Elaboration of a consensual definition of de-escalation allowing a ranking of β-lactams

Implementation of the EUCAST rapid antimicrobial susceptibility test (RAST) for carbapenemase/ESBL-producing Escherichia coli and Klebsiella pneumoniae isolates, and its effect on mortality

OBJECTIVES

With the rise in antimicrobial resistance, there is a growing demand for rapid antimicrobial susceptibility testing (RAST). In this study, we applied the EUCAST RAST method to ESBL/carbapenemase-producing Escherichia coli and Klebsiella pneumoniae isolates without using advanced identification systems and analysed the effect of this method on mortality rates Also the clinical impact of this method on patients infected with these bacteria and its effect on mortality rates were investigated.

METHODS

RAST was used for clinical blood cultures containing carbapenemase/ESBL-producing E. coli and K. pneumoniae without advanced identification systems (e.g. MALDI TOF), with preliminary identification by simple diagnostic tests (predicted RAST, or p-RAST), and its categorical agreement was investigated. The impact of the method on mortality was analysed by comparing the clinical data of patients whose blood cultures were subject to p-RAST (p-RAST group, n = 49) and those who were not subject to p-RAST (non-RAST group, n = 145).

RESULTS

p-RAST results were analysed based on 539 antibiotic-bacteria combinations. Total error rates at 4, 6 and 8 h of incubation were 2.9%, 3.9% and 3.8%, respectively. In the p-RAST group, patients who did not receive appropriate antibiotics (29/45, 59.1%) were switched to appropriate treatment within 8 h at the latest. In contrast, in the non-RAST group, treatment of patients who received inappropriate antibiotics (79/145, 54.5%) could be changed after at least 24 h. Mortality rates were lower in the p-RAST group than in the non-RAST group (28.6% versus 51.7%, P = 0.005).

CONCLUSIONS

p-RAST can be used safely in hospital laboratories with high rates of antimicrobial resistance and can reduce mortality rates by shortening the transition time to appropriate treatment.

Simplified Spectrum Score (S3) app for pathogen-agnostic antimicrobial drug spectrum ranking to assess for antimicrobial de-escalation events

Antimicrobial/antibiotic de-escalation (ADE) is a key feature of antimicrobial stewardship programs (ASP) that relies mainly on individual panels for determining ADE events based on subjective ranking of antibiotics' spectrum activity. The lack of consensus among ASP experts leads to reproducibility issues in the measure of this clinical outcome, making difficult to assess its real impact on patient care. The S3 score (Simplified Spectrum Score) app was developed to allow an objective ranking of antibiotics. Ranking was achieved by developing a database harboring pairs of bacteria-antibiotics for which each molecule was assigned a score based on published and clinically validated data from a recognized international committee. S3 score shows a strong correlation relationship and substantial agreement to a clinically validated spectrum score, and its framework enables any person to use it for ADE detection without assuming prior knowledge or training. In addition, its design enables regular updates and sustainability.

Can Chatbot Artificial Intelligence Replace Infectious Diseases Physicians in the Management of Bloodstream Infections? A Prospective Cohort Study

BACKGROUND

The development of chatbot artificial intelligence (AI) has raised major questions about their use in healthcare. We assessed the quality and safety of the management suggested by Chat Generative Pre-training Transformer 4 (ChatGPT-4) in real-life practice for patients with positive blood cultures.

METHODS

Over a 4-week period in a tertiary care hospital, data from consecutive infectious diseases (ID) consultations for a first positive blood culture were prospectively provided to ChatGPT-4. Data were requested to propose a comprehensive management plan (suspected/confirmed diagnosis, workup, antibiotic therapy, source control, follow-up). We compared the management plan suggested by ChatGPT-4 with the plan suggested by ID consultants based on literature and guidelines. Comparisons were performed by 2 ID physicians not involved in patient management.

RESULTS

Forty-four cases with a first episode of positive blood culture were included. ChatGPT-4 provided detailed and well-written responses in all cases. AI's diagnoses were identical to those of the consultant in 26 (59%) cases. Suggested diagnostic workups were satisfactory (ie, no missing important diagnostic tests) in 35 (80%) cases; empirical antimicrobial therapies were adequate in 28 (64%) cases and harmful in 1 (2%). Source control plans were inadequate in 4 (9%) cases. Definitive antibiotic therapies were optimal in 16 (36%) patients and harmful in 2 (5%). Overall, management plans were considered optimal in only 1 patient, as satisfactory in 17 (39%), and as harmful in 7 (16%).

CONCLUSIONS

The use of ChatGPT-4 without consultant input remains hazardous when seeking expert medical advice in 2023, especially for severe IDs.

Diagnostic Accuracy of Blind Bronchial Sample Testing by BioFire Pneumonia plus Panel in Pediatric Intensive Care Unit Patients and Its Impact in Early Adaptation of Antimicrobial Therapy: A Prospective Observational Study

BACKGROUND

Community-acquired and nosocomial lower-respiratory-tract infections in critically ill pediatric patients require early appropriate antibiotic therapy to optimize outcomes. Using blind bronchial samples, we assessed the diagnostic performance of the rapid-multiplex polymerase chain reaction (PCR) assay BioFire Pneumonia plus Panel vs. reference standard culturing with antimicrobial susceptibility testing.

METHODS

For this prospective observational study in a single pediatric intensive care unit, we included consecutive patients younger than 18 years admitted for suspected community-, hospital- or ventilator-associated pneumonia in 2021-2022. Sensitivity, specificity, positive predictive value and negative predictive value of the multiplex PCR assay were determined. The kappa coefficient was computed to assess agreement, and univariate analyses were done to identify factors associated with discrepancies between the 2 diagnostic methods.

RESULTS

Of the 36 included patients (median age, 1.4 years; interquartile range, 0.2-9.2), 41.7%, 27.8%, and 30.5% had community-, hospital- and ventilator-associated pneumonia, respectively. The overall κ was 0.74, indicating good agreement. Overall, the sensitivity of the multiplex PCR assay was 92% (95% CI: 77%-98%) and specificity 95% (95% CI: 92%-97%), with variations across microorganisms. The median time from sample collection to antimicrobial susceptibility test results was 3.9 (2.5-15) hours with the multiplex PCR assay and 60.5 (47.6-72.2) hours with the reference technique.

CONCLUSION

The BioFire Pneumonia plus Panel used to test blind bronchial samples had satisfactory diagnostic performance in critically ill pediatric patients. The rapid results provided by this test may improve the appropriateness of antimicrobial therapy and help minimize the use of antibiotics.

Temocillin for febrile urinary tract infections caused by ESBL-producing Enterobacteriaceae in children: a monocentric exposed/non-exposed study

OBJECTIVES

To compare the efficacy of temocillin with standard of care (SOC) for treatment of ESBL-producing Enterobacteriaceae (ESBL-E) febrile urinary tract infection (ESBL-E FUTI) in children.

METHODS

A monocentric retrospective study of children hospitalized with confirmed ESBL-E FUTI from January 2015 to May 2022 was conducted, comparing clinical cure and a 3 month relapse between two groups of patients: 'exposed' patients (EP) and 'non-exposed' patients (NEP) to temocillin. EP received temocillin for at least 3 days. They were matched (1:1 ratio) on age group, sex and presence of uropathy with NEP who received SOC antibiotic therapy.

RESULTS

Thirty-six temocillin-treated children (EP) were matched with 36 SOC children (NEP); 72.2% were under 2 years old (n = 52) and 75.0% had a congenital uropathy (n = 54). EPs had more FUTI history (97.2%, n = 35) than NEPs (61.1%, n = 22) (P < 0.01). Clinical cure rate was 98.6% overall, with no difference between the two groups, as for the FUTI relapse rate, which was 37.1% for EPs versus 27.8% for NEPs (P = 0.45). In bivariate analyses, factors associated with relapses were congenital uropathy (91.3% versus 66.7%, P = 0.04) and subtypes of uropathy, with refluxing uropathy and posterior urethral valves being the more prevalent. Median duration of hospitalization was longer in the EPs (8.0 versus 5.0 days) (P = 0.01).

CONCLUSIONS

The high clinical cure rate and comparable outcomes suggest that temocillin may be an effective therapeutic alternative to standard treatment for ESBL-E FUTI in children.

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.

Identifying General Practitioners' Antibiotic Prescribing Profiles Based on National Health Reimbursement Data

Background

Antibiotic selection pressure in human medicine is a significant driver of antibiotic resistance in humans. The primary aspect of antibiotic consumption is associated with general practitioner (GP) prescriptions. We aimed to identify prescriber profiles for targeted antimicrobial stewardship programs using novel indicators.

Methods

A cross-sectional study was conducted in 2018 investigating GPs' antibiotic prescriptions in a French department, utilizing the reimbursement database of the national health service. Three antibiotic prescribing indicators were used. Specific targets were established for each indicator to identify the antibiotic prescribers most likely contributing to the emergence of resistance.

Results

Over 2018, we had 2,908,977 visits to 784 GPs, leading to 431,549 antibiotic prescriptions. Variations between GPs were shown by the 3 indicators. The median antibiotic prescription rate per visit was 13.6% (interquartile range [IQR], 9.8%-17.7%). Median ratios of the prescriptions of low-impact antibiotics to the prescriptions of high-impact antibiotics and of amoxicillin prescriptions to amoxicillin-clavulanic acid prescriptions were 2.5 (IQR, 1.7-3.7) and 2.94 (IQR, 1.7-5), respectively. We found 163 (21%) high prescribers of antibiotics with 3 distinct patterns: The first group overuses broad-spectrum antibiotics but without an overprescription rate per visit, the second group displays an overprescription rate but no excessive use of broad-spectrum antibiotics, and the third group shows both an overprescription rate and excessive use of broad-spectrum antibiotics.

Conclusions

Prescription-based indicators enable the identification of distinct profiles of antibiotic prescribers. This identification may allow for targeted implementation of stewardship programs focused on the specific prescribing patterns of each profile.

Antibiotic definitive treatment in ventilator associated pneumonia caused by AmpC-producing Enterobacterales in critically ill patients: a prospective multicenter observational study

BACKGROUND

Ventilator associated pneumonia (VAP) due to wild-type AmpC-producing Enterobacterales (wtAE) is frequent in intensive care unit (ICU) patients. Despite a low level of evidence, definitive antimicrobial therapy (AMT) with third generation cephalosporins (3GCs) or piperacillin is discouraged.

METHODS

Observational prospective study including consecutive wtAE VAP patients in 20 French ICUs. The primary objective was to assess the association of the choice of definitive AMT, i.e. piperacillin ± tazobactam (PTZ), 3GCs or other molecule (4GCs, carbapenems, quinolones, cotrimoxazole; control group), with treatment success at day-7. Recurrence of infection was collected as a secondary outcome, and analyzed accounting for the competing risk of death.

RESULTS

From February 2021 to June 2022, 274 patients were included. Enterobacter cloacae was the most prevalent specie (31%). Seventy-eight patients (28%) had PTZ as definitive AMT while 44 (16%) had 3GCs and 152 (56%) were classified in the control group. Day-7 success rate was similar between the 3 groups (74% vs. 73% vs. 68% respectively, p = 0.814). Recurrence probability at day-28 was 31% (95% CI 21-42), 40% (95% CI 26-55) and 21% (95% CI 15-28) for PTZ, 3GCs and control groups (p = 0.020). In multivariable analysis, choice of definitive AMT was not associated with clinical success, but definitive AMT with 3GCs was associated with recurrence at day-28 [csHR(95%CI) 10.9 (1.92-61.91)].

CONCLUSION

Choice of definitive antimicrobial therapy was not associated with treatment success at day 7. However, recurrence of pneumonia at day-28 was higher in patients treated with third generation cephalosporins with no differences in mortality or mechanical ventilation duration.

Real-life use of ceftobiprole for severe infections in a French intensive care unit

Ceftobiprole (CBP) is an anti-methicillin-resistant Staphylococcus aureus (MRSA) cephalosporin with a wide spectrum of activity. We aimed to describe our experience of real-life use of CBP for the treatment of severe infections of critically ill patients with multiple infected sites and related trough CBP concentrations. We performed a retrospective, observational, monocentric study in our intensive care unit (ICU) that included all patients treated with CBP for documented infections between January 2016 and December 2021. We collected demographic, clinical, and microbiological data. When available, we report the CBP trough concentrations. The primary endpoint was clinical cure at the end of treatment. The secondary endpoints were in-hospital mortality and documentation of the carriage of multidrug-resistant (MDR) bacteria not present before CBP treatment. Between January 2016 and December 2021, 47 patients were treated in the ICU with CBP. The main indication for treatment was pneumonia (51%) and most patients presented with associated bacteremia (72%). All infections were polymicrobial. A clinical cure was achieved for nearly 80% of the patients. Only five patients presented new carriage of MDR bacteria. In-hospital mortality was 32%. Out of 21 strains of Enterobacterales for which the MIC was available, 33% were considered to be resistant to CBP according to the EUCAST 2023 clinical breakpoint. Trough CBP concentrations were reported for 16 patients. In our real-life experience, treatment of ICU patients with CBP for polymicrobial severe infections resulted in most cases in a clinical cure. Monitoring of trough concentrations is critical, especially in cases of high MIC.

Multiple Blood Culture Sampling, Proper Antimicrobial Choice, and Adequate Dose in Definitive Therapy Supported by the Antimicrobial Stewardship Team Could Decrease 30-Day Sepsis Mortality Rates

Objective

This study aimed to identify factors that should be focused on by the antimicrobial stewardship team for treating patients with sepsis, by investigating the mortality of patients with sepsis within 30 days and the mortality-related factors in our hospital over a 10-year period from the perspective of appropriate antimicrobial use.

Methods

Factors associated with 30-day mortality were investigated using hierarchical multiple logistic regression in 1406 patients with pathogen-identified sepsis in Hirosaki University Hospital. These factors were clinical data, microbiological data, antimicrobials used in empiric and definitive therapies, presence/absence of ineffective use, underdosing as evaluated using Monte Carlo simulation, and practice of de-escalation.

Results

The ineffective use of antimicrobials in empiric therapy and the underdosing and ineffective use in definitive therapy were significantly associated with 30-day mortality (odds ratio [OR] = 2.70, 3.72, and 3.65, respectively). Multiple blood culture sampling was inversely associated with these inappropriate antimicrobial uses. Every year, the 30-day mortality rate has been decreasing, in line with the increase in multiple blood culture sampling and de-escalation; the inappropriate use of antimicrobials has also decreased.

Conclusion

Multiple blood culture sampling, proper choice of antimicrobial, and using an adequate dose in definitive therapy could decrease the 30-day mortality rate in patients with sepsis and these factors could be supported by the antimicrobial stewardship team.

The use of information technology to improve interdisciplinary communication during infectious diseases ward rounds on the paediatric intensive care unit

Prospective audit with feedback during infectious diseases ward rounds (IDWR) is a common antimicrobial stewardship (AMS) practice on the Paediatric Intensive Care Unit (PICU). These interdisciplinary meetings rely on the quality of handover, with high risk of omission of information. We developed an electronic platform integrating infection-related patient data (COSARAPed). In the mixed PICU of a Belgian tertiary hospital we conducted an observational prospective cohort study comparing patient handovers during IDWRs using the COSARAPed-platform to those with access only to conventional resources. The quality of handover was investigated directly by assessment if the narrative was in accordance with Situation-Background-Assessment-Recommendation principles and if adequate demonstration of diagnostic information occurred, and also indirectly by registration if this was only achieved after intervention by the non-presenting AMS team members. We also recorded all AMS-recommendations. During a 6-month study period, 24 IDWRs and 82 patient presentations were assessed. We could only find a statistically significant advantage in favor of COSARAPed by indirect evaluation. We registered 92 AMS-recommendations, mainly resulting in reduced antibiotic pressure. We concluded that the IDWR is an appropriate platform for AMS on the PICU and that the utilisation of COSARAPed may enhance the quality of patient handover.

Efficacy of an antimicrobial stewardship intervention for early adaptation of antibiotic therapy in high-risk neutropenic patients

BACKGROUND

The 4th European Conference on Infections in Leukemia recommends early adaptation of empirical antibiotic therapy (EAT) for febrile neutropenia in stable patients.

OBJECTIVES

To assess the efficacy of an antimicrobial stewardship (AMS) intervention promoting early de-escalation and discontinuation of EAT in high-risk neutropenic patients.

METHODS

This before-after study was conducted in the hematology department of the University Hospital of Nice, France. The AMS intervention included the development of clinical decision support algorithms, a twice-weekly face-to-face review of all antibiotic prescriptions and monthly feedback on the intervention. The primary endpoint was overall antibiotic consumption during hospital stay, expressed as days of therapy (DOT).

RESULTS

A total of 113 admissions were included: 56 during the pre-intervention period and 57 during the intervention period. Induction chemotherapy and conditioning for allogeneic stem cell transplantation were the most frequent reasons for admission. In the intervention period, there was a significant decrease in overall antibiotic consumption (median DOT 20 vs. 28 days, p = 0.006), carbapenem consumption (median DOT 5.5 vs. 9 days, p = 0.017) and anti-resistant Gram-positive agents consumption (median DOT 8 vs. 11.5 days, p = 0.017). We found no statistical difference in the rates of intensive care unit admission (9% in each period) and 30-day mortality (5% vs. 0%, p = 0.243). Compliance with de-escalation and discontinuation strategies was significantly higher in the intervention period (77% vs. 8%, p < 0.001).

CONCLUSION

A multifaceted AMS intervention led to high compliance with early de-escalation and discontinuation of EAT and lower overall antibiotic consumption, without negatively affecting clinical outcomes.

Performance and Impact on Antibiotic Prescriptions of a Multiplex PCR in a Real-Life Cohort of Critically Ill Patients with Suspected Ventilated Pneumonia: A Retrospective Monocentric Observational Study

Pulmonary multiplex polymerase chain reaction (m-PCR) allows rapid pathogen detection. We aimed to assess its impact on initial antibiotic prescriptions in ventilated patients with suspected pneumonia. Between November 2020 and March 2022,ventilated patients with suspected pneumonia hospitalized in our ICU who benefited from respiratory sampling simultaneously tested using conventional microbiological methods and m-PCR were included. The proportion of appropriate changes in the initial antibiotic therapy following m-PCR results was assessed. We analyzed 104 clinical samples. Of the 47 negative m-PCR results, 16 (34%) led to an appropriate antibiotic strategy: 8 cessationsand 8 lack of initiation. Of the 57 positive m-PCR results, 51 (89%) resulted in an appropriate antibiotic strategy: 33 initiations, 2 optimizations, and 9 de-escalations. In the multivariate analysis, a positive m-PCR was associated with an appropriate antibiotic change (OR: 96.60; IC95% [9.72; 960.20], p < 0.001). A higher SAPS II score was negatively associated with an appropriate antibiotic change (OR: 0.96; IC95% [0.931; 0.997], p = 0.034). In our cohort, a positive m-PCR allowed for early initiation or adjustment of antibiotic therapy in almost 90% of cases. A negative m-PCR spared antibiotic use in onethird of cases. The impact of m-PCR results was reduced in the most severe patients.

Antibiotic Prescriptions in Critically Ill Patients with Bloodstream Infection Due to ESBL-Producing Enterobacteriaceae: Compliance with the French Guidelines for the Treatment of Infections with Third-Generation Cephalosporin-Resistant Enterobacteriaceae-A Multicentric Retrospective Cohort Study

National and international guidelines were recently published regarding the treatment of Enterobacteriaceae resistant to third-generation cephalosporins infections. We aimed to assess the implementation of the French guidelines in critically ill patients suffering from extended-spectrum β-lactamase-producing Enterobacteriaceae bloodstream infection (ESBL-E BSI). We conducted a retrospective observational cohort study in the ICU of three French hospitals. Patients treated between 2018 and 2022 for ESBL-E BSI were included. The primary assessment criterion was the proportion of adequate empirical carbapenem prescriptions, defined as prescriptions consistent with the French guidelines. Among the 185 included patients, 175 received an empirical anti-biotherapy within 24 h of ESBL-E BSI onset, with a carbapenem for 100 of them. The proportion of carbapenem prescriptions consistent with the guidelines was 81%. Inconsistent prescriptions were due to a lack of prescriptions of a carbapenem, while it was recommended in 25% of cases. The only factor independently associated with adequate empirical carbapenem prescription was ESBL-E colonization (OR: 107.921 [9.303-1251.910], p = 0.0002). The initial empirical anti-biotherapy was found to be appropriate in 83/98 patients (85%) receiving anti-biotherapy in line with the guidelines and in 56/77 (73%) patients receiving inadequate anti-biotherapy (p = 0.06). Our results illustrate the willingness of intensivists to spare carbapenems. Promoting implementation of the guidelines could improve the proportion of initial appropriate anti-biotherapy in critically ill patients with ESBL-E BSI.

Assessing the Utility of Multiplexed Polymerase Chain Reaction in Detecting Microorganisms Causing Infections in Critically ill Patients

Early sepsis diagnosis is crucial for implementing adequate antibiotic therapy and for patient survival. This study investigated whether using multiplexed PCR for detecting microorganisms in critical septic patients affects initial antibiotic treatment and compared it to microbiological culture. It also explored scenarios where PCR is more effective in clinical practice. One hundred nineteen specimens (83 blood and 36 respiratory specimens) belonging to 93 patients were analyzed. Multiplexed PCR determinations were performed using the FA-BCID Panel (bioMérieux) for blood samples and the FA-Pneumo for respiratory samples. The mean turnaround times were 1.7 h for the FA-BCID and 1.5h for the FA-Pneumo. Conversely, they were 96.1 h for blood cultures and 72.3 h for respiratory cultures. FA-BCID showed a mean sensitivity of 97% and specificity of 100%. FA-Pneumo showed a sensitivity of 100% and specificity of 90%. However, the positive predictive value was only 39%. Discrepancies were common in polymicrobial samples. Based on the PCR results, initial empirical treatment should have been changed in 71% of patients with bloodstream infections and 61% with respiratory infections. We conclude that multiplexed PCR improves the response time in identifying germs with a high degree of coincidence for blood cultures and moderate for respiratory cultures. These results highlight the importance of PCR in choosing an appropriate antibiotic therapy.

Bloodstream Infections: Comparison of Diagnostic Methods and Therapeutic Consequences between a Hospital in a Resource-Limited Setting and Two French Hospitals

In recent years, the diagnosis of bloodstream infections has been complemented by rapid microbiological methods, unattainable to most clinical laboratories in resource-limited settings. We evaluated the impact of their shortage on antibiotic therapy adequacy. We conducted a prospective multicenter cohort study including 150 adult Gram-negative bacilli bacteremia episodes, evenly distributed across three university hospitals: one in Lebanon, a resource-limited setting, and two in France, a resource-rich setting. Previous colonization by multidrug-resistant organisms (MDRO) was significantly more prevalent among the Lebanese than the French group of patients (16/50 vs. 5/100; p < 0.01). Bloodstream infections by carbapenemase-producing Enterobacterales and other MDRO were higher among the Lebanese than the French group of patients (25/50 vs. 12/100; p < 0.01). For the French group, rapid identification of species and mechanisms of resistance significantly shortened turnaround time for definitive laboratory diagnosis and increased antibiotic therapy adequacy. No statistically significant differences were noted in targeted antibiotic therapy between the two groups. This study suggests that, in settings where bacterial resistance is prevalent, rapid microbiological methods have not provided any additional value. The clinical and economic impact of rapid microbiological methods will likely depend on local CPE, VRE, and other MDRO epidemiology and are areas for future research.

Antibiotic prescription patterns during last days of hospitalized patients with advanced cancer: the role of palliative care consultation

OBJECTIVES

Issues regarding antibiotic use in end-of-life patients with advanced cancer present a challenging ethical dilemma in academic referral centres. This study aimed to investigate the role of palliative care consultation on antibiotic prescription patterns among hospitalized patients with advanced cancer during their last days of life.

METHODS

This retrospective cohort study included adult patients with metastatic solid cancer admitted to a tertiary referral hospital for at least 4 days and subsequently died and who were given antibiotics 4 days before death between January 2018 and December 2021. Patients were divided into palliative care consultation (PC) and non-consultation (non-PC) groups. The outcomes were the proportion of patients who received antibiotic combination treatment, antibiotic escalation and antibiotic de-escalation within 3 days of death. Propensity score analysis with the inverse probability of the treatment weighting method was used to compare the outcomes.

RESULTS

Among the 1177 patients enrolled, 476 (40.4%) received palliative care consultation and 701 (59.6%) did not. The PC group received considerably less antibiotic combination treatment (49.0% versus 61.1%, adjusted OR: 0.69, 95% CI: 0.53-0.90, P = 0.006) and antibiotic escalation (15.8% versus 34.8%, adjusted OR: 0.41, 95% CI: 0.30-0.57, P < 0.001) than the non-PC group. Additionally, the PC group reported significantly higher antibiotic de-escalation (30.7% versus 17.4%, adjusted OR: 1.74, 95% CI: 1.28-2.36, P < 0.001).

CONCLUSION

Receiving palliative care consultation may minimize aggressive antibiotic prescription patterns in the last days of patients with advanced cancer in an academic referral centre setting.

Risk factors for infections caused by carbapenem-resistant Enterobacterales: an international matched case-control-control study (EURECA)

BACKGROUND

Data on risk factors for carbapenem-resistant Enterobacterales (CRE) with wider applicability are needed to inform preventive measures and efficient design of randomised trials.

METHODS

An international matched case-control-control study was performed in 50 hospitals with high CRE incidence from March 2016 to November 2018 to investigate different aspects of infections caused by CRE (NCT02709408). Cases were patients with complicated urinary tract infection (cUTI), complicated intraabdominal (cIAI), pneumonia or bacteraemia from other sources (BSI-OS) due to CRE; control groups were patients with infection caused by carbapenem-susceptible Enterobacterales (CSE), and by non-infected patients, respectively. Matching criteria included type of infection for CSE group, ward and duration of hospital admission. Conditional logistic regression was used to identify risk factors.

FINDINGS

Overall, 235 CRE case patients, 235 CSE controls and 705 non-infected controls were included. The CRE infections were cUTI (133, 56.7%), pneumonia (44, 18.7%), cIAI and BSI-OS (29, 12.3% each). Carbapenemase genes were found in 228 isolates: OXA-48/like, 112 (47.6%), KPC, 84 (35.7%), and metallo-β-lactamases, 44 (18.7%); 13 produced two. The risk factors for CRE infection in both type of controls were (adjusted OR for CSE controls; 95% CI; p value) previous colonisation/infection by CRE (6.94; 2.74-15.53; <0.001), urinary catheter (1.78; 1.03-3.07; 0.038) and exposure to broad spectrum antibiotics, as categorical (2.20; 1.25-3.88; 0.006) and time-dependent (1.04 per day; 1.00-1.07; 0.014); chronic renal failure (2.81; 1.40-5.64; 0.004) and admission from home (0.44; 0.23-0.85; 0.014) were significant only for CSE controls. Subgroup analyses provided similar results.

INTERPRETATION

The main risk factors for CRE infections in hospitals with high incidence included previous colonization, urinary catheter and exposure to broad spectrum antibiotics.

FUNDING

The study was funded by the Innovative Medicines Initiative Joint Undertaking (https://www.imi.europa.eu/) under Grant Agreement No. 115620 (COMBACTE-CARE).

Recent Approaches for Downplaying Antibiotic Resistance: Molecular Mechanisms

Antimicrobial resistance (AMR) is a ubiquitous public health menace. AMR emergence causes complications in treating infections contributing to an upsurge in the mortality rate. The epidemic of AMR in sync with a high utilization rate of antimicrobial drugs signifies an alarming situation for the fleet recovery of both animals and humans. The emergence of resistant species calls for new treatments and therapeutics. Current records propose that health drug dependency, veterinary medicine, agricultural application, and vaccination reluctance are the primary etymology of AMR gene emergence and spread. Recently, several encouraging avenues have been presented to contest resistance, such as antivirulent therapy, passive immunization, antimicrobial peptides, vaccines, phage therapy, and botanical and liposomal nanoparticles. Most of these therapies are used as cutting-edge methodologies to downplay antibacterial drugs to subdue the resistance pressure, which is a featured motive of discussion in this review article. AMR can fade away through the potential use of current cutting-edge therapeutics, advancement in antimicrobial susceptibility testing, new diagnostic testing, prompt clinical response, and probing of new pharmacodynamic properties of antimicrobials. It also needs to promote future research on contemporary methods to maintain host homeostasis after infections caused by AMR. Referable to the microbial ability to break resistance, there is a great ultimatum for using not only appropriate and advanced antimicrobial drugs but also other neoteric diverse cutting-edge therapeutics.

Days of Antibiotic Spectrum Coverage Trends and Assessment in Patients with Bloodstream Infections: A Japanese University Hospital Pilot Study

The antibiotic spectrum is not reflected in conventional antimicrobial metrics. Days of antibiotic spectrum coverage (DASC) is a novel quantitative metric for antimicrobial consumption developed with consideration of the antibiotic spectrum. However, there were no data regarding disease and pathogen-specific DASC. Thus, this study aimed to evaluate the DASC trend in patients with bloodstream infections (BSIs). DASC and days of therapy (DOT) of in-patients with positive blood culture results during a 2-year interval were evaluated. Data were aggregated to calculate the DASC, DOT, and DASC/DOT per patient stratified by pathogens. During the 2-year study period, 1443 positive blood culture cases were identified, including 265 suspected cases of contamination. The overall DASC, DASC/patient, DOT, DOT/patient, and DASC/DOT metrics were 226,626; 157.1; 28,778; 19.9; and 7.9, respectively. A strong correlation was observed between DASC and DOT, as well as DASC/patient and DOT/patient. Conversely, DASC/DOT had no correlation with other metrics. The combination of DASC and DOT would be a useful benchmark for the overuse and misuse evaluation of antimicrobial therapy in BSIs. Notably, DASC/DOT would be a robust metric to evaluate the antibiotic spectrum that was selected for patients with BSIs.

A novel approach for combining the metagenome, metaresistome, metareplicome and causal inference to determine the microbes and their antibiotic resistance gene repertoire that contribute to dysbiosis

The use of whole metagenomic data to infer the relative abundance of all its microbes is well established. The same data can be used to determine the replication rate of all eubacterial taxa with circular chromosomes. Despite their availability, the replication rate profiles (metareplicome) have not been fully exploited in microbiome analyses. Another relatively new approach is the application of causal inferencing to analyse microbiome data that goes beyond correlational studies. A novel scalable pipeline called MeRRCI (Metagenome, metaResistome, and metaReplicome for Causal Inferencing) was developed. MeRRCI combines efficient computation of the metagenome (bacterial relative abundance), metaresistome (antimicrobial gene abundance) and metareplicome (replication rates), and integrates environmental variables (metadata) for causality analysis using Bayesian networks. MeRRCI was applied to an infant gut microbiome data set to investigate the microbial community's response to antibiotics. Our analysis suggests that the current treatment stratagem contributes to preterm infant gut dysbiosis, allowing a proliferation of pathobionts. The study highlights the specific antibacterial resistance genes that may contribute to exponential cell division in the presence of antibiotics for various pathogens, namely Klebsiella pneumoniae, Citrobacter freundii, Staphylococcus epidermidis, Veilonella parvula and Clostridium perfringens. These organisms often contribute to the harmful long-term sequelae seen in these young infants.

Potential of Multiplex Polymerase Chain Reaction Performed on Protected Telescope Catheter Samples for Early Adaptation of Antimicrobial Therapy in ARDS Patients

Background: Diagnosis of co/superinfection in patients with Acute Respiratory Distress Syndrome (ARDS) is challenging. The FilmArray Pneumonia plus Panel (bioMérieux, France), a new rapid multiplex Polymerase Chain Reaction (mPCR), has never been assessed on a blinded protected telescope catheter (PTC) samples, a very common diagnostic tool in patients under mechanical ventilation. We evaluated the performance of mPCR on PTC samples compared with conventional culture and its impact on antibiotic stewardship. Methods: Observational study in two intensive care units, conducted between March and July 2020, during the first wave of the COVID-19 pandemic in France. Results: We performed 125 mPCR on blinded PTC samples of 95 ARDS patients, including 73 (77%) SARS-CoV-2 cases and 28 (29%) requiring extracorporeal membrane oxygenation. Respiratory samples were drawn from mechanically ventilated patients either just after intubation (n = 48; 38%) or later for suspected ventilator-associated pneumonia (VAP) (n = 77; 62%). The sensitivity, specificity, positive, and negative predictive values of mPCR were 93% (95% CI 84–100), 99% (95% CI 99–100), 68% (95% CI 54–83), and 100% (95% CI 100–100), respectively. The overall coefficient of agreement between mPCR and standard culture was 0.80 (95% CI 0.68–0.89). Intensivists changed empirical antimicrobial therapy in only 14% (18/125) of cases. No new antibiotic was initiated in more than half of the CAP/HAP pneumonia-suspected cases (n = 29; 60%) and in more than one-third of those suspected to have VAP without affecting or delaying their antimicrobial therapy. Conclusions: Rapid mPCR was feasible on blinded PTC with good sensitivity and specificity. New antibiotics were not initiated in more than half of patients and more than one-third of VAP-suspected cases. Further studies are needed to assess mPCR potential in improving antibiotic stewardship.

The Production of Antibiotics Must Be Reoriented: Repositioning Old Narrow-Spectrum Antibiotics, Developing New Microbiome-Sparing Antibiotics

The development of broad-spectrum antibiotics to control multidrug-resistant bacteria is an outdated business model. This strategy has led to the introduction of highly effective antibiotics, but their widespread use has contributed to the emergence of even broader antibiotic resistance. In a strategy to combat antimicrobial resistance, we believe that the use of narrow-spectrum antibiotics should be promoted. This should involve both the repositioning of old antibiotics and the reorientation of research and development towards new narrow-spectrum antibiotics with a low ecological impact. These antibiotics could be prescribed for common conditions such as sore throats and cystitis, which account for the bulk of antibiotic use in humans. Narrow-spectrum, targeted, microbiome-sparing antibiotics could help control antibiotic resistance while being economically sustainable. Their development and production should be supported by governments, which would ultimately benefit from reduced health care costs.

Antimicrobial stewardship in high-risk febrile neutropenia patients

BACKGROUND

The 2011 4th European Conference on Infections in Leukemia (ECIL4) guidelines recommend antibiotics de-escalation/discontinuation in selected febrile neutropenia (FN) patients. We aimed to assess the impact of an antimicrobial stewardship (AMS) program based on these guidelines on antibiotics use and clinical outcomes in high-risk FN patients.

METHODS

We conducted an observational study in the hematology department of Cochin University Hospital in Paris, France. An ECIL4-based antibiotics de-escalation and discontinuation strategy was implemented jointly by the hematologists and the AMS team. The pre-intervention (January-October 2018) and post-intervention (January-October 2019) periods were compared. We retrospectively collected clinical and microbiological data. We compiled antibiotics consumptions via hospital pharmacy data and standardized them by calculating defined daily doses per 1000 patient-days. We analyzed the two-monthly antibiotic consumption using an interrupted time series method and built a composite endpoint for clinical outcomes based on transfer to the intensive care unit (ICU) and/or hospital death.

RESULTS

Overall, 273 hospital stays (164 patients) in the pre-intervention and 217 (148 patients) in the post-intervention periods were analyzed. Patients were mainly hospitalized for intensive chemotherapy for acute leukemia or autologous stem-cell transplant for myeloma. Patients were slightly younger in the pre-intervention compared to the post-intervention period (median age 60.4 vs 65.2 years, p = 0.049), but otherwise comparable. After implementation of the AMS program, glycopeptide and carbapenem use decreased by 85% (p = 0.03) and 72% (p = 0.04), respectively. After adjustment on confounders, the risk of transfer to the ICU/death decreased significantly after implementation of the AMS program (post-intervention period: odds-ratio = 0.29, 95% Confidence Interval: 0.15-0.53, p < 0.001).

CONCLUSION

Implementation of a multidisciplinary AMS program for high-risk neutropenic patients was associated with lower carbapenem and glycopeptide use and improved clinical outcomes.

Relationship between the appropriateness of antibiotic treatment and clinical outcomes/medical costs of patients with community-acquired acute pyelonephritis: a multicenter prospective cohort study

BACKGROUND

Inappropriate use of antibiotics not only increases antibiotic resistance as collateral damage but also increases clinical failure rates and medical costs. The purpose of this study was to determine the relationship between the appropriateness of antibiotic prescription and outcomes of community-acquired acute pyelonephritis (CA-APN).

METHODS

A multicenter prospective cohort study was conducted at eight hospitals in Korea between September 2017 and August 2018. All hospitalized patients aged ≥ 19 years who were diagnosed with CA-APN on admission were recruited. The appropriateness of empirical and definitive antibiotics, as well as the appropriateness of antibiotic treatment duration and route of administration, was evaluated in accordance with the guideline and expert opinions. Clinical outcomes and medical costs were compared between patients who were administered antibiotics 'appropriately' and 'inappropriately.'

RESULTS

A total of 397 and 318 patients were eligible for the analysis of the appropriateness of empirical and definitive antibiotics, respectively. Of them, 10 (2.5%) and 18 (5.7%) were administered 'inappropriately' empirical and definitive antibiotics, respectively. Of the 119 patients whose use of both empirical and definitive antibiotics was classified as 'optimal,' 57 (47.9%) received antibiotics over a longer duration than that recommended; 67 (56.3%) did not change to oral antibiotics on day 7 of hospitalization, even after stabilization of the clinical symptoms. Patients who were administered empirical antibiotics 'appropriately' had shorter hospitalization days (8 vs. 10 days, P = 0.001) and lower medical costs (2381.9 vs. 3235.9 USD, P = 0.002) than those who were administered them 'inappropriately.' Similar findings were observed for patients administered both empirical and definitive antibiotics 'appropriately' and those administered either empirical or definitive antibiotics 'inappropriately'.

CONCLUSIONS

Appropriate use of antibiotics leads to better outcomes, including reduced hospitalization duration and medical costs.

Empiric antimicrobial therapy for early-onset pneumonia in severe trauma patients

PURPOSE

The bacterial ecology involved in early pneumonia of severe trauma patients is mostly commensal and would allow wide use of narrow-spectrum antibiotics. We describe risk factors for treatment failure of severe trauma patients' pneumonia with the use of narrow-spectrum antimicrobial therapy in order to develop a score that could help clinicians to determine which patients might be treated with narrow-spectrum antibiotics.

METHODS

A retrospective, observational, monocentric cohort study was conducted of severe trauma patients requiring mechanical ventilation for > 48 h and developing a first episode of microbiologically confirmed pneumonia occurring within the first 10 days after admission.

RESULTS

Overall, 370 patients were included. The resistance rate against narrow-spectrum antibiotics (amoxicillin/clavulanic acid) was 22.7% (84 pneumonia). In a multivariate analysis, two independent risk factors were associated with this resistance: prior antimicrobial therapy ≥ 48 h (OR 4.00; 95 CI [2.39; 6.75]) and age ≥ 30y (OR 2.10; 95 CI [1.21; 3.78]). We created a prediction score that defined patient with one or two risk factors at high risk of resistance. This score presented a sensitivity of 0.92 [0.88; 0.94], a specificity of 0.33 [0.28; 0.38], a positive predictive value of 0.29 [0.24; 0.33] and a negative predictive value of 0.93 [0.90; 0.95].

CONCLUSION

Simple risk factors may help clinicians to identify severe trauma patients at high risk of pneumonia treatment failure with the use of narrow-spectrum antimicrobial therapy and, thus, use better tailored empiric therapy and limit the use of unnecessary broad-spectrum antimicrobial therapy.

Antimicrobial Stewardship Program: Reducing Antibiotic's Spectrum of Activity Is not the Solution to Limit the Emergence of Multidrug-Resistant Bacteria

Overconsumption of antibiotics in hospitals has led to policy implementation, including the control of antibiotic prescriptions. The impact of these policies on the evolution of antimicrobial resistance remains uncertain. In this work, we review the possible limits of such policies and focus on the need for a more efficient approach. Establishing a causal relationship between the introduction of new antibiotics and the emergence of new resistance mechanisms is difficult. Several studies have demonstrated that many resistance mechanisms existed before the discovery of antibiotics. Overconsumption of antibiotics has worsened the phenomenon of resistance. Antibiotics are responsible for intestinal dysbiosis, which is suspected of being the source of bacterial resistance. The complexity of the intestinal microbiota composition, the impact of the pharmacokinetic properties of antibiotics, and the multiplicity of other factors involved in the acquisition and emergence of multidrug-resistant organisms, lead us to think that de-escalation, in the absence of studies proving its effectiveness, is not the solution to limiting the spread of multidrug-resistant organisms. More studies are needed to clarify the ecological risk caused by different antibiotic classes. In the meantime, we need to concentrate our efforts on limiting antibiotic prescriptions to patients who really need it, and work on reducing the duration of these treatments.

The role of the microbiota in the management of intensive care patients

The composition of the gut microbiota is highly dynamic and changes according to various conditions. The gut microbiota mainly includes difficult-to-cultivate anaerobic bacteria, hence knowledge about its composition has significantly arisen from culture-independent methods based on next-generation sequencing (NGS) such as 16S profiling and shotgun metagenomics. The gut microbiota of patients hospitalized in intensive care units (ICU) undergoes many alterations because of critical illness, antibiotics, and other ICU-specific medications. It is then characterized by lower richness and diversity, and dominated by opportunistic pathogens such as Clostridioides difficile and multidrug-resistant bacteria. These alterations are associated with an increased risk of infectious complications or death. Specifically, at the time of writing, it appears possible to identify distinct microbiota patterns associated with severity or infectivity in COVID-19 patients, paving the way for the potential use of dysbiosis markers to predict patient outcomes. Correcting the microbiota disturbances to avoid their consequences is now possible. Fecal microbiota transplantation is recommended in recurrent C. difficile infections and microbiota-protecting treatments such as antibiotic inactivators are currently being developed. The growing interest in the microbiota and microbiota-associated therapies suggests that the control of the dysbiosis could be a key factor in the management of critically ill patients. The present narrative review aims to provide a synthetic overview of microbiota, from healthy individuals to critically ill patients. After an introduction to the different techniques used for studying the microbiota, we review the determinants involved in the alteration of the microbiota in ICU patients and the latter's consequences. Last, we assess the means to prevent or correct microbiota alteration.

Impact of Extended and Restricted Antibiotic Deescalation on Mortality

BACKGROUND

More data are needed about the safety of antibiotic de-escalation in specific clinical situations as a strategy to reduce exposure to broad-spectrum antibiotics. This study aims to compare the survival curve of patient de-escalated (early or late) against those not de-escalated on antibiotics, to determine the association of patient related, clinical related, and pressure sore/device related characteristics on all-cause 30-day mortality and determine the impact of early and late antibiotic de-escalation on 30-day all-cause mortality.

METHODS

This is a retrospective cohort study on patients in medical ward Hospital Kuala Lumpur, admitted between January 2016 and June 2019. A Kaplan-Meier survival curve and Fleming-Harrington test were used to compare the overall survival rates between early, late, and those not de-escalated on antibiotics while multivariable Cox proportional hazards regression was used to determine prognostic factors associated with mortality and the impact of de-escalation on 30-day all-cause mortality.

RESULTS

Overall mortality rates were not significantly different when patients were not de-escalated on extended or restricted antibiotics, compared to those de-escalated early or later (p = 0.760). Variables associated with 30-day all-cause mortality were a Sequential Organ Function Assessment (SOFA) score on the day of antimicrobial stewardship (AMS) intervention and Charlson's comorbidity score (CCS). After controlling for confounders, early and late antibiotics were not associated with an increased risk of mortality.

CONCLUSION

The results of this study reinforce that restricted or extended antibiotic de-escalation in patients does not significantly affect 30-day all-cause mortality compared to continuation with extended and restricted antibiotics.

Antibiotic Therapy in the Intensive Care Unit

Antibiotic resistance is a public health concern. A critical care clinician is faced with a clinical dilemma of using the appropriate treatment without compromising the antibiotic armamentarium. Postoperative and trauma patients in the intensive care unit (ICU) pose a unique challenge of mounting a systemic inflammatory response, which makes it even more difficult to differentiate inflammation from infection. The decision for type of empirical therapy should be individualized to the patient and local ecology data and resistance profiles. After initiation of empirical therapy, deescalation should be done once microbiology data are available. Antibiotic stewardship programs are essential in the ICU.

Assessment of Antibiotic De-escalation by Spectrum Score in Patients With Nosocomial Pneumonia: A Single-Center, Retrospective Cohort Study

BACKGROUND

Hospital-acquired and ventilator-associated pneumonia (HAP/VAP) cause significant mortality. Guidelines recommend empiric broad-spectrum antibiotics followed by de-escalation (DE). This study sought to assess the impact of DE on treatment failure.

METHODS

This single-center retrospective cohort study screened all adult patients with a discharge diagnosis code for pneumonia from 2016 to 2019. Patients were enrolled if they met predefined criteria for HAP/VAP ≥48 hours after admission. Date of pneumonia diagnosis was defined as day 0. Spectrum scores were calculated, and DE was defined as a score reduction on day 3 versus day 1. Patients with DE were compared to patients with no de-escalation (NDE). The primary outcome was composite treatment failure, defined as all-cause mortality or readmission for pneumonia within 30 days of diagnosis.

RESULTS

Of 11860 admissions screened, 1812 unique patient-admissions were included (1102 HAP, 710 VAP). Fewer patients received DE (876 DE vs 1026 NDE). Groups were well matched at baseline, although more patients receiving DE had respiratory cultures ordered (56.6% vs 50.6%, P = .011). There was no difference in composite treatment failure (35.0% DE vs 33.8% NDE, P = .604). De-escalation was not associated with treatment failure on multivariable Cox regression analysis (hazard ratio, 1.13; 95% confidence interval, 0.96-1.33). Patients receiving DE had fewer antibiotic days (median 9 vs 11, P < .0001), episodes of Clostridioides difficile infection (2.2% vs 3.8%, P = .046), and hospital days (median 20 vs 22 days, P = .006).

CONCLUSIONS

De-escalation and NDE resulted in similar rates of 30-day treatment failure; however, DE was associated with fewer antibiotic days, episodes of C difficile infection, and days of hospitalization.

Antimicrobial prescription in severe COVID-19 and CAP: a matched case-control study

BACKGROUND

In severe coronavirus diseases 2019 (COVID-19), a high and potentially excessive use of antimicrobials for suspected bacterial co-infection and intensive care unit (ICU)-acquired infections has been repeatedly reported.

OBJECTIVES

To compare an ICU cohort of community-acquired pneumonia (CAP) with a cohort of severe COVID-19 pertaining to co-infections, ICU-acquired infections and associated antimicrobial consumption.

METHODS

We retrospectively compared a cohort of CAP patients with a cohort of COVID-19 patients matched according to organ failure, ICU length of stay (LOS) and ventilation days. Patient data such as demographics, infection focus, probability and severity, ICU severity scores and ICU and in-hospital mortality, days of antimicrobial therapy (DOT) and number of antimicrobial prescriptions, using an incremental scale, were registered and analysed. The total number of cultures (sputum, urinary, blood cultures) was collected and corrected for ICU LOS.

FINDINGS

CAP patients (n = 148) were matched to COVID-19 patients (n = 74). Significantly less sputum cultures (68.2% versus 18.9%, P < 0.05) and bronchoalveolar lavages (BAL) (73.7% versus 36.5%, P < 0.05) were performed in COVID-19 patients. Six (8.1%) COVID-19 patients were diagnosed with a co-infection. Respectively, 58 of 148 (39.2%) CAP and 38 of 74 (51.4%) COVID-19 patients (P = 0.09) developed ICU-acquired infections. Antimicrobial distribution, both in the number of prescriptions and DOT, was similar in both cohorts.

CONCLUSIONS

We found a low rate of microbiologically confirmed bacterial co-infection and a high rate of ICU-acquired infections in COVID-19 patients. Infection probabilities, antimicrobial prescriptions and DOT were comparable with a matched CAP cohort.

Comparison of therapy with β-lactam/β-lactamase inhibitor combinations or carbapenems for bacteraemia of nonurinary source caused by ESBL-producing Escherichia coli or Klebsiella pneumoniae

Background

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae has become a public health concern. This study aimed to compare the clinical outcomes of patients with nonurinary source bacteraemia caused by ESBL-producing Escherichia coli (E. coli) or Klebsiella pneumoniae (ESBL-producing EK) receiving β-lactam/β-lactamase inhibitor combinations (BLICs) versus carbapenem treatment and assess the risk factors of mortality with these two drugs.

Methods

We conducted a retrospective single-centre study of adult hospitalised patients with ESBL-producing EK bloodstream infection (BSI) from nonurinary source at our centre over a 4-year period. One hundred and eighty patients who received BLICs or carbapenems were included in the analysis. The outcome variables were 14-day treatment failure and 30-day mortality. For more reliable results, propensity score analysis was performed to compare the efficacy of the two drugs and analyse their risk factors for 30-day mortality.

Results

Out of 180 patients, 114 received BLICs, and 66 received carbapenem therapy. Compared to carbapenem-treated patients, those treated with BLICs were older and had higher age-adjusted Charlson comorbidity index, but they had shorter stay in the hospital. Additionally, their Pitt bacteraemia score, SOFA score, rate of leukaemia, and immune compromise were lower. After propensity score matching (PSM), the baseline characteristics of patients in the two treatment groups were balanced. BLICs were associated with a higher 14-day treatment failure rate (20.6%, 13/63) than carbapenems (16.3%, 7/43), although the difference was not significant in either univariate analysis (P = 0.429) or multivariate analysis (P = 0.122). And the 30-day mortality rate in BTG (11.1%, 7/63) and CTG (11.6%, 5/43) did not significantly differ (univariate analysis, P = 0.926; multivariate analysis, P = 0.420). In the multivariate analysis, after PSM, leukaemia was the only independent predictor of mortality in both BTG and CTG.

Conclusions

Our study showed that BLICs had higher 14-day treatment failure rate compared with carbapenems, although there were no statistically significant differences because of the small number of patients, therefore, further evaluation of the efficacy of BLICs is needed.

Desirability of Outcome Ranking for the Management of Antimicrobial Therapy (DOOR MAT): A Framework for Assessing Antibiotic Selection Strategies in the Presence of Drug Resistance

The complexities of antibiotic resistance mean that successful stewardship must consider both the effectiveness of a given antibiotic and the spectrum of that therapy to minimize imposing further selective pressure. To meet this challenge, we propose the Desirability of Outcome Ranking approach for the Management of Antimicrobial Therapy (DOOR MAT), a flexible quantitative framework that evaluates the desirability of antibiotic selection. Herein, we describe the steps required to implement DOOR MAT and present examples to illustrate how the desirability of treatment selection can be evaluated using resistance information. While treatments and the scoring of treatment selections must be adapted to specific clinical settings, the principle of DOOR MAT remains constant: The most desirable antibiotic choice effectively treats the patient while exerting minimal pressure on future resistance.

Impact of a restrictive antibiotic policy on the acquisition of extended-spectrum beta-lactamase-producing Enterobacteriaceae in an endemic region: a before-and-after, propensity-matched cohort study in a Caribbean intensive care unit

BACKGROUND

High-level antibiotic consumption plays a critical role in the selection and spread of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) in the ICU. Implementation of a stewardship program including a restrictive antibiotic policy was evaluated with respect to ESBL-E acquisition (carriage and infection).

METHODS

We implemented a 2-year, before-and-after intervention study including all consecutive adult patients admitted for > 48 h in the medical-surgical 26-bed ICU of Guadeloupe University Hospital (French West Indies). A conventional strategy period (CSP) including a broad-spectrum antibiotic as initial empirical treatment, followed by de-escalation (period before), was compared to a restrictive strategy period (RSP) limiting broad-spectrum antibiotics and shortening their duration. Antibiotic therapy was delayed and initiated only after microbiological identification, except for septic shock, severe acute respiratory distress syndrome and meningitis (period after). A multivariate Cox proportional hazard regression model adjusted on propensity score values was performed. The main outcome was the median time of being ESBL-E-free in the ICU. Secondary outcome included all-cause ICU mortality.

RESULTS

The study included 1541 patients: 738 in the CSP and 803 in the RSP. During the RSP, less patients were treated with antibiotics (46.8% vs. 57.9%; p < 0.01), treatment duration was shorter (5 vs. 6 days; p < 0.01), and administration of antibiotics targeting anaerobic pathogens significantly decreased (65.3% vs. 33.5%; p < 0.01) compared to the CSP. The incidence of ICU-acquired ESBL-E was lower (12.1% vs. 19%; p < 0.01) during the RSP. The median time of being ESBL-E-free was 22 days (95% CI 16-NA) in the RSP and 18 days (95% CI 16-21) in the CSP. After propensity score weighting and adjusted analysis, the median time of being ESBL-E-free was independently associated with the RSP (hazard ratio, 0.746 [95% CI 0.575-0.968]; p = 0.02, and hazard ratio 0.751 [95% CI 0.578-0.977]; p = 0.03, respectively). All-cause ICU mortality was lower in the RSP than in the CSP (22.5% vs. 28.6%; p < 0.01).

CONCLUSIONS

Implementation of a program including a restrictive antibiotic strategy is feasible and is associated with less ESBL-E acquisition in the ICU without any worsening of patient outcome.

Towards personalized guidelines: using machine-learning algorithms to guide antimicrobial selection

BACKGROUND

Electronic decision support systems could reduce the use of inappropriate or ineffective empirical antibiotics. We assessed the accuracy of an open-source machine-learning algorithm trained in predicting antibiotic resistance for three Gram-negative bacterial species isolated from patients' blood and urine within 48 h of hospital admission.

METHODS

This retrospective, observational study used routine clinical information collected between January 2010 and October 2016 in Birmingham, UK. Patients from whose blood or urine cultures Escherichia coli, Klebsiella pneumoniae or Pseudomonas aeruginosa was isolated were identified. Their demographic, microbiology and prescribing data were used to train an open-source machine-learning algorithm-XGBoost-in predicting resistance to co-amoxiclav and piperacillin/tazobactam. Multivariate analysis was performed to identify predictors of resistance and create a point-scoring tool. The performance of both methods was compared with that of the original prescribers.

RESULTS

There were 15 695 admissions. The AUC of the receiver operating characteristic curve for the point-scoring tools ranged from 0.61 to 0.67, and performed no better than medical staff in the selection of appropriate antibiotics. The machine-learning system performed statistically but marginally better (AUC 0.70) and could have reduced the use of unnecessary broad-spectrum antibiotics by as much as 40% among those given co-amoxiclav, piperacillin/tazobactam or carbapenems. A validation study is required.

CONCLUSIONS

Machine-learning algorithms have the potential to help clinicians predict antimicrobial resistance in patients found to have a Gram-negative infection of blood or urine. Prospective studies are required to assess performance in an unselected patient cohort, understand the acceptability of such systems to clinicians and patients, and assess the impact on patient outcome.

Increased risk of acquisition and transmission of ESBL-producing Enterobacteriaceae in malnourished children exposed to amoxicillin

OBJECTIVES

Routine amoxicillin for children with uncomplicated severe acute malnutrition raises concerns of increasing antibiotic resistance. We performed an ancillary study nested within a double-blind, placebo-controlled trial in Niger testing the role of routine 7 day amoxicillin therapy in nutritional recovery of children 6 to 59 months of age with uncomplicated severe acute malnutrition.

METHODS

We screened 472 children for rectal carriage of ESBL-producing Enterobacteriaceae (ESBL-E) as well as their household siblings under 5 years old, at baseline and Week 1 (W1) and Week 4 (W4) after start of therapy, and characterized strains by WGS. ClinicalTrials.gov: NCT01613547.

RESULTS

Carriage in index children at baseline was similar in the amoxicillin and the placebo groups (33.8% versus 27.9%, P = 0.17). However, acquisition of ESBL-E in index children at W1 was higher in the amoxicillin group than in the placebo group (53.7% versus 32.2%, adjusted risk ratio = 2.29, P = 0.001). Among 209 index and sibling households possibly exposed to ESBL-E transmission, 16 (7.7%) had paired strains differing by ≤10 SNPs, suggesting a high probability of transmission. This was more frequent in households from the amoxicillin group than from the placebo group [11.5% (12/104) versus 3.8% (4/105), P = 0.04].

CONCLUSIONS

Among children exposed to amoxicillin, ESBL-E colonization was more frequent and the risk of transmission to siblings higher. Routine amoxicillin should be carefully balanced with the risks associated with ESBL-E colonization.

Carbapenem use in critically ill patients

PURPOSE OF REVIEW

To review available data on carbapenem use in ICU. Carbapenem is a broad spectrum well tolerated antibiotic family that keep an excellent activity to extended spectrum β-lactamases and AmpC hyperproducer and in susceptible Pseudomonas aeruginosa and Acinetobacter baumannii. It becomes a drug of choice for empirical therapy of suspected sepsis in known or presumably known ESBLE carriers.

RECENT FINDINGS

Carbapenems remained the drug of choice for severe ESBLE infections. In severe critically ill patients, high off-label dose is necessary especially in patients with sepsis and glomerular hyperfiltration. Nevertheless, large spectrum of carbapenems leads to initial overuse. The increase in the overall consumption in the past years with lack of systematic re-evaluation observed is responsible of and carbapenem-selection pressure that contribute to the increase of carbapenem-resistant enterobacteriaceae, A. Baumannii and P. Aeruginosa in ICUs.

SUMMARY

Carbapenems remained a cornerstone of antibiotic therapy of severe infections. Emerging carbapenem resistance is related to the increase of carbapenem consumption. High doses are recommended for early therapy followed by systematic reevaluation on a daily basis with shift to narrow spectrum antimicrobials if possible and early stopping rules.

Impact of rapid multiplex PCR on management of antibiotic therapy in COVID-19-positive patients hospitalized in intensive care unit

Because the diagnosis of co/superinfection in COVID-19 patients is challenging, empirical antibiotic therapy is frequently initiated until microbiological analysis results. We evaluated the performance and the impact of the BioFire® FilmArray® Pneumonia plus Panel on 112 respiratory samples from 67 COVID-19 ICU patients suspected of co/superinfections. Globally, the sensitivity and specificity of the test were 89.3% and 99.1%, respectively. Positive tests led to antibiotic initiation or adaptation in 15% of episodes and de-escalation in 4%. When negative, 28% of episodes remained antibiotic-free (14% no initiation, 14% withdrawal). Rapid multiplex PCRs can help to improve antibiotic stewardship by administering appropriate antibiotics earlier and avoiding unnecessary prescriptions.

Epidemiology, clinical relevance and prognosis of staphylococci in hospital-acquired postoperative intra-abdominal infections: an observational study in intensive care unit

The pathogenic role of staphylococci in hospital-acquired postoperative intra-abdominal infections (HAIs) has never been evaluated. In a tertiary care university hospital, we assessed the clinical characteristics and outcomes of patients admitted to the intensive care unit for HAIs according to the presence of staphylococci (S-HAI) or their absence (nS-HAI) in peritoneal cultures. Patients with S-HAIs were compared to nS-HAIs patients. Overall, 380 patients were analyzed, including 87 (23%) S-HAI patients [29 Staphylococcus aureus (Sa-HAIs) and 58 coagulase-negative staphylococci (CoNS-HAIs)]. The clinical characteristics did not differ between the S-HAI and nS-HAI patients. Adequacy of empirical anti-infective therapy was achieved less frequently in the staphylococci group (54 vs 72%, respectively, p < 0.01). The 90-day (primary endpoint) and one-year mortality rates did not differ between these groups. The S-HAI patients had decreased rates of postoperative complication (p < 0.05). The adjusted analysis of the clinical outcomes reported a decreased frequency of surgical complications in the staphylococci group (OR 0.43, 95% CI [0.20–0.93], p = 0.03). While the trends toward decreased morbidity criteria were observed in S-HAI patients, the clinical outcomes were not different between the CoNS-HAI and Sa-HAI patients. In summary, our data are not substantial enough to conclude that staphylococci exhibit no pathogenicity in HAIs.

Impact of the multidisciplinary antimicrobial stewardship team intervention focusing on carbapenem de-escalation: A single-centre and interrupted time series analysis

BACKGROUND

As a result of the constant increase in carbapenem resistance amongst gram-negative bacteria in several countries, the inappropriate use of carbapenems must be reduced. Antimicrobial stewardship programmes (ASPs) aim to improve carbapenem usage by implementing interventions, including the promotion of the de-escalation (DE) strategy. Thus, this study aimed to evaluate the impact of this strategy on carbapenem use based on a clear definition of DE.

METHODS

The post-prescription review and feedback (PPRF) strategy, which is used to optimise carbapenem use, was implemented by the antimicrobial stewardship team (AST). We compared the DE rate during the pre-AST intervention period (from April 2017 to March 2018) and post-AST intervention period (from April 2018 to March 2019).

RESULT

A total of 1500 patients (n = 771 in the pre-AST intervention period and n = 729 in the intervention post-AST period) were admitted to the hospital. The average duration of antibiotic therapy decreased from 9.9 to 7.7 days. The DE rate significantly increased in the post-AST intervention period compared with the pre-AST intervention period (51.4% vs 40.3%; P < .001).

CONCLUSION

The PPRF strategy implemented by the AST could improve the carbapenem usage by increasing the DE rate of carbapenem.

Combination Therapy with Aminoglycoside in Bacteremiasdue to ESBL-Producing Enterobacteriaceae in ICU

Objectives: Evaluation of the efficacy of empirical aminoglycoside in critically ill patients with bloodstream infections caused by extended-spectrum β-lactamase producing Enterobacteriaceae (ESBL-E BSI). Methods: Patients treated between 2011 and 2018 for ESBL-E BSI in the ICU of six French hospitals were included in a retrospective observational cohort study. The primary endpoint was mortality on day 30. Results: Among 307 patients, 169 (55%) were treated with empirical aminoglycoside. Death rate was 40% (43% with vs. 39% without aminoglycoside, p = 0.55). Factors independently associated with death were age ≥70 years (OR: 2.67; 95% CI: 1.09–6.54, p = 0.03), history of transplantation (OR 5.2; 95% CI: 1.4–19.35, p = 0.01), hospital acquired infection (OR 8.67; 95% CI: 1.74–43.08, p = 0.008), vasoactive drugs >48 h after BSI onset (OR 3.61; 95% CI: 1.62–8.02, p = 0.001), occurrence of acute respiratory distress syndrome (OR 2.42; 95% CI: 1.14–5.16, p = 0.02), or acute renal failure (OR 2.49; 95% CI: 1.14–5.47, p = 0.02). Antibiotherapy appropriateness was more frequent in the aminoglycoside group (91.7% vs. 77%, p = 0.001). Rate of renal impairment was similar in both groups (21% vs. 24%, p = 0.59). Conclusions: In intensive care unit (ICU) patients with ESBL-E BSI, empirical treatment with aminoglycoside was frequent. It demonstrated no impact on mortality, despite increasing treatment appropriateness.

Outpatient management or hospitalization of patients with proven or suspected SARS-CoV-2 infection: the HOME-CoV rule

In the context of the COVID-19 pandemic and overloaded hospitals, a central issue is the need to define reliable and consensual criteria for hospitalization or outpatient management in mild cases of COVID-19. Our aim was to define an easy-to-use clinical rule aiming to help emergency physicians in hospitalization or outpatient management decision-making for patients with suspected or confirmed SARS-CoV-2 infection (the HOME-CoV rule). The Delphi method was used to reach a consensus of a large panel of 51 experts: emergency physicians, geriatricians, infectious disease specialists, and ethical consultants. A preliminary list of eligible criteria was compiled based on a literature review. Four rounds of anonymized expert consultations were performed. The experts were asked to score each item as relevant, possibly relevant and non-relevant, as major or minor, and to choose the cut-off. They were also able make suggestions and remarks. Eight criteria constituting the HOME-CoV were selected: six correspond to the severity of clinical signs, one to the clinical course (clinically significant worsening within the last 24 h), and the last corresponds to the association of a severe comorbidity and an inadequate living context. Hospitalization is deemed necessary if a patient meets one or more of the criteria. In the end, 94.4% of the experts agreed with the defined rule. Thanks to the Delphi method, an absolute consensus was obtained of a large panel of experts on the HOME-CoV rule, a decision-making support mechanism for clinicians to target patients with suspected or confirmed COVID-19 requiring hospitalization.Trial registration: NCT04338841.

Is the term "anti-anaerobic" still relevant?

For decades, the term "anti-anaerobic" has been commonly used to refer to antibiotics exhibiting activity against anaerobic bacteria, also designated as anaerobes. This term is used in various situations ranging from infections associated with well-identified pathogens like Clostridioides difficile, or Fusobacterium necrophorum in Lemierre's syndrome, that require specific antibiotic treatments to polymicrobial infections generally resulting from the decreased permeability of anatomical barriers (e.g., intestinal translocation and stercoral peritonitis) or infectious secondary localizations (e.g., brain abscess and infectious pleurisy). In these cases, the causal bacteria generally remain unidentified and the antimicrobial treatment is empirical. However, major progress in the knowledge of human bacterial microbiotas in the last 10 years has shown how diverse are the species involved in these communities. Here, we sought to reappraise the concept of anti-anaerobic spectrum in the light of recent advances in the microbiota field. We first highlight that the term anaerobic itself does not represent the tremendous diversity of the bacteria it spans, and then we stress that the antibiotic susceptibility profiles for most anaerobic bacteria remain unaddressed. Furthermore, we provide examples challenging the relevance of the "anti-anaerobic" spectrum from a clinical and ecological perspective.

Metapopulation ecology links antibiotic resistance, consumption, and patient transfers in a network of hospital wards

Antimicrobial resistance (AMR) is a global threat. A better understanding of how antibiotic use and between-ward patient transfers (or connectivity) impact population-level AMR in hospital networks can help optimize antibiotic stewardship and infection control strategies. Here, we used a metapopulation framework to explain variations in the incidence of infections caused by seven major bacterial species and their drug-resistant variants in a network of 357 hospital wards. We found that ward-level antibiotic consumption volume had a stronger influence on the incidence of the more resistant pathogens, while connectivity had the most influence on hospital-endemic species and carbapenem-resistant pathogens. Piperacillin-tazobactam consumption was the strongest predictor of the cumulative incidence of infections resistant to empirical sepsis therapy. Our data provide evidence that both antibiotic use and connectivity measurably influence hospital AMR. Finally, we provide a ranking of key antibiotics by their estimated population-level impact on AMR that might help inform antimicrobial stewardship strategies.

A Retrospective Study on Amoxicillin Susceptibility in Severe Haemophilus influenzae Pneumonia

Introduction

Treatment of Haemophilus influenzae (Hi) pneumonia is on concern because resistance to amoxicillin is largely diffused. This study describes the evolution of resistance to amoxicillin and amoxicillin/clavulanic acid (AMC) in Hi isolates and characteristics of patients with Hi severe pneumonia.

Methods

A monocentric retrospective observational study including patients from 2008 to 2017 with severe pneumonia hospitalized in ICU. Evolution of amoxicillin and AMC susceptibility was showed. Characteristics of patients with Hi pneumonia were compared to characteristics of patients with Streptococcus pneumoniae (Sp) pneumonia, as reference. Risk factors for amoxicillin resistance in Hi were investigated.

Results

Overall, 113 patients with Hi and 132 with Sp pneumonia were included. The percentages of AMC resistance among Hi strains decreased over the years (from 10% in 2008-2009 to 0% in 2016-2017) while resistance to amoxicillin remained stable at 20%. Also, percentages of Sp resistant strains for amoxicillin decreased over years (from 25% to 3%). Patients with Hi pneumonia experienced higher prevalence of bronchitis (18% vs. 8%, p=0.02, chronic obstructive pulmonary disease (43% vs. 30% p=0.03), HAP (18% vs. 7%, p=0.01, ventilator-associated pneumonia (27% vs. 17%, p=0.04, and longer duration of mechanical ventilation (8 days vs. 6 days, p=0.04) than patients with Sp pneumonia. Patients with Sp pneumonia had more frequently local complications than patients with Hi pneumonia (17% vs. 7%, p=0.03). De-escalation of antibiotics was more frequent in patients with Sp than in patients with Hi (67% vs. 53%, p=0.03). No risk factors were associated with amoxicillin resistance among patients with Hi pneumonia.

Conclusions

Amoxicillin resistance was stable over time, but no risk factors were detected. AMC resistance was extremely low, suggesting that AMC could be used for empiric treatment of Hi pneumonia, as well as other molecules, namely, cephalosporins. Patients with Hi pneumonia had more pulmonary comorbidities and severe diseases than patients with Sp pneumonia.

Clinical impact of rapid susceptibility testing on MHR-SIR directly from blood cultures

BACKGROUND

In a previous study, we demonstrated that rapid antibiotic susceptibility tests (ASTs) can be performed directly on blood culture samples tested on Mueller-Hinton Rapid agar (MHR-SIR) with a time delay of 6-8 h.

OBJECTIVES

Using this rapid disc diffusion method, we analysed the clinical impact associated with rapid reporting of results in our hospital setting.

METHODS

All patients with bloodstream infections (BSIs) related to Enterobacteriaceae or Staphylococcus aureus were prospectively included in the study. The rapid ASTs were performed by incubation of positive blood cultures on MHR-SIR for 6-8 h by direct inoculation according to BSAC recommendations.

RESULTS

One hundred and sixty-seven patients with BSIs were included as MHR-guided adaptation therapy cases. Eighty percent had Enterobacteriaceae-related BSIs, of which 12 (9%) were ESBL producers and 20% were S. aureus-related BSIs. A urinary or intra-abdominal infection was observed in 44.3% and 19.8%, respectively, of Enterobacteriaceae-related infections. The most frequent sources of infections for S. aureus BSIs were cutaneous and endovascular, in 43% and 23% of cases, respectively. Forty-four percent of the patients benefited from therapeutic modification according to the results of the MHR-SIR AST. Thus, empirical antibiotic therapy was modified by using antibiotic therapy that had too wide a spectrum or was unsuitable in 26% and 18% of cases, respectively. Compared with the 24 h required for the reference method, the median length of time to provision of susceptibility test results by MHR-SIR was 7 h.

CONCLUSIONS

This study showed a significant time saving (17 h) on the appropriateness of antibiotic prescription and demonstrated a significant impact regarding the choice and reduction of the spectrum of antibiotic therapy.