Risk factors for persistent enterococcal bacteraemia: a multicentre retrospective study

Enterococcal bacteraemia; Enterococcus; Persistent bacteraemiaBacteriemia enterocócica, Enterococo; Bacteriemia persistenteBacterèmia enterocòccica; Enterococ; Bacterèmia persistentObjectives Conditions favouring persistent enterococcal bacteraemia (p-EB) have not been fully investigated yet. The aim of our study is to analyse risk factors for p-EB and its impact on mortality. Methods International two-centre retrospective study of all hospitalised adults with enterococcal bacteraemia managed with follow-up blood cultures (BCs) during the period 2011–2019. Exclusion criteria were: (1) death within 72 hours from index BCs and (2) polymicrobial bacteraemia. Primary endpoint was p-EB, defined as further isolation of the same species of Enterococcus spp. from BCs after at least 72 hours of appropriate antibiotic therapy. Multivariable logistic regression model was performed to assess risk factors for p-EB. The impact of p-EB on 30-day mortality was assessed by Kaplan-Meier survival curve and Cox regression multivariable model. Results During the study period, 244 enterococcal bacteraemia were diagnosed. P-EB were 13.5% (33/244). At multivariable analysis, factors independently associated with p-EB were hematologic malignancy (OR 4.60 [95% CI 1.32–16.00], P = 0.01), infective endocarditis (OR 7.99 [95% CI 2.20–28.9], P = 0.002), and use of daptomycin as initial treatment (OR 4.50 [95% CI 1.29–15.61], P = 0.018). Mortality rate was higher in the p-EB group (32% vs. 18%). Kaplan-Meier survival curve showed that patients with p-EB were less likely to survive at 30 days from index BCs (log-rank P = 0.002). Using a Cox regression model, independent predictors of 30-day mortality were hematologic malignancy (HR 2.30 [95% CI 1.02–4.11], P = 0.043), p-EB (HR 1.93 [95% CI 0.92–4.04], P = 0.08), and septic shock (HR 5.92 [95% CI 2.17–16.30], P = 0.001). Conclusion P-EB was diagnosed mainly in very fragile patients and in those receiving daptomycin as frontline therapy. P-EB may have an impact on mortality

Relationship between Pharmacokinetic/Pharmacodynamic Target Attainment and Microbiological Outcome in Critically Ill COVID-19 Patients with Documented Gram-Negative Superinfections Treated with TDM-Guided Continuous-Infusion Meropenem

Objectives: The objective of this study was to explore the relationship between pharmacokinetic/pharmacodynamic (PK/PD) target attainment of continuous-infusion (CI) meropenem and microbiological outcome in critical COVID-19 patients with documented Gram-negative superinfections. Methods: Patients receiving CI meropenem for documented Gram-negative infections at the COVID ICU of the IRCCS Azienda Ospedaliero-Universitaria di Bologna and undergoing therapeutic drug monitoring from January 2021 to February 2022 were retrospectively assessed. Average steady-state meropenem concentrations (C-ss) were calculated and the C-ss/MIC ratio was selected as a pharmacodynamic parameter of meropenem efficacy. The C-ss/MIC ratio was defined as optimal if >= 4, quasi-optimal if between 1 and 4, and suboptimal if <1. The relationship between C-ss/MIC and microbiological outcome was assessed. Results: Overall, 43 critical COVID-19 patients with documented Gram-negative infections were retrieved. Combination therapy was implemented in 26 cases. C-ss/MIC ratios were optimal in 27 (62.8%), quasi-optimal in 7 (16.3%), and suboptimal in 9 cases (20.9%). Microbiological failure occurred in 21 patients (48.8%), with no difference between monotherapy and combination therapy (43.8% vs. 53.8%; p = 0.53). The microbiological failure rate was significantly lower in patients with an optimal C-ss/MIC ratio compared to those with a quasi-optimal or suboptimal C-ss/MIC ratio (33.3% vs. 75.0%; p = 0.01). Conclusion: Suboptimal attainment of meropenem PK/PD targets may be a major determinant impacting on microbiological failure in critical COVID-19 patients with Gram-negative superinfections

Cefiderocol treatment for carbapenem-resistant Acinetobacter baumannii infection in the ICU during the COVID-19 pandemic: a multicentre cohort study

open16noFunding: This study was carried out as part of our routine work and supported by internal funding.Objectives: To analyse the impact of cefiderocol use on outcome in patients admitted to the ICU for severe COVID-19 and further diagnosed with carbapenem-resistant Acinetobacter baumannii (CR-Ab) infection.Methods: Retrospective multicentre observational study was performed at four Italian hospitals, from January 2020 to April 2021. Adult patients admitted to ICU for severe COVID-19 and further diagnosed with CR-Ab infections were enrolled. Patients treated with cefiderocol, as compassionate use, for at least 72 h were compared with those receiving alternative regimens. Primary endpoint was all-cause 28 day mortality. The impact of cefiderocol on mortality was evaluated by multivariable Cox regression model.Results: In total, 107 patients were enrolled (76% male, median age 65 years). The median time from ICU admission to CR-Ab infection diagnosis was 14 (IQR 8-20) days, and the main types of CR-Ab infections were bloodstream infection (58%) and lower respiratory tract infection (41%). Cefiderocol was administered to 42 patients within a median of 2 (IQR 1-4) days after CR-Ab infection diagnosis and as monotherapy in all cases. The remaining patients received colistin, mostly (82%) administered as combination therapy. All-cause 28 day mortality rate was 57%, without differences between groups (cefiderocol 55% versus colistin 58% P = 0.70). In multivariable analysis, the independent risk factor for mortality was SOFA score (HR 1.24, 95% CI 1.15-1.38, P < 0.001). Cefiderocol was associated with a non-significant lower mortality risk (HR 0.64, 95% CI 0.38-1.08, P = 0.10).Conclusions: Our study confirms the potential role of cefiderocol in the treatment of CR-Ab infection, but larger clinical studies are needed.openPascale, Renato; Pasquini, Zeno; Bartoletti, Michele; Caiazzo, Luca; Fornaro, Giacomo; Bussini, Linda; Volpato, Francesca; Marchionni, Elisa; Rinaldi, Matteo; Trapani, Filippo; Temperoni, Chiara; Gaibani, Paolo; Ambretti, Simone; Barchiesi, Francesco; Viale, Pierluigi; Giannella, MaddalenaPascale, Renato; Pasquini, Zeno; Bartoletti, Michele; Caiazzo, Luca; Fornaro, Giacomo; Bussini, Linda; Volpato, Francesca; Marchionni, Elisa; Rinaldi, Matteo; Trapani, Filippo; Temperoni, Chiara; Gaibani, Paolo; Ambretti, Simone; Barchiesi, Francesco; Viale, Pierluigi; Giannella, Maddalen

Risk factors for persistent enterococcal bacteraemia: a multicentre retrospective study

Objectives: Conditions favouring persistent enterococcal bacteraemia (p-EB) have not been fully investigated yet. The aim of our study is to analyse risk factors for p-EB and its impact on mortality.Methods: International two-centre retrospective study of all hospitalised adults with enterococcal bacteraemia managed with follow-up blood cultures (BCs) during the period 2011-2019. Exclusion criteria were: (1) death within 72 hours from index BCs and (2) polymicrobial bacteraemia. Primary endpoint was p-EB, defined as further isolation of the same species of Enterococcus spp. from BCs after at least 72 hours of appropriate antibiotic therapy. Multivariable logistic regression model was performed to assess risk factors for p-EB. The impact of p-EB on 30-day mortality was assessed by Kaplan-Meier survival curve and Cox regression multivariable model.Results: During the study period, 244 enterococcal bacteraemia were diagnosed. P-EB were 13.5% (33/244). At multivariable analysis, factors independently associated with p-EB were hematologic malignancy (OR 4.60 [95% CI 1.32-16.00], P = 0.01), infective endocarditis (OR 7.99 [95% CI 2.20-28.9], P = 0.002), and use of daptomycin as initial treatment (OR 4.50 [95% CI 1.29-15.61], P = 0.018). Mortality rate was higher in the p-EB group (32% vs. 18%). Kaplan-Meier survival curve showed that patients with p-EB were less likely to survive at 30 days from index BCs (log-rank P = 0.002). Using a Cox regression model, independent predictors of 30-day mortality were hematologic malignancy (HR 2.30 [95% CI 1.02-4.11], P = 0.043), p-EB (HR 1.93 [95% CI 0.92-4.04], P = 0.08), and septic shock (HR 5.92 [95% CI 2.17-16.30], P = 0.001).Conclusion: P-EB was diagnosed mainly in very fragile patients and in those receiving daptomycin as frontline therapy. P-EB may have an impact on mortality.(c) 2022 Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/

A modular phage vector platform for targeted photodynamic therapy of Gram-negative bacterial pathogens

: Growing antibiotic resistance has encouraged the revival of phage-inspired antimicrobial approaches. On the other hand, photodynamic therapy (PDT) is considered a very promising research domain for the protection against infectious diseases. Yet, very few efforts have been made to combine the advantages of both approaches in a modular, retargetable platform. Here, we foster the M13 bacteriophage as a multifunctional scaffold, enabling the selective photodynamic killing of bacteria. We took advantage of the well-defined molecular biology of M13 to functionalize its capsid with hundreds of photo-activable Rose Bengal sensitizers and contemporarily target this light-triggerable nanobot to specific bacterial species by phage display of peptide targeting moieties fused to the minor coat protein pIII of the phage. Upon light irradiation of the specimen, the targeted killing of diverse Gram(-) pathogens occurred at subnanomolar concentrations of the phage vector. Our findings contribute to the development of antimicrobials based on targeted and triggerable phage-based nanobiotherapeutics

Relationship between immune response to SARS-CoV2 vaccines and development of breakthrough infection in solid organ transplant recipients: the CONTRAST cohort

Background: SARS-CoV-2 vaccination in solid organ transplant (SOT) is associated with poorer antibody response (AbR) compared to non-SOT recipients. However, its impact on the risk of breakthrough infection (BI) should yet be assessed. Methods: Single-center prospective longitudinal cohort study enrolling adult SOT recipients who received SARS-CoV2 vaccination during 1-year period from February 2021, and followed-up to April 30th 2022. Patients were tested for AbR at multiple timepoints. Primary endpoint was BI (laboratory confirmed SARS-CoV2 infection ≥14 days after 2nd dose). Immunization (positive AbR) was considered an intermediate state between vaccination and BI. Probabilities of being in vaccination, immunization and BI states were obtained for each type of graft and vaccination sequence with multistate survival analysis, then multivariable logistic regression was performed to analyse the risk of BI in AbR levels. Results: 614 SOT (275 kidney, 163 liver, 137 heart, 39 lung) recipients were included. Most patients (84.7%) received three vaccine doses, the first two consisted of BNT162b2 and mRNA-1273 in 73.5% and 26.5% of cases, respectively; while at the third dose mRNA-1273 was administered in 59.8% of patients. Overall, 75.4% of patients reached immunization and 18.4% developed BI. Heart transplant recipients showed lowest probability of immunization (0.418) and highest of BI (0.323), all-mRNA-1273 vaccine-sequence showed higher probability of immunization (0.732) and lowest of BI (0.098). Risk of BI was higher for non-high-level AbR, younger age and shorter time from transplant. Conclusions: SOT patients with non-high-level AbR, shorter time from transplantation, and heart recipients are at highest risk of BI

Impact of Inflammation on Voriconazole Exposure in Critically ill Patients Affected by Probable COVID-19-Associated Pulmonary Aspergillosis

(1) Background: To explore the impact of the degree of inflammation on voriconazole exposure in critically ill patients affected by COVID-associated pulmonary aspergillosis (CAPA); (2) Methods: Critically ill patients receiving TDM-guided voriconazole for the management of proven or probable CAPA between January 2021 and December 2022 were included. The concentration/dose ratio (C/D) was used as a surrogate marker of voriconazole total clearance. A receiving operating characteristic (ROC) curve analysis was performed by using C-reactive protein (CRP) or procalcitonin (PCT) values as the test variable and voriconazole C/D ratio > 0.375 (equivalent to a trough concentration [Cmin] value of 3 mg/L normalized to the maintenance dose of 8 mg/kg/day) as the state variable. Area under the curve (AUC) and 95% confidence interval (CI) were calculated; (3) Results: Overall, 50 patients were included. The median average voriconazole Cmin was 2.47 (1.75–3.33) mg/L. The median (IQR) voriconazole concentration/dose ratio (C/D) was 0.29 (0.14–0.46). A CRP value > 11.46 mg/dL was associated with the achievement of voriconazole Cmin > 3 mg/L, with an AUC of 0.667 (95% CI 0.593–0.735; p 0.3 ng/mL was associated with the attainment of voriconazole Cmin > 3 mg/L (AUC 0.651; 95% CI 0.572–0.725; p = 0.0015). (4) Conclusions: Our findings suggest that in critically ill patients with CAPA, CRP and PCT values above the identified thresholds may cause the downregulation of voriconazole metabolism and favor voriconazole overexposure, leading to potentially toxic concentrations

A comparative analysis of unintegrated HIV-1 DNA measurement as a potential biomarker of the cellular reservoir in the blood of patients controlling and non-controlling viral replication

The persistence of HIV-1 in reservoir cells is one of the major obstacles to eradicating the virus in infected individuals receiving combination antiretroviral therapy (ART). HIV-1 persists in infected cells as a stable integrated genome and more labile unintegrated DNA (uDNA), which includes linear, 1-LTR and 2-LTR circular DNA. 2-LTR circle DNA, although less abundant, is considered a surrogate marker of recent infection events and is currently used instead of the other unintegrated species as a diagnostic tool. This pilot study aimed to investigate how to best achieve the measurement of uDNA

A comparative analysis of unintegrated HIV-1 DNA measurement as a potential biomarker of the cellular reservoir in the blood of patients controlling and non-controlling viral replication

Background: The persistence of HIV-1 in reservoir cells is one of the major obstacles to eradicating the virus in infected individuals receiving combination antiretroviral therapy (ART). HIV-1 persists in infected cells as a stable integrated genome and more labile unintegrated DNA (uDNA), which includes linear, 1-LTR and 2-LTR circular DNA. 2-LTR circle DNA, although less abundant, is considered a surrogate marker of recent infection events and is currently used instead of the other unintegrated species as a diagnostic tool. This pilot study aimed to investigate how to best achieve the measurement of uDNA. Methods: A comparative analysis of two qPCR-based methods (U-assay and 2-LTR assay) was performed on the blood of 12 ART-naïve, 14 viremic and 29 aviremic On-ART patients and 20 untreated spontaneous controllers (HIC), sampled at a single time point. Results: The U-assay, which quantified all unintegrated DNA species, showed greater sensitivity than the 2-LTR assay (up to 75%, p < 0.0001), especially in viremic subjects, in whom other forms, in addition to 2-LTR circles, may also accumulate due to active viral replication. Indeed, in aviremic On-ART samples, the U-assay unexpectedly measured uDNA in a higher proportion of samples (76%, 22/29) than the 2-LTR assay (41%, 12/29), (p = 0.0164). A trend towards lower uDNA levels was observed in aviremic vs viremic On-ART patients, reaching significance when we combined aviremic On-ART and HIC (controllers) vs Off-ART and viremic On-ART subjects (non-controllers) (p = 0.0003), whereas 2-LTR circle levels remained constant (p ≥ 0.2174). These data were supported by the high correlation found between uDNA and total DNA (r = 0.69, p < 0.001). Conclusions: The great advantage of the U-assay is that, unlike the 2-LTR assay, it allows the accurate evaluation of the totality of uDNA that can still be measured even during successful ART when plasma viremia is below the cut-off of common clinical tests (< 50 copies/mL) and 2-LTR circles are more likely to be under the quantification limit. UDNA measurement in blood cells may be used as a biomarker to reveal a so far hidden or underestimated viral reservoir. The potential clinical relevance of uDNA quantification may lead to improvements in diagnostic methods to support clinical strategies

Neutralizing monoclonal antibodies for early treatment of hospital‐acquired SARS‐CoV‐2 infection in hematologic patients

Abstract Efficacy of early treatment with anti‐SARS‐CoV‐2 spike protein monoclonal antibodies (mAbs) for nosocomial SARS‐CoV‐2 infection in hematologic patients is unknown. Retrospective, cohort study conducted in four Italian teaching hospitals. We included adult patients with hematologic malignancies and hospital‐acquired SARS‐CoV‐2 infection diagnosed between November 2020 and December 2021. The principal exposure variable was administration of mAbs. The primary endpoint was clinical failure dea composite outcome of mortality and/or invasive and noninvasive ventilation within 90 days from infection onset. We included 52 patients with hospital‐acquired SARS‐CoV‐2 infection. Males were 29 (60%), median age was 62 (interquartile range [IQR] 48–70). Forty‐five (86%) patients were on chemotherapy or had received chemotherapy within 30 days. MAbs were administered in 19/52 (36%) patients. Clinical failure occurred in 22 (42%) patients; 21% (4/19) in mAbs group versus 54% (18/33) in non‐mAbs group (p = 0.03). Other predictors of clinical failure were older age (median [IQR] 69 [61–72] versus 58 [46–66], p = 0.001), and higher Charlson comorbidity index (median [IQR], 5 [3.25‐5] versus 3 [2–5], p = 0.002). At multivariable Cox regression model, mAbs were independently associated with a significantly lower rate of clinical failure (HR 0.11, 95% CI 0.01–0.85, p = 0.01), after adjusting for confounders. In conclusion, mAbs are promising for early treatment of hematologic patients with healthcare‐related SARS‐CoV‐2 infection