinine rises, is ongoing.

Evaluation of Short Versus Long Courses of Antibiotics in Critically Ill Patients With Gram-Negative Bloodstream Infections

BACKGROUND

Short courses of antibiotics (7-10 days) are effective for uncomplicated gram-negative bloodstream infections (GN-BSI). However, prior studies have been limited to small cohorts of critically ill patients.

OBJECTIVE

The objective of this study was to evaluate the safety and efficacy of short courses of therapy compared with longer courses in patients admitted to the intensive care unit (ICU) with GN-BSI.

METHODS

Propensity-matched, retrospective cohort study of critically ill patients with GN-BSI. The primary outcome was a composite of 30-day mortality or 60-day relapse. Secondary endpoints were components of the composite, 30-day relapse, cure with or without adverse drug events (ADE), and ADEs. Regression analysis was performed to identify factors predictive of the composite outcome.

RESULTS

225 patients were included in the propensity analysis, 145 in the long cohort and 80 in the short cohort. The primary outcome occurred in 3.8% of patients in the short group and 9.0% of patients in the long group (P = 0.24). There was no difference in 30-day mortality (3.8% vs 5.5%, P = 0.79), 60-day relapse (0% vs 3.4%, P = 0.23), or 30-day readmission (20% vs 22.8%, P = 0.76). ADEs were more common in the long group (47.2% vs 34.1%, OR 1.7, 95% CI 1.04-2.9), primarily attributable to diarrhea.

CONCLUSION AND RELEVANCE

In critically ill patients with GN-BSI, there were no efficacy outcome differences in patients treated with a short course of antibiotics compared with longer. However, patients in the short group were less likely to experience ADE. These findings suggest that short courses of antibiotics are effective for GN-BSI in critically ill patients.

An investigation of broad-spectrum antibiotic-induced liver injury based on the FDA Adverse Event Reporting System and retrospective observational study

Tazobactam/piperacillin and meropenem are commonly used as an empiric treatment in patients with severe bacterial infections. However, few studies have investigated the cause of tazobactam/piperacillin- or meropenem-induced liver injury in them. Our objective was to evaluate the association between tazobactam/piperacillin or meropenem and liver injury in the intensive care unit patients. We evaluated the expression profiles of antibiotics-induced liver injury using the US Food and Drug Administration Adverse Event Reporting System (FAERS) database. Further, in the retrospective observational study, data of patients who initiated tazobactam/piperacillin or meropenem in the intensive care unit were extracted. In FAERS database, male, age, the fourth-generation cephalosporin, carbapenem, β-lactam and β-lactamase inhibitor combination, and complication of sepsis were associated with liver injury (p < 0.001). In the retrospective observational study, multivariate logistic regression analyses indicated that the risk factors for liver injury included male (p = 0.046), administration period ≥ 7 days (p < 0.001), and alanine aminotransferase (p = 0.031). Not only administration period but also sex and alanine aminotransferase should be considered when clinicians conduct the monitoring of liver function in the patients receiving tazobactam/piperacillin or meropenem.

Stewardship Prompts to Improve Antibiotic Selection for Urinary Tract Infection: The INSPIRE Randomized Clinical Trial

Importance

Urinary tract infection (UTI) is the second most common infection leading to hospitalization and is often associated with gram-negative multidrug-resistant organisms (MDROs). Clinicians overuse extended-spectrum antibiotics although most patients are at low risk for MDRO infection. Safe strategies to limit overuse of empiric antibiotics are needed.

Objective

To evaluate whether computerized provider order entry (CPOE) prompts providing patient- and pathogen-specific MDRO risk estimates could reduce use of empiric extended-spectrum antibiotics for treatment of UTI.

Design, Setting, and Participants

Cluster-randomized trial in 59 US community hospitals comparing the effect of a CPOE stewardship bundle (education, feedback, and real-time and risk-based CPOE prompts; 29 hospitals) vs routine stewardship (n = 30 hospitals) on antibiotic selection during the first 3 hospital days (empiric period) in noncritically ill adults (≥18 years) hospitalized with UTI with an 18-month baseline (April 1, 2017-September 30, 2018) and 15-month intervention period (April 1, 2019-June 30, 2020).

Interventions

CPOE prompts recommending empiric standard-spectrum antibiotics in patients ordered to receive extended-spectrum antibiotics who have low estimated absolute risk (<10%) of MDRO UTI, coupled with feedback and education.

Main Outcomes and Measures

The primary outcome was empiric (first 3 days of hospitalization) extended-spectrum antibiotic days of therapy. Secondary outcomes included empiric vancomycin and antipseudomonal days of therapy. Safety outcomes included days to intensive care unit (ICU) transfer and hospital length of stay. Outcomes were assessed using generalized linear mixed-effect models to assess differences between the baseline and intervention periods.

Results

Among 127 403 adult patients (71 991 baseline and 55 412 intervention period) admitted with UTI in 59 hospitals, the mean (SD) age was 69.4 (17.9) years, 30.5% were male, and the median Elixhauser Comorbidity Index count was 4 (IQR, 2-5). Compared with routine stewardship, the group using CPOE prompts had a 17.4% (95% CI, 11.2%-23.2%) reduction in empiric extended-spectrum days of therapy (rate ratio, 0.83 [95% CI, 0.77-0.89]; P < .001). The safety outcomes of mean days to ICU transfer (6.6 vs 7.0 days) and hospital length of stay (6.3 vs 6.5 days) did not differ significantly between the routine and intervention groups, respectively.

Conclusions and Relevance

Compared with routine stewardship, CPOE prompts providing real-time recommendations for standard-spectrum antibiotics for patients with low MDRO risk coupled with feedback and education significantly reduced empiric extended-spectrum antibiotic use among noncritically ill adults admitted with UTI without changing hospital length of stay or days to ICU transfers.

Trial Registration

ClinicalTrials.gov Identifier: NCT03697096.

Diagnosing and Managing Urinary Tract Infections in Kidney Transplant Recipients

In the article, the authors review antibiotic treatment options for both acute uncomplicated UTI and complicated UTI. In addition, they review alternative regimens which are needed in the setting of drug-resistant pathogens including vancomycin-resistant Enterococcus, -extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales, and carbapenem-resistant Pseudomonas, which are encountered with more frequency.

Urinary Tract Infection Diagnostic and Management Considerations in People with Spinal Cord Injury and Neurogenic Bladder

Urinary tract infections (UTIs) are common complications in people with neurogenic bladder. Prevention, diagnosis, and treatment are challenging for several reasons, including a high prevalence of asymptomatic bacteriuria and catheter use, frequent ambiguous nonlocalizing signs and symptoms, increased risk for complications and difficult-to-treat pathogens, and a lack of effective preventative methods. Current research aims to improve elicitation and evaluation of signs and symptoms, implement algorithms to avoid urine cultures in asymptomatic patients and use appropriate antibiotics for UTI, and identify novel effective prevention methods.

SWOT and Root Cause Analyses of Antimicrobial Resistance to Oral Antimicrobial Treatment of Cystitis

Nearly 150 million cases of urinary tract infections (UTIs) are reported each year, of which uncomplicated cystitis triggers > 25% of outpatient prescriptions of oral antimicrobial treatment (OAT). OAT aids immune cells infiltrating the urothelium in eliminating uropathogens capable of invading the urothelium and surviving hyperosmotic urine. This self-evident adaptability of uropathogens and the short interval between the introduction of Penicillin and the first report of antimicrobial resistance (AMR) implicate AMR as an evolutionary conserved heritable trait of mutant strains selected by the Darwinian principle to survive environmental threats through exponential proliferation. Therefore, AMR can only be countered by antimicrobial stewardship (AMS) following the principle of the five Ds-drug, dose, duration, drug route, and de-escalation. While convenient to administer, the onset of the minimum inhibitory concentration (MIC) for OAT in urine leaves a window of opportunity for uropathogens to survive the first contact with an antimicrobial and arm their descendant colonies with AMR for surviving subsequent higher urine antimicrobial levels. Meanwhile, the initial dose of intravesical antimicrobial treatment (IAT) may be well above the MIC. Therefore, the widespread clinical use of OAT for cystitis warrants an analysis of the strengths, weaknesses, opportunity, and threats (SWOTs) and a root cause analysis of the AMR associated with OAT and IAT.

Real-World Effectiveness of Intravenous and Oral Antibiotic Stepdown Strategies for Gram-Negative Complicated Urinary Tract Infection With Bacteremia

Background

Robust data are lacking regarding the optimal route, duration, and antibiotic choice for gram-negative bloodstream infection from a complicated urinary tract infection source (GN-BSI/cUTI).

Methods

In this multicenter observational cohort study, we simulated a 4-arm registry trial using a causal inference method to compare effectiveness of the following regimens for GN-BSI/cUTI: complete course of an intravenous β-lactam (IVBL) or oral stepdown therapy within 7 days using fluoroquinolones (FQs), trimethoprim-sulfamethoxazole (TMP-SMX), or high-bioavailability β-lactams (HBBLs). Adults treated between January 2016 and December 2022 for Escherichia coli or Klebsiella species GN-BSI/cUTI were included. Propensity weighting was used to balance characteristics between groups. The 60-day recurrence was compared using a multinomial Cox proportional hazards model with probability of treatment weighting.

Results

Of 2571 patients screened, 759 (30%) were included. Characteristics were similar between groups. Compared with IVBLs, we did not observe a difference in effectiveness for FQs (adjusted hazard ratio, 1.09 [95% confidence interval, .49-2.43]) or TMP-SMX (1.44 [.54-3.87]), and the effectiveness of TMP-SMX/FQ appeared to be optimal at durations of >10 days. HBBLs were associated with nearly 4-fold higher risk of recurrence (adjusted hazard ratio, 3.83 [95% confidence interval, 1.76-8.33]), which was not mitigated by longer treatment durations. Most HBBLs (67%) were not optimally dosed for bacteremia. Results were robust to multiple sensitivity analyses.

Conclusions

These real-world data suggest that oral stepdown therapy with FQs or TMP-SMX have similar effectiveness as IVBLs. HBBLs were associated with higher recurrence rates, but dosing was suboptimal. Further data are needed to define optimal dosing and duration to mitigate treatment failures.

Is Short-Course Antibiotic Therapy Suitable for Pseudomonas aeruginosa Bloodstream Infections in Onco-hematology Patients With Febrile Neutropenia? Results of a Multi-institutional Analysis

BACKGROUND

Several studies have suggested that short-course antibiotic therapy was effective in Pseudomonas aeruginosa (PA) bloodstream infections (BSI) in immunocompetent patients. But similar studies in patients with hematological malignancies were rare.

METHODS

This cohort study included onco-hematology patients at 2 hematology centers in China. Inverse probability of treatment weighting was used to balance the confounding factors. Multivariate regression model was used to evaluate the effect of short-course antibiotic therapy on clinical outcomes.

RESULTS

In total, 434 patients met eligibility criteria (short-course, 7-11 days, n = 229; prolonged, 12-21 days, n = 205). In the weighted cohort, the univariate and multivariate analysis indicated that short course antibiotic therapy had similar outcomes to the prolonged course. The recurrent PA infection at any site or mortality within 30 days of completing therapy occurred in 8 (3.9%) patients in the short-course group and in 10 (4.9%) in the prolonged-course group (P = .979). The recurrent infection within 90 days occurred in 20 (9.8%) patients in the short-course group and in 13 (6.3%) patients in the prolonged-course group (P = .139), and the recurrent fever within 7 days occurred in 17 (8.3%) patients in the short-course group and in 15 (7.4%) in the prolonged-course group (P = .957). On average, patients who received short-course antibiotic therapy spent 3.3 fewer days in the hospital (P < .001).

CONCLUSIONS

In the study, short-course therapy was non-inferior to prolonged-course therapy in terms of clinical outcomes. However, due to its biases and limitations, further prospective randomized controlled trials are needed to generalize our findings.

Treatment, outcomes and characterization of pathogens in urinary tract infections caused by ESBL-producing Enterobacterales: a prospective multicentre study

OBJECTIVES

Treatment options for urinary tract infections (UTIs) caused by ESBL-producing Enterobacterales are limited. Moreover, evidence to support therapeutic decisions is lacking. This study assessed current treatment strategies and patient and pathogen characteristics in relation to clinical and microbiological outcomes.

METHODS

Patients with UTI caused by ESBL-producing Enterobacterales were prospectively recruited by investigators at 15 infectious disease hospital departments. Data were collected on patient characteristics, treatments, clinical and microbiological cure 10-14 days after the end of treatment, and relapse within 3 months. Bacterial isolates were subjected to MIC determination and WGS.

RESULTS

In total, 235 patients (107 febrile UTI, 128 lower UTI) caused by Escherichia coli (n = 223) and Klebsiella spp. (n = 12) were included. Clinical and microbiological cure rates were 83% and 64% in febrile UTI, and 79% and 65% in lower UTI. Great variability in treatments was observed, especially in oral therapy for febrile UTI. No difference was seen in clinical outcomes with piperacillin/tazobactam (n = 28) compared with carbapenems (n = 41). Pivmecillinam was frequently used in lower UTI (n = 62), and was also associated with high clinical cure rates when used as initial therapy (10/10) or follow-up (7/8) for febrile UTI. Recurrent infection, diabetes mellitus and urogenital disease were associated (P < 0.05) with clinical failure and relapse. In E. coli, ST131 was significantly associated with relapse, and haemolysin with microbiological failure or relapse.

CONCLUSIONS

Antibiotic treatments were highly variable. Patient and pathogen factors were identified as potential determinants of disease presentation and outcomes and may prove useful to guide individualized treatment and follow-up.

Oral β-Lactams, Fluoroquinolones, or Trimethoprim-Sulfamethoxazole for Definitive Treatment of Uncomplicated Escherichia coli or Klebsiella Species Bacteremia From a Urinary Tract Source

Background

Fluoroquinolones (FQs) are effective for oral step-down therapy for gram-negative bloodstream infections but are associated with unfavorable toxic effects. Robust data are lacking for trimethoprim-sulfamethoxazole (TMP-SMX) and high-bioavailability β-lactams (HBBLs).

Methods

In this multicenter observational cohort study, we simulated a 3-arm registry trial using causal inference methods to compare the effectiveness of FQs, TMP-SMX, or HBBLs for gram-negative bloodstream infections oral step-down therapy. The study included adults treated between January 2016 and December 2022 for uncomplicated Escherichia coli or Klebsiella species bacteremia of urinary tract origin who were who were transitioned to an oral regimen after ≤4 days of effective intravenous antibiotics. Propensity weighting was used to balance characteristics between groups. 60-day recurrence was compared using a multinomial Cox proportional hazards model with probability of treatment weighting.

Results

Of 2571 patients screened, 648 (25%) were included. Their median age (interquartile range) was 67 (45-78) years, and only 103 (16%) were male. Characteristics were well balanced between groups. Compared with FQs, TMP-SMX had similar effectiveness (adjusted hazard ratio, 0.91 [95% confidence interval, .30-2.78]), and HBBLs had a higher risk of recurrence (2.19 [.95-5.01]), although this difference was not statistically significant. Most HBBLs (70%) were not optimally dosed for bacteremia. A total antibiotic duration ≤8 days was associated with a higher recurrence rate in select patients with risk factors for failure.

Conclusions

FQs and TMP-SMX had similar effectiveness in this real-world data set. HBBLs were associated with higher recurrence rates but suboptimal dosing may have contributed. Further studies are needed to define optimal BL dosing and duration to mitigate treatment failures.

Oral Antibiotics for Bacteremia and Infective Endocarditis: Current Evidence and Future Perspectives

Bacteremia and endocarditis are two clinical syndromes that, for decades, were managed exclusively with parenteral antimicrobials, irrespective of a given patient's clinical condition, causative pathogen, or its antibiotic susceptibility profile. This clinical approach, however, was based on low-quality data and outdated expert opinions. When a patient's condition has improved, gastrointestinal absorption is not compromised, and an oral antibiotic regimen reaching adequate serum concentrations is available, a switch to oral antibacterials can be applied. Although available evidence has reduced the timing of the oral switch in bacteremia to three days/until clinical improvement, there are only scarce data regarding less than 10-day intravenous antibiotic therapy in endocarditis. Many standard or studied oral antimicrobial dosages are smaller than the approved doses for parenteral administration, which is a risk factor for treatment failure; in addition, the gastrointestinal barrier may affect drug bioavailability, especially when the causative pathogen has a minimum inhibitory concentration that is close to the susceptibility breakpoint. A considerable number of patients infected by such near-breakpoint strains may not be potential candidates for oral step-down therapy to non-highly bioavailable antibiotics like beta-lactams; different breakpoints should be determined for this setting. This review will focus on summarizing findings about pathogen-specific tailoring of oral step-down therapy for bacteremia and endocarditis, but will also present laboratory and clinical data about antibiotics such as beta-lactams, linezolid, and fosfomycin that should be studied more in order to elucidate their role and optimal dosage in this context.

Using antibiotics wisely

PURPOSE OF REVIEW

This review will describe role of shorter antibiotic therapies, early switch from intravenous to oral therapy, and artificial intelligence in infectious diseases.

RECENT FINDINGS

There is evidence that shorter courses of antibiotics are noninferior to standard durations of therapy. This has been demonstrated with Enterobacterales bacteremia that can be treated with 7 days of therapy, community acquired pneumonia with 3 days and ventilator associated pneumonia with just 7 days of antibiotic therapy. The conversion from intravenous to oral therapy in treating bacteremia, endocarditis and bone and joint infections is safe and effective and reduces line complications and costs. Also, for clean surgical procedures only one dose of antibiotic is needed, but it should be the most effective antibiotic which is cefazolin. This means avoiding clindamycin, removing penicillin allergies where possible for improved outcomes. Finally, the role of artificial intelligence to incorporate into using antibiotics wisely is rapidly emerging but is still in early stages.

SUMMARY

In using antibiotics wisely, targeting such as durations of therapy and conversion from intravenous antibiotic therapy to oral are low hanging fruit. The future of artificial intelligence could automate a lot of this work and is exciting but needs to be proven.

VIDEO ABSTRACT

http://links.lww.com/COID/A50.

Clinical pharmacological considerations in an early intravenous to oral antibiotic switch: are barriers real or simply perceived?

BACKGROUND

Traditionally, there has been a common belief that ongoing i.v. antibiotic therapy is superior to an early i.v. to oral switch, especially for severe infections. However, this may be at least partly based on early observations rather than robust, high-quality data and contemporary clinical studies. It is important to examine whether these traditional views align with clinical pharmacological considerations, or conversely, if these considerations may support the broader application of an early i.v. to oral switch under appropriate circumstances.

OBJECTIVES

To examine the rationale for an early i.v. to oral antibiotic switch in the context of clinical pharmacokinetic and pharmacodynamic principles and to discuss whether commonly encountered pharmacological barriers are real or simply perceived.

SOURCES

We conducted PubMed searches on barriers and clinicians' perceptions about an early i.v. to oral switch, clinical studies comparing switching with i.v.-only dosing, and pharmacological factors affecting oral antimicrobials.

CONTENT

We focused on general pharmacological and clinical pharmacokinetic and pharmacodynamic principles and considerations that are relevant when clinicians ponder whether to switch from i.v. to oral antimicrobial dosing. The main focus of this review was on antibiotics. The discussion of the general principles is accompanied by specific examples from the literature.

IMPLICATIONS

Clinical pharmacological considerations and an imposing and increasing number of clinical studies, including randomized clinical trials, support an early i.v. to oral switch for the treatment of a number of infection types, under appropriate circumstances. We hope that the information provided here will add to calls for a critical examination of the role of i.v. to oral switching for many infections that are currently treated almost exclusively with i.v.-only therapy, and that it will inform health policy and guideline development by infectious diseases organizations.