Invasive Aspergillosis in Liver Transplant Recipients in The Current Era

Invasive aspergillosis (IA) is a rare but fatal disease among liver transplant recipients (LiTRs). We performed a multi-center 1:2 case-control study comparing LiTRs diagnosed with proven/probable IA and controls with no invasive fungal infection. We included 62 IA cases and 124 matched controls. Disseminated infection occurred only in eight cases (13%). 12-week all-cause mortality of IA was 37%. In multivariate analyses, systemic antibiotics usage (adjusted odds ratio [aOR], 4.74; p=0.03) and history of pneumonia (aOR, 48.7; p=0.01) were identified as independent risk factors associated with the occurrence of IA. Moreover, reoperation (aOR, 5.99; p=0.01), systemic antibiotics usage (aOR, 5.03; p=0.04), and anti-mold prophylaxis (aOR, 11.9; p=0.02) were identified as independent risk factors associated with the occurrence of early IA. Among IA cases, Aspergillus colonization (adjusted hazard ration [aHR], 86.9; p<0.001), ICU stay (aHR, 3.67; p=0.02), disseminated IA (aHR, 8.98; p<0.001), and dialysis (aHR, 2.93; p=0.001) were identified as independent risk factors associated with 12-week all-cause mortality; while recent receipt of tacrolimus (aHR, 0.11; p=0.001) was protective. Mortality among LiTRs with IA remains high in the current era. The identified risk factors and protective factors may be useful for establishing robust targeted anti-mold prophylactic and appropriate treatment strategies against IA.

A Randomized, Double-Blind, Phase 3 Safety and Efficacy Study of Ridinilazole Versus Vancomycin for Treatment of Clostridioides difficile Infection: Clinical Outcomes With Microbiome and Metabolome Correlates of Response

BACKGROUND

Exposure to antibiotics predisposes to dysbiosis and Clostridioides difficile infection (CDI) that can be severe, recurrent (rCDI), and life-threatening. Nonselective drugs that treat CDI and perpetuate dysbiosis are associated with rCDI, in part due to loss of microbiome-derived secondary bile acid (SBA) production. Ridinilazole is a highly selective drug designed to treat CDI and prevent rCDI.

METHODS

In this phase 3 superiority trial, adults with CDI, confirmed with a stool toxin test, were randomized to receive 10 days of ridinilazole (200 mg twice daily) or vancomycin (125 mg 4 times daily). The primary endpoint was sustained clinical response (SCR), defined as clinical response and no rCDI through 30 days after end of treatment. Secondary endpoints included rCDI and change in relative abundance of SBAs.

RESULTS

Ridinilazole and vancomycin achieved an SCR rate of 73% versus 70.7%, respectively, a treatment difference of 2.2% (95% CI: -4.2%, 8.6%). Ridinilazole resulted in a 53% reduction in recurrence compared with vancomycin (8.1% vs 17.3%; 95% CI: -14.1%, -4.5%; P = .0002). Subgroup analyses revealed consistent ridinilazole benefit for reduction in rCDI across subgroups. Ridinilazole preserved microbiota diversity, increased SBAs, and did not increase the resistome. Conversely, vancomycin worsened CDI-associated dysbiosis, decreased SBAs, increased Proteobacteria abundance (∼3.5-fold), and increased the resistome.

CONCLUSIONS

Although ridinilazole did not meet superiority in SCR, ridinilazole greatly reduced rCDI and preserved microbiome diversity and SBAs compared with vancomycin. These findings suggest that treatment of CDI with ridinilazole results in an earlier recovery of gut microbiome health. Clinical Trials Registration.Ri-CoDIFy 1 and 2: NCT03595553 and NCT03595566.

Slaying the "Troll of Transplantation"-new frontiers in cytomegalovirus management: A report from the CMV International Symposium 2023

The 2023 International CMV Symposium took place in Barcelona in May 2023. During the 2-day meeting, delegates and faculty discussed the ongoing challenge of managing the risk of cytomegalovirus infection (the Troll of Transplantation) after solid organ or hematopoietic cell transplantation. Opportunities to improve outcomes of transplant recipients by applying advances in antiviral prophylaxis or pre-emptive therapy, immunotherapy, and monitoring of cell-mediated immunity to routine clinical practice were debated and relevant educational clinical cases presented. This review summarizes the presentations, cases, and discussions from the meeting and describes how further advances are needed before the Troll of Transplantation is slain.

Phenotypic and Molecular Characterization of an Enterobacter ludwigii Clinical Isolate Carrying a Plasmid-Mediated blaIMI-6 Gene

We report a plasmid-encoded IMI-6 carbapenemase in a clinical isolate of Enterobacter ludwigii from Spain. The isolate belongs to ST641 and was susceptible to expanded-spectrum cephalosporins and resistant to carbapenems. The modified carbapenem inactivation method (mCIM) test was positive, but β-Carba was negative. Whole-genome sequencing identified the blaIMI-6 gene located in a conjugative IncFIIY plasmid and associated with the LysR-like regulator imiR. Both genes were bracketed by an ISEclI-like insertion sequence and a putatively defective ISEc36 insertion sequence. IMPORTANCE IMI carbapenemases confer an unusual resistance pattern of susceptibility to broad-spectrum cephalosporins and piperacillin-tazobactam but decreased susceptibility to carbapenems, which may make them difficult to detect in routine practice. Commercially available molecular methods for the detection of carbapenemases in clinical laboratories do not usually include blaIMI genes, which could contribute to the hidden dissemination of bacteria producing these enzymes. Techniques should be implemented to detect minor carbapenemases that are not very frequent in our environment and control their dissemination.

Real-life use of cefiderocol for salvage therapy of severe infections due to carbapenem-resistant Gram-negative bacteria

Treatment of infections caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) is challenging and new active antibiotics are urgently needed. This study describes the efficacy and safety of cefiderocol in a retrospective series of 13 patients with severe CR-GNB infection and limited treatment options. Pseudomonas aeruginosa was the predominant CR-GNB (n=8) followed by Burkholderia cepacia (n=3), Sthenotrophomona maltophilia (n=1) and KPC-producing Klebsiella pneumoniae (n=1). The source of infection was nosocomial pneumonia in 92.3% of cases (12/13), of which 11 cases were ventilator-associated pneumonia (VAP). Five patients were lung transplant recipients (38.5%). The median duration of treatment was 10 days (range, 6-21 days). No severe adverse effects required reducing the dose or interrupting the treatment. Clinical and microbiological cure was assessed 7 days after the end of treatment and achieved in 84.6% (11/13) of the patients. Crude mortality at day 28 was observed in 23.1% (3/13) of the cases. Cefiderocol is a valid alternative for the treatment of susceptible CR-GNB infections in patients with limited therapeutic options.

Cytomegalovirus in the transplant setting: Where are we now and what happens next? A report from the International CMV Symposium 2021

The CMV Symposium in September 2021 was an international conference dedicated to cytomegalovirus (CMV) infection after solid organ or hematopoietic stem cell transplantation. This review provides an overview of the presentations given by the expert faculty, supplemented with educational clinical cases. Topics discussed include CMV epidemiology and diagnosis, the burden of CMV infection and disease, CMV-specific immunity and management of CMV in transplant settings. Major advances in the prevention and treatment of CMV in the past decade and increased understanding of CMV immunity have led to improved patient outcomes. In the future, management algorithms may be individualized based on the transplant recipient's immune profile, which will mark the start of a new era for patients with CMV.

Community-acquired bacteremia by Klebsiella pneumoniae producing KPC-3 and resistant to ceftazidime/avibactam

OBJECTIVES

To describe the clinical and microbiological features of a case of community-acquired infection by KPC-producing K. pneumoniae (KPCKP) resistant to ceftazidime/avibactam (CAZ-AVI).

METHODS

Identification of microorganisms was performed with MALDI Biotyper CA System (BrukerDaltonics, Madrid, Spain). Antimicrobial susceptibility testing was performed using Sensitre EURGNCOL panels (Thermo Fisher Scientific, Madrid, Spain) and gradient strips (Etest, bioMérieux, Madrid, Spain) in the case of CAZ-AVI, using EUCAST breakpoints for interpretation. Whole Genome Sequencing of blood culture and rectal swab isolates was performed using the Illumina NovaSeq 6000 sequencing system, with 2 × 150-bp paired-end reads (Illumina Inc).

RESULTS

Blood culture and rectal swab KPCKP isolates were resistant to carbapenems and to CAZ-AVI. The blood culture isolate showed susceptibility to trimethoprim-sulfamethoxazole (TMP-SMX) but the rectal swab culture isolate was resistant to this antibiotic. Both isolates belonged to clonal lineage ST512, harboured a single copy of bla_KPC-3 gene, and showed 16 Single Nucleotide Polymorphism (SNP) between them and 38 SNPs with regards to the first KPC-3 producing K. pneumoniae isolated in our hospital in an initial outbreak in 2012. Genome-wide resistome analysis revealed the presence of a IncFIB(K) plasmid harbouring sul1 and dfrA12 genes only in the rectal swab culture isolate, which may explain its resistance to TMP-SMX.

CONCLUSIONS

Resistance to ceftazidime-avibactam is an emerging nosocomial problem. This case shows that CAZ-AVI-resistant KPCKP strains may disseminate into the community and cause serious infections.

Extended-spectrum β-lactamase-producing and carbapenem-resistant Enterobacterales bloodstream infection after solid organ transplantation: Recent trends in epidemiology and therapeutic approaches

Background

Infections caused by multidrug‐resistant gram‐negative bacilli (MDR GNB), in particular extended‐spectrum β‐lactamase‐producing (ESBL‐E) and carbapenem‐resistant Enterobacterales (CRE), pose a major threat in solid organ transplantation (SOT). Outcome prediction and therapy are challenging due to the scarcity of randomized clinical trials (RCTs) or well‐designed observational studies focused on this population.

Methods

Narrative review with a focus on the contributions provided by the ongoing multinational INCREMENT‐SOT consortium (ClinicalTrials identifier NCT02852902) in the fields of epidemiology and clinical management.

Results

The Spanish Society of Transplantation (SET), the Group for Study of Infection in Transplantation of the Spanish Society of Infectious Diseases and Clinical Microbiology (GESITRA‐SEIMC), and the Spanish Network for Research in Infectious Diseases (REIPI) recently published their recommendations for the management of MDR GNB infections in SOT recipients. We revisit the SET/GESITRA‐SEIMC/REIPI document taking into consideration new evidence that emerged on the molecular epidemiology, prognostic stratification, and treatment of post‐transplant ESBL‐E and CRE infections. Results derived from the INCREMENT‐SOT consortium may support the therapeutic approach to post‐transplant bloodstream infection (BSI). The initiatives devoted to sparing the use of carbapenems in low‐risk ESBL‐E BSI or to repurposing existing non‐β‐lactam antibiotics for CRE in both non‐transplant and transplant patients are reviewed, as well as the eventual positioning in the specific SOT setting of recently approved antibiotics.

Conclusion

Due to the clinical complexity and relative rarity of ESBL‐E and CRE infections in SOT recipients, multinational cooperative efforts such as the INCREMENT‐SOT Project should be encouraged. In addition, RCTs focused on post‐transplant serious infection remain urgently needed.

Randomised, double-blind, placebo-controlled, phase 2, superiority trial to demonstrate the effectiveness of faecal microbiota transplantation for selective intestinal decolonisation of patients colonised by carbapenemase-producing Klebsiella pneumoniae (KAPEDIS)

INTRODUCTION

Infections caused by carbapenemase-producing Enterobacterales are frequent and associated with high rates of mortality. Intestinal carriers are at increased risk of infection by these microorganisms. Decolonisation strategies with antibiotics have not obtained conclusive results. Faecal microbiota transplantation (FMT) could be an effective and safe strategy to decolonise intestinal carriers of KPC-producing Klebsiella pneumoniae (KPC-Kp) but this hypothesis needs evaluation in appropriate clinical trials.

METHODS AND ANALYSIS

The KAPEDIS trial is a single-centre, randomised, double-blind, placebo-controlled, phase 2, superiority clinical trial of FMT for eradication of intestinal colonisation by KPC-Kp. One hundred and twenty patients with rectal colonisation by KPC-Kp will be randomised 1:1 to receive encapsulated lyophilised FMT or placebo. The primary outcome is KPC-Kp eradication at 30 days. Secondary outcomes are: (1) frequency of adverse events; (2) changes in KPC-Kp relative load within the intestinal microbiota at 7, 30 and 90 days, estimated by real-time quantitative PCR analysis of rectal swab samples and (3) rates of persistent eradication, KPC-Kp infection and crude mortality at 90 days. Participants will be monitored for adverse effects throughout the intervention.

ETHICS AND DISSEMINATION

Ethical approval was obtained from Reina Sofía University Hospital Institutional Review Board (approval reference number: 2019-003808-13). Trial results will be published in peer-reviewed journals and disseminated at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT04760665.

Impact of COVID-19 on Global Kidney Transplantation Service Delivery: Interim Report

This article gives a personal, historical, account of the impact of the COVID-19 pandemic on transplantation services. The content is based on discussions held at two webinars in November 2020, at which kidney transplantation experts from prestigious institutions in Europe and the United States reflected on how the pandemic affected working practices. The group discussed adaptations to clinical care (i.e., ceasing, maintaining and re-starting kidney transplantations, and cytomegalovirus infection management) across the early course of the pandemic. Discussants were re-contacted in October 2021 and asked to comment on how transplantation services had evolved, given the widespread access to COVID-19 testing and the roll-out of vaccination and booster programs. By October 2021, near-normal life and service delivery was resuming, despite substantial ongoing cases of COVID-19 infection. However, transplant recipients remained at heightened risk of COVID-19 infection despite vaccination, given their limited response to mRNA vaccines and booster dosing: further risk-reduction strategies required exploration. This article provides a contemporaneous account of these different phases of the pandemic from the transplant clinician’s perspective, and provides constructive suggestions for clinical practice and research.

Factors associated with recruitment success in the phase 2a study of aztreonam-avibactam development programme: a descriptive qualitative analysis among sites in Spain

OBJECTIVE

Successful clinical trials are subject to recruitment. Recently, the REJUVENATE trial, a prospective phase 2a open-label, single-arm interventional clinical trial conducted within the Innovative Medicines Initiative-supported Combatting Bacterial Resistance in Europe-Carbapenem Resistance project, was published, with 85% of the recruitment performed in Spain. We analysed the recruitment success in this trial by establishing a model of recruitment practice.

METHODS

A descriptive qualitative study was performed from May 2016 to October 2017 at 10 participating Spanish centres. Data were extracted from: (1) feasibility questionnaires to assess the centre's potential for patient enrolment; (2) delegation of responsibility records; (3) pre-screening records including an anonymised list of potentially eligible and (4) screening and enrolment records. A descriptive analysis of the features was performed by the participating centre. Pearson's and Spearman's correlation coefficients were calculated to determine factors of recruitment success.

RESULTS

The highest recruitment rate was observed in Hospitals 3 and 6 (58.8 and 47.0 patients per month, respectively). All the study teams were multidisciplinary with a median of 15 members (range: 7-22). Only Hospitals 3, 5 and 6 had dedicated nursing staff appointed exclusively to this study. Moreover, in those three hospitals and in Hospital 9, the study coordinator performed exclusive functions as a research planner, and did not assume these functions for the other hospitals. The univariate analysis showed a significant association between recruitment success and months of recruitment (p=0.024), number of staff (p<0.001), higher number of pharmacists (p=0.005), infectious disease specialists (p<0.001), the presence of microbiologist in the research team (p=0.018) and specifically dedicated nursing staff (p=0.036).

CONCLUSIONS

The existence of broad multidisciplinary teams with staff dedicated exclusively to the study as well as the implementation of a well-designed local patient assessment strategy were the essential optimisation factors for recruitment success in Spain.

TRIAL REGISTRATION NUMBER

NCT02655419; EudraCT 2015-002726-39; analysis of pre-screened patients.

In vivo selection of KPC-94 and KPC-95 in Klebsiella pneumoniae isolates from patients treated with ceftazidime-avibactam

BACKGROUND

Ceftazidime-avibactam (CZA) is used to treat infections caused by KPC-producing Klebsiella pneumoniae (KPC-Kp). Resistance to CZA is commonly related to point mutations in the bla_KPC gene.

OBJECTIVES

We describe the in vivo emergence of CZA resistance in clinical isolates of KPC-Kp from four patients treated with this combination therapy.

METHODS

Four pre-therapy and five post-therapy isolates were examined. Antibiogram (microdilution; gradient strips) and whole genome sequencing were performed. The role of KPC mutations was validated by cloning bla_KPC genes into competent E. coli.

RESULTS

All isolates recovered before treatment with CZA were susceptible to CZA and produced KPC-3. Five KPC-Kp isolates recovered after treatment were resistant to this combination. Three post-therapy isolates from two patients produced KPC-31 (D179Y mutation). Additionally, we identified the novel substitution LN169-170H (KPC-94) in one isolate and the combination in another isolate of two independently described mutations, D179Y and A172T (KPC-95). All KPC-producing K. pneumoniae isolates belonged to ST512. All CZA-resistant isolates with bla_KPC variants had restoration of carbapenem susceptibility.

CONCLUSIONS

Resistance to CZA was related to bla_KPC mutations, including the new KPC-94 and KPC-95 alleles, which did not cause carbapenem resistance.

Association Between Administration of IL-6 Antagonists and Mortality Among Patients Hospitalized for COVID-19: A Meta-analysis

Importance

Clinical trials assessing the efficacy of IL-6 antagonists in patients hospitalized for COVID-19 have variously reported benefit, no effect, and harm.

Objective

To estimate the association between administration of IL-6 antagonists compared with usual care or placebo and 28-day all-cause mortality and other outcomes.

Data Sources

Trials were identified through systematic searches of electronic databases between October 2020 and January 2021. Searches were not restricted by trial status or language. Additional trials were identified through contact with experts.

Study Selection

Eligible trials randomly assigned patients hospitalized for COVID-19 to a group in whom IL-6 antagonists were administered and to a group in whom neither IL-6 antagonists nor any other immunomodulators except corticosteroids were administered. Among 72 potentially eligible trials, 27 (37.5%) met study selection criteria.

Data Extraction and Synthesis

In this prospective meta-analysis, risk of bias was assessed using the Cochrane Risk of Bias Assessment Tool. Inconsistency among trial results was assessed using the I2 statistic. The primary analysis was an inverse variance-weighted fixed-effects meta-analysis of odds ratios (ORs) for 28-day all-cause mortality.

Main Outcomes and Measures

The primary outcome measure was all-cause mortality at 28 days after randomization. There were 9 secondary outcomes including progression to invasive mechanical ventilation or death and risk of secondary infection by 28 days.

Results

A total of 10 930 patients (median age, 61 years [range of medians, 52-68 years]; 3560 [33%] were women) participating in 27 trials were included. By 28 days, there were 1407 deaths among 6449 patients randomized to IL-6 antagonists and 1158 deaths among 4481 patients randomized to usual care or placebo (summary OR, 0.86 [95% CI, 0.79-0.95]; P = .003 based on a fixed-effects meta-analysis). This corresponds to an absolute mortality risk of 22% for IL-6 antagonists compared with an assumed mortality risk of 25% for usual care or placebo. The corresponding summary ORs were 0.83 (95% CI, 0.74-0.92; P < .001) for tocilizumab and 1.08 (95% CI, 0.86-1.36; P = .52) for sarilumab. The summary ORs for the association with mortality compared with usual care or placebo in those receiving corticosteroids were 0.77 (95% CI, 0.68-0.87) for tocilizumab and 0.92 (95% CI, 0.61-1.38) for sarilumab. The ORs for the association with progression to invasive mechanical ventilation or death, compared with usual care or placebo, were 0.77 (95% CI, 0.70-0.85) for all IL-6 antagonists, 0.74 (95% CI, 0.66-0.82) for tocilizumab, and 1.00 (95% CI, 0.74-1.34) for sarilumab. Secondary infections by 28 days occurred in 21.9% of patients treated with IL-6 antagonists vs 17.6% of patients treated with usual care or placebo (OR accounting for trial sample sizes, 0.99; 95% CI, 0.85-1.16).

Conclusions and Relevance

In this prospective meta-analysis of clinical trials of patients hospitalized for COVID-19, administration of IL-6 antagonists, compared with usual care or placebo, was associated with lower 28-day all-cause mortality.

Trial Registration

PROSPERO Identifier: CRD42021230155.

Pharmacokinetics and safety of aztreonam/avibactam for the treatment of complicated intra-abdominal infections in hospitalized adults: results from the REJUVENATE study

Objectives

To investigate pharmacokinetics (PK) and safety (primary objectives) and efficacy (secondary objective) of the investigational monobactam/β-lactamase inhibitor combination aztreonam/avibactam in patients with complicated intra-abdominal infection (cIAI).

Methods

This Phase 2a open-label, multicentre study (NCT02655419; EudraCT 2015-002726-39) enrolled adults with cIAI into sequential cohorts for 5–14 days treatment. Cohort 1 patients received an aztreonam/avibactam loading dose of 500/137 mg (30 min infusion), followed by maintenance doses of 1500/410 mg (3 h infusions) q6h; Cohort 2 received 500/167 mg (30 min infusion), followed by 1500/500 mg (3 h infusions) q6h. Cohort 3 was an extension of exposure at the higher dose regimen. Doses were adjusted for creatinine clearance of 31–50 mL/min (Cohorts 2 + 3). All patients received IV metronidazole 500 mg q8h. PK, safety and efficacy were assessed.

Results

Thirty-four patients (Cohort 1, n = 16; Cohorts 2 + 3, n = 18) comprised the modified ITT (MITT) population. Mean exposures of aztreonam and avibactam in Cohorts 2 + 3 were consistent with those predicted to achieve joint PK/pharmacodynamic target attainment in >90% patients. Adverse events (AEs) were similar between cohorts. The most common AEs were hepatic enzyme increases [n = 9 (26.5%)] and diarrhoea [n = 5 (14.7%)]. Clinical cure rates at the test-of-cure visit overall were 20/34 (58.8%) (MITT) and 14/23 (60.9%) (microbiological-MITT population).

Conclusions

Observed AEs were consistent with the known safety profile of aztreonam monotherapy, with no new safety concerns identified. These data support selection of the aztreonam/avibactam 500/167 mg (30 min infusion) loading dose and 1500/500 mg (3 h infusions) maintenance dose q6h regimen, in patients with creatinine clearance >50 mL/min, for the Phase 3 development programme.

Invasive aspergillosis in solid organ transplantation: Diagnostic challenges and differences in outcome in a Spanish national cohort (Diaspersot study)

BACKGROUND

The diagnosis of invasive aspergillosis (IA) can be problematic in solid organ transplantation (SOT). The prognosis greatly varies according to the type of transplant, and the impact of prophylaxis is not well defined.

PATIENTS AND METHODS

The Diaspersot cohort analyses the impact of IA in SOT in Spain during the last 10 years. Proven and probable/putative IA was included.

RESULTS

We analysed 126 cases of IA. The incidences of IA were as follows: 6.5%, 2.9%, 1.8% and 0.6% for lung, heart, liver and kidney transplantation, respectively. EORTC/MSG criteria confirmed only 49.7% of episodes. Tree-in-bud sign or ground-glass infiltrates were present in 56.3% of patients, while serum galactomannan (optical density index >0.5) was positive in 50.6%. A total of 41.3% received combined antifungal therapy. Overall mortality at 3 months was significantly lower (p < 0.001) in lung transplant recipients (14.8%) than in all other transplants [globally: 48.6%; kidney 52.0%, liver 58.3%, heart 31.2%, and combined 42.9%]. Fifty-four percent of episodes occurred despite the receipt of antifungal prophylaxis, and in 10%, IA occurred during prophylaxis (breakthrough infection), with both nebulised amphotericin (in lung transplant recipients) and candins (in the rest).

CONCLUSIONS

Invasive aspergillosis diagnostic criteria, applied to SOT patients, may differ from those established for haematological patients. IA in lung transplants has a higher incidence, but is associated with a better prognosis than other transplants. Combination therapy is frequently used for IA in SOT. Prophylactic measures require optimisation of its use within this population.

Incidence and predictive biomarkers of Clostridioides difficile infection in hospitalized patients receiving broad-spectrum antibiotics

Trial enrichment using gut microbiota derived biomarkers by high-risk individuals can improve the feasibility of randomized controlled trials for prevention of Clostridioides difficile infection (CDI). Here, we report in a prospective observational cohort study the incidence of CDI and assess potential clinical characteristics and biomarkers to predict CDI in 1,007 patients ≥ 50 years receiving newly initiated antibiotic treatment with penicillins plus a beta-lactamase inhibitor, 3rd/4th generation cephalosporins, carbapenems, fluoroquinolones or clindamycin from 34 European hospitals. The estimated 90-day cumulative incidences of a first CDI episode is 1.9% (95% CI 1.1-3.0). Carbapenem treatment (Hazard Ratio (95% CI): 5.3 (1.7-16.6)), toxigenic C. difficile rectal carriage (10.3 (3.2-33.1)), high intestinal abundance of Enterococcus spp. relative to Ruminococcus spp. (5.4 (2.1-18.7)), and low Shannon alpha diversity index as determined by 16 S rRNA gene profiling (9.7 (3.2-29.7)), but not normalized urinary 3-indoxyl sulfate levels, predicts an increased CDI risk.

Efficacy and safety of cefiderocol or best available therapy for the treatment of serious infections caused by carbapenem-resistant Gram-negative bacteria (CREDIBLE-CR): a randomised, open-label, multicentre, pathogen-focused, descriptive, phase 3 trial

BACKGROUND

New antibiotics are needed for the treatment of patients with life-threatening carbapenem-resistant Gram-negative infections. We assessed the efficacy and safety of cefiderocol versus best available therapy in adults with serious carbapenem-resistant Gram-negative infections.

METHODS

We did a randomised, open-label, multicentre, parallel-group, pathogen-focused, descriptive, phase 3 study in 95 hospitals in 16 countries in North America, South America, Europe, and Asia. We enrolled patients aged 18 years or older admitted to hospital with nosocomial pneumonia, bloodstream infections or sepsis, or complicated urinary tract infections (UTI), and evidence of a carbapenem-resistant Gram-negative pathogen. Participants were randomly assigned (2:1 by interactive web or voice response system) to receive either a 3-h intravenous infusion of cefiderocol 2 g every 8 h or best available therapy (pre-specified by the investigator before randomisation and comprised of a maximum of three drugs) for 7-14 days. For patients with pneumonia or bloodstream infection or sepsis, cefiderocol treatment could be combined with one adjunctive antibiotic (excluding polymyxins, cephalosporins, and carbapenems). The primary endpoint for patients with nosocomial pneumonia or bloodstream infection or sepsis was clinical cure at test of cure (7 days [plus or minus 2] after the end of treatment) in the carbapenem-resistant microbiological intention-to-treat population (ITT; ie, patients with a confirmed carbapenem-resistant Gram-negative pathogen receiving at least one dose of study drug). For patients with complicated UTI, the primary endpoint was microbiological eradication at test of cure in the carbapenem-resistant microbiological ITT population. Safety was evaluated in the safety population, consisting of all patients who received at least one dose of study drug. Mortality was reported through to the end of study visit (28 days [plus or minus 3] after the end of treatment). Summary statistics, including within-arm 95% CIs calculated using the Clopper-Pearson method, were collected for the primary and safety endpoints. This trial is registered with ClinicalTrials.gov (NCT02714595) and EudraCT (2015-004703-23).

FINDINGS

Between Sept 7, 2016, and April 22, 2019, we randomly assigned 152 patients to treatment, 101 to cefiderocol, 51 to best available therapy. 150 patients received treatment: 101 cefiderocol (85 [85%] received monotherapy) and 49 best available therapy (30 [61%] received combination therapy). In 118 patients in the carbapenem-resistant microbiological ITT population, the most frequent carbapenem-resistant pathogens were Acinetobacter baumannii (in 54 patients [46%]), Klebsiella pneumoniae (in 39 patients [33%]), and Pseudomonas aeruginosa (in 22 patients [19%]). In the same population, for patients with nosocomial pneumonia, clinical cure was achieved by 20 (50%, 95% CI 33·8-66·2) of 40 patients in the cefiderocol group and ten (53%, 28·9-75·6) of 19 patients in the best available therapy group; for patients with bloodstream infection or sepsis, clinical cure was achieved by ten (43%, 23·2-65·5) of 23 patients in the cefiderocol group and six (43%, 17·7-71·1) of 14 patients in the best available therapy group. For patients with complicated UTIs, microbiological eradication was achieved by nine (53%, 27·8-77·0) of 17 patients in the cefiderocol group and one (20%, 0·5-71·6) of five patients in the best available therapy group. In the safety population, treatment-emergent adverse events were noted for 91% (92 patients of 101) of the cefiderocol group and 96% (47 patients of 49) of the best available therapy group. 34 (34%) of 101 patients receiving cefiderocol and nine (18%) of 49 patients receiving best available therapy died by the end of the study; one of these deaths (in the best available therapy group) was considered to be related to the study drug.

INTERPRETATION

Cefiderocol had similar clinical and microbiological efficacy to best available therapy in this heterogeneous patient population with infections caused by carbapenem-resistant Gram-negative bacteria. Numerically more deaths occurred in the cefiderocol group, primarily in the patient subset with Acinetobacter spp infections. Collectively, the findings from this study support cefiderocol as an option for the treatment of carbapenem-resistant infections in patients with limited treatment options.

FUNDING

Shionogi.

Efficacy of β-lactam/β-lactamase inhibitors to treat extended-spectrum beta-lactamase-producing Enterobacterales bacteremia secondary to urinary tract infection in kidney transplant recipients (INCREMENT-SOT Project)

BACKGROUND

Whether active therapy with β-lactam/β-lactamase inhibitors (BLBLI) is as affective as carbapenems for extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) bloodstream infection (BSI) secondary to urinary tract infection (UTI) in kidney transplant recipients (KTRs) remains unclear.

METHODS

We retrospectively evaluated 306 KTR admitted to 30 centers from January 2014 to October 2016. Therapeutic failure (lack of cure or clinical improvement and/or death from any cause) at days 7 and 30 from ESBL-E BSI onset was the primary and secondary study outcomes, respectively.

RESULTS

Therapeutic failure at days 7 and 30 occurred in 8.2% (25/306) and 13.4% (41/306) of patients. Hospital-acquired BSI (adjusted OR [aOR]: 4.10; 95% confidence interval [CI]: 1.50-11.20) and Pitt score (aOR: 1.47; 95% CI: 1.21-1.77) were independently associated with therapeutic failure at day 7. Age-adjusted Charlson Index (aOR: 1.25; 95% CI: 1.05-1.48), Pitt score (aOR: 1.72; 95% CI: 1.35-2.17), and lymphocyte count ≤500 cells/μL at presentation (aOR: 3.16; 95% CI: 1.42-7.06) predicted therapeutic failure at day 30. Carbapenem monotherapy (68.6%, primarily meropenem) was the most frequent active therapy, followed by BLBLI monotherapy (10.8%, mostly piperacillin-tazobactam). Propensity score (PS)-adjusted models revealed no significant impact of the choice of active therapy (carbapenem-containing vs any other regimen, BLBLI- vs carbapenem-based monotherapy) within the first 72 hours on any of the study outcomes.

CONCLUSIONS

Our data suggest that active therapy based on BLBLI may be as effective as carbapenem-containing regimens for ESBL-E BSI secondary to UTI in the specific population of KTR. Potential residual confounding and unpowered sample size cannot be excluded (ClinicalTrials.gov identifier: NCT02852902).

Invasive Fusariosis in Nonneutropenic Patients, Spain, 2000-2015

Invasive fusariosis (IF) is associated with severe neutropenia in patients with concurrent hematologic conditions. We conducted a retrospective observational study to characterize the epidemiology of IF in 18 Spanish hospitals during 2000-2015. In that time, the frequency of IF in nonneutropenic patients increased from 0.08 cases per 100,000 admissions in 2000-2009 to 0.22 cases per 100,000 admissions in 2010-2015. Nonneutropenic IF patients often had nonhematologic conditions, such as chronic cardiac or lung disease, rheumatoid arthritis, history of solid organ transplantation, or localized fusariosis. The 90-day death rate among nonneutropenic patients (28.6%) and patients with resolved neutropenia (38.1%) was similar. However, the death rate among patients with persistent neutropenia (91.3%) was significantly higher. We used a multivariate Cox regression analysis to characterize risk factors for death: persistent neutropenia was the only risk factor for death, regardless of antifungal therapy.

Efficacy and safety of early treatment with sarilumab in hospitalised adults with COVID-19 presenting cytokine release syndrome (SARICOR STUDY): protocol of a phase II, open-label, randomised, multicentre, controlled clinical trial

INTRODUCTION

About 25% of patients with COVID-19 develop acute respiratory distress syndrome (ARDS) associated with a high release of pro-inflammatory cytokines such as interleukin-6 (IL-6). The aim of the SARICOR study is to demonstrate that early administration of sarilumab (an IL-6 receptor inhibitor) in hospitalised patients with COVID-19, pulmonary infiltrates and a high IL-6 or D-dimer serum level could reduce the progression of ARDS requiring high-flow nasal oxygen or mechanical ventilation (non-invasive or invasive).

METHODS AND ANALYSIS

Phase II, open-label, randomised, multicentre, controlled clinical trial to study the efficacy and safety of the administration of two doses of sarilumab (200 and 400 mg) plus best available therapy (BAT) in hospitalised adults with COVID-19 presenting cytokine release syndrome. This strategy will be compared with a BAT control group. The efficacy and safety will be monitored up to 28 days postadministration. A total of 120 patients will be recruited (40 patients in each arm).

ETHICS AND DISSEMINATION

The clinical trial has been approved by the Research Ethics Committee of the coordinating centre and authorised by the Spanish Agency of Medicines and Medical Products. If the hypothesis is verified, the dissemination of the results could change clinical practice by increasing early administration of sarilumab in adult patients with COVID-19 presenting cytokine release syndrome, thus reducing intensive care unit admissions.

TRIAL REGISTRATION NUMBER

NCT04357860.

Safety, immunogenicity, and efficacy of a Clostridioides difficile toxoid vaccine candidate: a phase 3 multicentre, observer-blind, randomised, controlled trial

BACKGROUND

In the absence of a licensed vaccine, Clostridioides (formerly Clostridium) difficile infection represents a substantial health burden. The aim of this study was to evaluate the efficacy, immunogenicity, and safety of a toxoid vaccine candidate.

METHODS

We did a phase 3 multicentre, observer-blind, randomised, controlled trial at 326 hospitals, clinics, and clinical research centres in 27 countries in the USA, Canada, Latin America, Europe, and the Asia-Pacific region. We included adults aged 50 years or older who were considered to be at an increased risk of C difficile infection because they had previously had two hospital stays (each ≥24 h in duration) and had received systemic antibiotics in the previous 12 months (risk stratum 1), or because they were anticipating being admitted to hospital for 72 h or more for elective surgery within 60 days of enrolment (risk stratum 2). Eligible participants were stratified by geographical region and the two risk strata, and randomly assigned (2:1), with a fixed block size of three, to receive either a C difficile toxoid vaccine candidate, containing toxoids A and B (C difficile vaccine candidate group), or a placebo vaccine (placebo group). Participants, investigators, and personnel responsible for collecting safety data and analysing blood and stool samples were masked to group assignment. Personnel responsible for study product preparation and administration were not masked to group assignment. One dose (0·5 mL) of C difficile vaccine candidate or placebo vaccine was administered intramuscularly on days 0, 7, and 30. The primary outcome was the efficacy of the vaccine in preventing symptomatic C difficile infection, defined as having three or more loose stools in a period of 24 h or less, loose stools for 24 h or more, and a PCR-positive test for C difficile toxin B in a loose stool sample, within 3 years after the final vaccine dose. The primary outcome was measured in the modified intention-to-treat population (ie, all participants who received at least one injection of the assigned vaccine). The safety of the vaccine was assessed in the safety analysis set (ie, all participants who had received at least one injection, analysed according to the product received). This study is registered with WHO/ICTRP, number U111-1127-7162, and ClinicalTrials.gov, number NCT01887912, and has been terminated.

FINDINGS

Between July 30, 2013, and Nov 17, 2017, we enrolled and randomly assigned 9302 participants to the C difficile vaccine candidate group (n=6201) or to the placebo group (n=3101). 6173 (99·5%) participants in the C difficile vaccine candidate group and 3085 (99·5%) participants in the placebo group received at least one dose of the vaccine. The study was terminated after the first planned interim analysis because of futility. In the C difficile vaccine candidate group, 34 C difficile infections were reported over 11 697·2 person-years at risk (0·29 infections per 100 person-years [95% CI 0·20-0·41]) compared with 16 C difficile infections over 5789·4 person-years at risk in the placebo group (0·28 infections per 100 person-years [0·16-0·45]), indicating a vaccine efficacy of -5·2% (95% CI -104·1 to 43·5). In the C difficile vaccine candidate group, 2847 (46·6%) of 6113 participants reported an adverse event within 30 days of injection compared with 1282 (41·9%) of 3057 participants in the placebo group. The proportion of participants who had an adverse event leading to study discontinuation was 4·8% in both groups (296 participants in the C difficile vaccine candidate group and 146 participants in the placebo group). 1662 (27·2%) participants in the C difficile vaccine candidate group reported at least one serious adverse event compared with 851 (27·8%) participants in the placebo group.

INTERPRETATION

In adults at risk for C difficile infection, a bivalent C difficile toxoid vaccine did not prevent C difficile infection. Since the C difficile vaccine candidate met the criteria for futility, the study was terminated and clinical development of this vaccine candidate was stopped.

FUNDING

Sanofi Pasteur.

Genomic analysis of 40 prophages located in the genomes of 16 carbapenemase-producing clinical strains of Klebsiella pneumoniae

Klebsiella pneumoniae is the clinically most important species within the genus Klebsiella and, as a result of the continuous emergence of multi-drug resistant (MDR) strains, the cause of severe nosocomial infections. The decline in the effectiveness of antibiotic treatments for infections caused by MDR bacteria has generated particular interest in the study of bacteriophages. In this study, we characterized a total of 40 temperate bacteriophages (prophages) with a genome range of 11.454-84.199 kb, predicted from 16 carbapenemase-producing clinical strains of K. pneumoniae belonging to different sequence types, previously identified by multilocus sequence typing. These prophages were grouped into the three families in the order Caudovirales (27 prophages belonging to the family Myoviridae, 10 prophages belonging to the family Siphoviridae and 3 prophages belonging to the family Podoviridae). Genomic comparison of the 40 prophage genomes led to the identification of four prophages isolated from different strains and of genome sizes of around 33.3, 36.1, 39.6 and 42.6 kb. These prophages showed sequence similarities (query cover >90 %, identity >99.9 %) with international Microbe Versus Phage (MVP) (http://mvp.medgenius.info/home) clusters 4762, 4901, 3499 and 4280, respectively. Phylogenetic analysis revealed the evolutionary proximity among the members of the four groups of the most frequently identified prophages in the bacterial genomes studied (33.3, 36.1, 39.6 and 42.6 kb), with bootstrap values of 100 %. This allowed the prophages to be classified into three clusters: A, B and C. Interestingly, these temperate bacteriophages did not infect the highest number of strains as indicated by a host-range assay, these results could be explained by the development of superinfection exclusion mechanisms. In addition, bioinformatic analysis of the 40 identified prophages revealed the presence of 2363 proteins. In total, 59.7 % of the proteins identified had a predicted function, mainly involving viral structure, transcription, replication and regulation (lysogenic/lysis). Interestingly, some proteins had putative functions associated with bacterial virulence (toxin expression and efflux pump regulators), phage defence profiles such as toxin-antitoxin modules, an anti-CRISPR/Cas9 protein, TerB protein (from terZABCDE operon) and methyltransferase proteins.

In vitro and in vivo efficacy of combinations of colistin and different endolysins against clinical strains of multi-drug resistant pathogens

The emergence of multidrug resistant (MDR) pathogenic bacteria is jeopardizing the value of antimicrobials, which had previously changed the course of medical science. In this study, we identified endolysins ElyA1 and ElyA2 (GH108-PG3 family), present in the genome of bacteriophages Ab1051Φ and Ab1052Φ, respectively. The muralytic activity of these endolysins against MDR clinical isolates (Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae) was tested using the turbidity reduction assay. Minimal inhibitory concentrations (MICs) of endolysin, colistin and a combination of endolysin and colistin were determined, and the antimicrobial activity of each treatment was confirmed by time kill curves. Endolysin ElyA1 displayed activity against all 25 strains of A. baumannii and P. aeruginosa tested and against 13 out of 17 strains of K. pneumoniae. Endolysin ElyA2 did not display any such activity. The combined antimicrobial activity of colistin and ElyA1 yielded a reduction in the colistin MIC for all strains studied, except K. pneumoniae. These results were confirmed in vivo in G. mellonella survival assays and in murine skin and lung infection models. In conclusion, combining colistin (1/4 MIC) with the new endolysin ElyA1 (350 µg) enhanced the bactericidal activity of colistin in both in vitro and in vivo studies. This will potentially enable reduction of the dose of colistin used in clinical practice.