Role of Early De-escalation of Antimicrobial Therapy on Risk of Clostridioides difficile Infection Following Enterobacteriaceae Bloodstream Infections

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.

Ceftriaxone versus cefepime or carbapenems for definitive treatment of low-risk AmpC-Harboring Enterobacterales bloodstream infections in hospitalized adults: A retrospective cohort study

OBJECTIVE

To compare outcomes of ceftriaxone to AmpC-stable therapies in patients with bacteremia caused by low-risk AmpC harboring Enterobacterales.

METHODS

IRB-approved, retrospective cohort of hospitalized patients ≥18 years old with Serratia marcescens, Morganella morganii, or Providencia spp. bacteremia from 1/1/2017-2/28/2024. Patients were compared by definitive therapy with ceftriaxone vs AmpC-stable therapy (cefepime, carbapenem). The primary endpoint was 30-day all-cause mortality; secondary endpoints were clinical failure and development of ceftriaxone resistance.

RESULTS

163 patients were included; 33.1 % received ceftriaxone, 66.9 % AmpC-stable therapies. 30-day all-cause mortality was 9.3 % ceftriaxone vs 10.1 % AmpC stable patients (P = 0.87); ceftriaxone definitive therapy was not associated with 30-day all-cause mortality (adjOR, 0.79; 95 %CI, 0.23-2.3). There were no differences in clinical failure (9.3 % vs 21.1 %, P = 0.059) or relapsing infection (5.6 % vs 9.3 %, P = 0.55) between ceftriaxone and AmpC-stable treated patients.

CONCLUSIONS

Patients treated with definitive ceftriaxone for low-risk AmpC Enterobacterales bacteremia had similar outcomes to AmpC stable therapies.

Clinical Outcomes of Early Phenotype-Desirable Antimicrobial Therapy for Enterobacterales Bacteremia

Importance

Initiating effective therapy early is associated with improved survival among patients hospitalized with gram-negative bloodstream infections; furthermore, providing early phenotype-desirable antimicrobial therapy (PDAT; defined as receipt of a β-lactam antibiotic with the narrowest spectrum of activity to effectively treat the pathogen's phenotype) is crucial for antimicrobial stewardship. However, the timing of targeted therapy among patients hospitalized with gram-negative bloodstream infections is not well understood.

Objective

To compare the clinical outcomes between patients who were hospitalized with Enterobacterales bloodstream infections receiving early vs delayed PDAT.

Design, Setting, and Participants

This retrospective cohort study used a large, geographically diverse, hospital-based US database (PINC AI Healthcare Database). Participants were adult (aged ≥18 years) patients with an inpatient admission between January 1, 2017, and June 30, 2022, with at least 1 blood culture isolate positive for Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, or Proteus mirabilis and receiving PDAT on blood culture collection days 0 to 4.

Exposure

Early vs delayed PDAT, with early PDAT defined as receipt of PDAT on blood culture collection days 0 to 2.

Main Outcomes and Measures

The main outcome was desirability of outcome ranking, in which patients were assigned a mutually exclusive rank 1 through 5. Rank 1 indicated the most desirable outcome (alive with no events), whereas rank 5 indicated the least desirable outcome and included all patients who died within 30 days of blood culture collection.

Results

Among 8193 eligible patients (mean [SD] age, 69.0 [16.4] years; 4758 [58.1%] female; 1200 [14.6%] African American or Black, 729 [8.9%] Hispanic, and 5778 [70.5%] White) from 252 hospitals, 5033 (61.4%) received early PDAT. Patients receiving early PDAT were similar in age (mean [SD], 68.2 [16.9] vs 70.3 [15.6] years) but more likely to have a lower median (IQR) Charlson-Deyo comorbidity score (2 [1-5] vs 3 [1-5]) compared with patients receiving delayed PDAT. After adjusting for comorbidities and severity of illness, patients receiving early PDAT were 20% less likely to be readmitted within 30 days compared with those receiving delayed PDAT (odds ratio, 0.80; 95% CI, 0.69-0.92; P < .001). A higher percentage of patients receiving early PDAT had a desirability of outcome ranking of 1 compared with patients receiving delayed PDAT (56.3% vs 52.2%, P < .001). Those receiving early PDAT had a 52.5% probability (95% CI, 51.3%-53.7%) of a more desirable outcome than those receiving delayed PDAT, a finding that persisted in the adjusted analysis (probability, 52.0%; 95% CI, 50.9%-53.2%).

Conclusions and Relevance

Receiving early PDAT was associated with favorable 30-day clinical outcomes among patients hospitalized with Enterobacterales blood stream infections. Early PDAT may be important not only for antimicrobial stewardship but also for improving patient outcomes.

Early antibiotic de-escalation in patients with severe infections due to bloodstream infection by enterobacterales: A post hoc analysis of a prospective multicentre cohort

BACKGROUND

Data about antibiotic de-escalation in sepsis associated with the bloodstream and caused by Enterobacterales are scarce. The objectives of this study are to identify factors associated with early de-escalation and to analyse the impact of de-escalation on mortality in patients with Enterobacterales bloodstream infection (BSI) with a Sequential Organ Failure Assessment (SOFA) score ≥ 2.

METHODS

A prospective, multicentre cohort study was performed including episodes of BSI due to Enterobacterales and a SOFA score ≥ 2 who were receiving an active antipseudomonal β-lactam; the isolate should be susceptible to at least 1 narrower-spectrum antibiotic. Variables associated with de-escalation were identified using logistic binary regression. The association of de-escalation with 30-day mortality was investigated. Confounding was controlled by calculating a propensity score used as covariate, as matching variable, and for inverse probability treatment weighting.

RESULTS

Of the 582 patients included, de-escalation was performed in 311 (53.4%). Neutropenia (adjusted odds ratio [aOR] = 0.37; 95% confidence interval [95% CI] = 0.18-0.75), central venous catheter (aOR = 0.52; 95% CI = 0.32-0.83), and extended-spectrum β-lactamase (ESBL)-producing isolate (aOR = 0.28; 95% CI = 0.17-0.48) were negatively associated with de-escalation, and urinary tract source was positively associated (aOR = 2.27; 95% CI = 1.56-3.33). The 30-day mortality was 6.8% (21 patients) in de-escalated patients and 14.4% (39) in not de-escalated patients (relative risk, 0.63; 95% CI = 0.44-0.89). In multivariate analysis including the propensity score, de-escalation was not associated with mortality (AOR = 0.98; 95% CI = 0.39-2.47) and was protective in the case of urinary or biliary tract source (AOR = 0.31, 95% CI = 0.09-1.06). Matched and inverse probability treatment weighting analysis showed similar results.

CONCLUSIONS

These results suggest that early de-escalation from antipseudomonal β-lactams is safe in patients with Enterobacterales bacteremia and SOFA ≥ 2.

Missed Opportunities for Early De-Escalation of Antipseudomonal Beta-Lactam Antimicrobial Therapy in Enterobacterales Bloodstream Infection

Background: Antipseudomonal β-lactams (APBL) are commonly used for empirical therapy of Gram-negative bloodstream infections (BSI). This retrospective cohort study examines risk factors for prolonged APBL use (≥48 h) in patients with Enterobacterales BSI and compares 28-day mortality between early de-escalation of APBL and prolonged APBL therapy. Methods: Adult patients admitted to two community hospitals in South Carolina with Enterobacterales BSI from January 2010 to June 2015 were included in this study. Data were extracted manually from medical records. Multivariate logistic regression and Cox proportional hazards analyses were used to examine predictors of prolonged APBL therapy and mortality, respectively. Results: Among 993 patients with Enterobacterales BSI, 491 (49%) underwent early de-escalation of APBL and 502 (51%) received prolonged APBL therapy. Cancer, immune compromised status, residence at a skilled nursing facility, a high Pitt bacteremia score, non-urinary source of infection, and BSI due to AmpC-producing Enterobacterales were independently associated with prolonged use of APBL. Antimicrobial stewardship interventions were inversely associated with prolonged APBL use. Early de-escalation of APBL was not associated with increased mortality. Conclusions: This study exemplifies the safety and effectiveness of early de-escalation of APBL in Enterobacterales BSI. Antimicrobial stewardship strategies should be implemented to encourage the practice of early de-escalation of antimicrobial therapy, including in high-risk populations.

Incidence and variability in receipt of phenotype-desirable antimicrobial therapy for Enterobacterales bloodstream infections among hospitalized United States patients

Background

Using a large, geographically diverse, hospital-based database in the United States (Premier PINC AI Healthcare Database), we aimed to describe the proportion and characteristics of patients receiving phenotype-desirable antimicrobial therapy (PDAT) among those hospitalized with Enterobacterales bloodstream infections.

Methods

Adult patients with an admission between January 1, 2017 and June 30, 2022 with ≥1 blood culture positive for Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, or Proteus mirabilis and receiving an empiric antibiotic therapy on blood culture collection (BCC) Days 0 or 1 were included. Receiving PDAT (defined as receipt of any antimicrobial categorized as "desirable" for the respective phenotype) on BCC Days 0-2 was defined as receiving early PDAT.

Results

Among 35,880 eligible patients, the proportion of patients receiving PDAT increased (from 6.8% to 22.8%) from BCC Day 0-4. Patients who received PDAT (8,193, 22.8%) were more likely to visit large (500 + beds, 36% vs 31%), teaching (45% vs 39%), and urban (85% vs 82%) hospitals in the Northeast (22% vs 13%) compared to patients not receiving PDAT (all P <. 01). Among patients receiving PDAT, 61.4% (n = 5,033) received it early; they had a lower mean comorbidity score (3.2 vs 3.6), were less likely to have severe or extreme severity of illness (71% vs 79%), and were less likely to have a pathogen susceptible to narrow-spectrum β-lactams (31% vs 71%) compared to patients in the delayed PDAT group (all P < .01).

Conclusions

The proportion of patients receiving desirable therapy increased between BCC Day 0 and 4. Receipts of PDAT and early PDAT were associated with hospital, clinical, and pathogen characteristics.

Evaluating the impact of rapid antimicrobial susceptibility testing for bloodstream infections: a review of actionability, antibiotic use and patient outcome metrics

Antimicrobial susceptibility testing (AST) is a core function of the clinical microbiology laboratory and is critical to the management of patients with bloodstream infections (BSIs) to facilitate optimal antibiotic therapy selection. Recent technological advances have resulted in several rapid methods for determining susceptibility direct from positive blood culture that can provide turnaround times in under 8 h, which is considerably shorter than conventional culture-based methods. As diagnostic results do not directly produce a medical intervention, actionability is a primary determinant of the effect these technologies have on antibiotic use and ultimately patient outcomes. Randomized controlled trials and observational studies consistently show that rapid AST significantly reduces time to results and improves antimicrobial therapy for patients with BSI across various methods, patient populations and organisms. To date, the clinical impact of rapid AST has been demonstrated in some observational studies, but randomized controlled trials have not been sufficiently powered to validate many of these findings. This article reviews various metrics that have been described in the literature to measure the impact of rapid AST on actionability, antibiotic exposure and patient outcomes, as well as highlighting how implementation and workflow processes can affect these metrics.

Assessment of De-Escalation of Empirical Antimicrobial Therapy in Medical Wards with Recognized Prevalence of Multi-Drug-Resistant Pathogens: A Multicenter Prospective Cohort Study in Non-ICU Patients with Microbiologically Documented Infection

Antimicrobial resistance poses a major threat to human health worldwide and the implementation of antimicrobial stewardship programs (ASPs), including antimicrobial de-escalation (ADE), is a multifaceted tool for minimizing unnecessary or inappropriate antibiotic exposure. This was a prospective observational study of 142 non-Intensive Care Unit (ICU) patients with microbiologically documented infection who were initially administered empirical antimicrobial therapy and admitted to the medical wards of 6 tertiary-care hospitals in Greece from January 2017 to December 2018. Patients were divided into two groups, the ADE and non-ADE group, based on whether ADE was applied or not, respectively. Exploratory end-points were ADE feasibility, safety and efficacy. ADE was applied in 76 patients at a median time of 4 days (IQR: 3, 5). An increased likelihood of ADE was observed in patients with urinary tract (OR: 10.04, 95% CI: 2.91, 34.57; p < 0.001), skin and soft tissue (OR: 16.28, 95% CI: 1.68, 158.08; p = 0.016) and bloodstream infections (OR: 2.52, 95% CI: 1, 6.36; p = 0.05). Factors significantly associated with higher rates of ADE were clarithromycin administration, diagnosis of urinary tract infection (UTI), isolation of E. coli, age and symptoms type on admission. Mortality was lower in the ADE group (18.4% vs. 30.3% p < 0.1) and ADE was not significantly associated with the probability of death (p = 0.432). ADE was associated with favorable clinical outcomes and can be performed even in settings with high prevalence of multi-drug resistant (MDR) pathogens without compromising safety.

Efficacy and safety of a structured de-escalation from antipseudomonal β-lactams in bloodstream infections due to Enterobacterales (SIMPLIFY): an open-label, multicentre, randomised trial

BACKGROUND

De-escalation from broad-spectrum to narrow-spectrum antibiotics is considered an important measure to reduce the selective pressure of antibiotics, but a scarcity of adequate evidence is a barrier to its implementation. We aimed to determine whether de-escalation from an antipseudomonal β-lactam to a narrower-spectrum drug was non-inferior to continuing the antipseudomonal drug in patients with Enterobacterales bacteraemia.

METHODS

An open-label, pragmatic, randomised trial was performed in 21 Spanish hospitals. Patients with bacteraemia caused by Enterobacterales susceptible to one of the de-escalation options and treated empirically with an antipseudomonal β-lactam were eligible. Patients were randomly assigned (1:1; stratified by urinary source) to de-escalate to ampicillin, trimethoprim-sulfamethoxazole (urinary tract infections only), cefuroxime, cefotaxime or ceftriaxone, amoxicillin-clavulanic acid, ciprofloxacin, or ertapenem in that order according to susceptibility (de-escalation group), or to continue with the empiric antipseudomonal β-lactam (control group). Oral switching was allowed in both groups. The primary outcome was clinical cure 3-5 days after end of treatment in the modified intention-to-treat (mITT) population, formed of patients who received at least one dose of study drug. Safety was assessed in all participants. Non-inferiority was declared when the lower bound of the 95% CI of the absolute difference in cure rate was above the -10% non-inferiority margin. This trial is registered with EudraCT (2015-004219-19) and ClinicalTrials.gov (NCT02795949) and is complete.

FINDINGS

2030 patients were screened between Oct 5, 2016, and Jan 23, 2020, of whom 171 were randomly assigned to the de-escalation group and 173 to the control group. 164 (50%) patients in the de-escalation group and 167 (50%) in the control group were included in the mITT population. 148 (90%) patients in the de-escalation group and 148 (89%) in the control group had clinical cure (risk difference 1·6 percentage points, 95% CI -5·0 to 8·2). The number of adverse events reported was 219 in the de-escalation group and 175 in the control group, of these, 53 (24%) in the de-escalation group and 56 (32%) in the control group were considered severe. Seven (5%) of 164 patients in the de-escalation group and nine (6%) of 167 patients in the control group died during the 60-day follow-up. There were no treatment-related deaths.

INTERPRETATION

De-escalation from an antipseudomonal β-lactam in Enterobacterales bacteraemia following a predefined rule was non-inferior to continuing the empiric antipseudomonal drug. These results support de-escalation in this setting.

FUNDING

Plan Nacional de I+D+i 2013-2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, Spanish Network for Research in Infectious Diseases; Spanish Clinical Research and Clinical Trials Platform, co-financed by the EU; European Development Regional Fund "A way to achieve Europe", Operative Program Intelligence Growth 2014-2020.

Multifaceted Evaluation of Antibiotic Therapy as a Factor Associated with Candidemia in Non-Neutropenic Patients

We aimed to evaluate various aspects of antibiotic therapy as factors associated with candidemia in non-neutropenic patients. A retrospective, matched, case-control study was conducted in two teaching hospitals. Patients with candidemia (cases) were compared to patients without candidemia (controls), matched by age, intensive care unit admission, duration of hospitalization, and type of surgery. Logistic regression analyses were performed to identify factors associated with candidemia. A total of 246 patients were included in the study. Of 123 candidemia patients, 36% had catheter-related bloodstream infections (CRBSIs). Independent factors in the whole population included immunosuppression (adjusted odds ratio [aOR] = 2.195; p = 0.036), total parenteral nutrition (aOR = 3.642; p < 0.001), and anti-methicillin-resistant S. aureus (MRSA) therapy for ≥11 days (aOR = 5.151; p = 0.004). The antibiotic factor in the non-CRBSI population was anti-pseudomonal beta-lactam treatment duration of ≥3 days (aOR = 5.260; p = 0.008). The antibiotic factors in the CRBSI population included anti-MRSA therapy for ≥11 days (aOR = 10.031; p = 0.019). Antimicrobial stewardship that reduces exposure to these antibacterial spectra could help prevent the development of candidemia.

Epidemiology and Economic Outcomes Associated with Timely versus Delayed Receipt of Appropriate Antibiotic Therapy among US Patients Hospitalized for Native Septic Arthritis: A Retrospective Cohort Study

Timely administration of appropriate antibiotic therapy is associated with better patient outcomes and lower costs of care compared to delayed appropriate therapy, yet initial treatment is often empiric since causal pathogens are typically unknown upon presentation. The challenge for clinicians is balancing selection of adequate coverage treatment regimens, adherence to antimicrobial stewardship principles to deter resistance, and financial constraints. This retrospective cohort study aimed to assess the magnitude and impact of delayed appropriate antibiotic therapy among patients hospitalized with septic arthritis (SA) in the U.S. from 2017 to 2019 using healthcare encounter data. Timely appropriate therapy was defined as the receipt of antibiotic(s) with in vitro activity against identified pathogens within two days of admission; all other patients were assumed to have received delayed appropriate therapy. Of the 517 patients admitted to hospital for SA who met all selection criteria, 26 (5.0%) received delayed appropriate therapy. In inverse-probability-treatment-weighting-adjusted analyses, the receipt of delayed appropriate therapy was associated with an additional 1.1 days of antibiotic therapy, 1.4 days in length of stay, and $3531 in hospital costs (all vs. timely appropriate therapy; all p ≤ 0.02). Timely appropriate therapy was associated with a twofold increased likelihood of antibiotic de-escalation during the SA admission.

Impact of continuous pharmacist intervention for injectable antimicrobials on the treatment of patients with Escherichia coli bacteremia

BACKGROUND

A prospective audit with intervention and feedback (PAF) by pharmacists is important for the appropriate use of antimicrobials. Clinically, Escherichia coli (E. coli) bacteremia is a common condition, but only few researchers have examined the role of PAF in its appropriate use of antimicrobials.

METHODS

We started PAF by pharmacists in 2017 for all injectable antibiotics. This study included cases of E. coli bacteremia that resulted in hospitalization over a 4 year period from 2016 to 2019. Patients were grouped by year (Period 0-3), and clinical outcomes were examined.

RESULTS

The pharmacists had 12 and 54 suggestions in Periods 0 and 3, respectively. The most common suggestion was de-escalation. The median duration of antimicrobial use was 12 (interquartile range: 8-15) days in Periods 0-2. The duration of antimicrobial use was significantly reduced to 9 (7-12) days in Period 3. In Period 3, the duration of antimicrobial use was reduced by 29%, while anti-pseudomonal drug use was reduced by 42% compared with that in period 0. The 30 day mortality rates were not significantly different between the groups.

CONCLUSIONS

PAF by pharmacists promotes the appropriate use of antimicrobials in patients with E. coli bacteremia; it is important to continue the program for several years.

Use of broad-spectrum antimicrobials for more than 72 h and the detection of multidrug-resistant bacteria in Japanese intensive care units: a multicenter retrospective cohort study

Background

Large multicenter studies reporting on the association between the duration of broad-spectrum antimicrobial administration and the detection of multidrug-resistant (MDR) bacteria in the intensive care unit (ICU) are scarce. We evaluated the impact of broad-spectrum antimicrobial therapy for more than 72 h on the detection of MDR bacteria using the data from Japanese patients enrolled in the DIANA study.

Methods

We analyzed the data of ICU patients in the DIANA study (a multicenter international observational cohort study from Japan). Patients who received empirical antimicrobials were divided into a broad-spectrum antimicrobial group and a narrow-spectrum antimicrobial group, based on whether they received broad-spectrum antimicrobials for more or less than 72 h, respectively. Differences in patient characteristics, background of infectious diseases and empirical antimicrobial administration, and outcomes between the two groups were compared using the chi-square tests (Monte Carlo method) for categorical variables and the Mann–Whitney U-test for continuous variables. We also conducted a logistic regression analysis to investigate the factors associated with the detection of new MDR bacteria.

Results

A total of 254 patients from 31 Japanese ICUs were included in the analysis, of whom 159 (62.6%) were included in the broad-spectrum antimicrobial group and 95 (37.4%) were included in the narrow-spectrum antimicrobial group. The detection of new MDR bacteria was significantly higher in the broad-spectrum antimicrobial group (11.9% vs. 4.2%, p = 0.042). Logistic regression showed that broad-spectrum antimicrobial continuation for more than 72 h (OR [odds ratio] 3.09, p = 0.047) and cerebrovascular comorbidity on ICU admission (OR 2.91, p = 0.041) were associated with the detection of new MDR bacteria.

Conclusions

Among Japanese ICU patients treated with empirical antimicrobials, broad-spectrum antimicrobial usage for more than 72 h was associated with the increased detection of new MDR bacteria. Antimicrobial stewardship programs in ICUs should discourage the prolonged use of empirical broad-spectrum antimicrobial therapy.

Trial registration ClinicalTrials.gov, NCT02920463, Registered 30 September 2016, https://clinicaltrials.gov/ct2/show/NCT02920463

Association between duration of antipseudomonal beta-lactam therapy and Clostridioides difficile infections in monomicrobial Enterobacterales bloodstream infections at an academic medical center

Objective:

To evaluate the effects early de-escalation of antipseudomonal β-lactam (APBL) on 90-day CDI risk in Enterobacterales bloodstream infections (BSIs).

Design:

Retrospective cohort analysis.

Setting:

An academic medical center in South Carolina.

Patients:

We included patients aged >18 years with monomicrobial BSIs with Enterobacterales who received APBL between July 1, 2015, and June 30, 2020.

Methods:

Rates of CDI were compared between patients who received an APBL for >72 hours and <72 hours, followed by comparison between formulary APBLs utilized.

Results:

In total, 447 patients were included; 292 and 155 patients received APBL for < 72 hours and > 72 hours, respectively. The incidences of CDI for <72 hours compared to >72 hours were 2.4% and 6.5%, respectively (unadjusted hazard ratio [HR], 2.70; 95% confidence interval [CI], 1.03–7.10; P = .04). This difference was not statistically significant in the adjusted model (HR, 2.66; 95% CI, 0.97–7.31; P = .06). Meropenem was associated with an increased risk of CDI when compared with all other formulary APBLs: 4 (26.7%) of 15 versus 13 (3.0%) of 432 (P < .001).

Conclusions:

Utilization of an APBL for >72 hours was associated with a statistically significant increase in the incidence of CDI in an unadjusted model and with a numerically higher CDI incidence in the adjusted model. Meropenem was the formulary APBL that carried the highest risk of CDI. The results of this study provide further evidence supporting active antimicrobial stewardship to reduce unnecessary broad-spectrum antibiotics in the effort to alleviate the burden that CDI imposes on the healthcare system.

Real Life Clinical Impact of Antimicrobial Stewardship Actions on the Blood Culture Workflow from a Microbiology Laboratory

BACKGROUND

Accelerating the diagnosis of bacteremia is one of the biggest challenges in clinical microbiology departments. The fast establishment of a correct treatment is determinant on bacteremic patients' outcomes. Our objective was to evaluate the impact of antimicrobial therapy and clinical outcomes of a rapid blood culture workflow protocol in positive blood cultures with Gram-negative bacilli (GNB).

METHODS

A quasi-experimental before-after study was performed with two groups: (i) control group (conventional work-protocol) and (ii) intervention group (rapid workflow-protocol: rapid identification by Matrix-Assisted Laser Desorption/Ionization-Time-Of-Flight (MALDI-TOF) and antimicrobial susceptibility testing (AST) from bacterial pellet without overnight incubation). Patients were divided into different categories according to the type of intervention over treatment. Outcomes were compared between both groups.

RESULTS

A total of 313 patients with GNB-bacteremia were included: 125 patients in the control group and 188 in the intervention. The time from positive blood culture to intervention on antibiotic treatment decreased from 2.0 days in the control group to 1.0 in the intervention group (p < 0.001). On the maintenance of correct empirical treatment, the control group reported 2.0 median days until the clinical decision, while in the intervention group was 1.0 (p < 0.001). In the case of treatment de-escalation, a significant difference between both groups (4.0 vs. 2.0, p < 0.001) was found. A decreasing trend on the change from inappropriate treatments to appropriate ones was observed: 3.5 vs. 1.5; p = 0.12. No significant differences were found between both groups on 7-days mortality or on readmissions in the first 30-days.

CONCLUSIONS

Routine implementation of a rapid workflow protocol anticipates the report of antimicrobial susceptibility testing results in patients with GNB-bacteremia, decreasing the time to effective and optimal antibiotic therapy.

Implications of Gut Microbiota in Complex Human Diseases

Humans, throughout the life cycle, from birth to death, are accompanied by the presence of gut microbes. Environmental factors, lifestyle, age and other factors can affect the balance of intestinal microbiota and their impact on human health. A large amount of data show that dietary, prebiotics, antibiotics can regulate various diseases through gut microbes. In this review, we focus on the role of gut microbes in the development of metabolic, gastrointestinal, neurological, immune diseases and, cancer. We also discuss the interaction between gut microbes and the host with respect to their beneficial and harmful effects, including their metabolites, microbial enzymes, small molecules and inflammatory molecules. More specifically, we evaluate the potential ability of gut microbes to cure diseases through Fecal Microbial Transplantation (FMT), which is expected to become a new type of clinical strategy for the treatment of various diseases.

Change in Antimicrobial Use During COVID-19 Pandemic in South Carolina Hospitals: A Multicenter Observational Cohort Study

Objectives

This retrospective cohort study examined the impact of the pandemic on antimicrobial use (AU) in South Carolina hospitals.

Methods

Antimicrobial use in days of therapy (DOT) per 1000 days-present was evaluated in 17 hospitals in South Carolina. Matched-pairs mean difference was used to compare AU during the pandemic (March–June 2020) with that during the same months in 2019 in hospitals that did and did not admit patients with COVID-19.

Results

There was a 6.6% increase in overall AU in the seven hospitals that admitted patients with COVID-19 (from 530.9 to 565.8; mean difference (MD) 34.9 DOT/1000 days-present; 95% CI 4.3, 65.6; P = 0.03). There was no significant change in overall AU in the remaining 10 hospitals that did not admit patients with COVID-19 (MD 6.0 DOT/1000 days-present; 95% CI –55.5, 67.6; P = 0.83). Most of the increase in AU in the seven hospitals that admitted patients with COVID-19 was observed in broad-spectrum antimicrobial agents. A 16.4% increase was observed in agents predominantly used for hospital-onset infections (from 122.3 to 142.5; MD 20.1 DOT/1000 days-present; 95% CI 11.1, 29.1; P = 0.002). There was also a 9.9% increase in the use of anti-methicillin-resistant Staphylococcus aureus (MRSA) agents (from 66.7 to 73.3; MD 6.6 DOT/1000 days-present; 95% CI 2.3, 10.8; P = 0.01).

Conclusion

The COVID-19 pandemic appears to drive overall and broad-spectrum antimicrobial use in South Carolina hospitals admitting patients with COVID-19. Additional antimicrobial stewardship resources are needed to curtail excessive antimicrobial use in hospitals to prevent subsequent increases in antimicrobial resistance and Clostridioides difficile infection rates, given the continuing nature of the pandemic.

Challenges of Antibiotic Stewardship in the Pediatric and Neonatal Intensive Care Units

The goals of antimicrobial stewardship programs (ASPs) are to optimize antimicrobial prescribing habits in order to improve patient outcomes, reduce antimicrobial resistance, and reduce hospital costs. Multiple society-endorsed guidelines and government policies reinforce the importance of ASP implementation. Effective antimicrobial stewardship can impact unique patients, hospitals, and societal antibiotic-resistance burden. The role and subsequent success of these programs has largely been reported in the adult population. Pediatric and neonatal intensive care units present unique challenges for traditional antimicrobial stewardship approaches. The purpose of this review article is to explore the challenges of appropriate antibiotic use in the pediatric and neonatal intensive care units and to summarize strategies ASPs can use to overcome these challenges. These problems include non-specific disease presentations, limited evidence for definitive treatment durations in many pediatric infections, fewer pediatric-trained infectious disease physicians, and applicability of intensive laboratory obtainment, collection, and interpretation. Additionally, many ASP implementation studies evaluating the efficacy of ASPs exclude the PICU and NICU. Areas of focus for pediatric ASPs should likely include appropriate antibiotic initiation, appropriate antibiotic duration, and appropriate antibiotic de-escalation.

Randomized Trial Evaluating Clinical Impact of RAPid IDentification and Susceptibility Testing for Gram-negative Bacteremia: RAPIDS-GN

BACKGROUND

Rapid blood culture diagnostics are of unclear benefit for patients with gram-negative bacilli (GNB) bloodstream infections (BSIs). We conducted a multicenter, randomized, controlled trial comparing outcomes of patients with GNB BSIs who had blood culture testing with standard-of-care (SOC) culture and antimicrobial susceptibility testing (AST) vs rapid organism identification (ID) and phenotypic AST using the Accelerate Pheno System (RAPID).

METHODS

Patients with positive blood cultures with Gram stains showing GNB were randomized to SOC testing with antimicrobial stewardship (AS) review or RAPID with AS. The primary outcome was time to first antibiotic modification within 72 hours of randomization.

RESULTS

Of 500 randomized patients, 448 were included (226 SOC, 222 RAPID). Mean (standard deviation) time to results was faster for RAPID than SOC for organism ID (2.7 [1.2] vs 11.7 [10.5] hours; P < .001) and AST (13.5 [56] vs 44.9 [12.1] hours; P < .001). Median (interquartile range [IQR]) time to first antibiotic modification was faster in the RAPID arm vs the SOC arm for overall antibiotics (8.6 [2.6-27.6] vs 14.9 [3.3-41.1] hours; P = .02) and gram-negative antibiotics (17.3 [4.9-72] vs 42.1 [10.1-72] hours; P < .001). Median (IQR) time to antibiotic escalation was faster in the RAPID arm vs the SOC arm for antimicrobial-resistant BSIs (18.4 [5.8-72] vs 61.7 [30.4-72] hours; P = .01). There were no differences between the arms in patient outcomes.

CONCLUSIONS

Rapid organism ID and phenotypic AST led to faster changes in antibiotic therapy for gram-negative BSIs.

CLINICAL TRIALS REGISTRATION

NCT03218397.

Impact of an Antimicrobial Stewardship Program-bundled initiative utilizing Accelerate Pheno™ system in the management of patients with aerobic Gram-negative bacilli bacteremia

PURPOSE

Gram-negative bacteria (GNB) are a leading cause of bloodstream infections (BSI) and management is complicated by antibiotic resistance. The Accelerate Pheno™ system (ACC) can provide rapid organism identification and antimicrobial susceptibility testing (AST).

METHODS

A retrospective, pre-intervention/post-intervention study was conducted to compare management of non-critically ill patients with GNB BSI before and after implementation of a bundled initiative. This bundled initiative included dissemination of a clinical decision algorithm, ACC testing on all GNB isolated from blood cultures, real-time communication of results to the Antimicrobial Stewardship Program (ASP), and prospective audit with feedback by the ASP. The pre-intervention period was January 2018 through December 2018, and the post-intervention period was May 2019 through February 2020.

RESULTS

Seventy-seven and 129 patients were included in the pre-intervention and post-intervention cohorts, respectively. When compared with the pre-intervention group, the time from Gram stain to AST decreased from 46.1 to 6.9 h (p < 0.001), and the time to definitive therapy (TTDT) improved from 32.6 to 10.5 h (p < 0.001). Implementation led to shorter median total duration of antibiotic therapy (14.2 vs 9.5 days; p < 0.001) and mean hospital length of stay (7.9 vs 5.3 days; p = 0.047) without an increase in 30-day readmissions (22.1% vs 14%; p = 0.13).

CONCLUSION

Implementation of an ASP-bundled approach incorporating the ACC aimed at optimizing antibiotic therapy in the management GNB BSI in non-critically ill patients led to reduced TTDT, shorter duration of antibiotic therapy, and shorter hospital length of stay without adversely affecting readmission rates.

Importance of Reviewing Antibiotic Courses by 48 Hours: Risk Factors for Third-Generation Cephalosporin Resistance Among AmpC Harboring Organisms in Urine and Respiratory Cultures

BACKGROUND

Citrobacter, Enterobacter, Morganella, and Serratia (AmpC organisms) species can exhibit third-generation cephalosporin (TGC) resistance after TGC exposure. We aimed to assess if institutional TGC utilization correlated with institutional AmpC organism susceptibility and if prior TGC exposure ≤48 hours were associated with TGC resistance in the first culture of a future infection episode caused by an AmpC organism.

METHODS

A 5-year retrospective cohort study was performed, including AmpC organisms isolated from pediatric urinary and respiratory tract cultures at an institution with TGC courses reviewed by the antimicrobial stewardship program at 48 hours. Correlations were assessed by Pearson's correlation. Multivariable logistic regression identified factors independently associated with TGC resistance in a subcohort of infection episodes.

RESULTS

Among 654 cultures, AmpC organism TGC susceptibility increased from 74% in 2013 to 89.3% in 2017, and this correlated with a 26.1% decrease in TGC utilization (R = -0.906; P = 0.034). Among 275 AmpC organism infections, 21.1% were resistant. Resistance occurred in 13.6%, 17.4%, and 56.5% of infections with no exposure, ≤48 hours, and >48 hours of TGC exposure in the past 30 days, respectively. TGC exposure ≤48 hours was not associated with resistance (odds ratio [OR], 1.26; 95% confidence interval [CI], 0.32-4.94; P = 0.74), whereas, TGC exposure >48 hours was (OR, 8.7; 95% CI, 3.67-20.6; P  < 0.001). Infections in 2017 were less likely to be resistant (OR, 0.25; 95% CI, 0.08-0.8; P = 0.019).

CONCLUSIONS

Decreased TGC utilization, likely related to antimicrobial stewardship, correlated with increased AmpC organism susceptibility. Limiting TGC exposure to ≤48 hours when possible may reduce AmpC organism resistance in future infections.

Impact of cascade reporting of antimicrobial susceptibility on fluoroquinolone and meropenem consumption at a Veterans' Affairs medical center

OBJECTIVE

To determine whether cascade reporting is associated with a change in meropenem and fluoroquinolone consumption.

DESIGN

A quasi-experimental study was conducted using an interrupted time series to compare antimicrobial consumption before and after the implementation of cascade reporting.

SETTING

A 399-bed, tertiary-care, Veterans' Affairs medical center.

PARTICIPANTS

Antimicrobial consumption data across 8 inpatient units were extracted from the Center for Disease Control and Prevention (CDC) National Health Safety Network (NHSN) antimicrobial use (AU) module from April 2017 through March 2019, reported as antimicrobial days of therapy (DOT) per 1,000 days present (DP).

INTERVENTION

Cascade reporting is a strategy of reporting antimicrobial susceptibility test results in which secondary agents are only reported if an organism is resistant to primary, narrow-spectrum agents. A multidisciplinary team developed cascade reporting algorithms for gram-negative bacteria based on local antibiogram and infectious diseases practice guidelines, aimed at restricting the use of fluoroquinolones and carbapenems. The algorithms were implemented in March 2018.

RESULTS

Following the implementation of cascade reporting, mean monthly meropenem (P =.005) and piperacillin/tazobactam (P = .002) consumption decreased and cefepime consumption increased (P < .001). Ciprofloxacin consumption decreased by 2.16 DOT per 1,000 DP per month (SE, 0.25; P < .001). Clostridioides difficile rates did not significantly change.

CONCLUSION

Ciprofloxacin consumption significantly decreased after the implementation of cascade reporting. Mean meropenem consumption decreased after cascade reporting was implemented, but we observed no significant change in the slope of consumption. cascade reporting may be a useful strategy to optimize antimicrobial prescribing.

Physician Responsiveness to Positive Blood Culture Results at the Minneapolis Veterans Affairs Hospital-Is Anyone Paying Attention?

Background

Patients presenting with suspected infections are typically placed on empiric broad-spectrum antibiotics. With mounting evidence supporting the efficacy of using the narrowest spectrum of antimicrobial therapy to cover the suspected pathogen, current guidelines recommend decreasing the breadth of coverage in response to culture results both in relation to microbe identification and antibiotic sensitivity.

Methods

A retrospective chart review of electronic health records at the Minneapolis Veterans Affairs Medical Center (VAMC) in Minnesota was performed for 208 positive blood cultures with antibiotic spectrum analysis from July 1, 2015 to June 30, 2016. The time of reporting for pathogen identification and subsequent pathogen susceptibilities were compared to the time at which any alterations to antibiotic coverage were made. The breadth of antibiotic coverage was recorded using a nonlinear spectrum score. The use of this score allowed for the reliable classification of antibiotic adjustments as either deescalation, escalation, or no change.

Results

The percentage of cases deescalated was higher in response to physician (house staff or attending physician) notification of pathogen susceptibility information when compared with a response to pathogen identification alone (33.2% vs 22.6%). Empiric antibiotics were not altered within 24 hours in response to pathogen identification in 70.7% of cases and were not altered within 24 hours in response to pathogen sensitivity determination in 58.6% of cases. However, when considering the time frame from when empiric antibiotics were started to 24 hours after notification of susceptibility information, 49.5% of cases were deescalated and 41.5% of cases had no net change in the antibiotic spectrum score. The magnitude of deescalations were notably larger than escalations. The mean (SD) time to deescalation of antibiotic coverage was shorter (P =.049) in response to pathogen identification at 8 (7.4) hours compared with sensitivity information at 10.4 (7) hours, but may not be clinically relevant.

Conclusion

Health care providers at the Minneapolis VAMC appear to be using positive blood culture results in a timely fashion consistent with best practices. Because empirically initiated antibiotics typically are broad in spectrum, the magnitude of deescalations were notably larger than escalations. Adherence to these standards may be a reflection of the infectious disease staff oversight of antibiotic administration. Furthermore, the systems outlined in this quality improvement study may be replicated at other VAMCs across the country by either in-house infectious disease staff or through remote monitoring of the electronic health record by other infectious disease experts at a more centralized VAMC. Widespread adoption throughout the Veterans Health Administration may result in improved antibiotic resistance profiles and better clinical outcomes for our nation's veterans.

Implementation of a Rapid Phenotypic Susceptibility Platform for Gram-Negative Bloodstream Infections with Paired Antimicrobial Stewardship Intervention: Is the Juice Worth the Squeeze?

BACKGROUND

Implementation of the Accelerate Pheno TM Gram-negative platform (RDT) paired with antimicrobial stewardship program (ASP) intervention projects to improve time to institutional-preferred antimicrobial therapy (IPT) for Gram-negative bacilli (GNB) bloodstream infections (BSI). However, few data describe the impact of discrepant RDT results from standard of care (SOC) methods on antimicrobial prescribing.

METHODS

A single-center, pre-/post-intervention study of consecutive, non-duplicate blood cultures for adult inpatients with GNB BSI following combined RDT + ASP intervention was performed. The primary outcome was time to IPT. An a priori definition of IPT was utilized to limit bias and allow for an assessment of the impact of discrepant RDT results with the SOC reference standard.

RESULTS

Five hundred fourteen patients (PRE 264; POST 250) were included. Median time to antimicrobial susceptibility testing (AST) results decreased 29.4 hours (p < 0.001) post-intervention, and median time to IPT was reduced by 21.2 hours (p <0.001). Utilization (days of therapy [DOTs]/1000 days present) of broad-spectrum agents decreased (PRE 655.2 vs. POST 585.8; p = 0.043) and narrow-spectrum beta-lactams increased (69.1 vs 141.7; p <0.001). Discrepant results occurred in 69/250 (28%) post-intervention episodes, resulting in incorrect ASP recommendations in 10/69 (14%). No differences in clinical outcomes were observed.

CONCLUSIONS

While implementation of a phenotypic RDT + ASP can improve time to IPT, close coordination with Clinical Microbiology and continued ASP follow up are needed to optimize therapy. Although uncommon, the potential for erroneous ASP recommendations to de-escalate to inactive therapy following RDT results warrants further investigation.

Application of Standardized Antimicrobial Administration Ratio as a Motivational Tool within a Multi-Hospital Healthcare System

The standardized antimicrobial administration ratio (SAAR) is a novel antimicrobial stewardship metric that compares actual to expected antimicrobial use (AU). This prospective cohort study examines the utility of SAAR reporting and inter-facility comparisons as a motivational tool to improve overall and broad-spectrum AU within a three-hospital healthcare system. Transparent inter-facility comparisons were deployed during system-wide antimicrobial stewardship meetings beginning in October 2017. Stakeholders were advised to interpret the results to foster competition and incorporate SAAR data into focused antimicrobial stewardship interventions. Student’s t-test was used to compare mean SAARs in the pre- (July 2017 through October 2017) and post-intervention periods (November 2017 through June 2019). The mean pre-intervention SAARs for hospitals A, B, and C were 0.69, 1.09, and 0.60, respectively. Hospital B experienced significant reductions in SAAR for overall AU (from 1.09 to 0.83; p < 0.001), broad-spectrum antimicrobials used for hospital-onset infections (from 1.36 to 0.81; p < 0.001), and agents used for resistant gram-positive infections in the intensive care units (from 1.27 to 0.72; p < 0.001) after the interventions. The alignment of the SAAR across the health-system and sustained reduction in overall and broad-spectrum AU through implementation of inter-facility comparisons demonstrate the utility in the motivational application of this antimicrobial use metric.

Critical Care Management of the Patient with Clostridioides difficile

OBJECTIVES

To review published clinical evidence on management of Clostridioides difficile infection in critically ill patients.

DATA SOURCES

We obtained relevant studies from a PubMed literature review and bibliographies of reviewed articles.

STUDY SELECTION

We selected English-language studies addressing aspects of C. difficile infection relevant to critical care clinicians including epidemiology, risk factors, diagnosis, treatment, and prevention, with a focus on high-quality clinical evidence.

DATA EXTRACTION

We reviewed potentially relevant studies and abstracted information on study design, methods, patient selection, and results of relevant studies. This is a synthetic (i.e., not systematic) review.

DATA SYNTHESIS

C. difficile infection is the most common healthcare-associated infection in the United States. Antibiotics are the most significant C. difficile infection risk factor, and among antibiotics, cephalosporins, clindamycin, carbapenems, fluoroquinolones, and piperacillin-tazobactam confer the highest risk. Age, diabetes mellitus, inflammatory bowel disease, and end-stage renal disease are risk factors for C. difficile infection development and mortality. C. difficile infection diagnosis is based on testing appropriately selected patients with diarrhea or on clinical suspicion for patients with ileus. Patients with fulminant disease (C. difficile infection with hypotension, shock, ileus, or megacolon) should be treated with oral vancomycin and IV metronidazole, as well as rectal vancomycin in case of ileus. Patients who do not respond to initial therapy should be considered for fecal microbiota transplant or surgery. Proper infection prevention practices decrease C. difficile infection risk.

CONCLUSIONS

Strong clinical evidence supports limiting antibiotics when possible to decrease C. difficile infection risk. For patients with fulminant C. difficile infection, oral vancomycin reduces mortality, and adjunctive therapies (including IV metronidazole) and interventions (including fecal microbiota transplant) may benefit select patients. Several important questions remain regarding fulminant C. difficile infection management, including which patients benefit from fecal microbiota transplant or surgery.

The Changing Landscape of Uncomplicated Gram-Negative Bacteremia: A Narrative Review to Guide Inpatient Management

Gram-negative bacteremia secondary to focal infection such as skin and soft-tissue infection, pneumonia, pyelonephritis, or urinary tract infection is commonly encountered in hospital care. Current practice guidelines lack sufficient detail to inform evidence-based practices. Specifically, antimicrobial duration, criteria to transition from intravenous to oral step-down therapy, choice of oral antimicrobials, and reassessment of follow-up blood cultures are not addressed. The presence of bacteremia is often used as a justification for a prolonged course of antimicrobial therapy regardless of infection source or clinical response. Antimicrobials are lifesaving but not benign. Prolonged antimicrobial exposure is associated with adverse effects, increased rates of Clostridioides difficile infection, antimicrobial resistance, and longer hospital length of stay. Emerging evidence supports shorter overall duration of antimicrobial treatment and earlier transition to oral agents among patients with uncomplicated Enterobacteriaceae bacteremia who have achieved adequate source control and demonstrated clinical stability and improvement. After appropriate initial treatment with an intravenous antimicrobial, transition to highly bioavailable oral agents should be considered for total treatment duration of 7 days. Routine follow-up blood cultures are not cost-effective and may result in unnecessary healthcare resource utilization and inappropriate use of antimicrobials. Clinicians should incorporate these principles into the management of gram-negative bacteremia in the hospital.

Impact of unit-specific metrics and prescribing tools on a family medicine ward

Objective:

Prescribing metrics, cost, and surrogate markers are often used to describe the value of antimicrobial stewardship (AMS) programs. However, process measures are only indirectly related to clinical outcomes and may not represent the total effect of an intervention. We determined the global impact of a multifaceted AMS initiative for hospitalized adults with common infections.

Design:

Single center, quasi-experimental study.

Methods:

Hospitalized adults with urinary, skin, and respiratory tract infections discharged from family medicine and internal medicine wards before (January 2017–June 2017) and after (January 2018–June 2018) an AMS initiative on a family medicine ward were included. A series of AMS-focused initiatives comprised the development and dissemination of: handheld prescribing tools, AMS positive feedback cases, and academic modules. We compared the effect on an ordinal end point consisting of clinical resolution, adverse drug events, and antimicrobial optimization between the preintervention and postintervention periods.

Results:

In total, 256 subjects were included before and after an AMS intervention. Excessive durations of therapy were reduced from 40.3% to 22% (P < .001). Patients without an optimized antimicrobial course were more likely to experience clinical failure (OR, 2.35; 95% CI, 1.17–4.72). The likelihood of a better global outcome was greater in the family medicine intervention arm (62.0%, 95% CI, 59.6–67.1) than in the preintervention family medicine arm.

Conclusion:

Collaborative, targeted feedback with prescribing metrics, AMS cases, and education improved global outcomes for hospitalized adults on a family medicine ward.

Time to Result for Pathogen Identification and Antimicrobial Susceptibility Testing of Bronchoalveolar Lavage and Endotracheal Aspirate Specimens in U.S. Acute Care Hospitals

Identification (ID) and antimicrobial susceptibility testing (AST) of respiratory pathogens are critical to the management of patients with pneumonia to facilitate optimal antibiotic therapy selection. Few studies have examined the time to results (TTR) for this critical specimen, and such data can be valuable for benchmarking the current paradigm of diagnostic approaches. TTR for bronchoalveolar lavage (BAL) and endotracheal aspirate (ETA) specimens from hospitalized patients was evaluated using the Premier Healthcare Database, a comprehensive database of 194 U.S. hospitals. Times from specimen collection to reporting of organism ID/AST were evaluated and compared by specimen types and characteristics. A total of 79,662 (43,129 BAL; 36,533 ETA) specimens were included, of which 19.3% harbored no growth, 47.1% contained normal respiratory flora alone (including yeast), and 0.6% contained mycobacteria/molds. Potential bacterial pathogens (PBP) were recovered from 33.0%. ETA specimens had a higher proportion of specimens with isolation of PBP (39.2% versus 27.7%) and with normal respiratory flora (52.0% versus 43.0%) and were less likely to be negative (8.2% versus 28.6%) than BAL specimens (all P < 0.0001). Staphylococcus aureus and Pseudomonas aeruginosa were isolated in 10.5 and 6.4% of the specimens, respectively, and were the most common organisms identified. Median (interquartile range) TTR were 37.0 h (21.8 to 51.7 h) and 60.5 h (46.6 to 72.4 h) for ID and AST, respectively. Median TTR for major respiratory pathogens by organism ranged from 29.2 to 43.9 h for ID and from 47.9 to 73.9 h for AST. Organism type, specimen collection time, and hospital teaching status influenced TTR. Mechanically vented patients and ETA specimens were more likely to recover PBP.

Gut dysbacteriosis and intestinal disease: mechanism and treatment

The gut microbiome functions like an endocrine organ, generating bioactive metabolites, enzymes or small molecules that can impact host physiology. Gut dysbacteriosis is associated with many intestinal diseases including (but not limited to) inflammatory bowel disease, primary sclerosing cholangitis-IBD, irritable bowel syndrome, chronic constipation, osmotic diarrhoea and colorectal cancer. The potential pathogenic mechanism of gut dysbacteriosis associated with intestinal diseases includes the alteration of composition of gut microbiota as well as the gut microbiota-derived signalling molecules. The many correlations between the latter and the susceptibility for intestinal diseases has placed a spotlight on the gut microbiome as a potential novel target for therapeutics. Currently, faecal microbial transplantation, dietary interventions, use of probiotics, prebiotics and drugs are the major therapeutic tools utilized to impact dysbacteriosis and associated intestinal diseases. In this review, we systematically summarized the role of intestinal microbiome in the occurrence and development of intestinal diseases. The potential mechanism of the complex interplay between gut dysbacteriosis and intestinal diseases, and the treatment methods are also highlighted.

A Baker's Dozen of Top Antimicrobial Stewardship Intervention Publications in 2019

Staying current on literature related to antimicrobial stewardship can be challenging given the ever-increasing number of published articles. The Southeastern Research Group Endeavor (SERGE-45) identified antimicrobial stewardship–related peer-reviewed literature that detailed an actionable intervention for 2019. The top 13 publications were selected using a modified Delphi technique. These manuscripts were reviewed to highlight the actionable intervention used by antimicrobial stewardship programs to provide key stewardship literature for teaching and training and to identify potential intervention opportunities within one’s institution.

Pharmacist-Driven Implementation of Fast Identification and Antimicrobial Susceptibility Testing Improves Outcomes for Patients with Gram-Negative Bacteremia and Candidemia

Bloodstream infections (BSI) are associated with increased morbidity and mortality, especially when caused by Gram-negative or fungal pathogens. The objective of this study was to assess the impact of fast identification-antimicrobial susceptibility testing (ID/AST) with the Accelerate Pheno system (AXDX) from May 2018 to December 2018 on antibiotic therapy and patient outcomes. A pre-post quasiexperimental study of 200 patients (100 pre-AXDX implementation and 100 post-AXDX implementation) was conducted.

Bloodstream infections (BSI) are associated with increased morbidity and mortality, especially when caused by Gram-negative or fungal pathogens. The objective of this study was to assess the impact of fast identification-antimicrobial susceptibility testing (ID/AST) with the Accelerate Pheno system (AXDX) from May 2018 to December 2018 on antibiotic therapy and patient outcomes. A pre-post quasiexperimental study of 200 patients (100 pre-AXDX implementation and 100 post-AXDX implementation) was conducted. The primary endpoints measured were time to first antibiotic intervention, time to most targeted antibiotic therapy, and 14-day hospital mortality. Secondary endpoints included hospital and intensive care unit (ICU) length of stay (LOS), antibiotic intensity score at 96 h, and 30-day readmission rates. Of 100 patients with Gram-negative bacteremia or candidemia in each cohort, 84 in the preimplementation group and 89 in the AXDX group met all inclusion criteria. The AXDX group had a decreased time to first antibiotic intervention (26.3 versus 8.0, P = 0.003), hours to most targeted therapy (14.4 versus 9, P = 0.03), hospital LOS (6 versus 8, P = 0.002), and average antibiotic intensity score at 96 h (16 versus 12, P = 0.002). Both groups had a comparable 14-day mortality (0% versus 3.6%, P = 0.11). In this analysis of patients with Gram-negative bacteremia or candidemia, fast ID/AST implementation was associated with decreased hospital LOS, decreased use of broad-spectrum antibiotics, shortened time to targeted therapy, and an improved utilization of antibiotics within the first 96 h of therapy.

Pharmacist-Driven Culture and Sexually Transmitted Infection Testing Follow-Up Program in the Emergency Department

Expanding pharmacist-driven antimicrobial stewardship efforts in the emergency department (ED) can improve antibiotic management for both admitted and discharged patients. We piloted a pharmacist-driven culture and rapid diagnostic technology (RDT) follow-up program in patients discharged from the ED. This was a single-center, pre- and post-implementation, cohort study examining the impact of a pharmacist-driven culture/RDT follow-up program in the ED. Adult patients discharged from the ED with subsequent positive cultures and/or RDT during the pre- (21 August 2018–18 November 2018) and post-implementation (19 November 2018–15 February 2019) periods were screened for inclusion. The primary endpoints were time from ED discharge to culture/RDT review and completion of follow-up. Secondary endpoints included antimicrobial agent prescribed during outpatient follow-up, repeat ED encounters within 30 days, and hospital admissions within 30 days. Baseline characteristics were analyzed using descriptive statistics. Time-to-event data were analyzed using the Wilcoxon signed-rank test. One-hundred-and-twenty-seven patients were included, 64 in the pre-implementation group and 63 in the post-implementation group. There was a 36.3% reduction in the meantime to culture/RDT data review in the post-implementation group (75.2 h vs. 47.9 h, p < 0.001). There was a significant reduction in fluoroquinolone prescribing in the post-implementation group (18.1% vs. 5.4%, p = 0.036). The proportion of patients who had a repeat ED encounter or hospital admission within 30 days was not significantly different between the pre- and post-implementation groups (15.6 vs. 19.1%, p = 0.78 and 9.4% vs. 7.9%, p = 1.0, respectively). Introduction of a pharmacist culture and RDT follow-up program in the ED reduced time to data review, time to outpatient intervention and outpatient follow-up of fluoroquinolone prescribing.

Evaluation of Empiric β-Lactam Susceptibility Prediction among Enterobacteriaceae by Molecular β-Lactamase Gene Testing

The use of rapid diagnostic tests (RDTs) for blood cultures has become standard of care in the United States to inform early antimicrobial optimization. The relative ability of genotypic and phenotypic approaches to identify beta-lactam susceptibility in Escherichia coli, Klebsiella spp., and Proteus mirabilis was evaluated, using incidence rates of resistance mechanisms to third-generation cephalosporins, aztreonam, and piperacillin-tazobactam seen across U.S. census regions. Overall, the presence of CTX-M, KPC, and/or NDM genes was 81% (range, 57 to 87%) sensitive for the prediction of ceftriaxone, ceftazidime, and aztreonam resistance and 73% (range, 25 to 90%) sensitive for the detection of piperacillin-tazobactam resistance. The sensitivity of KPC or NDM to predict imipenem or meropenem resistance was 94.3% overall, and for meropenem ranged from 70 to 100% across U.S. census regions. Institutions that use genotypic RDTs to inform therapeutic de-escalation decisions should be aware of the incidence-base performance across U.S. geographies and in different patient populations, where resistance rates may vary.

Direct Measurement of Performance: A New Era in Antimicrobial Stewardship

For decades, the performance of antimicrobial stewardship programs (ASPs) has been measured by incidence rates of hospital-onset Clostridioides difficile and other infections due to multidrug-resistant bacteria. However, these represent indirect and nonspecific ASP metrics. They are often confounded by factors beyond an ASP’s control, such as changes in diagnostic testing methods or algorithms and the potential of patient-to-patient transmission. Whereas these metrics remain useful for global assessment of healthcare systems, antimicrobial use represents a direct metric that separates the performance of an ASP from other safety and quality teams within an institution. The evolution of electronic medical records and healthcare informatics has made measurements of antimicrobial use a reality. The US Centers for Disease Control and Prevention’s initiative for reporting antimicrobial use and standardized antimicrobial administration ratio in hospitals is highly welcomed. Ultimately, ASPs should be evaluated based on what they do best and what they can control, that is, antimicrobial use within their own institution. This narrative review critically appraises existing stewardship metrics and advocates for adopting antimicrobial use as the primary performance measure. It proposes novel formulas to adjust antimicrobial use based on quality of care and microbiological burden at each institution to allow for meaningful inter-network and inter-facility comparisons.

Delay of appropriate antibiotic treatment is associated with high mortality in patients with community-onset sepsis in a Swedish setting

Early appropriate antimicrobial therapy is crucial in patients with sepsis and septic shock. Studies often focus on time to first dose of appropriate antibiotics, but subsequent dosing is equally important. Our aim was to investigate the impact of fulfillment of early treatment, with focus on appropriate administration of first and second doses of antibiotics, on 28-day mortality in patients with community-onset severe sepsis and septic shock. A retrospective study on adult patients admitted to the emergency department with community-onset sepsis and septic shock was conducted 2012–2013. The criterion “early appropriate antibiotic treatment” was defined as administration of the first dose of adequate antibiotics within 1 h, and the second dose given with less than 25% delay after the recommended dose interval. A high-risk patient was defined as a septic patient with either shock within 24 h after arrival or red triage level on admittance according to the Medical Emergency Triage and Treatment System Adult. Primary endpoint was 28-day mortality. Of 90 patients, less than one in four (20/87) received early appropriate antibiotic treatment, and only one in three (15/44) of the high-risk patients. The univariate analysis showed a more than threefold higher mortality among high-risk patients not receiving early appropriate antibiotic treatment. Multivariable analysis identified early non-appropriate antibiotic treatment as an independent predictor of mortality with an odds ratio for mortality of 10.4. Despite that the importance of early antibiotic treatment has been established for decades, adherence to this principle was very poor.

Efficacy and safety of antimicrobial de-escalation as a clinical strategy

INTRODUCTION

De-escalation is a widely recommended strategy in regard to guidelines, with an associated adherence to guidelines being around 50%. This review discusses data supporting de-escalation and possible obstacles for its implementation. Areas covered: Although it does not have a consensual definition, de-escalation consists of reducing the spectrum of empirical antimicrobial treatment based on the microbiological findings. Many observational studies have suggested that this strategy is likely safe and efficient for treating various types of infection. However, randomized controlled trials published as of now have not shown any improvement on the outcomes. Regarding the adverse effects of de-escalation on ecological pressure and multidrug resistance emergence, the data are contradictory. The implementation of new techniques, such as rapid diagnosis, can help guide clinicians. Expert opinion: De-escalation should be included as part of a large antibiotic stewardship program to balance the risk and benefit of each administration, and each physician prescribing antibiotics should be challenged for the quality of her/his prescription on a daily basis. In the future, one of our duties will involve determining whether a delay of antimicrobial treatment - making it possible to improve diagnostic performance and obtain the first laboratory results - is either safe or unsafe for our patients.

Bloodstream Infection due to Piperacillin/Tazobactam Non-Susceptible, Cephalosporin-Susceptible Escherichia coli: A Missed Opportunity for De-Escalation of Therapy

An increasing number of reports describing Escherichia coli isolates with piperacillin/tazobactam resistance, despite retained cephalosporin susceptibility, suggest further emergence of this phenotypic resistance pattern. In this report, a patient with metastatic breast cancer presented to medical care after two days of chills, nausea, vomiting, reduced oral intake, and generalized weakness. Blood and urine cultures grew E. coli as identified by rapid diagnostics multiplex PCR and MALDI-TOF, respectively. The patient continued to manifest signs of sepsis with hypotension and tachypnea during the first three days of hospitalization despite empirical antimicrobial therapy with intravenous piperacillin/tazobactam. After in vitro antimicrobial susceptibility testing demonstrated a piperacillin/tazobactam minimal inhibitory concentration (MIC) of 64 and a ceftriaxone MIC of ≤1 mcg/mL, antimicrobial therapy was switched from intravenous piperacillin/tazobactam to ceftriaxone. All symptoms and signs of infection resolved within 48 h of starting ceftriaxone therapy. This report describes the clinical failure of piperacillin/tazobactam in the treatment of a bloodstream infection due to E. coli harboring a phenotypic resistance pattern of isolated piperacillin/tazobactam non-susceptibility. The case demonstrates the role of cephalosporins as potential treatment options and highlights the value of early de-escalation of antimicrobial therapy based on rapid diagnostic testing for microbial identification.