The impact of armed conflict on the development and global spread of antibiotic resistance: a systematic review

BACKGROUND

Scant data are available on the link between armed conflicts and the development and spread of antimicrobial resistance.

OBJECTIVES

We performed a systematic review with the aim to summarize the available data on the prevalence and features of antibiotic resistance and the causes of antibiotic resistance development during armed conflicts in the 21st century.

METHODS

Data sources: PubMed and SCOPUS databases were searched from 1 January 2000 to 30 November 2023.

STUDY ELIGIBILITY CRITERIA

Original articles reporting data on armed conflicts and antimicrobial resistance were included in this systematic review. No attempt was made to obtain information from unpublished studies. No language restriction was applied. Methods of data synthesis: Both quantitative and qualitative information were summarized by means of textual descriptions.

PARTICIPANTS

Patients or soldiers deployed in armed conflict zones.

TESTS

culture-dependent antibiotic sensitivity testing or molecular detection of the genetic determinants of antibiotic resistance after a confirmed diagnosis of bacterial infection. Assessment of risk of bias: To evaluate the quality of the included studies, we adapted the tool recommended by the Joanna Briggs Institute.

RESULTS

Thirty-four studies were identified, published between November 2004 and November 2023. The quality of included studies was high and medium in 47% and 53% of the studies, respectively. The included studies reported high infection and colonization rates of multidrug-resistant bacteria. Studies performed during the Eastern Ukraine conflict reported high rates of New Delhi metallo-β-lactamase producers.

DISCUSSION

Our findings confirm that wars lead to a large pool of multidrug-resistant infections that could potentially spread. Infection control in healthcare facilities in conflict zones and proper antimicrobial stewardship are crucial.

On the use of intravenous metronidazole for severe and complicated Clostridioides difficile infection: a review and meta-analysis

The European Society of Clinical Microbiology and Infectious Disease (ESCMID) has advised against the use of metronidazole for fulminant Clostridioides difficile (C. difficile) infection (CDI) in their latest guidelines. They suggest using oral vancomycin alone instead. This recommendation is based on a few retrospective studies, which have multiple biases. We evaluated the three studies that led ESCMID to advise against intravenous metronidazole for fulminant CDI and performed a meta-analysis. The meta-analysis revealed a mild (2.7%), not statistically significant (p=0.8) difference in mortality between the two groups. The high heterogeneity (I2= 89%) should also be noted. The decision to add or remove metronidazole should be discussed in the near future. In the meantime, combination therapy could be a cautious treatment for fulminant CDI.

Intravenous Fosfomycin for Systemic Multidrug-Resistant Pseudomonas aeruginosa Infections

Human Pseudomonas infections have high morbidity and mortality rates. Pseudomonas bacteria can cause sepsis or septic shock; they produce biofilm and commonly exhibit a multidrug-resistant phenotype. The choice of antimicrobial therapy in many cases is challenging, and deep knowledge of clinical, microbiological, and pharmacological issues is required. Intravenous fosfomycin is being repurposed in a combination given its favorable pharmacokinetic/pharmacodynamic properties (a small molecule with favorable kinetic both in bloodstream infection and in deep-seated infections), antibiofilm activity, and its interesting synergistic effects with other antimicrobials. Recent literature on epidemiological, microbiological, pharmacological, and clinical data on intravenous fosfomycin therapy against Pseudomonas is herein reviewed and discussed.

Streptococcus intermedius Brain Abscess with Lung Abscess and Aortic Valve Endocarditis: A Case Report and Literature Review

Streptococcus intermedius is frequently associated with brain and liver abscesses, while pleuropulmonary infections are considered rarer. Even less frequent is the association of lung and brain abscesses due to this agent with infective endocarditis. We describe the case of a 40-year-old man complaining of cough, fever, and headache who was diagnosed with a brain abscess due to S. intermedius, a concomitant lung abscess, and aortic native valve endocarditis. He was treated with surgical drainage of the brain abscess and a 4-week course of intravenous ceftriaxone, followed by oral amoxicillin/clavulanate, obtaining healing of the lesions without relapse of the infection.

Tackling Acinetobacter baumannii

Globally, multidrug-resistant (MDR) bacteria represent a menace to public health [...].

Clostridioides difficile and Enterococci's Interplay in the Human Gut: Bacterial Alliance or Competition? A Systematic Literature Review

Clostridioides difficile and Enterococcus spp. are two common bacterial pathogens populating the human microbiota. We possess scant data on how Clostridioides difficile interacts with Enterococcus spp. in the gut microbiota in subjects colonized with Clostridioides difficile or during a Clostridioides difficile infection. We carried out a systematic review of studies on Enterococcus spp. and Clostridioides difficile's interaction in the gut microbiota and on the effect of Enterococcus spp. gut colonization on CDI development. Studies on Enterococcus spp. and Clostridioides difficile's interaction in the gut microbiota and on the effect of Enterococcus spp. gut colonization on CDI were searched using the search terms "clostridium", "clostridioides", "difficile" and "enterococcus" on the MEDLINE and SCOPUS databases. PubMed was searched until 1 May 2023. An English language restriction was applied. The risk of bias in the included studies was not assessed. Quantitative and qualitative information was summarized in textual descriptions. Fourteen studies, published from August 2012 to November 2022, on Clostridioides difficile and Enterococcus spp.'s interaction in the gut microbiota met the inclusion criteria. The studies included in our systematic review reported evidence that the Enterococcus spp. intestinal burden represents a risk factor for the occurrence of CDI. There is supporting evidence that Enterococcus spp. play a role in CDI development and clinical outcomes.

Defective peripheral B cell selection in common variable immune deficiency patients with autoimmune manifestations

Common variable immune deficiency (CVID) is a heterogeneous disorder characterized by recurrent infections, low levels of serum immunoglobulins, and impaired vaccine responses. Autoimmune manifestations are common, but B cell central and peripheral selection mechanisms in CVID are incompletely understood. Here, we find that receptor editing, a measure of central tolerance, is increased in transitional B cells from CVID patients and that these cells have a higher immunoglobulin κ:λ ratio in CVID patients with autoimmune manifestations than in those with infection only. Contrariwise, the selection pressure in the germinal center on CD27^bright memory B cells is decreased in CVID patients with autoimmune manifestations. Finally, functionally, T cell-dependent activation showed that naive B cells in CVID patients are badly equipped for activation and induction of mismatch repair genes. We conclude that central tolerance is functional whereas peripheral selection is defective in CVID patients with autoimmune manifestations, which could underpin the development of autoimmunity.

Efficacy of bezlotoxumab in preventing recurrence of Clostridioides difficile infection: an Italian multicenter cohort study

OBJECTIVES

Bezlotoxumab (BEZ) is a promising tool for preventing 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 standard of care (SoC) vs. SoC alone.

METHODS

A multicenter cohort study was conducted including 442 patients with CDI from 2018 to 2022 collected from 18 Italian centers. The main outcome was the 30-days occurrence of rCDI. Secondary outcomes were: (i) all-cause mortality at 30 days (ii) 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%, OR=0.58, 95%CI:0.31-1.09, p=0.09). The difference between BEZ+SoC vs. SoC was statistically significant after controlling for confounding factors (aOR=0.40, 95%CI:018-0.88, p=0.02) and even more using the composite outcome (aOR=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 CDI therapy (vancomycin vs. fidaxomicin) and number of risk factors.

European survey on the current surveillance practices, management guidelines, treatment pathways and heterogeneity of testing of Clostridioides difficile, 2018-2019: results from The Combatting Bacterial Resistance in Europe CDI (COMBACTE-CDI)

BACKGROUND

Awareness and compliance with international guidelines for diagnosis and clinical management of Clostridioides difficile infection (CDI) are unknown.

AIM

To compare the awareness and compliance with the recommended strategies for diagnosis and clinical management of CDI across Europe in 2018-2019.

METHODS

Hospital sites and their associated community practices across 12 European countries completed an online survey in 2018-2019, to report on their practices in terms of surveillance, prevention, diagnosis, and treatment of CDI. Responses were collected from 105 hospitals and 39 community general practitioners (GPs).

FINDINGS

Hospital sites of 11 countries reported participation in national surveillance schemes compared with six countries for international schemes. The European Society of Clinical Microbiology and Infectious Diseases (ESCMID)-recommended CDI testing methodologies were used by 82% (86/105) of hospitals, however countries reporting the highest incidence of CDI used non-recommended tests. Over 75% (80/105) of hospitals were aware of the most recent European CDI treatment guidelines at the time of this survey compared with only 26% (10/39) of surveyed GPs. However, up to 15% (16/105) of hospitals reported using the non-recommended metronidazole for recurrent CDI cases, sites in countries with lower awareness of CDI treatment guidelines. Only 37% (39/105) of hospitals adopted contact isolation precautions in case of suspected CDI.

CONCLUSION

Good awareness of guidelines for the management of CDI was observed across the surveyed European hospital sites. However, low compliance with diagnostic testing guidelines, infection control measures for suspected CDI, and insufficient awareness of treatment guidelines continued to be reported in some countries.

Bezlotoxumab in Patients with a Primary Clostridioides difficile Infection: A Literature Review

BACKGROUND

Nowadays, one of the main issues in the management of Clostridioides difficile infection (CDI) is the high rate of recurrences (rCDI), causing increased mortality and higher health care costs.

OBJECTIVES

To assess the available evidence on the use of bezlotoxumab for the prevention of rCDI during a first CDI episode.

METHODS

Published articles on bezlotoxumab during a primary CDI episode were identified through computerized literature searches with the search terms [(bezlotoxumab) AND (CDI) OR (Clostridioides difficile infection)] using PubMed and by reviewing the references of retrieved articles. PubMed was searched until 31 August 2022.

RESULTS

Eighty-eight studies were identified as published from December 2014 to June 2022. Five studies were included in this study, one was a phase III clinical trial and four were sub-analyses or extensions of the previous phase III clinical trial. In the phase III clinical trial, the subgroup analysis on the included primary CDI patients showed that 13.5% of patients receiving bezlotoxumab had an rCDI, whilst 20.9% of patients in the placebo group had an rCDI at the twelve weeks follow-up (absolute difference: -7.4).

CONCLUSIONS

Bezlotoxumab administration during the standard of care antibiotic therapy is effective and safe in reducing the rate of rCDI. Despite its high cost, evidence suggests considering bezlotoxumab in patients with a primary CDI episode. Further studies are needed to assess the benefit in specific subgroups of primary CDI patients and to define the risk factors to guide bezlotoxumab use.

Invasive cryptococcal disease in COVID-19: systematic review of the literature and analysis

During the Coronavirus Disease 2019 (COVID-19) pandemic, an increasing number of fungal infections associated with SARS-CoV-2 infection have been reported. Among them, cryptococcosis could be a life-threatening disease. We performed a Systematic Review (PRISMA Statement) of cryptococcosis and COVID-19 co-infection, case report/series were included: a total of 34 cases were found, then we added our case report. We collected patients' data and performed a statistical analysis comparing two groups of patients sorted by outcome: "dead" and "alive". Three cases were excluded for lack of information. To compare categorical data, we used a Fisher-exact test (α=0.05). To compare quantitative variables a U Mann-Whitney test was used (α=0.05), with a 95% Confidence Interval. A total of 32 co-infected patients were included in the statistical analysis. Mortality rate was 17/32 (53.1%): these patients were included in "dead" group, and 15/32 (46.9%) patients survived and were included in "alive" group. Overall, males were 25/32 (78.1%), the median age was 60 years (IQR 53-70) with non-statistically significant difference between groups (p=0.149 and p=0.911, respectively). Three variables were associated with mortality: ARDS, ICU admission and inadequate treatment. Overall, 21 out of 24 (87.5%) patients were in ARDS with a statistically significant difference among two groups (p=0.028). ICU admission for COVID-19 was observed in 18/26 (69.2%), more frequently among dead group (p=0.034). Finally, 15/32 (46.9%) patients had adequate treatment (amphotericin B + flucytosine for invasive cryptococcosis) mostly among alive patients (p=0.039). In conclusion, mortality due to cryptococcal infection among COVID-19 patients remains high but an early diagnosis and appropriate treatment could reduce mortality.

Clinical Management of Adult Patients with COVID-19 Outside Intensive Care Units: Guidelines from the Italian Society of Anti-Infective Therapy (SITA) and the Italian Society of Pulmonology (SIP)

INTRODUCTION

The Italian Society of Anti-Infective Therapy (SITA) and the Italian Society of Pulmonology (SIP) constituted an expert panel for developing evidence-based guidance for the clinical management of adult patients with coronavirus disease 2019 (COVID-19) outside intensive care units.

METHODS

Ten systematic literature searches were performed to answer ten different key questions. The retrieved evidence was graded according to the Grading of Recommendations Assessment, Development, and Evaluation methodology (GRADE).

RESULTS AND CONCLUSION

The literature searches mostly assessed the available evidence on the management of COVID-19 patients in terms of antiviral, anticoagulant, anti-inflammatory, immunomodulatory, and continuous positive airway pressure (CPAP)/non-invasive ventilation (NIV) treatment. Most evidence was deemed as of low certainty, and in some cases, recommendations could not be developed according to the GRADE system (best practice recommendations were provided in similar situations). The use of neutralizing monoclonal antibodies may be considered for outpatients at risk of disease progression. For inpatients, favorable recommendations were provided for anticoagulant prophylaxis and systemic steroids administration, although with low certainty of evidence. Favorable recommendations, with very low/low certainty of evidence, were also provided for, in specific situations, remdesivir, alone or in combination with baricitinib, and tocilizumab. The presence of many best practice recommendations testified to the need for further investigations by means of randomized controlled trials, whenever possible, with some possible future research directions stemming from the results of the ten systematic reviews.

The burden of Clostridioides difficile infection in COVID-19 patients: A systematic review and meta-analysis

OBJECTIVES

The main aim of this systematic review and meta-analysis was to assess the proportion of confirmed COVID-19 patients with Clostridioides difficile infection (CDI) and to describe risk factors and outcome of these patients.

METHODS

MEDLINE and Cochrane Central Register of Controlled Trials databases were searched up to July 15, 2021. We included studies reporting data on CDI occurring in patients with a confirmed diagnosis of COVID-19. We pooled proportion of CDI patients using a random effects model (DerSimonian-Laird method) stabilising the variances using the Freeman-Tukey double arcsine transformation.

RESULTS

Thirteen studies were included in the systematic review. All the studies retrospectively collected data between February 2020 and February 2021. The reported CDI incidence rates ranged from 1.4 to 4.4 CDI cases per 10,000 patient-days. Seven studies reported data on the number of COVID-19 patients who developed CDI and the total number of COVID-19 patients in the study period and were included in the meta-analysis, comprising 23,697 COVID-19 patients. The overall pooled proportion of COVID-19 patients who had CDI was 1% [95% confidence interval: 1-2]. Among studies reporting CDI occurrence in patients with and without COVID-19, the majority of them reported reduced or unchanged CDI rates compared to pre-COVID period.

CONCLUSIONS

CDI is a relevant issue for COVID-19 patients. Adherence to infection prevention and control measures and to the antimicrobial stewardship principles is crucial even during the COVID-19 pandemic.

Hospitalized patients with diarrhea: Rate of Clostridioides difficile infection underdiagnosis and drivers of clinical suspicion

OBJECTIVES

Clostridioides difficile infection (CDI) represents a challenging issue, with an evolving epidemiology. Main objectives of our study were: to assess the frequency of diarrhea of overall etiology, including CDI, as a cause of hospital admission or occurring during hospital stay;- to determine the rate of underdiagnosis of community-acquired (CA-), health care associated (HCA)- and hospital onset (HO-) CDI, and explore factors associated with its clinical suspicion by physicians.

METHODS

A prospective cohort study included all hospitalized patients with diarrhea at two acute-care hospitals. C. difficile (CD) tests were performed on every stool samples, irrespective of the treating physician request. Factors associated with the likelihood of CD test request by physicians were assessed.

RESULTS

We enrolled 871 (6%) patients with diarrhea. CD test performed on all diarrheic stool samples was positive in 228 cases (26%); 37, 106, 85 cases of CA- (14%), HCA- (42%) and HO- diarrhea (24%), respectively. Treating physicians did not request CD test in 207 (24%) diarrhea cases. The rate of CDI underdiagnosis was 11% (24/228); it was higher in CA-CDI (27%, 10/37). Logistic regression analysis identified age >65 years (RR 1.1; 95 CI 1.06-1.2) and hospitalizations in the previous 3 months (RR 1.2; 95% CI 1.1-1.3) as independent factors associated with the likelihood of requesting the CD test by the physician. These risk factors differed by epidemiological classification of diarrhea and by hospital.

CONCLUSIONS

Our study confirmed the relevance of CDI underdiagnosis and provided new insights in the factors underlying the lack of CDI clinical suspicion.

Prospective Study on Incidence, Risk Factors and Outcome of Recurrent Clostridioides difficile Infections

Background: Limited and wide-ranging data are available on the recurrent Clostridioides difficile infection (rCDI) incidence rate. Methods: We performed a cohort study with the aim to assess the incidence of and risk factors for rCDI. Adult patients with a first CDI, hospitalized in 15 Italian hospitals, were prospectively included and followed-up for 30 d after the end of antimicrobial treatment for their first CDI. A case–control study was performed to identify risk factors associated with 30-day onset rCDI. Results: Three hundred nine patients with a first CDI were included in the study; 32% of the CDI episodes (99/309) were severe/complicated; complete follow-up was available for 288 patients (19 died during the first CDI episode, and 2 were lost during follow-up). At the end of the study, the crude all-cause mortality rate was 10.7% (33 deaths/309 patients). Two hundred seventy-one patients completed the follow-up; rCDI occurred in 21% of patients (56/271) with an incidence rate of 72/10,000 patient-days. Logistic regression analysis identified exposure to cephalosporin as an independent risk factor associated with rCDI (RR: 1.7; 95% CI: 1.1–2.7, p = 0.03). Conclusion: Our study confirms the relevance of rCDI in terms of morbidity and mortality and provides a reliable estimation of its incidence.

Risk and predictive factors of prolonged viral RNA shedding in upper respiratory specimens in a large cohort of COVID-19 patients admitted to an Italian reference hospital

Background

Limited data are available about the predictors and outcomes associated with prolonged SARS-CoV-2 RNA shedding (VS).

Methods

A retrospective study including COVID-19 patients admitted to an Italian hospital between March 1 and July 1, 2020. Predictors of viral clearance (VC) and prolonged VS from the upper respiratory tract were assessed by Poisson regression and logistic regression analyses. The causal relation between VS and clinical outcomes was evaluated through an inverse probability weighted Cox model.

Results

The study included 536 subjects. The median duration of VS from symptoms onset was 18 days. The estimated 30-day probability of VC was 70.2%. Patients with comorbidities, lymphopenia at hospital admission, or moderate/severe respiratory disease had a lower chance of VC. The development of moderate/severe respiratory failure, delayed hospital admission after symptoms onset, baseline comorbidities, or D-dimer >1000 ng/mL at admission independently predicted prolonged VS. The achievement of VC doubled the chance of clinical recovery and reduced the probability of death/mechanical ventilation.

Conclusions

Respiratory disease severity, comorbidities, delayed hospital admission and inflammatory markers negatively predicted VC, which resulted to be associated with better clinical outcomes. These findings highlight the importance of prompt hospitalization of symptomatic patients, especially where signs of severity or comorbidities are present.

Cortical plasticity after hand prostheses use: Is the hypothesis of deafferented cortex "invasion" always true?

OBJECTIVE

To study motor cortex plasticity after a period of training with a new prototype of bidirectional hand prosthesis in three left trans-radial amputees, correlating these changes with the modification of Phantom Limb Pain (PLP) in the same period.

METHODS

Each subject underwent a brain motor mapping with Transcranial Magnetic Stimulation (TMS) and PLP evaluation with questionnaires during a six-month training with a prototype of bidirectional hand prosthesis.

RESULTS

The baseline motor maps showed in all three amputees a smaller area of muscles representation of the amputated side compared to the intact limb. After training, there was a partial reversal of the baseline asymmetry. The two subjects affected by PLP experienced a statistically significant reduction of pain.

CONCLUSIONS

Two apparently opposite findings, the invasion of the "deafferented" cortex by neighbouring areas and the "persistence" of neural structures after amputation, could vary according to different target used for measurement. Our results do not support a correlation between PLP and motor cortical changes.

SIGNIFICANCE

The selection of the target and of the task is essential for studies investigating motor brain plasticity. This study boosts against a direct and unique role of motor cortical changes on PLP genesis.

Insights into the Clinical Management of Carbapenem-Resistant Gram-Negative Infections: An Italian Retrospective Clinical Chart Review

There is a lack of consensus regarding management of infections with carbapenem- resistant Gram-negative (CR-GN) pathogens. This study comprised a medical chart review to assess patient management in a high CR prevalence setting. Data was collated retrospectively from medical records of patients hospitalized between November 1^st, 2015 and October 31^st, 2016. Of 29 patients, 66% had respiratory tract infections. Median duration of hospitalization was 28 days and ~50% of patients were admitted to the intensive care unit, with 77% remaining for >2 weeks. Median time to obtain respiratory culture results was 5 days. Isolation of patients with diagnosed CR-GN infection took ≥5 days in >50% of patients. A majority (76%) of patients received ≥1 antibiotic before providing a specimen for culture; a total of 17 antibiotic treatments were used. Overall, 72% of patients, and 68% of those with respiratory infections, were discharged alive; 38% were discharged without further antibiotics. The difficulties in achieving effective management in patients with CR-GN infections are largely due to complex co-morbidities, a history of prior antibiotic treatment, and multiple referrals across health care facilities.

Bezlotoxumab for Preventing Recurrent Clostridioides difficile Infection: A Narrative Review from Pathophysiology to Clinical Studies

Clostridioides difficile infection (CDI) and recurrent CDI (rCDI) remain associated with a reduction in the patients’ quality of life and with increased healthcare costs. Bezlotoxumab is a monoclonal antibody against toxin B of C. difficile, approved for prevention of rCDI. In this narrative review, we briefly discuss the pathophysiology of CDI and the mechanism of action of bezlotoxumab, as well as the available evidence from investigational and observational studies in terms of efficacy, effectiveness, and safety of bezlotoxumab for the prevention of rCDI. Overall, bezlotoxumab has proved efficacious in reducing the burden of rCDI, thereby providing clinicians with an important novel strategy to achieve sustained cure. Nonetheless, experiences outside randomized controlled trials (RCTs) remain scant, and mostly represented by case series without a control group. Along with the conduction of RCTs to directly compare bezlotoxumab with faecal microbiota transplantation (or to precisely evaluate the role of their combined use), further widening our post-marketing experience remains paramount to firmly guide the use of bezlotoxumab outside RCTs, and to clearly identify those real-life settings where its preventive benefits can be exploited most.

Balancing evidence and frontline experience in the early phases of the COVID-19 pandemic: current position of the Italian Society of Anti-infective Therapy (SITA) and the Italian Society of Pulmonology (SIP)

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), which has rapidly become epidemic in Italy and other European countries. The disease spectrum ranges from asymptomatic/mildly symptomatic presentations to acute respiratory failure. At the present time the absolute number of severe cases requiring ventilator support is reaching or even surpassing the intensive care unit bed capacity in the most affected regions and countries.

OBJECTIVES

To narratively summarize the available literature on the management of COVID-19 in order to combine current evidence and frontline opinions and to provide balanced answers to pressing clinical questions.

SOURCES

Inductive PubMed search for publications relevant to the topic.

CONTENT

The available literature and the authors' frontline-based opinion are summarized in brief narrative answers to selected clinical questions, with a conclusive statement provided for each answer.

IMPLICATIONS

Many off-label antiviral and anti-inflammatory drugs are currently being administered to patients with COVID-19. Physicians must be aware that, as they are not supported by high-level evidence, these treatments may often be ethically justifiable only in those worsening patients unlikely to improve only with supportive care, and who cannot be enrolled onto randomized clinical trials. Access to well-designed randomized controlled trials should be expanded as much as possible because it is the most secure way to change for the better our approach to COVID-19 patients.

1183 Three-dimensional echocardiographic paramenters for mitral valve quantification: a feasibility and validation study

Introduction

Mitral regurgitation (MR) severity affects prognosis and a correct quantification is key for surgical indication. A multiparametric approach (MPA) is recommended, as singular parameters suffer pitfalls. Recently suggested three-dimensional echocardiographic (3DE) parameters lack clear reference values. No studies have assessed the feasibility of regurgitant volume (RV) and fraction (RF) using the 3D planimetric area of the mitral annulus (MAA) and of the left ventricular outflow tract (LVOTA).

Purpose

To assess the feasibility and reliability of 3DE, RV and RF obtained by doppler volumetric method using MAA and LVOTA, compare results with 2DE and 3D vena contracta area (VCA) and propose cut-offs for these parameters using MPA as gold standard.

Methods

Patients referred to our Department for MR assessment were enrolled from September 2018 to February 2019 without more than mild aortic regurgitation or severe stenosis, mitral stenosis and previous valvular surgery. Transthoracic 2DE was used to calculate a multiparametric index of MR severity including: jet area/left atrium (LA) area, CW characteristics, 2D vena contracta, PISA, pulmonary vein flow, LA volume and systolic pulmonary artery pressure. Transoesophageal 3DE was used to assess MAA and LVOTA from a 3D dataset. RV and RF were calculated by Doppler volumetric method using the planimetric areas instead of diameters. VCA 3D was calculated from a 3D color dataset as the cross-sectional area of the regurgitant jet. We compared the results between 2DE and 3DE and between functional and organic MR. ROC curves were analyzed to assess diagnostic performance and identify cut-offs for severity prediction. Intraclass correlation coefficient was calculated to assess variability in measurements.

Results

Population was composed by 87 patients (56 male, 65 ± 13 years), 72% organic MR. MAA was larger in 2DE (10.4 ± 3.2 vs 9.8 ± 2.9 cm2,) as was the RV (76.6 ± 36.1 vs 66.4 ± 31.9 ml) and RF (55.4 ± 12.4 vs 50.4 vs 10.9%, all p < 0.0001), while LVOTA was smaller (3.9 ± 0.98 vs 4.1 ± 1.0 cm2, p < 0.0001). RV 2D and RF 2D were larger in the organic MR group (p < 0.0001), meanwhile VCA 3D, RV 3D and RF 3D did not show a significant difference (all p > 0.1). VCA 3D had a good correlation with RV 3D (r = 0.593, p < 0.0001) and RF 3D (r = 0.576, p < 0.0001).

We proposed a cut-off value of 41.5 mm2 for VCA 3D (94% sens, 96% spec, AUC 0.978), 52 ml for RV 3D (84% sens, 78% spec, AUC 0.901) and 47.6% for RF 3D (91% sens, 90% spec, AUC 0.966) to predict MR severity as assessed by MPA.

Intraclass correlation coefficient was 0.980 for MAA and 0.985 for LVOTA for intra-observer variability, while for inter-observer variability it was 0.951 for MAA and 0.962 for LVOTA.

Conclusion

2DE overestimates MA dimensions and underestimates LVOT dimensions thus overestimating RV and RF. 3DE measures are relatively simple and reproducible. Proposed cut-offs for RV, RF and VCA 3D have a good diagnostic power.

P218 Accuracy and reproducibility of aortic root assessment by eSie Valves in patients candidate to transcatheter aortic valve implantation: a comparative study with computed tomography

Background

Accurate imaging assessment of the aortic root (AR) is critical for prosthesis sizing in transcatheter aortic valve implantation. Multislice computed tomography (MSCT) is the gold standard for this purpose. 3D transesophageal (3D-TOE) reconstruction tools have recently been introduced, which automatically configures a geometric model of AR from 3D-TOE dataset and perform quantitative analyses of the AR.

Purpose

The aim of the study was to compare semi-automated measurements of AR obtained by eSie Valves (EV) (Siemens Medical Solution, California, USA) tool with MSCT.

Methods

We prospectively enrolled 26 consecutive patients (mean age 79.5 ± 7.5 years; 38% men) with severe symptomatic aortic stenosis (mean gradient 48.8± 13.6 mmHg) who underwent both 3D-TOE and MSCT as part of TAVI evaluation protocol. Volumetric datasets of the AR, acquired with 3D-TOE in mid-esophageal view, were analyzed with EV tool. EV tool automatically detected AR landmarks and, after user validation, created 3D model of AR providing values of area, perimeter, diameters of aortic annulus (AA) and coronary ostia heights (Fig 1).

Results

EV tool analysis on 3D-TOE volumetric data sets was feasible in all patients.

Strong correlation between EV tool and MSCT assessment for AA major diameter (r = 0.79), AA minor diameter (r = 0.81), AA perimeter (r = 0.89) and AA area (r = 0.89) (all p< 0.0001) was found. On average EV tool underestimated MSCT measurements of AA major diameter (1.2 mm, 4.5%), AA minor diameter (2.6 mm, 11.3%), AA perimeter (4 mm, 5.2%) and AA area (65.3 mmq, 13.6%).

Moderate correlation between the two methods, already in this initial sample, for right coronary artery ostium height (r = 0.53, p = 0.007) was discovered. Finally, weak correlation for left coronary artery ostium height (r = 0.33, p = 0.1) was revealed.

EV tool measurements from two different volumetric datasets of the same patient showed an excellent reproducibility

intraclass correlation coefficient (ICC) for AA area 0.94 and ICC for right coronary height 0.98.

Conclusion

With these initial results EV tool could be used in clinical practice for quick and reliable assessment of AA area, perimeter and diameters. A larger group of patients will be needed to assess the consistency of coronary ostia height evaluation by EV tool.

Abstract P218 Figure. eSie Valve landmarks and 3D model of AR

1107 An unusual vegetation on a prosthetic pulmonary valve

Conclusion

Differential diagnosis of cardiac vegetations is a challenging process including microbological tests, multi modality imaging and clinical reasoning. It is always necessary to consider alternative diagnosis, even when traditional imaging tests seem to suggest infective endocarditis.

Non infective thrombotic endocarditis are a rare form of negative blood culteres endocarditis related to systemic hypercoagulable state (i.e. antiphospholipid syndrome, systemic lupus, behcet syndrome, cancer). Malignancies can be considered an unusual cause of cardiac vegetation and they must be taken into account on differential diagnosis.

Abstract 1107 Figure. FDG uptake in pulmonary position

P781 Role of serum biomarkers combined with two-dimensional speckle tracking echocardiography for screening of immunotherapy-induced cardiotoxicity

Background

Immune checkpoint inhibitors (ICIs) are a novel class of antineoplastic drugs which have dramatically changed the management of non-small cell lung cancer. ICI-associated cardiotoxicity is rare, but potentially fatal, presenting in most of cases as autoimmune acute myocarditis during the first phase of treatment. However, since an extensive cardiac monitoring is not routinely performed in most immunotherapy trials, the true incidence of ICIs related cardiac effects is largely unknown.

Aim

Aim of our study is to ascertain a possible subclinical cardiac involvement in patients with non-small cell lung cancer treated with ICIs.

Methods

We prospectively recruited 40 patients (13 males; mean age 64.3 ± 8.3 years) starting immunotherapy with PD-1/PDL-1 inhibitors for non-small lung cancer between January and August 2018. Demographic and clinical data were recorded and all patients underwent a standard 12-lead ECG and a transthoracic echocardiogram with assessment of left ventricular global longitudinal strain (LV GLS). Furthermore, blood samples for pro BNP-nt and high sensitivity Troponin T (hsTnT) measurements were collected. Serial assessments were performed before and 1 and 3 months after initiation of immunotherapy.

Results

A history of previous coronary artery disease was documented in eight cases (20%). At follow-up no cardiovascular events were recorded. Compared with baseline, echocardiographic parameters of ventricular function did not significantly changed at 1 and 3 months (LVEF 61 ± 6% at baseline, 61 ± 5% at 1 month, 60,2 ± 5% at 3 months, p =0.1; E/E’at baseline 9.2 ± 3, 9.2 ± 2.8 at 1 month, 9.1 ±3,5 at 3 months, p = 0.2;TAPSE 20 ± 3.4 mm at baseline, 21.3 ± 2.8 mm at 1 month, 20 ± 3.8 mm at 3 months, p =0.1; LV GLS -20.3 ± 3.6% at baseline, -20.8 ± 2.3% at 1 month, -20.6 ± 3% at 3 months; p = 0.4). Analogously, no significant increase in circulating levels of cardiac biomarkers was found with hsTnT <0.015 ng/ml in all patients at baseline, 1 month and 3 months and median proBNP-nt 118 pg/ml (IQR 47-200) at baseline, 171 pg/ml (IQR 91-520) at 1 month, and 182 pg/ml (IQR 78-470) at 3 months, p = 0.9.

Conclusions

In our study no significant clinical or subclinical evidence of myocardial involvement was detected during treatment with ICIs in patients with non-small cell lung cancer, thus suggesting the potential cardiovascular safety of this promising class of antineoplastic drugs.

Characterization of multi-channel intraneural stimulation in transradial amputees

Although peripheral nerve stimulation using intraneural electrodes has been shown to be an effective and reliable solution to restore sensory feedback after hand loss, there have been no reports on the characterization of multi-channel stimulation. A deeper understanding of how the simultaneous stimulation of multiple electrode channels affects the evoked sensations should help in improving the definition of encoding strategies for bidirectional prostheses. We characterized the sensations evoked by simultaneous stimulation of median and ulnar nerves (multi-channel configuration) in four transradial amputees who had been implanted with four TIMEs (Transverse Intrafascicular Multichannel Electrodes). The results were compared with the characterization of single-channel stimulation. The sensations were characterized in terms of location, extent, type, and intensity. Combining two or more single-channel configurations caused a linear combination of the sensation locations and types perceived with such single-channel stimulations. Interestingly, this was also true when two active sites from the same nerve were stimulated. When stimulating in multi-channel configuration, the charge needed from each electrode channel to evoke a sensation was significantly lower than the one needed in single-channel configuration (sensory facilitation). This result was also supported by electroencephalography (EEG) recordings during nerve stimulation. Somatosensory potentials evoked by multi-channel stimulation confirmed that sensations in the amputated hand were perceived by the subjects and that a perceptual sensory facilitation occurred. Our results should help the future development of more efficient bidirectional prostheses by providing guidelines for the development of more complex stimulation approaches to effectively restore multiple sensations at the same time.

Preventing sepsis development in complicated urinary tract infections

Introduction: Urinary tract infections (UTIs) are the most prevalent infections in the community and the most common reason for antimicrobial prescribing in ambulatory care. A UTI is defined as complicated when urinary tract anatomical abnormalities or urinary devices are present, when it is recurrent and when associated with immunodeficiency. Complicated UTIs (cUTIs) have a higher risk of treatment failure and often require longer antimicrobial treatment courses. cUTIs, especially those which are healthcare-associated, are often due to multidrug resistant organisms (MDROs).Areas covered: This article will review the available evidence in relation to prevention of sepsis in cUTI, evaluating the risk factors associated with sepsis development. Published articles from January 2005 to September 2019 on UTIs and sepsis prevention in complicated UTIs were identified by using MEDLINE (National Library of Medicine Bethesda MD) and by reviewing the references of retrieved articles.Expert opinion: Prevention of sepsis relies on prompt and timely diagnosis of cUTI, early identification of the causative organism, removal of obstructions and source control, proper and adequate empirical/targeted antimicrobial treatment. In particular, source control, i.e. removal of urinary obstructions, infected stents, urinary catheters, nephrostomies, and drainage of hydronephrosis/abscess, is essential for preventing the development and progression of sepsis.

Present and future of siderophore-based therapeutic and diagnostic approaches in infectious diseases

Iron is an essential micronutrient required for the growth of almost all aerobic organisms; the iron uptake pathway in bacteria therefore represents a possible target for novel antimicrobials, including hybrids between antimicrobials and siderophores. Siderophores are low molecular weight iron chelators that bind to iron and are actively transported inside the cell through specific binding protein complexes. These binding protein complexes are present both in Gram negative bacteria, in their outer and inner membrane, and in Gram positive bacteria in their cytoplasmic membrane. Most bacteria have the ability to produce siderophores in order to survive in environments with limited concentrations of free iron, however some bacteria synthetize natural siderophore-antibiotic conjugates that exploit the siderophore-iron uptake pathway to deliver antibiotics into competing bacterial cells and gain a competitive advantage. This approach has been referred to as a Trojan Horse Strategy. To overcome the increasing global problem of antibiotic resistance in Gram negative bacteria, which often have reduced outer membrane permeability, siderophore-antibiotic hybrid conjugates have been synthetized in vitro. Cefiderocol is the first siderophore-antibiotic conjugate that progressed to late stage clinical development so far. In studies on murine models the iron-siderophore uptake pathway has been also exploited for diagnostic imaging of infectious diseases, in which labelled siderophores have been used as specific probes. The aim of this review is to describe the research progress in the field of siderophore-based therapeutic and diagnostic approaches in infectious diseases.

Treatment Options for Colistin Resistant Klebsiella pneumoniae: Present and Future

Multidrug-resistant (MDR) Klebsiella pneumoniae represents an increasing threat to human health, causing difficult-to-treat infections with a high mortality rate. Since colistin is one of the few treatment options for carbapenem-resistant K. pneumoniae infections, colistin resistance represents a challenge due to the limited range of potentially available effective antimicrobials, including tigecycline, gentamicin, fosfomycin and ceftazidime/avibactam. Moreover, the choice of these antimicrobials depends on their pharmacokinetics/pharmacodynamics properties, the site of infection and the susceptibility profile of the isolated strain, and is sometimes hampered by side effects. This review describes the features of colistin resistance in K. pneumoniae and the characteristics of the currently available antimicrobials for colistin-resistant MDR K. pneumoniae, as well as the characteristics of novel antimicrobial options, such as the soon-to-be commercially available plazomicin and cefiderocol. Finally, we consider the future use of innovative therapeutic strategies in development, including bacteriophages therapy and monoclonal antibodies.

Use of colistin in adult patients: A cross-sectional study

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.

Bloodstream infections caused by carbapenem-resistant Acinetobacter baumannii: Clinical features, therapy and outcome from a multicenter study

OBJECTIVES

bloodstream infections (BSI) due to multidrug-resistant (MDR) Acinetobacter baumannii (AB) have been increasingly observed among hospitalized patients.

METHODS

prospective, observational study conducted among 12 large tertiary-care hospitals, across 7 Italian regions. From June 2017 to June 2018 all consecutive hospitalized patients with bacteremia due to MDR-AB were included and analyzed in the study.

RESULTS

During the study period 281 episodes of BSI due to MDR-AB were observed: 98 (34.8%) episodes were classified as primary bacteremias, and 183 (65.2%) as secondary bacteremias; 177 (62.9%) of them were associated with septic shock. Overall, 14-day mortality was observed in 172 (61.2%) patients, while 30-day mortality in 207 (73.6%) patients. On multivariate analysis, previous surgery, continuous renal replacement therapy, inadequate source control of infection, and pneumonia were independently associated with higher risk of septic shock. Instead, septic shock and Charlson Comorbidity Index >3 were associated with 14-day mortality, while adequate source control of infection and combination therapy with survival. Finally, septic shock, previous surgery, and aminoglycoside-containing regimen were associated with 30-day mortality, while colistin-containing regimen with survival.

CONCLUSIONS

BSI caused by MDR-AB represents a difficult challenge for physicians, considering the high rates of septic shock and mortality associated with this infection.

Optimal integration of intraneural somatosensory feedback with visual information: a single-case study

Providing somatosensory feedback to amputees is a long-standing objective in prosthesis research. Recently, implantable neural interfaces have yielded promising results in this direction. There is now considerable evidence that the nervous system integrates redundant signals optimally, weighting each signal according to its reliability. One question of interest is whether artificial sensory feedback is combined with other sensory information in a natural manner. In this single-case study, we show that an amputee with a bidirectional prosthesis integrated artificial somatosensory feedback and blurred visual information in a statistically optimal fashion when estimating the size of a hand-held object. The patient controlled the opening and closing of the prosthetic hand through surface electromyography, and received intraneural stimulation proportional to the object's size in the ulnar nerve when closing the robotic hand on the object. The intraneural stimulation elicited a vibration sensation in the phantom hand that substituted the missing haptic feedback. This result indicates that sensory substitution based on intraneural feedback can be integrated with visual feedback and make way for a promising method to investigate multimodal integration processes.

Comparison of linear frequency and amplitude modulation for intraneural sensory feedback in bidirectional hand prostheses

Recent studies have shown that direct nerve stimulation can be used to provide sensory feedback to hand amputees. The intensity of the elicited sensations can be modulated using the amplitude or frequency of the injected stimuli. However, a comprehensive comparison of the effects of these two encoding strategies on the amputees' ability to control a prosthesis has not been performed. In this paper, we assessed the performance of two trans-radial amputees controlling a myoelectric hand prosthesis while receiving grip force sensory feedback encoded using either linear modulation of amplitude (LAM) or linear modulation of frequency (LFM) of direct nerve stimulation (namely, bidirectional prostheses). Both subjects achieved similar and significantly above-chance performance when they were asked to exploit LAM or LFM in different tasks. The feedbacks allowed them to discriminate, during manipulation through the robotic hand, objects of different compliances and shapes or different placements on the prosthesis. Similar high performances were obtained when they were asked to apply different levels of force in a random order on a dynamometer using LAM or LFM. In contrast, only the LAM strategy allowed the subjects to continuously modulate the grip pressure on the dynamometer. Furthermore, when long-lasting trains of stimulation were delivered, LFM strategy generated a very fast adaptation phenomenon in the subjects, which caused them to stop perceiving the restored sensations. Both encoding approaches were perceived as very different from the touch feelings of the healthy limb (natural). These results suggest that the choice of specific sensory feedback encodings can have an effect on user performance while grasping. In addition, our results invite the development of new approaches to provide more natural sensory feelings to the users, which could be addressed by a more biomimetic strategy in the future.

A Double-Labeling Assay for Simultaneous Estimation and Characterization of Estrogen and Progesterone Receptors using Radioiodinated Estradiol and Tritiated Org 2058

Estrogen (ER) and progesterone receptors (PgR) appear to be a prerequisite to elicit a biologic response by a hormone-target organ. Current methodologies for analysis of these proteins (e.g., dextran-coated charcoal, DCC) in single-label assay (SLA) require relatively large amounts of tissue material, time and laboriousness. Therefore, we have developed for breast cancer tissue an improved dual-label assay (DLA) for simultaneous titration (by DCC) and/or characterization (by sedimentation properties) of ER and PgR on the same sample, using 125I-E2 and 3H-Org 2058 as tracers. The interaction of 125I-E2 with ER and plasma proteins in comparison to 3H-E2 was studied in terms of specificity, time course, affinity binding and sedimentation pattern. 125I-E2 bound the same molecular forms displayed by 3H-E2 (9 and 3S) but with lower titers (about 1.3-fold), irrespective of the technique used, and did not bind to sex hormone-binding globulin. Simultaneous detection of 125I and 3H was achieved by use of a gamma counter plus a beta counter sequentially. ER and PgR titrations with DCC in DLA were in good agreement with those obtained with SLA, in terms of titers and Ka values. An analogous result was obtained with sucrose density gradient (SDG) analysis. Both the DLA methods were highly reproducible (CV < 8.0 %). Between the rotors available for SDG, the vertical one was preferable because of the larger number of samples processed and of less purturbation of sedimenting receptor molecules. Furthermore, a biochemical application of the method is described. In conclusion, the DLA procedure, by simplifying ER and PgR estimation, makes it possible to study, even on small tumor biopsies, the molecular properties of these proteins in relation to the clinical response of the disease.

Novel Antimicrobials for the Treatment of Clostridium difficile Infection

The current picture of Clostridium difficile infection (CDI) is alarming with a mortality rate ranging between 3% and 15% and a CDI recurrence rate ranging from 12% to 40%. Despite the great efforts made over the past 10 years to face the CDI burden, there are still gray areas in our knowledge on CDI management. The traditional anti-CDI antimicrobials are not always adequate in addressing the current needs in CDI management. The aim of our review is to give an update on novel antimicrobials for the treatment of CDI, considering the currently available evidences on their efficacy, safety, molecular mechanism of action, and their probability to be successfully introduced into the clinical practice in the near future. We identified, through a PubMed search, 16 novel antimicrobial molecules under study for CDI treatment: cadazolid, surotomycin, ridinilazole, LFF571, ramoplanin, CRS3123, fusidic acid, nitazoxanide, rifampin, rifaximin, tigecycline, auranofin, NVB302, thuricin CD, lacticin 3147, and acyldepsipeptide antimicrobials. In comparison with the traditional anti-CDI antimicrobial treatment, some of the novel antimicrobials reviewed in this study offer several advantages, i.e., the favorable pharmacokinetic and pharmacodynamic profile, the narrow-spectrum activity against CD that implicates a low impact on the gut microbiota composition, the inhibitory activity on CD sporulation and toxins production. Among these novel antimicrobials, the most active compounds in reducing spore production are cadazolid, ridinilazole, CRS3123, ramoplanin and, potentially, the acyldepsipeptide antimicrobials. These antimicrobials may potentially reduce CD environment spread and persistence, thus reducing CDI healthcare-associated acquisition. However, some of them, i.e., surotomycin, fusidic acid, etc., will not be available due to lack of superiority versus standard of treatment. The most CD narrow-spectrum novel antimicrobials that allow to preserve microbiota integrity are cadazolid, ridinilazole, auranofin, and thuricin CD. In conclusion, the novel antimicrobial molecules under development for CDI have promising key features and advancements in comparison to the traditional anti-CDI antimicrobials. In the near future, some of these new molecules might be effective alternatives to fight CDI.

Design, synthesis and antibacterial evaluation of a polycationic calix[4]arene derivative alone and in combination with antibiotics

The growing antibiotic resistance phenomenon continues to stimulate the search for new compounds and strategies to combat bacterial infections. In this study, we designed and synthesized a new polycationic macrocyclic compound (2) bearing four N-methyldiethanol ammonium groups clustered and circularly organized by a calix[4]arene scaffold. The in vitro activity of compound 2, alone and in combination with known antibiotics (ofloxacin, chloramphenicol or tetracycline), was assessed against strains of Staphylococcus aureus (ATCC 6538 and methicillin-resistant isolate 15), S. epidermidis (ATCC 35984 and methicillin-resistant isolate 57), and Pseudomonas aeruginosa (ATCC 9027 and antibiotic-resistant isolate 1). Calix[4]arene derivative 2 showed significant antibacterial activity against ATCC and methicillin-resistant Gram positive Staphylococci, improved the stability of tetracycline in water, and in combination with antibiotics enhanced the antibiotic efficacy against Gram negative P. aeruginosa by an additive effect.

Antibacterial Prophylaxis for Surgical Site Infection in the Elderly: Practical Application

Surgical site infections are among the most common healthcare-associated infections and are linked with increased length of hospitalization, re-admission, mortality and significant financial burden. Risk factors for the occurrence of surgical site infections include variables related to the surgical procedure as well as host factors. Increasing age is associated with the occurrence of surgical site infections. The aim of this review is to give an update on the antibiotic prophylaxis for surgical site infection in elderly people. We focused on specific issues and practical applications, such as the importance of targeting the antimicrobial agent to the susceptibility pattern of colonizing flora in selected cases and the need for dosage modifications.

Clostridium difficile infection: new approaches to prevention, non-antimicrobial treatment, and stewardship

INTRODUCTION

Despite the large amount of scientific publications exploring the epidemiology and the clinical management of Clostridium difficile (CD) infection, some issues remain unsolved or need further studies. The aim of this review is to give an update on the hot topics on CD prevention, including stewardship programs, and on the non-microbiological treatment of CD infection. Areas covered: This article will review the importance of minimizing the CD spore shedding in the healthcare environment for potentially reducing CD transmission. Moreover, antimicrobial stewardship programs aimed to reduce CD incidence will be reviewed. Finally, new strategies for reducing CD infection recurrence will be described. Expert commentary: Besides the basic infection control and prevention practices, including hand hygiene, contact isolation and environmental cleaning, in the prevention of CD infection other issues should be addressed including minimizing the spread of CD in the healthcare setting, and implementing the best strategy for reducing CD infection occurrence, including tailored antimicrobial stewardship programs. Regarding new advancements in treatment and management of CDI episodes, non-antimicrobial approaches seem to be promising in reducing and managing recurrent CD infection.

Resistance to Colistin in Klebsiella Pneumoniae: A 4.0 Strain?

The global rise of multidrug-resistant gram-negative bacteria represents an increasing threat to patient safety. From the first observation of a carbapenem-resistant gram-negative bacteria a global spread of extended-spectrum beta-lactamases and carbapenemases producing Klebsiella pneumoniae has been observed. Treatment options for multidrug-resistant K. pneumoniae are actually limited to combination therapy with some aminoglycosides, tigecycline and to older antimicrobial agents. Unfortunately, the prevalence of colistin-resistant and tigecycline-resistant K. pneumoniae is increasing globally. Infection due to colistin-resistant K. pneumoniae represents an independent risk factor for mortality. Resistance to colistin in K. pneumoniae may be multifactorial, as it is mediated by chromosomal genes or plasmids. The emergence of transmissible, plasmid-mediated colistin resistance is an alarming finding. The absence of new agents effective against resistant Gram-negative pathogens means that enhanced surveillance, compliance with infection prevention procedures, and antimicrobial stewardship programs will be required to limit the spread of colistin-resistant K. pneumoniae.