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Abstract After allogeneic HSCT (allo-HSCT), the diversity of the intestinal microbiota significantly decreases. The changes can be rapid and are thought to be caused by chemotherapy, antibiotics, or intestinal inflammation. Most patients are exposed to prophylactic and therapeutic antibiotics during neutropenia and several patients are colonized by ESBL bacteria. We investigated the changes in gut microbiota composition in allo-HSCT, aiming at investigating if the acquisition of ESBL colonization may affect gut microbiome diversity during allo-HSCT. This was a single-center prospective pilot study. All patients consecutively admitted to the Haematological Unit of the City of Health and Science, Molinette Hospital in Turin, Italy, and undergoing allo-HSCT between August 2017 to August 2020 were enrolled in the study. Microbiome analysis on fecal samples were collected every 7 days from hospital admission to discharge and until 1 year after HSCT. 48 patients were enrolled in the study. At baseline 14 patients (29.16%) were colonized by MDR bacteria, mostly extended-spectrum beta-lactamase (ESBL)-producing gram negatives (N = 11; 78.57%). During allo-HSCT, one patient had a positive rectal swab for a carbapenemase-producing Klebsiella pneumoniae and eight patients lost the colonization during the hospital stay. Microbiota composition was compared between patients colonized by ESBL at baseline and non-colonized patients. Patients colonized by ESBL had a greater abundances of Bifidobacterium, Blautia, Clostridium, Coprococcus, L-Ruminococcus Mogibacteriaceae, Peptostreptococceae and Oscillospira, while non-colonized ESBL patients had a greater abundance of Actinomycetales, Staphylococcus and Sutterella. Moreover, microbiota composition of colonized by ESBL that retained colonization after HSCT showed an increased in abundances of Akkermansia, Dialister, Erysipelotrichaceae and Methanobrevibacter when compared with patients that become negative at rectal swabs. From a clinical perspective, the evolution of this prospective pilot study will be to investigate markers of gut barrier functions, SCFA productions and to correlate the predictivity of these parameters with risk of invasive infections and clinical outcomes in allo-HSCT population.

Abstract Introduction Real-world data from multinational observational studies are required to better understand the role and performance of isavuconazole in real-world practice in Europe. Methods A retrospective medical record review was conducted at 16 sites in Europe (France, Germany, Italy, Spain, and the United Kingdom). Eligible records were from patients aged ≥ 18 years at the time of isavuconazole initiation and received at least one dose of isavuconazole for suspected or confirmed invasive aspergillosis (IA) or invasive mucormycosis (IM) during the eligibility period (October 15, 2015 to June 30, 2019). Data were descriptively analysed. Success rates, overall survival, and times to these events were descriptively analysed. Results Data were abstracted from 218 patients (201, IA; 17, IM) who received isavuconazole as monotherapy (initiated as infusion, 52%; oral, 46%). Isavuconazole was initiated as primary therapy in 92 patients (42.2%) and salvage therapy in 121 patients (55.5%) (unknown for five patients). Mean (standard deviation) age was 56.8 (15.6) years, 66% were men and 62% had at least three comorbidities, most frequently haematologic malignancy (62%). Estimated clinical response rate at week 24 was 54.5% (95% confidence interval [CI], 38.2–66.5%) for primary treatment and 73.5% (95% CI, 62.7–81.1%) for salvage therapy. Overall, 45 patients (21%) experienced at least one adverse event (AE). Serious AEs were experienced by 37 patients (17%), with seven related to isavuconazole; five patients (2.3%) discontinued isavuconazole monotherapy due to the serious AE. A total of 137 patients (63%) died, with 17 deaths (12.4%) related to their invasive fungal infection, 11 of whom initiated isavuconazole as salvage therapy. Conclusions This study adds to the growing body of evidence that whether used as first-line therapy or after the failure of other antifungal therapies, isavuconazole appears to have a promising clinical response and a good safety profile as an antifungal agent in patients with varied underlying conditions.

Objectives: Acinetobacter baumannii (A. baumannii) nosocomial infections represent a serious hazard to public health, given high mortality rates and rapid spread of multidrug-resistance. The primary outcome of this study was to evaluate predictors of 14- and 30-d mortality in bloodstream infections (BSIs) due to both carbapenem-resistant and carbapenem-sensitive Acinetobacter. Secondary end points were to identify risk factors for BSIs due to carbapenem-resistant A. baumannii (CRAB) and to develop a predictive model for mortality in CRAB-related BSIs. Methods: Between 2019 and 2023, all consecutive hospitalized adult patients with bacteraemia due to A. baumannii were retrospectively enrolled at a single-centre. Results: One hundred twenty-six episodes of BSI caused by A. baumannii were recorded, 89.7% of which were due to CRAB. Recent burn injuries, older age, previous CRAB colonization, and antibiotics exposure were identified as risk factors for acquiring CRAB BSI. Overall, 14-d mortality was observed in 26.1% of the patients and 30-d mortality in 30.9% of the patients. On multivariate analysis, the Sequential Organ Failure Assessment (SOFA) score was associated with both 14- and 30-d mortality, whereas burn injuries correlated with 30-d survival. Concurrent coronavirus disease (COVID) was associated with mortality, although not reaching statistical figures. No major impact of receiving appropriate treatment was observed. Based on these findings, a multivariable model to predict mortality among patients with CRAB BSI was built and internally validated. Conclusions: A. baumannii BSIs are characterized by poor outcomes and limited therapeutic options. This study aimed to assist physicians in prompt identification of patients who are at greater risk of death, contributing to more informed clinical decision making.

Abstract Introduction Cefiderocol is a siderophore cephalosporin showing activity against various carbapenem-resistant Gram-negative bacteria (CR-GNB). No data currently exist about real-world use of cefiderocol in terms of types of therapy (e.g., empirical or targeted, monotherapy or combined regimens), indications, and patient characteristics. Methods In this multicenter, prospective study, we aimed at describing the use of cefiderocol in terms of types of therapy, indications, and patient characteristics. Results Cefiderocol was administered as empirical and targeted therapy in 27.5% (55/200) and 72.5% (145/200) of cases, respectively. Overall, it was administered as monotherapy in 101/200 cases (50.5%) and as part of a combined regimen for CR-GNB infections in the remaining 99/200 cases (49.5%). In multivariable analysis, previous isolation of carbapenem-resistant Acinetobacter baumannii odds ratio (OR) 2.56, with 95% confidence interval (95% CI) 1.01–6.46, p = 0.047] and previous hematopoietic stem cell transplantation (OR 8.73, 95% CI 1.05–72.54, p = 0.045) were associated with administration of cefiderocol as part of a combined regimen, whereas chronic kidney disease was associated with cefiderocol monotherapy (OR 0.38 for combined regimen, 95% CI 0.16–0.91, p = 0.029). Cumulative 30-day mortality was 19.8%, 45.0%, 20.7%, and 22.7% in patients receiving targeted cefiderocol for infections by Enterobacterales, A. baumannii, Pseudomonas aeruginosa, and any metallo-β-lactamase producers, respectively. Conclusions Cefiderocol is mainly used for targeted treatment, although empirical therapies account for more than 25% of prescriptions, thus requiring dedicated standardization and guidance. The almost equal distribution of cefiderocol monotherapy and cefiderocol-based combination therapies underlines the need for further study to ascertain possible differences in efficacy between the two approaches.

Abstract Intra-abdominal infections (IAIs) are common surgical emergencies and are an important cause of morbidity and mortality in hospital settings, particularly if poorly managed. The cornerstones of effective IAIs management include early diagnosis, adequate source control, appropriate antimicrobial therapy, and early physiologic stabilization using intravenous fluids and vasopressor agents in critically ill patients. Adequate empiric antimicrobial therapy in patients with IAIs is of paramount importance because inappropriate antimicrobial therapy is associated with poor outcomes. Optimizing antimicrobial prescriptions improves treatment effectiveness, increases patients’ safety, and minimizes the risk of opportunistic infections (such as Clostridioides difficile) and antimicrobial resistance selection. The growing emergence of multi-drug resistant organisms has caused an impending crisis with alarming implications, especially regarding Gram-negative bacteria. The Multidisciplinary and Intersociety Italian Council for the Optimization of Antimicrobial Use promoted a consensus conference on the antimicrobial management of IAIs, including emergency medicine specialists, radiologists, surgeons, intensivists, infectious disease specialists, clinical pharmacologists, hospital pharmacists, microbiologists and public health specialists. Relevant clinical questions were constructed by the Organizational Committee in order to investigate the topic. The expert panel produced recommendation statements based on the best scientific evidence from PubMed and EMBASE Library and experts’ opinions. The statements were planned and graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) hierarchy of evidence. On November 10, 2023, the experts met in Mestre (Italy) to debate the statements. After the approval of the statements, the expert panel met via email and virtual meetings to prepare and revise the definitive document. This document represents the executive summary of the consensus conference and comprises three sections. The first section focuses on the general principles of diagnosis and treatment of IAIs. The second section provides twenty-three evidence-based recommendations for the antimicrobial therapy of IAIs. The third section presents eight clinical diagnostic-therapeutic pathways for the most common IAIs. The document has been endorsed by the Italian Society of Surgery.

Abstract Background In the region of Piedmont, in Northern Italy, formal monitoring of antimicrobial stewardship (AMS) programs has been in place since 2012. The objective of our study was to provide an updated assessment of AMS programs operating in our region, and to assess the impact of the COVID-19 pandemic on stewardship activities. Methods A retrospective observational study was conducted to investigate AMS programs implemented in acute-care trusts participating in a broader healthcare-associated infections and antimicrobial resistance (AMR) prevention and control program, promoted by the regional health department. Within this program, structure, process, and outcome indicators of AMS programs were investigated, using a previously developed scoring system. Differences between scores prior to (2019) and during the pandemic (2021) were assessed. Linear regression was used to assess whether the 5-year trends (2017–2021) in outcome measures in relation to structure and process scores were statistically significant. Compound annual growth rates (CAGR) for each outcome were calculated to illustrate changes in outcome rates over time. Results All public trusts in the Region (20) and a small number of private institutions (3) provided data for this study. A modest, non-significant improvement was found for 2021 structure, process, and total scores compared to respective 2019 scores. A significant improvement was found concerning the definition of a formal mission statement, whereas significantly less trusts included monitoring adherence to antimicrobial policy or treatment guidelines in their programs. Overall consumption of antibiotics for systemic use saw an increase in 2021, with 2021 recording the highest median overall consumption compared to all previous years considered in this study. Methicillin-resistant Staphylococcus aureus (MRSA) and carbapenem-resistant enterobacteria (CRE) rates decreased over the 5-year period. Significant downwards trends in MRSA rates were identified for high-outlier structure and process groups. Conclusions Results of this study suggest AMS programs in Piedmont were not set back following the pandemic. This outcome was possible thanks to well-established programs, coordinated within a regional framework. Continued efforts should be dedicated to supporting AMS programs and contrasting AMR, even when the focus is shifted towards other public health emergencies.

Abstract Background The COVID-19 pandemic has increased the incidence of ventilator-associated pneumonia (VAP) among critically ill patients. However, a comparison of VAP incidence in COVID-19 and non-COVID-19 cohorts, particularly in a context with a high prevalence of multidrug-resistant (MDR) organisms, is lacking. Material and Methods We conducted a single-center, mixed prospective and retrospective cohort study comparing COVID-19 patients admitted to the intensive care unit (ICU) of the “Città della Salute e della Scienza” University Hospital in Turin, Italy, between March 2020 and December 2021 (COVID-19 group), with a historical cohort of ICU patients admitted between June 2016 and March 2018 (NON-COVID-19 group). The primary objective was to define the incidence of VAP in both cohorts. Secondary objectives were to evaluate the microbial cause, resistance patters, risk factors and impact on 28 days, ICU and in-hospital mortality, duration of ICU stay, and duration of hospitalization). Results We found a significantly higher incidence of VAP (51.9% - n = 125) among the 241 COVID-19 patients compared to that observed (31.2% - n = 78) among the 252 NON-COVID-19 patients. The median SOFA score was significantly lower in the COVID-19 group (9, Interquartile range, IQR: 7–11 vs. 10, IQR: 8–13, p

Abstract Background In the last decades, several adjunctive treatments have been proposed to reduce mortality in septic shock patients. Unfortunately, mortality due to sepsis and septic shock remains elevated and NO trials evaluating adjunctive therapies were able to demonstrate any clear benefit. In light of the lack of evidence and conflicting results from previous studies, in this multidisciplinary consensus, the authors considered the rational, recent investigations and potential clinical benefits of targeted adjunctive therapies. Methods A panel of multidisciplinary experts defined clinical phenotypes, treatments and outcomes of greater interest in the field of adjunctive therapies for sepsis and septic shock. After an extensive systematic literature review, the appropriateness of each treatment for each clinical phenotype was determined using the modified RAND/UCLA appropriateness method. Results The consensus identified two distinct clinical phenotypes: patients with overwhelming shock and patients with immune paralysis. Six different adjunctive treatments were considered the most frequently used and promising: (i) corticosteroids, (ii) blood purification, (iii) immunoglobulins, (iv) granulocyte/monocyte colony-stimulating factor and (v) specific immune therapy (i.e. interferon-gamma, IL7 and AntiPD1). Agreement was achieved in 70% of the 25 clinical questions. Conclusions Although clinical evidence is lacking, adjunctive therapies are often employed in the treatment of sepsis. To address this gap in knowledge, a panel of national experts has provided a structured consensus on the appropriate use of these treatments in clinical practice.

Objectives: To retrospectively describe the patterns of use of dalbavancin for treating infections in diabetic patients in Italian and Spanish standard clinical practice. Methods: DALBADIA [NCT04959799] was a multicentre, observational, retrospective cohort study, conducted in Italy and Spain. The study enrolled 97 adults with type 1 or 2 diabetes mellitus, treated with dalbavancin as per standard clinical practice for a Gram-positive bacterial infection or the Gram-positive component of a mixed infection. Results: Dalbavancin was used to treat cellulitis (18/92 patients, 19.6%), followed by prosthetic joint infection (14 patients, 15.2%), endocarditis (13 patients, 14.1%), and primary bacteraemia (10 patients, 10.9%); 78/92 (84.8%) patients had Gram-positive infections only, and 14 (15.2%) had mixed infections. The most frequently isolated microorganisms were Staphylococcus aureus in 43 (55.8% of the patients with microbial isolation), 25.6% of which methicillin-resistant; Staphylococcus epidermidis in 13 (16.9%), 53.8% of which methicillin-resistant; Enterococcus faecalis in 11 (14.3%). The main reason for the dalbavancin choice was the intent to simplify the antibiotic regimen (81.5% of cases). A multidisciplinary team participated in the treatment choice process for 53 (57.6%) patients. Dalbavancin was given as first-line antibiotic in 34 (37.0%) patients and administered as one infusion in 32 (34.8%), and as two infusions in 39 (42.4%). In total, 57/62 (91.9%) eligible patients with available assessment were judged clinically cured or improved at the end of observation. Conclusion: In clinical practice, dalbavancin was used in diabetic patients to treat ABSSSIs and other difficult-to-treat infections with a favourable safety profile and a high rate of positive clinical responses.

Introduction: Patients with hematologic malignancies are more likely to develop severe and prolonged SARS-CoV-2 infection, often showing viral persistence despite the use of authorized antivirals. Herein, we report the cases of four patients who received rituximab for different conditions and developed persistent COVID-19 treated with an extended course of dual antivirals, Nirmatrelvir/Ritonavir and Remdesivir. Moreover, we describe the pharmacokinetics and pharmacogenetics (PK/PG) characteristics of Nirmatrelvir/Ritonavir and Remdesivir treatment in two of these patients. Methods: Plasma specimens for evaluation of trough concentrations (Ctrough) were collected 10 min before the daily dose administration, in addition to 3 h (Cmax), 4 h (C4h), 6 h (C6h) and 1 h (Cmax) after the administration of Nirmatrelvir/Ritonavir and Remdesivir, respectively. The following gene single-nucleotide polymorphisms (SNPs) were investigated: ABCB1 3435 (rs1045642) C > T, ABCB1 1236 (rs1128503) C > T, PXR 63396 (rs2472667) T > C, CYP2D6 (rs1135840) G > C, and CYP3A4*1B (rs2740574) G > A. Results: Double antiviral treatment was successful in terms of symptoms resolution, whereas three out of four patients achieved microbiological eradication. Based on our results, concentrations of Nirmatrelvir ranging from 50 to 5000 ng/mL were effective, whereas a higher concentration (range 1068–3377 ng/mL), compared to that previously reported in patients with similar weight and BMI, was evidenced for Ritonavir. Considering the genetic variant analysis, ABCB1 3435 CT and 1236 CT genotypes were found in patient 1; and ABCB1 3435 CC and 1236 CC in patient 2. In conclusion, this real-life study supports the usefulness of TDM and genetics in immunocompromised patients with persistent SARS-CoV-2 infection, a challenging setting for clinicians in which personalized medicine may improve outcome.

Herpes zoster ophthalmicus results from the reactivation of the latent varicella zoster virus, affecting the first branch of the trigeminal nerve. In 20–70% of cases, Zoster Ophthalmicus can lead to ocular involvement, affecting various orbital structures. Orbital myositis is a rare but severe complication of herpes zoster ophthalmicus. We present a case of a 52-year-old man with no significant medical history who developed zoster-associated right ocular myositis and dacryocystitis. He was treated with intravenous acyclovir and oral steroids. A review of the literature identified 29 patients across 19 studies. The median age was 61 years, with a slight female predominance. In 55% of cases, the patients had no notable medical history. The most common presentation of myositis involved all oculomotor muscles. There were 22 cases who were treated with intravenous antiviral therapy and 19 received steroids. A full resolution of symptoms was achieved in 51.7% of patients. Zoster-related orbital myositis is a rare complication that should be considered even in immunocompetent individuals. It may occur either before or after the appearance of a vesicular rash. Magnetic resonance imaging is the preferred radiological exam for assessing orbital involvement. Intravenous antiviral therapy should be started within 72 h of symptom onset, and its combination with systemic corticosteroids appears to be an effective treatment for zoster-related ocular myositis.

BackgroundAcute graft pyelonephritis (AGPN) is a relatively common complication in kidney transplants (KTs); however, the effects on allograft function, diagnostic criteria, and risk factors are not well established.MethodsRetrospective analysis of all consecutive adult KTs was performed between 01 January 2011 and 31 December 2018 (follow-up ended on 31 December 2019) to examine the association between the diagnosis of AGPN (confirmed with magnetic resonance imaging [MRI]) during the first post-transplantation year and graft outcomes.ResultsAmong the 939 consecutive KTs (≈50% with donors ≥60 years), we identified 130 MRI-confirmed AGPN episodes, with a documented association with recurrent and multidrug-resistant bacterial urinary tract infections (UTIs) (p

Objectives: Bezlotoxumab (BEZ) is a promising tool for preventing the recurrence of Clostridioides difficile infection (rCDI). The aim of the study was to emulate, in a real-world setting, the MODIFY trials in a cohort of participants with multiple risk factors for rCDI treated with BEZ in addition to the standard of care (SoC) versus SoC alone. Methods: A multicenter cohort study was conducted including 442 patients with Clostridioides difficile infection from 2018 to 2022, collected from 18 Italian centers. The main outcome was the 30-day occurrence of rCDI. The secondary outcomes were (i) all-cause mortality at 30 days (ii) and the composite outcome (30-day recurrence and/or all-cause death). Results: rCDI at day 30 occurred in 54 (12%): 11 in the BEZ + SoC group and 43 treated with SoC alone (8% vs 14%, odds ratio [OR] = 0.58, 95% confidence interval [CI]: 0.31-1.09, P = 0.09). The difference between BEZ + SoC versus SoC was statistically significant after controlling for confounding factors (adjusted OR = 0.40, 95% CI: 018-0.88, P = 0.02) and even more using the composite outcome (adjusted OR = 0.35, 95% CI: 0.17-0.73, P = 0.005). Conclusion: Our study confirms the efficacy of BEZ + SoC for the prevention of rCDI and death in a real-world setting. BEZ should be routinely considered among participants at high risk of rCDI regardless of age, type of Clostridioides difficile infection therapy (vancomycin vs fidaxomicin), and number of risk factors.

Ceftobiprole is a fifth-generation cephalosporin approved by European and American regulatory agencies for the treatment of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP). Ceftobiprole administration is useful in severe CAP as well as HAP where the potential is to save other β-lactams including carbapenems or linezolid/vancomycin in clinical practice. The aim of this study was to report the real-world evidence of ceftobiprole in patients with CAP and HAP in a single center. In this retrospective study, we included 159 patients with CAP or HAP: 105 (66%) had CAP and 54 (34%) had HAP. The median age was 70 years (IQR 60–77), the median Charlson Comorbidity Index was 5 (IQR 3–7.5) and baseline INCREMENT ESBL score was 8 (IQR 6–11). Ceftobiprole was mostly given as a combination treatment (77%) or as a carbapenem-sparing strategy (44%). There were no differences in mortality between shorter and longer duration of treatment (p = 0.93) or between first-line (HR 1.00, C.I. 0.46–2.17, p = 0.989) and second-line therapy. Ceftobiprole use in CAP or HAP in the real world is effective as a first- and second-line treatment as well as a carbapenem-sparing strategy. Further studies are needed to explore the full potential of ceftobiprole, including its real-world use in antimicrobial stewardship programs.

Background and Objectives: the principal purpose of this literature review is to cluster adults with hematological malignancies after treatment or on maintenance with obinutuzumab who experienced disseminated EV infection to understand clinical characteristics and outcome of this rare condition in these patients. We report the first clinical case of a male affected by follicular lymphoma treated with immune-chemotherapy including obinutuzumab who was affected by disseminated EV infection with cardiovascular involvement. Materials and Methods: this narrative review summarizes all the research about disseminated EV infection in immunosuppressed adult patients treated with obinutuzumab from January 2000 to January 2024 using the Scale for the Assessment of Narrative Review Articles (SANRA) flow-chart. We performed a descriptive statistic using the standard statistical measures for quantitative data. Results: we included six studies, five case reports, and one case report with literature analysis. We collected a total of seven patients, all female, with disseminated EV infection. The most common signs and clinical presentations of EV infection were fever and encephalitis symptoms (N = 6, 85.7%), followed by hepatitis/acute liver failure (N = 5, 71.4%). Conclusions: onco-hematological patients who receive immune-chemotherapy with a combination of treatments which depress adaptative immunity, which includes the antiCD20 obinutuzumab, could be at higher risk of disseminated EV infection, including CNS and cardiac involvement.

Abstract Background The efficacy of early treatment with convalescent plasma in patients with COVID-19 is debated. Nothing is known about the potential effect of other plasma components other than anti-SARS-CoV-2 antibodies. Methods To determine whether convalescent or standard plasma would improve outcomes for adults in early phase of Covid19 respiratory impairment we designed this randomized, three-arms, clinical trial (PLACO COVID) blinded on interventional arms that was conducted from June 2020 to August 2021. It was a multicentric trial at 19 Italian hospitals. We enrolled 180 hospitalized adult patients with COVID-19 pneumonia within 5 days from the onset of respiratory distress. Patients were randomly assigned in a 1:1:1 ratio to standard of care (n = 60) or standard of care + three units of standard plasma (n = 60) or standard of care + three units of high-titre convalescent plasma (n = 60) administered on days 1, 3, 5 after randomization. Primary outcome was 30-days mortality. Secondary outcomes were: incidence of mechanical ventilation or death at day 30, 6-month mortality, proportion of days with mechanical ventilation on total length of hospital stay, IgG anti-SARS-CoV-2 seroconversion, viral clearance from plasma and respiratory tract samples, and variations in Sequential Organ Failure Assessment score. The trial was analysed according to the intention-to-treat principle. Results 180 patients (133/180 [73.9%] males, mean age 66.6 years [IQR 57–73]) were enrolled a median of 8 days from onset of symptoms. At enrollment, 88.9% of patients showed moderate/severe respiratory failure. 30-days mortality was 20% in Control arm, 23% in Convalescent (risk ratio [RR] 1.13; 95% confidence interval [CI], 0.61–2.13, P = 0.694) and 25% in Standard plasma (RR 1.23; 95%CI, 0.63–2.37, P = 0.544). Time to viral clearance from respiratory tract was 21 days for Convalescent, 28 for Standard plasma and 23 in Control arm but differences were not statistically significant. No differences for other secondary endpoints were seen in the three arms. Serious adverse events were reported in 1.7%, 3.3% and 5% of patients in Control, Standard and Convalescent plasma arms respectively. Conclusions Neither high-titer Convalescent nor Standard plasma improve outcomes of COVID-19 patients with acute respiratory failure. Trial Registration Clinicaltrials.gov Identifier: NCT04428021. First posted: 11/06/2020

Objectives: To date limited information about cefiderocol use is provided by real life studies. Our aim is to evaluate characteristics and outcome of patients with Gram-negative infections with limited therapeutic options treated with cefiderocol in combination or monotherapy. Methods: We retrospectively collected data on demographical, clinical characteristics and clinical cure, in-hospital and 30-days mortality, microbiological failure and Clostridioides difficile infections of all patients ≥ 18 years old treated with cefiderocol for ≥ 48 h. Results: There were 18 patients of which 14 (77.8%) treated with cefiderocol in combination and 4 (22.2%) with monotherapy. Median age was 54.5 (IQR 35.25–65.75) vs 70.5 (IQR 57.5–78.25) years old, respectively and ward of admission was the ICU in the 78.57% vs 100% of cases. In the 50% vs 100% of cases infections were VAP with concomitant bloodstream infections. Median SOFA score was 10 (IQR 4.5–12.5) vs 5 (IQR 4–6) and APACHE II score was 13.5 (IQR 7.5–18) vs 16 (IQR 8.5–23.5), respectively. Isolated pathogen was carbapenems-resistant Acinetobacter baumannii in 78.57% vs 100% of cases. Median duration of cefiderocol treatment was 9.5 (IQR 7–13.25) vs 9 days (IQR 5.5–12.5) and in 77.8% patients it was used in combination therapy, of which 57.1% were colistin-spairing regimens. Clinical cure was achieved in 64.29% for combination therapy vs 75% of monotherapy treated patients, 30-days mortality rate was 28.57% vs 25% and 30-day ICU admission rate was 14.29% vs 50%, respectively. No statistically significant differences were observed between combination therapy and monotherapy treated patients. Conclusions: To date, no differences have been demonstrated between cefiderocol monotherapy or combination. Further studies are required to understand whether cefiderocol combination therapy could provide an advantage in outcome in seriously-ill patients.

Abstract Eight hot topics regarding the diagnosis and management of bacterial skin infections were selected and reviewed by five experts from different European countries, chosen based on their expertise in microbiology, infectious diseases, and dermatology. As noninfectious skin diseases/conditions such as atopic dermatitis can be complicated by infections, including Acute Bacterial Skin and Skin Structure Infections (ABSSSI), a collaboration between dermatologists and infectious disease specialists can promote a rational approach to diagnosis and a more functional treatment approach, especially for complicated infections. In addition, an important role would be played by microbiologists as they are crucial for the isolation and classification of the bacterial pathogen to guide clinicians toward the most effective antibiotic therapy. Although there are many therapeutic options for the treatment of bacterial skin infections, including those due to methicillin‐resistant Staphylococcus aureus, these drugs often require multiple daily administrations leading to patient noncompliance and are associated with gastrointestinal adverse events and drug resistance. With their characteristics of being long‐acting, safety and single‐dose regimens, long‐acting antibiotics, such as dalbavancin and oritavancin, represent an effective alternative that could change the management of these infections with a considerable reduction of hospitalisation costs and risks.

Left ventricular assist devices (LVADs) have been increasingly used as a valid option to improve the prognosis and reduce the symptoms of end-stage heart failure. However, long-term complications, mostly infections and coagulation disorders, are frequent. We described the epidemiology and risk factors for nosocomial infections (NIs) in a cohort of adult patients who underwent continuous-flow LVAD implant between January 2010 and December 2017 in Turin, Italy. Secondary outcomes were the prevalence of multidrug-resistant (MDR) bacteria and mortality. Results: Overall, 64 LVADs were implanted. A total of 32 (50%) patients experienced at least one episode of NI, with a total of 46 infectious events. VAD-related infections occurred in 22 patients (68.8%). Non VAD-related NIs occurred in 12 patients (37.5%), mainly low respiratory tract infections. Length of intensive care unit admission was a risk factor for NI (OR 1.224, 95%CI; 1.049, 1.429). Gram-negative bacilli were responsible for 58.8% of VAD-related infections and 79.5% of non-VAD related infections. In sixteen patients (50%), at least one episode of infection was related to an MDR strain. INTERMACS class and length of MV were independent risk factors for NIs by MDR strains (respectively, OR 2.12, 95%CI: 1.08, 6.80; p = 0.02 and OR 1.46, 95%CI: 1.07, 5.52, p = 0.047). In-hospital mortality was 6.3%. No differences in mortality were observed between infected and non-infected patients (p = 0.61) even when caused by MDR strains (p = 0.143). Conclusion: the rate of nosocomial infections in LVAD patients is associated with the length of ICU admission, and the etiology of nosocomial infection after LVAD implant is mainly due to GNB, including a high rate of MDR strains, especially KPC-KP and MDR PA.

Background and Objectives: Stenotrophomonas maltophilia is a ubiquitous, aerobic, Gram-negative bacillus causing increasing concern in patients affected by haematological malignancies. Materials and Methods: We report a case series from two centres in Northern Italy to describe the characteristics, outcome and microbiological response of S. maltophilia infections in patients with haematological malignancies and/or allogenic hematopoietic stem cell transplantation (aHSCT). Results: Ten patients were included. The median age was 67 years, and seven patients (70%) were males. The median Charlson Comorbidity Index was 6 (IQR: 4–8). The most frequent haematological comorbidities were acute myeloid leukaemia (AML; n = 3; 30%) and non-Hodgkin’s lymphoma (n = 3; 30%). Three (30%) patients underwent aHSCT before infection, all for AML. All the patients had undergone a recent antibiotics course and had an indwelling central venous catheter before infection. The main clinical presentations were nosocomial pneumonia, with (2; 20%) or without (4; 40%) secondary bloodstream infection and CRBSI (3; 30%). Four patients were treated with cefiderocol in monotherapy or combinations therapy with cotrimoxazole. The rest of the patients were treated with cotrimoxazole or levofloxacin in monotherapy. Conclusions: Despite a high rate of clinical improvement (90%) after starting antimicrobial therapy, we faced high 30-day mortality (30%) and in-hospital mortality (50%) rates in a highly comorbid population.

(1) Background: The widespread use of MALDI-TOF coupled to mass spectrometry has improved diagnostic accuracy by identifying uncommon bacteria. Among Enterobacterales, Pantoea species have been seen to be implicated in several human infections, but their clinical and microbiological framework is currently based on a few anecdotal reports. (2) Methods: We conducted this five-year (2018–2023) single-center study aimed at investigating the prevalence and clinical and microbiological findings of Pantoea species bloodstream infections. (3) Results: Among the 4996 bloodstream infection Gram-negative isolates collected during the study period, Pantoea species accounted for 0.4% (n = 19) of isolates from 19 different patients, 5 of them being pediatric cases. Among Pantoea species isolates, P. agglomerans was the most frequently detected (45%; n = 9) followed by P. eucrina (30%; n = 6) and P. septica (15%; n = 3). Malignancy (35.7%) in adults and malignancy (40%) and cerebrovascular disease following meconium aspiration (40%) in pediatric patients as comorbidities and shivering and/or fever following parenteral infusion (36.8%) as a symptom/sign of Pantoea species bloodstream infection onset were the most frequently observed clinical features. Among adults, primary bloodstream infection was the most frequent (50%), whereas among pediatric patients, the most commonly identified sources of infection were catheter-related (40%) and the respiratory tract (40%). Overall, Pantoea species bloodstream infection isolates displayed high susceptibility to all the antibiotics except for ampicillin (63.2%), fosfomycin (73.7%), and piperacillin/tazobactam (84.2%). Targeted antibiotic treatment was prescribed as monotherapy for adults (71.4%) and combination therapy for pediatric patients (60%). The most prescribed antibiotic regimens were piperacillin/tazobactam (21.4%) in adults and meropenem- (40%) and aminoglycoside-containing (40%) antibiotics in pediatric patients. The overall 28-day all-cause mortality rate was 5.3% (n = 1). (4) Conclusions: The prevalence and 28-day mortality rate of Pantoea species bloodstream infections were low. The prescription of targeted therapy including broad-spectrum antibiotics could indicate an underestimation of the specific involvement of the Pantoea species in the onset of the disease, warranting further studies defining their pathogenic potential.

Monoclonal antibodies (mABs) are safe and effective proteins produced in laboratory that may be used to target a single epitope of a highly conserved protein of a virus or a bacterial pathogen. For this purpose, the epitope is selected among those that play the major role as targets for prevention of infection or tissue damage. In this paper, characteristics of the most important mABs that have been licensed and used or are in advanced stages of development for use in prophylaxis and therapy of infectious diseases are discussed. We showed that a great number of mABs effective against virus or bacterial infections have been developed, although only in a small number of cases these are licensed for use in clinical practice and have reached the market. Although some examples of therapeutic efficacy have been shown, not unlike more traditional antiviral or antibacterial treatments, their efficacy is significantly greater in prophylaxis or early post-exposure treatment. Although in many cases the use of vaccines is more effective and cost-effective than that of mABs, for many infectious diseases no vaccines have yet been developed and licensed. Furthermore, in emergency situations, like in epidemics or pandemics, the availability of mABs can be an attractive adjunct to our armament to reduce the impact. Finally, the availability of mABs against bacteria can be an important alternative, when multidrug-resistant strains are involved.

Summary: 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;

Background and objectives: acute myeloid leukemia (AML) patients are at high risk of infections during post induction neutropenia. Recently, the role of antibacterial prophylaxis has been reconsidered due to concerns about the emergence of multi-resistant pathogens. Aim of the present study was to evaluate the impact of prophylaxis omission on the rate of induction death (primary endpoint), neutropenic fevers, bloodstream infections (BSIs), resistant pathogens BSIs and septic shocks (secondary endpoints). Methods: we performed a retrospective single center study including 373 AML patients treated with intensive induction chemotherapy, divided in two groups according to levofloxacin prophylaxis given (group A, gA) or not (group B, gB). Results: neutropenic fever was observed in 91% of patients in gA and 97% in gB (OR 0.35, IC95% 0.08 – 1.52, p=0162).The rate of BSIs was 27% in gA compared to 34% in gB (OR 0.69, 0.38 – 1.25, p=0.222). Induction death rate was 5% in gA and 3% in gB (OR 1.50, 0.34 – 6.70, p=0.284). Fluoroquinolones (FQ) resistant pathogens were responsible for 59% of total BSIs in gA and 22% in gB (OR 5.07, 1.87 – 13.73, p=0.001); gram-negative BSIs due to multi-drug resistant organisms were 31% in gA and 36% in gB (OR 0.75, 0.15 – 3.70, p=0.727). Conclusions: levofloxacin prophylaxis omission was not associated with an increased risk of induction death. Cumulative incidence of neutropenic fever was higher in non-prophylaxis group, while no difference was observed for BSIs. In the prophylaxis group we observed a higher incidence of FQ resistant organisms.

Prolonged SARS-CoV-2 infections are widely described in immunosuppressed patients, but safe and effective treatment strategies are lacking. We aimed to outline our approach to treating persistent COVID-19 in patients with immunosuppression from different causes. In this case series, we retrospectively enrolled all immunosuppressed patients with persistent SARS-CoV-2 infections treated at our centers between March 2022 and February 2023. Patients received different sequential or combination regimens, including antivirals (remdesivir, nirmatrelvir/ritonavir, or molnupiravir) and/or monoclonal antibodies (mAbs) (tixagevimab/cilgavimab or sotrovimab). The main outcome was a complete virological response (negative SARS-CoV-2 RT-PCR on nasopharyngeal swabs) at the end of treatment. Fifteen patients were included as follows: eleven (11/15; 73%) with hematological disease and four (4/15; 27%) with recently diagnosed HIV/AIDS infection. Six patients (6/15; 40%) received a single antiviral course, four patients (4/15; 27%) received an antiviral and mAbs sequentially, and two patients (13%) received three lines of treatment (a sequence of three antivirals or two antivirals and mAbs). A combination of two antivirals or one antiviral plus mAbs was administered in three cases (3/15, 20%). One patient died while still positive for SARS-CoV-2, while fourteen (14/15; 93%) tested negative within 16 days after the end of treatment. The median time to negativization since the last treatment was 2.5 days. Both sequential and combination regimens used in this study demonstrated high efficacy and safety in the high-risk group of immunosuppressed patients.

Background: The relationship between superinfection by multidrug-resistant Gram-negative bacteria and mortality among SARS-CoV-2 hospitalized patients is still unclear. Carbapenem-resistant Acinetobacter baumannii and carbapenemase-producing Enterobacterales are among the most frequently isolated species when it comes to hospital-acquired superinfections among SARS-CoV-2 patients. Methods: Herein, a retrospective study was carried out using data from adult patients hospitalized for COVID-19. The interaction between in-hospital mortality and rectal carriage and superinfection by carbapenemase-producing Enterobacterales and/or carbapenem-resistant Acinetobacter baumannii was assessed. Results: The incidence of KPC-producing Klebsiella pneumoniae and/or carbapenem-resistant Acinetobacter baumannii rectal carriage was 30%. Bloodstream infection and/or pneumonia due to KPC-producing Klebsiella pneumoniae and/or carbapenem-resistant Acinetobacter baumannii occurred in 20% of patients. A higher Charlson comorbidity index (OR 1.41, 95% CI 1.24–1.59), being submitted to invasive mechanical ventilation/ECMO ≥ 96 h (OR 6.34, 95% CI 3.18–12.62), being treated with systemic corticosteroids (OR 4.67, 95% CI 2.43–9.05) and having lymphopenia at the time of admission (OR 0.54, 95% CI 0.40–0.72) were the features most strongly associated with in-hospital mortality. Conclusions: Although KPC-producing Klebsiella pneumoniae and/or carbapenem-resistant Acinetobacter baumannii rectal carriage, and/or bloodstream infection/pneumonia were diagnosed in a remarkable percentage of COVID-19 patients, their impact on in-hospital mortality was not significant. Further studies are needed to assess the burden of antimicrobial resistance as a legacy of COVID-19 in order to identify future prevention opportunities.

Abstract Background Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ). Methods In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung–Knapp–Sidik–Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. Results A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. Conclusions Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care.

Abstract Background The management of non-fermentative gram-negative bloodstream infection (NFGN-BSI) offers numerous challenges. In this study the aim is to analyse a large cohort of patients with NFGN-BSI recruited in the northern Italy to describe epidemiology, etiological and susceptibility pattern, therapeutic management and outcome. Methods Multicentre retrospective cohort study of patients hospitalised at three large teaching hospitals in northern Italy in a fourth year period. Results 355 BSI episodes were analyzed, due to P. aeruginosa (72.7%), A. baumannii (16.6%), and Stenotrophomonas maltophilia (10.7%). Overall, 21.4% of isolates were defined as DTR, highest rate among A. baumannii (64.4%). All-cause 30-day mortality rate was 17.5%. Rates of XDR or DTR A. baumannii isolation were significantly higher in non-surviving patients. Independent risk factors for 30-day mortality were: age (HR 1.03, 95%CI 1.00–1.04, p = 0.003), septic shock (HR 2.84, 95%CI 1.67–4.82, p

mRNA-based vaccines were effective in contrasting SARS-CoV-2 infection. However, they presented several limitations of storage and supply chain, and their parenteral administration elicited a limited mucosal IgA immune response. Extracellular vesicles (EVs) have been recognized as a mechanism of cell-to-cell communication well-preserved in all life kingdoms, including plants. Their membrane confers protection from enzyme degradation to encapsulated nucleic acids favoring their transfer between cells. In the present study, EVs derived from the juice of an edible plant (Citrus sinensis) (oEVs) were investigated as carriers of an orally administered mRNA vaccine coding for the S1 protein subunit of SARS-CoV-2 with gastro-resistant oral capsule formulation. The mRNA loaded into oEVs was protected and was stable at room temperature for one year after lyophilization and encapsulation. Rats immunized via gavage administration developed a humoral immune response with the production of specific IgM, IgG, and IgA, which represent the first mucosal barrier in the adaptive immune response. The vaccination also triggered the generation of blocking antibodies and specific lymphocyte activation. In conclusion, the formulation of lyophilized mRNA-containing oEVs represents an efficient delivery strategy for oral vaccines due to their stability at room temperature, optimal mucosal absorption, and the ability to trigger an immune response.

Strongyloides and cytomegalovirus co-infections are rarely reported, even though they are distinguished by high morbidity and mortality, especially in immunocompromised hosts. We narratively reviewed the literature on reported cases of Strongyloides and CMV co-infections in immunosuppressed patients. Most cases occurred in males with a median age of 47 (IQR, 37–59). Strongyloides/CMV co-infections occurred among immunocompromised hosts, especially in solid organ transplants and hematological or rheumatological diseases. Most of the patients underwent a course of steroid treatment before the diagnosis of co-infections. Other common immunomodulatory agents were tacrolimus and mycophenolate. The first clinical manifestations of co-infections were mainly gastrointestinal, followed by respiratory symptoms. CMV was, in most patients, co-infected with an isolated reactivation, although Strongyloides manifested especially as hyperinfection syndrome. Ganciclovir and ivermectin are the mainstays of CMV and Strongyloides treatment. However, the treatment mortality reported in this narrative review is around 52.4%. Interestingly secondary bacterial infections are common in CMV/Strongyloides-infected patients.

To our knowledge, we have described the first case of Strongyloides/Cytomegalovirus (CMV) concomitant infection that occurred in a European country. The patient was a 76-year-old woman affected by relapsed non-Hodgkin lymphoma who presented interstitial pneumonia with a rapidly progressive worsening of respiratory insufficiency, leading to cardiac dysfunction and consequent death. CMV reactivation is a common complication in immunocompromised patients, while hyperinfection/disseminated strongyloidiasis (HS/DS) is rare in low endemic regions, but has been widely described in Southeast Asia and American countries. HS and DS are two consequences of the failure of infection control by the immune system: HS is the uncontrolled replication of the parasite within the host and DS the spreading of the L3 larvae in organs other than the usual replication sites. Only a few cases of HS/CMV infection have been reported in the literature, and only in one patient with lymphoma as an underlying disease. The clinical manifestations of these two infections overlap, usually leading to a delayed diagnosis and a consequent poor outcome.

Summary: Aim: To evaluate the changes in antimicrobial consumption and multidrug-resistant microorganism trends after introducing an empiric antimicrobial therapy manual to support antimicrobial stewardship. Methods: A 4-year prospective interventional study assessed the effect of introducing an empiric antimicrobial therapy manual in medical and surgical wards during two periods: pre-intervention period (January 2015–May 2017) and post-intervention period (June 2017–December 2019). Outcomes included microorganism trends of bloodstream infections (BSI) for Klebsiella pneumoniae carbapenemase-producing bacteria (KPC), extended spectrum beta-lactamase ESBL-E. coli, meticillin-resistant Staphylococcus aureus (MRSA) and Candida albicans. Also, Clostridioides difficile infection (CDI) episodes were included. Rates were normalised per 1000 patient-days (PD). Antimicrobial consumption was assessed as defined daily dose (DDD)/1000 PD in interrupted time series analysis. Results: In medical wards, we observed a significant decrease in the consumption of piperacillin-tazobactam and a decrease in the trends of tigecycline and vancomycin consumption. In surgical wards, there was a significant decrease in consumption of fluoroquinolones and piperacillin-tazobactam. This decrease was maintained in trend for all the antimicrobials but was significant for tigecycline only. In medical wards, there was a significant reduction of MRSA and C. albicans. In surgical wards, we observed a decrease in MRSA, ESBL-E. coli, C. albicans and CDI. KPC cases decreased by 22.5% in medical wards and 74.3% in surgical wards. Conclusion: The results suggest that a persuasive educational approach to antimicrobial stewardship, with the introduction of an empiric antimicrobial manual and continuous education, resulted in reductions in both antimicrobial use and healthcare-associated BSI caused by multidrug-resistant organisms. More studies with longer follow up are needed to investigate the effect of antimicrobial stewardship on clinical outcomes.

Abstract Introduction Edwardsiella tarda uncommonly infects humans. The usual presentation is mild gastroenteritis, but systemic manifestations may occur. Lethal infections are rarely documented in patients with underlying disorders. Case presentation A previously healthy 37-year-old Southeast Asian woman presented to our hospital with recent onset of abdominal pain, fever, and vomiting. Her condition rapidly deteriorated with signs and symptoms of fulminant septic shock; thus, she was intubated, supported with intravenous vasopressors and fluids, and transferred to the intensive care unit. An abdominal computed tomographic scan with contrast revealed multiple liver abscesses. Blood cultures were obtained and computed tomography–guided percutaneous drainage of the liver abscesses with supplementary cultures was performed; thereafter, empirical broad-spectrum antibiotics were initiated. All cultures grew E. tarda, whereas an antibiogram showed resistance to broad-spectrum antibiotics and sensitivity to ciprofloxacin and aminoglycosides; thus, the antibiotic regimen was updated accordingly. The patient made an uneventful recovery and was discharged from the intensive care unit 14 days after admission. Conclusion E. tarda human infection can present as liver abscess and fulminant septic shock. E. tarda strains can be resistant to broad-spectrum antibiotics; hence, culture-based antibiotics should be used accordingly. Clinicians should be aware of this rare and potentially lethal infection.

Objectives: Following the public-health emergency of international concern (PHEIC) declared by the World Health Organization (WHO) on 30 January 2020 and the recent outbreak caused by 2019 novel coronavirus (2019-nCoV) [officially renamed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)] in China and 29 other countries, we aimed to summarise the clinical aspects of the novelBetacoronavirus disease (COVID-19) and its possible clinical presentations together with suggested therapeutic algorithms for patients who may require antimicrobial treatment. Methods: The currently available literature was reviewed for microbiologically confirmed infections by 2019-nCoV or COVID-19 at the time of writing (13 February 2020). A literature search was performed using the PubMed database and Cochrane Library. Search terms included ‘novel coronavirus’ or ‘2019-nCoV’ or ‘COVID-19’. Results: Published cases occurred mostly in males (age range, 8–92 years). Cardiovascular, digestive and endocrine system diseases were commonly reported, except previous chronic pulmonary diseases [e.g. chronic obstructive pulmonary disease (COPD), asthma, bronchiectasis] that were surprisingly underreported. Fever was present in all of the case series available, flanked by cough, dyspnoea, myalgia and fatigue. Multiple bilateral lobular and subsegmental areas of consolidation or bilateral ground-glass opacities were the main reported radiological features of 2019-nCoV infection, at least in the early phases of the disease. Conclusion: The new 2019-nCoV epidemic is mainly associated with respiratory disease and few extrapulmonary signs. However, there is a low rate of associated pre-existing respiratory co-morbidities.

Objectives: Infections caused by multidrug-resistant Gram-negative bacteria are associated with high mortality. A relevant concern is the efficacy of antibiotic therapy in burn patients in whom pathophysiological changes strongly influence pharmacokinetic (PK) parameters. This study aimed to describe the PK parameters of meropenem in a population of burn patients. Methods: Blood samples were collected immediately before and 2 h and 5 h after the start of intravenous drug administration. Plasma meropenem concentrations were determined using an ultra-performance liquid chromatography–photodiode array method. Results: Seventeen burn patients were enrolled in the study. Thirteen patients (76%) were treated with meropenem for infections byPseudomonas aeruginosa or Acinetobacter baumannii isolated from blood or wounds. Mean Cmax, Cmin, AUC0–24, half-life, drug clearance and volume of distribution were 28.9 mg/L, 3.7 mg/L, 280.2 mg h/L, 2.0 h, 19.0 L/h and 44.4 L, respectively. Six patients (35%) achieved a Cmin ≥3.3 mg/L and seven patients (41%) achieved a Cmax ≥ 28.4 mg/L, whilst nine patients (53%) achieved an AUC0–24 of >226 mg h/L. Given a minimum inhibitory concentration (MIC) of 0.5 mg/L, all patients satisfied the target AUC/MIC of >125, but when the MIC rises to 2 mg/L (the ECOFF), only five patients reached the desired AUC/MIC. Regarding fT>MIC at an MIC of 2 mg/L with a 2-h infusion time, 13 patients (76%) achieved the PK target (>75%). Conclusion: These data suggest that a combined 2-h infusion with a higher dosage of meropenem, including a loading dose, may be successful to achieve effective PK parameters.

Objectives: The aim of this study was to assess colistin use in a country endemic for multidrug-resistant Gram-negative bacteria (MDR-GNB). Methods: Colistin prescription patterns were evaluated in 22 Italian centres. Factors associated with use of colistin in combination with other anti-MDR-GNB agents were also assessed. Results: A total of 221 adults receiving colistin were included in the study. Their median age was 64 years (interquartile range 52–73 years) and 134 (61%) were male. Colistin was mostly administered intravenously (203/221; 92%) and mainly for targeted therapy (168/221; 76%). The most frequent indications for colistin therapy were bloodstream infection and lower respiratory tract infection. Intravenous colistin was administered in combination with at least another anti-MDR-GNB agent in 80% of cases (163/203). A loading dose of 9 MU of colistimethate was administered in 79% of patients receiving i.v. colistin and adequate maintenance doses in 85%. In multivariable analysis, empirical therapy [odds ratio (OR) = 3.25, 95% confidence interval (CI) 1.24–8.53;P = 0.017] and targeted therapy for carbapenem-resistant Enterobacterales infection (OR = 4.76, 95% CI 1.69–13.43; P = 0.003) were associated with use of colistin in combination with other agents, whilst chronic renal failure (OR = 0.39, 95% CI 0.17–0.88; P = 0.024) was associated with use of colistin monotherapy. Conclusion: Colistin remains an important option for severe MDR-GNB infections when other treatments are not available. Despite inherent difficulties in optimising its use owing to peculiar pharmacokinetic/pharmacodynamic characteristics, colistin was mostly used appropriately in a country endemic for MDR-GNB.

Background: COVID-19 is characterized by an uncontrolled inflammatory response with high pro-inflammatory cytokine production through the activation of intracellular pathways, such as mitogen-activated protein kinase (MAPK). Viruses are able to exploit the MAPK pathway to their advantage; this pathway relevance to severe COVID-19 is poorly described. The aim of this study was to quantify biomarkers involved in the MAPK pathway and to clarify its possible role in affecting some COVID-19-related clinical features. Methods: H-RAS, C-RAF, MAPK1, MAPK2, and ERK were quantified through ELISA, and genetic polymorphisms were evaluated through real-time PCR. Results: We prospectively recruited 201 individuals (158 positive and 43 negative for SARS-CoV-2): 35 were male, and their median age was 65 years. MAPK-related biomarker levels were increased in SARS-CoV-2-positive participants (n = 89) compared to negative ones (n = 29). Dyspnea was reported by 48%; this symptom was associated with PBMC C-RAF levels in positive participants (p = 0.022) and type of ventilation (p = 0.031). The highest degree of ventilation was used by 8% for invasive ventilation and 41% for continuous positive airway pressure (CPAP). Conclusions: This is the first study that showed a possible contribution of MAPK-related biomarkers in affecting COVID-19 clinical features, and this may be relevant for identifying COVID-19 positive participants at risk of serious complications.

Bloodstream infections (BSI) are an increasing cause of admissions to hospitals. Non-hospital-acquired BSI are defined by blood cultures that are positive less than 48 hours after admission, but a relevant difference exists between community-acquired and healthcare-associated (HCA) BSI in terms of risk of multidrug resistance (MDR). We planned a retrospective study in three different cohorts in order to develop and to temporally and spatially validate an easy and rapid prognostic model for identifying MDR non-hospital-acquired (non-HA) BSI. The pathogens most involved in BSI are Staphylococcus spp. and Escherichia coli, responsible for about 75% of all MDR isolated. The model includes age, gender, long-term care facility admission, immunocompromise, any recent invasive procedures and central line placement, recent intravenous treatment and antibiotic treatment. It shows an acceptable performance, especially for intermediate probabilities of MDR infection, with a C-index of 70%. The model was proposed in a nomogram that could allow better targeting of antibiotic therapy for non-HA BSI admitted in hospital. However, it should be further validated to determine its applicability in other populations.

Oritavancin is a long-acting lipoglycopeptide with in vitro activity against Gram-positive pathogens, as well as good bactericidal activity and sterilisation ability in biofilm. It has been approved for acute bacterial skin and skin structure infections (ABSSSI), but recent reports have demonstrated possible off-label uses, such as for vancomycin resistant enterococci (VRE), deep-seated infections including those involving prosthetic material and invasive infections. The aim of this work is to review the uses of oritavancin outside of ABSSSI, focusing on its real-life applications on infective endocarditis, catheter- or device-related infections, bloodstream infections, and bone and prosthetic joint infections in humans, as well as possible future applications. We performed a narrative review, collecting the literature published between 1 December 2002 and 1 November 2022 on PubMed and the Cochrane Library using the term ‘oritavancin’. Available studies have shown how effective it is in different settings, suggesting an opportunity for step-down strategies or outpatient management of infections requiring a long duration of antibiotic treatment. So far, evidence is still scarce, and limited to a few studies and case reports, mostly focusing on Staphylococcus aureus as the major isolate. Concerns about fluid intake for dilution and interaction with coagulation markers also need to be taken into account. Further studies are required in order to assess the safety and effectiveness of Oritavancin in vascular, prosthetic, or device-related infections, as well as in resistant Gram-positive bacteria or enterococcal infections.

The use of venoarterial (VA) extracorporeal membrane oxygenation therapy (ECMO) in patients admitted to cardiac intensive care units (CICU) has increased. Data regarding infections in this population are scarce. In this retrospective study, we analyzed the risk factors, outcome, and predictors of in-hospital mortality due to nosocomial infections in patients with ECMO admitted to a single coronary intensive care unit between July 2013 and March 2019 treated with VA-ECMO for >48 h. From 69 patients treated with VA-ECMO >48 h, (median age 58 years), 29 (42.0%) patients developed 34 episodes of infections with an infection rate of 0.92/1000 ECMO days. The most frequent were ventilator-associated pneumonia (57.6%), tracheobronchitis (9.1%), bloodstream infections (9.1%), skin and soft tissue infections (9.1%), and cytomegalovirus reactivation (9.1%). In-hospital mortality was 47.8%, but no association with nosocomial infections was found (p = 0.75). The number of days on ECMO (OR 1.14, 95% CI 1.01–1.30, p = 0.029) and noninfectious complications were higher in the infected patients (OR: 3.8 95% CI = 1.05–14.1). A higher baseline creatinine value (OR: 8.2 95% CI = 1.12–60.2) and higher blood lactate level at 4 h after ECMO initiation (OR: 2.0 95% CI = 1.23–3.29) were significant and independent risk factors for mortality. Conclusions: Nosocomial infections in medical patients treated with VA-ECMO are very frequent, mostly Gram-negative respiratory infections. Preventive measures could play an important role for these patients.

Background: Evidence has shown that short courses of antibiotic therapy are at least as effective as long courses with better clinical outcomes. CAZ/AVI has demonstrated its clinical efficacy in treating K. pneumoniae-KPC infections. Methods: We conducted an analysis based on the real-life data of our ten years retrospective cohort to assess the cost-effectiveness and cost-utility of a short course of CAZ/AVI plus source control compared to a long course plus source control. A Markov model was structured. Patient transition between health states was modeled, each transition has a probability, and each state has a cost and a utility. Incremental cost-effectiveness ratios (ICERs) were obtained by dividing the difference in costs by the difference in utilities between the two courses. Input parameter uncertainty was investigated through sensitivity analysis. We launched 1000 Monte Carlo simulations by iteratively perturbing variables within estimated variation ranges, obtaining an ICER result for each simulation. Results: In the first model (old appropriate treatment), a short course of treatment was associated with reduced costs per patient per year of €4818.60 and reduced effects (0.10 QALYs), compared to a long course. In the CAZ/AVI model, the short course was associated with increased costs of €1297.9 and with increased effects (0.04 QALYs), resulting in an ICER of €32,317.82 per QALY gained, below the WTP threshold of €40,000. Conclusions: Our findings highlight additional evidence regarding the cost-effectiveness of CAZ/AVI for policy-makers. We outline that CAZ/AVI could be cost-effective compared to old appropriate antibiotic therapies for KPC-Kp BSI.

Bloodstream infections (BSI) are life-threatening complications for onco-hematologic patients. Fluoroquinolones prophylaxis (FQP) was recommended for patients with neutropenia. Later, it was correlated with increased resistance rates among this population and its role became debated. While the role of FQ prophylaxis is still being studied, its cost-effectiveness is also unknown. The objective of this study was to evaluate the costs and effects associated with two alternative strategies (FQP vs. no prophylaxis) for patients with hematological malignancies undergoing allogenic stem cell transplant (HSCT). A decision-tree model was built integrating retrospectively collected data from a single transplant center, part of a tertiary teaching hospital in Northern Italy. Probabilities, costs and effects were considered in the assessment of the two alternative strategies. Probabilities of colonization, BSIs, extended-spectrum beta lactamase (ESBL) and Klebsiella pneumoniae carbapenemase (KPC) BSIs and mortality associated with infection, as well as median duration of length of stay (LOS) were calculated based on data collected between 2013 and 2021. The center applied the strategy of FQP between 2013 and 2016, and of no prophylaxis between 2016 and 2021. Data on 326 patients were collected during the considered time period. Overall, the rates of colonization, BSI, KPC/ESBL BSI, and mortality were 6.8% (95% confidence interval (CI) 2.7–13.5), 42% (9.9–81.4) and 20.72 (16.67–25.26), respectively. A mean bed-day cost of 132€ was estimated. Considering no prophylaxis vs. prophylaxis, the difference in costs ranged between additional 33.61 and 80.59€ per patient, whereas the difference in effects ranged between 0.11 and 0.03 life-years (LYs) lost (around 40 and 11 days). Given the small differences in terms of costs and effects between the two strategies, no prophylaxis seems an appropriate choice. Furthermore, this analysis did not consider the broader effect on hospital ecology of multiple doses of FQP, which could provide further support for the strategy of no prophylaxis. Our results suggest that the necessity for FQP in onco-hematologic setting should be determined based on local antibiotic resistance patterns.

Plant-derived extracellular vesicles (EVs) may represent a platform for the delivery of RNA-based vaccines, exploiting their natural membrane envelope to protect and deliver nucleic acids. Here, EVs extracted from orange (Citrus sinensis) juice (oEVs) were investigated as carriers for oral and intranasal SARS-CoV-2 mRNA vaccine. oEVs were efficiently loaded with different mRNA molecules (coding N, subunit 1 and full S proteins) and the mRNA was protected from degrading stress (including RNase and simulated gastric fluid), delivered to target cells and translated into protein. APC cells stimulated with oEVs loaded with mRNAs induced T lymphocyte activation in vitro. The immunization of mice with oEVs loaded with S1 mRNA via different routes of administration including intramuscular, oral and intranasal stimulated a humoral immune response with production of specific IgM and IgG blocking antibodies and a T cell immune response, as suggested by IFN-γ production by spleen lymphocytes stimulated with S peptide. Oral and intranasal administration also triggered the production of specific IgA, the mucosal barrier in the adaptive immune response. In conclusion, plant-derived EVs represent a useful platform for mRNA-based vaccines administered not only parentally but also orally and intranasally.

Background—Allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients are subject to major risks for bacterial bloodstream infections (BSIs), including emergent multidrug-resistant (MDR) organisms, which still represent the main cause of morbidity and mortality in transplanted patients. Methods: We performed an observational, retrospective, single-center study on patients undergoing allo-HSCT between 2004 and 2020 at the Stem Cell Transplant Unit in Turin to assess the incidence, etiology, and outcomes of BSIs and to explore any risk factors for bacteriaemia. Results: We observed a total of 178 bacterial BSIs in our cohort of 563 patients, resulting in a cumulative incidence of 19.4%, 23.8%, and 28.7% at 30, 100, and 365 days, respectively. Among isolated bacteria, 50.6% were Gram positive (GPB), 41.6% were Gram negative (GNB), and 7.9% were polymicrobial infections. Moreover, BSI occurrence significantly influenced 1-year overall survival. High and very high Disease Risk Index (DRI), an haploidentical donor, and antibacterial prophylaxis were found as results as independent risk factors for bacterial BSI occurrence in multivariate analysis. Conclusions: In our experience, GNB have overwhelmed GPB, and fluoroquinolone prophylaxis has contributed to the emergence of MDR pathogens. Local resistance patterns and patients’ characteristics should therefore be considered for better management of bacteremia in patients receiving an allogeneic HSCT.

Objectives: Arterial hypertension is still the most frequent cause of cardiovascular and cerebrovascular morbidity and mortality. Antihypertensive treatment has proved effective in reduction of cardiovascular risk. Nevertheless, lifestyle interventions and pharmacological therapy in some cases are ineffective in reaching blood pressure target values, despite full dose and poly-pharmacological treatment. Poor adherence to medications is an important cause of treatment failure. Different methods to assess therapeutic adherence are currently available: Therapeutic drug monitoring in biological fluids has previously demonstrated its efficacy and reliability. Plasma and urine have been already used for this purpose, but they may be affected by some practical limitations. Saliva may represent a feasible alternative.Methods: Fourteen antihypertensive drugs and two metabolites were simultaneously tested in plasma, urine, and saliva. Tested molecules included: atenolol, nebivolol, clonidine, ramipril, olmesartan, telmisartan, valsartan, amlodipine, nifedipine, doxazosin, chlorthalidone, hydrochlorothiazide, indapamide, sacubitril, ramiprilat, and sacubitrilat. Therapeutic drug monitoring was performed using ultra-high performance liquid chromatography, coupled to tandem mass spectrometry (UHPLC-MS/MS). The method has been preliminarily evaluated in a cohort of hypertensive patients.Results: The method has been validated according to US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines. The application on a cohort of 32 hypertensive patients has demonstrated sensibility and specificity of 98% and 98.1%, respectively, with a good feasibility in real-life clinical practice.Conclusion: Saliva may represent a feasible biological sample for therapeutic drug monitoring by non-invasive collection, prompt availability, and potential accessibility also in out-of-clinic settings.

BackgroundAllogeneic hematopoietic stem cell transplant (allo-HSCT) recipients are exposed to an increased risk of invasive fungal infections (IFIs) due to neutropenia, immunosuppressive treatments, graft-versus-host disease (GvHD) and incomplete immune reconstitution. Although clinical benefit from antifungal prophylaxis has been demonstrated, IFIs remain a leading cause of morbidity and mortality in these patients. In the last decades, attention has also been focused on potential risk factors for IFI to tailor an antifungal prevention strategy based on risk stratification.Aim of the StudyThis retrospective single-center study aimed to assess the epidemiology and the prognostic factors of IFI in a large cohort of allo-HSCT patients.MethodsBetween January 2004 and December 2020, 563 patients with hematological malignancies received an allo-HSCT at the Stem Cell Transplant Unit in Turin: 191 patients (34%) received grafts from a matched sibling donor, 284 (50.5%) from a matched unrelated donor, and 87 (15.5%) from an haploidentical family member. The graft source was peripheral blood in 81.5% of the patients. Our policy for antifungal prophylaxis included fluconazole in matched related and unrelated donors, while micafungin was administered in patients receiving haploidentical transplant. According to this practice, fluconazole was administered in 441 patients (79.6%) and micafungin in 62 (11.2%), while only 9 patients received mold-active prophylaxis. Galactomannan testing was routinely performed twice a week; patients with persisting fever unresponsive to broad spectrum antibiotics were evaluated with lung high-resolution computed tomography (HRCT) scan. In case of imaging suggestive of IFI, bronchoalveolar lavage (BAL) was performed whenever feasible.Statistical AnalysisOnly probable/proven IFI (PP-IFI) occurring during the first 12 months after transplant have been evaluated. IFIs were classified as probable or proven according to the new revised European Organization for Research and Treatment of Cancer (EORTC)/Mycoses Study Group (MSG) consensus criteria. Multivariate competing risk regression, binary logistic, and proportional hazard models were performed to identify risk factors for PP-IFI.ResultsA total of 58 PP-IFIs (n = 47 probable; n = 11 proven) occurred in our patients resulting in a cumulative incidence of 4.1%, 8.1%, and 9.6% at 30, 180, and 365 days, respectively. Molds were the predominant agents (n = 50 Aspergillus; n = 1 Mucor), followed by invasive candidemia (n = 5 non-albicans Candida; n = 1 Candida albicans; n = 1 Trichosporon). Lung was the most frequent site involved in patients with mold infections (47/51, 92.2%). Median time from HSCT to IFI was 98.44 days (0–365 days). Only 34.5% of patients with IFI were neutropenic at the time of infection. The presence of IFI had a significant impact on overall survival at 1 year (IFI, 32.8% vs. non-IFI, 54.6%; p < 0.001). IFI-related mortality rate was 20.7% in the overall population, 17% in patients with probable IFI, and 36% in patients with proven IFI. Multivariate competing risk regression revealed that donor type was the factor significantly associated to the risk of IFI [subdistribution hazard ratio (SDHR), 1.91, IC 1.13–3.20; p = 0.015]. BAL was informative in a consistent number of cases (36/57, 63.2%) leading to the identification of fungal (21), bacterial (4), viral (3), and polymicrobial (8) infections. Overall, 79 patients (14%) received a diagnostic-driven treatment, and 63 patients (11.2%) received a fever-driven treatment. Liposomal amphoteric B was the drug used in the majority of patients receiving diagnostic-driven therapy (30/79, 38%), while caspofungin was administered more frequently in patients who received a fever-driven strategy (27/63, 42.9%).ConclusionAccording to our experience, a non-mold active prophylaxis in patients undergoing allo-HSCT is feasible when combined with an intensive diagnostic work-up including CT scan and BAL. BAL performed at the onset of the disease may provide informative results in most patients. A diagnostic-driven treatment strategy may contribute to limit the use of costly antifungal therapies.

Objectives: To explore the Cytomegalovirus (CMV) burden on the long-term post-transplant course in different donor ages, we evaluated the incidence and risk factors for CMV in our kidney-transplanted patients (KTs) with extensive adoption of expanded-criteria donors (ECDs). Methods: Retrospective evaluation of 929 consecutive first KTs (49.5% receiving an organ from a donor ≥ 60 years) performed between 01-2003 and 12-2013. Overall survival was estimated using Kaplan–Meier curves; cumulative incidence function was additionally analyzed to consider the potential role of death with a functioning graft as a competitive event with graft dysfunction and to avoid overestimation. Apart from regular DNAemia monitoring in all patients, prophylaxis was adopted in high-risk groups (D+/R− or recipients of anti-thymocyte globulin induction), with pre-emptive therapy in the remaining groups. Results: CMV incidence was 19.5% (4–34.9% according to serostatus combination: D−/R−, D−/R+, D+/R+, D+/R−). Donor and recipient age, recipient pre-transplant hypertension, DR antigen compatibility, cold ischemia time, and post-transplant early complications, including rejection, urologic and renal artery stenosis, and lower renal function and proteinuria ≥ 0.5 g/day at one year after KT were associated with CMV. CMV determined lower death-censored graft survival (DCGS) (p < 0.01), with a prominent effect in R+ (p < 0.01) and without impact in R− (p = 0.32 in D−/R− and p = 0.006 in D+/R−). Interestingly, CMV occurrence influenced DCGS only in KTs who received grafts from donors < 50 or 50–69 years old (p < 0.01), while it was not significant with older donors (p = 0.07). The analysis of the cumulative incidence of graft loss accounting for death as a competing risk confirmed all these findings. In multivariate analysis, CMV replication/disease in the first year was an independent predictor for DCGS (HR 1.73 [1.3–2.3]). Conclusions: In a large population with extensive ECD adoption, CMV viremia in the first year demonstrates its harmful effect with an independent role for graft loss and significant impact among R+ recipients and KTs with donors < 70 years.

Legionella pneumophila (LP) is one of the main causative agents of community-acquired pneumonia in Europe and its fifth bacterial cause in Italy (4.9%). We conducted a seven year retrospective analysis of LP infection serogroup 1 in Asti, Piedmont, between 2016 and 2022. Patients were included if they tested positive for the Legionella urinary antigen. Clinical, laboratory, and radiologic data were analyzed to describe the risk factors for mortality. Fifty patients with LD were collected, mainly male, with a median age of 69 years. The main comorbidities were cardiovascular diseases (50%), pulmonary diseases (26%), and neurological diseases (12%). The most common clinical presentations were fever, respiratory, gastrointestinal, and neurologic symptoms. Older age (p = 0.004), underlying cardiovascular diseases (p = 0.009), late diagnosis at admission (p = 0.035), and neurological symptoms at diagnosis (p = 0.046) were more common in the non-survivor group. Moreover, a septic-shock presentation or the need for non-invasive ventilation at admission were associated with a higher mortality. No considerable differences in the biochemical data were found between the two groups except for the median neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio, and PCT value. We did not find any differences in mortality related to the choice of antibiotic regimen. Differences in outcome were associated with the median duration of treatment (p =< 0.001) but not to the choice of antibiotic regimen (mainly levofloxacin or azithromycin). In conclusion, early individuation of the wide spectrum of clinical characteristics of LP infection such as respiratory, cardiac, and neurological manifestations of the patient’s comorbidities, and significant biochemical data should help clinicians flag high risk patients and potentially improve their outcome.

Rapid detection of extended-spectrum-β-lactamase (ESBL) is of paramount importance to accelerate clinical decision-making, optimize antibiotic treatment, and implement adequate infection control measures. This study was aimed at assessing the impact of direct detection of CTX-M ESBL-producers on antimicrobial management of Escherichia coli bloodstream infections over a 2-year period. This study included all E. coli bloodstream infection (BSI) events that were serially processed through a rapid workflow with communication to the clinicians of direct detection of CTX-M ESBL-producers and conventional culture-based workflow. Antimicrobial management was retrospectively analyzed to assess the contribution of the rapid test result. A total of 199 E. coli BSI events with a report of direct detection of CTX-M ESBL production results were included. Of these, 33.7% (n = 67) and 66.3% (n = 132) were reported as positive and negative CTX-M producers, respectively. Detection of CTX-M positive results induced more antibiotic therapy modifications (mainly towards carbapenem-containing regimens, p < 0.01), and antimicrobial susceptibility testing results of CTX-M ESBL-producing E. coli isolates induced more antibiotic escalations towards carbapenem-containing regimens (p < 0.01). Direct detection of CTX-M ESBL-producing E. coli resulted in a remarkable rate of antibiotic optimizations on the same day of blood culture processing. Observing antibiotic management following the availability of antimicrobial susceptibility testing results, additional early optimizations in escalation could probably have been made if the rapid test data had been used. Detection of CTX-M negative results resulted in few therapeutic changes, which could have probably been higher, integrating epidemiological and clinical data.

Background: Cefiderocol is a novel parenteral siderophore cephalosporin, demonstrating enhanced activity against multidrug-resistant (MDR) Gram-negative bacteria and difficult-to-treat Acinetobacter baumannii (DTR-AB). Plasma-free trough concentration (fCtrough) over the minimum inhibitory concentration (MIC) was reported as the best pharmacokinetic parameter to describe the microbiological efficacy of cefiderocol. Materials and methods: We retrospectively described the pharmacokinetic and pharmacodynamic profile of three critically ill patients admitted to the intensive care unit, receiving cefiderocol under compassionate use to treat severe DTR-AB infections while undergoing continuous venovenous haemofiltration. Cefiderocol was administrated at a dosage of 2 g every 8 h infused over 3 h. Therapeutic drug monitoring (TDM) was assessed at the steady state. Cthrough was evaluated by assuming a plasma protein binding of 58.0%. The fCmin/MIC was calculated assuming a cefiderocol MIC equal to the PK-PD breakpoint of susceptibility ≤ 2. The association between the PK/PD parameters and microbiological outcome was assessed. Results: fCtrough/MIC were >12 in 2 patients and 2.9 in the 1 who rapidly recovered from renal failure. Microbiological cure occurred in 3/3 of patients. None of the 3 patients died within 30 days. Conclusions: A cefiderocol dosage of 2 g q8 h in critically ill patients with AKI undergoing CVVH may bring about a very high plasma concentration, corresponding to essentially 100% free time over the MIC for DTR-AB.