Clinical effectiveness of cefiderocol for the treatment of bloodstream infections due to carbapenem-resistant Acinetobacter baumannii during the COVID-19 era: a single center, observational study

BACKGROUND

We assessed the clinical effectiveness of cefiderocol (CFDC) in comparison with colistin (COL) for the treatment of carbapenem-resistant Acinetobacter baumannii (CRAB) bloodstream infections (BSI).

MATERIALS/METHODS

Retrospective cohort study including adults with CRAB-BSI. Outcomes were mortality, clinical cure and adverse events during therapy. The average treatment effect of CFDC compared to COL was weighted with the inverse-probability treatment weight (IPTW).

RESULTS

Overall, 104 patients were included (50 CFDC, 54 COL), median age 66.5 years, median Charlson Comorbidity Index 5, septic shock in 33.6% of patients. Primary BSI accounted for 43.3% of cases, followed by ventilator-associated pneumonia (VAP) (26%), catheter-related BSI (20.2%) and hospital-acquired pneumonia (HAP) (9.6%). Although not significantly, mortality at all time points was lower for CFDC than COL, while clinical cure was higher in CFDC than COL (66% vs. 44.4%, p = 0.027). Adverse events were more frequent in COL than CFDC-group (38.8% vs. 10%, p < 0.0001), primarily attributed to acute kidney injury (AKI) in the COL group. Patients with bacteremic HAP/VAP treated with CFDC had a significant lower 30-d mortality and higher clinical cure than COL (p = 0.008 and p = 0.0008, respectively). Increment of CCI (p = 0.005), ICU (p = 0.025), SARS-CoV2 (p = 0.006) and ECMO (p < 0.0001) were independently associated with 30-d mortality, while receiving CFDC was not associated with survival.

CONCLUSIONS

CFDC could represent an effective and safe treatment option for CRAB BSI, especially in patients with bacteremic HAP/VAP and frail patients where the risk of acute renal failure during therapy should be avoided.

New Antimicrobials and New Therapy Strategies for Endocarditis: Weapons That Should Be Defended

The overall low-quality evidence concerning the clinical benefits of different antibiotic regimens for the treatment of infective endocarditis (IE), which has made it difficult to strongly support or reject any regimen of antibiotic therapy, has led to a discrepancy between the available guidelines and clinical practice. In this complex scenario, very recently published guidelines have attempted to fill this gap. Indeed, in recent years several antimicrobials have entered the market, including ceftobiprole, ceftaroline, and the long-acting lipoglycopeptides dalbavancin and oritavancin. Despite being approved for different indications, real-world data on their use for the treatment of IE, alone or in combination, has accumulated over time. Furthermore, an old antibiotic, fosfomycin, has gained renewed interest for the treatment of complicated infections such as IE. In this narrative review, we focused on new antimicrobials and therapeutic strategies that we believe may provide important contributions to the advancement of Gram-positive IE treatment, providing a summary of the current in vitro, in vivo, and clinical evidence supporting their use in clinical practice.

Aero-Medical Evacuation during SARS-CoV-2 Pandemic: Extraordinary Measure or Emerging Treatment Option?

Aero-medical evacuation has been considered as a feasible and safe treatment option during COVID pandemic, particularly when the needs of affected patients exceed what local clinics and hospitals are supposed to provide. In this article, we analyzed the clinical course of 17 patients medically evacuated to the "L. Spallanzani" Institute in Rome, Italy from foreign countries, mainly Africa and Eastern Europe, who had COVID-19 pneumonia with, or without, coinfections such as malaria, HIV, tuberculosis and microbiologically confirmed sepsis syndrome. The aero-medical evacuation of patients with infectious diseases has become one of the greatest medical achievements we have reached during this pandemic; in fact, only two patients with life threatening coinfections have died. Although logistically difficult and cost consuming, medical evacuation should be considered as a treatment option more than a single extraordinary measure, especially among complex cases that require specific technical and human resources.

Effect of ceftazidime/avibactam plus fosfomycin combination on 30 day mortality in patients with bloodstream infections caused by KPC-producing Klebsiella pneumoniae: results from a multicentre retrospective study

Introduction

The primary outcome of the study was to evaluate the effect on 30 day mortality of the combination ceftazidime/avibactam + fosfomycin in the treatment of bloodstream infections (BSIs) caused by KPC-producing Klebsiella pneumoniae (KPC-Kp).

Materials and methods

From October 2018 to March 2021, a retrospective, two-centre study was performed on patients with KPC-Kp BSI hospitalized at Sapienza University (Rome) and ISMETT-IRCCS (Palermo) and treated with ceftazidime/avibactam-containing regimens. A matched cohort (1:1) analysis was performed. Cases were patients receiving ceftazidime/avibactam + fosfomycin and controls were patients receiving ceftazidime/avibactam alone or in combination with in vitro non-active drugs different from fosfomycin (ceftazidime/avibactam ± other). Patients were matched for age, Charlson comorbidity index, ward of isolation (ICU or non-ICU), source of infection and severity of BSI, expressed as INCREMENT carbapenemase-producing Enterobacteriaceae (CPE) score.

Results

Overall, 221 patients were included in the study. Following the 1:1 match, 122 subjects were retrieved: 61 cases (ceftazidime/avibactam + fosfomycin) and 61 controls (ceftazidime/avibactam ± other). No difference in overall mortality emerged between cases and controls, whereas controls had more non-BSI KPC-Kp infections and a higher number of deaths attributable to secondary infections. Almost half of ceftazidime/avibactam + fosfomycin patients were prescribed fosfomycin without MIC fosfomycin availability. No difference in the outcome emerged after stratification for fosfomycin susceptibility availability and dosage. SARS-CoV-2 infection and ICS ≥ 8 independently predicted 30 day mortality, whereas an appropriate definitive therapy was protective.

Conclusions

Our data show that fosfomycin was used in the treatment of KPC-Kp BSI independently from having its susceptibility testing available. Although no difference was found in 30 day overall mortality, ceftazidime/avibactam + fosfomycin was associated with a lower rate of subsequent KPC-Kp infections and secondary infections than other ceftazidime/avibactam-based regimens.

CURB-65 plus hypoalbuminemia: a new score system for prediction of the in-hospital mortality risk in patients with SARS-CoV-2 pneumonia

INTRODUCTION

There is the need of a simple but highly reliable score system for stratifying the risk of mortality and Intensive Care Unit (ICU) transfer in patients with SARS-CoV-2 pneumonia at the Emergency Room.

PURPOSE

In this study, the ability of CURB-65, extended CURB-65, PSI and CALL scores and C-Reactive Protein (CRP) to predict intra-hospital mortality and ICU admission in patients with SARS-CoV-2 pneumonia were evaluated.

METHODS

During March-May 2020, a retrospective, single-center study including all consecutive adult patients with diagnosis of SARS-CoV-2 pneumonia was conducted. Clinical, laboratory and radiological data as well as CURB-65, expanded CURB-65, PSI and CALL scores were calculated based on data recorded at hospital admission.

RESULTS

Overall, 224 patients with documented SARS-CoV-2 pneumonia were included in the study. As for intrahospital mortality (24/224, 11%), PSI performed better than all the other tested scores, which showed lower AUC values (AUC=0.890 for PSI versus AUC=0.885, AUC=0.858 and AUC=0.743 for expanded CURB-65, CURB-65 and CALL scores, respectively). Of note, the addition of hypoalbuminemia to the CURB-65 score increased the prediction value of intra-hospital mortality (AUC=0.905). All the tested scores were less predictive for the need of ICU transfer (26/224, 12%), with the best AUC for extended CURB-65 score (AUC= 0.708).

CONCLUSION

The addition of albumin level to the easy-to-calculate CURB-65 score at hospital admission is able to improve the quality of prediction of intra-hospital mortality in patients with SARS-CoV-2 pneumonia.

Interplay between Klebsiella pneumoniae producing KPC-31 and KPC-3 under treatment with high dosage meropenem: a case report

The objective was to study ceftazidime-avibactam resistant and susceptible Klebsiella pneumoniae isolated from a patient admitted to the Policlinico Umberto I of Rome for SARS-CoV2. Data on the evolution of patient's conditions, antimicrobial therapies, and microbiological data were collected. Whole-genome sequencing performed by Illumina and Nanopore sequencing methods were used to type the strains. During the hospitalization, a SARS-CoV2-infected patient was colonized by a KPC-producing K. pneumoniae strain and empirically treated with ceftazidime-avibactam (CZA) when presenting spiking fever symptoms. Successively, ST2502 CZA-resistant strain producing the KPC-31 variant gave a pulmonary infection to the patient. The infection was treated with high doses of meropenem. The KPC-31-producing strain disappeared but the patient remained colonized by a KPC-3-producing K. pneumoniae strain. An interplay between highly conserved KPC-31- and KPC-3-producing ST2502 strains occurred in the SARS-CoV2 patient during the hospitalization, selected by CZA and carbapenem treatments, respectively.

Convalescent plasma for haematological patients with SARS-CoV-2 pneumonia and severe depletion of B-cell lymphocytes following anti-CD20 therapy: a single-centre experience and review of the literature

Convalescent plasma (CP) therapy might be effective in patients with haematological malignanciesand B-cell depletion. We report a single-centre experience of COVID-19 patients with non-Hodgkinlymphoma and absence of B-cells as a consequence of anti-CD20 therapy successfully treated withCP from October 2020 to May 2021. CP was given in the presence of pneumonia with respiratoryfailure despite standard treatment and consisted of three infusions on an alternate-day basis. A reviewof the current literature on this topic was also performed. Six patients were identified (medianage 59.5 years (range 50-73)). The last anti-CD20 drug administration occurred 60 days before infection(range 0-360). CP was administered after a median of 51 days (range 9-120) from SARS-CoV-2diagnosis, with an early improvement in all but one subject. We suggest a possible clinical benefitof convalescent CP treatment in COVID-19 patients with haematological malignancies and B-celldepletion having persistent/recurrent pneumonia.

Synergistic Meropenem/Vaborbactam Plus Fosfomycin Treatment of KPC Producing K. pneumoniae Septic Thrombosis Unresponsive to Ceftazidime/Avibactam: From the Bench to the Bedside

Gram-negative bacilli septic thrombosis (GNB-ST) represents a subtle and often misleading condition, potentially fatal if not recognized early and requiring prolonged antimicrobial therapy and anticoagulation. Herein, reported for the first time, is a very challenging case of Klebsiella producing carbapenemase (KPC)-producing K. pneumoniae (KPC-Kp) ST unresponsive to ceftazidime/avibactam (CZA) relapsed first with meropenem/vaborbactam (MVB) monotherapy and subsequently cured with MVB plus fosfomycin (FOS) combination. The present case highlights the possibility of CZA underexposure on the infected thrombus and the risk of in vivo emergence of CZA resistance in the setting of persistent bacteremia and sub-optimal anticoagulation. Pharmacokinetic analyses showed that both MVB and FOS were in the therapeutic range. In vitro studies demonstrated a high level of MVB + FOS synergism that possibly allowed definitive resolution of the endovascular infection.

Increased sCD163 and sCD14 Plasmatic Levels and Depletion of Peripheral Blood Pro-Inflammatory Monocytes, Myeloid and Plasmacytoid Dendritic Cells in Patients With Severe COVID-19 Pneumonia

Background

Emerging evidence argues that monocytes, circulating innate immune cells, are principal players in COVID-19 pneumonia. The study aimed to investigate the role of soluble (s)CD163 and sCD14 plasmatic levels in predicting disease severity and characterize peripheral blood monocytes and dendritic cells (DCs), in patients with COVID-19 pneumonia (COVID-19 subjects).

Methods

On admission, in COVID-19 subjects sCD163 and sCD14 plasmatic levels, and peripheral blood monocyte and DC subsets were compared to healthy donors (HDs). According to clinical outcome, COVID-19 subjects were divided into ARDS and non-ARDS groups.

Results

Compared to HDs, COVID-19 subjects showed higher sCD163 (p<0.0001) and sCD14 (p<0.0001) plasmatic levels. We observed higher sCD163 plasmatic levels in the ARDS group compared to the non-ARDS one (p=0.002). The cut-off for sCD163 plasmatic level greater than 2032 ng/ml was predictive of disease severity (AUC: 0.6786, p=0.0022; sensitivity 56.7% [CI: 44.1–68.4] specificity 73.8% [CI: 58.9–84.7]). Positive correlation between plasmatic levels of sCD163, LDH and IL-6 and between plasmatic levels of sCD14, D-dimer and ferritin were found. Compared to HDs, COVID-19 subjects showed lower percentages of non-classical (p=0.0012) and intermediate monocytes (p=0.0447), slanDCs (p<0.0001), myeloid DCs (mDCs, p<0.0001), and plasmacytoid DCs (pDCs, p=0.0014). Compared to the non-ARDS group, the ARDS group showed lower percentages of non-classical monocytes (p=0.0006), mDCs (p=0.0346), and pDCs (p=0.0492).

Conclusions

The increase in sCD163 and sCD14 plasmatic levels, observed on hospital admission in COVID-19 subjects, especially in those who developed ARDS, and the correlations of these monocyte/macrophage activation markers with typical inflammatory markers of COVID-19 pneumonia, underline their potential use to assess the risk of progression of the disease. In an early stage of the disease, the assessment of sCD163 plasmatic levels could have clinical utility in predicting the severity of COVID-19 pneumonia.

Monocyte absolute count as a preliminary tool to distinguish between SARS-CoV-2 and influenza A/B infections in patients requiring hospitalization

Since the most frequent symptoms of novel coronavirus 2019 disease (COVID-19) are common in influenza A/B (FLU), predictive models to distinguish between COVID-19 and FLU using standardized non-specific laboratory indicators are needed. The aim of our study was to evaluate whether a recently dynamic nomogram, established in the Chinese population and based on age, lymphocyte percentage and monocyte absolute count, might apply to a different context. We collected data from 299 patients (243 with COVID-19 and 56 with FLU) at Policlinico Umberto I, Sapienza University of Rome. The nomogram included age, lymphocyte percentage and monocyte absolute count to differentiate COVID-19 from FLU. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for all associations. Multivariate logistic regression models were used to adjust for potential confounding. A p-value of less than 0.05 was considered statistically significant. Patients with COVID-19 had higher age, lymphocyte percentage and monocyte absolute count than patients with FLU. Although univariate analysis confirmed that age, lymphocyte percentage and monocyte absolute count were associated with COVID-19, only at multivariate analysis was monocyte count statistically significant as a predictive factor of COVID-19. Using receiver operating characteristic (ROC) curves, we found that a monocyte count >0.35x1000/mL showed an AUC of 0.680 (sensitivity 0.992, specificity 0.368). A dynamic nomogram including age, lymphocyte percentage and monocyte absolute count cannot be applied to our context, probably due to differences in demographic characteristics between Italian and Chinese populations. However, our data showed that monocyte absolute count is highly predictive of COVID-19, suggesting its potential role above all in settings where prompt PCR nasopharyngeal testing is lacking.

Rates of antibiotic resistance/sensitivity in bacterial cultures of hidradenitis suppurativa patients

BACKGROUND

Antibiotic (AB) treatment is one of the first steps in the management of hidradenitis suppurativa (HS). Bacteria, in HS patients, may play a double role, as triggering factors of inflammatory reactions and/or agents of infection.

OBJECTIVES

The aims of this study are as follows: (i) to assess prevalence and AB resistance of bacterial growths in HS patients (ii) assessment of the clinical relevance of obtained data in guiding the selection of the most effective AB therapy.

METHODS

Purulent material from 137 skin lesions of HS patients was collected with swabs. Bacterial flora and AB sensitivity were determined using microbiological cultures for aerobic and anaerobic bacteria.

RESULTS

A total of 114 samples resulted positive for bacteria. Sample was collected from the axillae, groin and perianal areas. A total of 163 single bacterial growths were observed; 55% were Gram-positive and 44% were Gram-negative. Among them, 18.4% were anaerobic. The most frequent bacterial families included enterobacteriaceae (30.7%), Staphylococcus (25.2%) and Streptococcus (14.1%). The most frequent genus or species were proteus spp. (13.5%) and Escherichia coli (9.8%). The prevalence of AB resistance observed was clindamycin 65.7%, rifampicin 69.3%, penicillin 70.0%, ciprofloxacin 74%, tetracycline 84.7% and erythromycin 89.0%. A limitation of the study is represented the short culture period adopted which may have impaired the isolation of anaerobes.

CONCLUSIONS

Bacterial growth in HS patients has shown a high level of resistance to ABs, including rifampicin, clindamycin and tetracyclines, cited as an empiric choice in HS therapeutic guidelines. A targeted and specific AB therapy, driven by microbiological evaluations with prolonged culture periods, seems more appropriate than empiric, generic, non-specific, therapeutic approaches. Current knowledge regarding HS bacterial AB resistance should be considered in the update of current therapeutic guidelines for HS.