Aztreonam-avibactam versus meropenem for the treatment of serious infections caused by Gram-negative bacteria (REVISIT): a descriptive, multinational, open-label, phase 3, randomised trial.

BACKGROUND: There is a need for additional therapeutic options for serious infections caused by Gram-negative pathogens. In the phase 3, descriptive REVISIT study, we investigated the safety and efficacy of aztreonam-avibactam in the treatment of complicated intra-abdominal infections or hospital-acquired pneumonia or ventilator-associated pneumonia (HAP-VAP) caused, or suspected to be caused, by Gram-negative bacteria. METHODS: This prospective, multinational, open-label, central assessor-masked study enrolled adults who were hospitalised with a complicated intra-abdominal infection or HAP-VAP. Patients were randomly allocated via block randomisation using interactive response technology stratified by infection type in a 2:1 ratio to aztreonam-avibactam (with metronidazole for complicated intra-abdominal infection) or meropenem with or without colistin for 5-14 days for complicated intra-abdominal infection or 7-14 days for HAP-VAP. The primary endpoint was clinical cure at the test-of-cure visit (within 3 days before or after day 28) in the intention-to-treat (ITT) population. Secondary endpoints included 28-day mortality in the ITT population and safety in patients in the ITT population who received study drug (safety analysis set). No formal hypothesis testing was planned. The study was registered with ClinicalTrials.gov (NCT03329092) and EudraCT (2017-002742-68) and is complete. FINDINGS: Between April 5, 2018, and Feb 23, 2023, we screened 461 patients. 422 patients were enrolled and randomly allocated (282 in the aztreonam-avibactam group and 140 in the meropenem group, forming the ITT analysis set), of whom ten patients (seven in the aztreonam-avibactam group and three in the meropenem group) were randomly allocated but did not receive study treatment. 271 (64%) of 422 patients had at least one Gram-negative pathogen from an adequate specimen identified at baseline. The most frequent baseline pathogens were Enterobacterales (252 [93%] of 271). Overall, 19 (24%) of 80 isolates tested for carbapenemases were carbapenemase-positive (serine, metallo-ß-lactamase, or both). 193 (68·4%) of 282 patients in the aztreonam-avibactam group and 92 (65·7%) of 140 in the meropenem group had clinical cure at the test-of-cure visit (treatment difference 2·7% [95% CI -6·6 to 12·4]). For patients with complicated intra-abdominal infection, the adjudicated clinical cure rate was 76·4% (159 of 208) for the aztreonam-avibactam group and 74·0% (77 of 104) for the meropenem group. Cure rates in patients with HAP-VAP were 45·9% (34 of 74) for aztreonam-avibactam and 41·7% (15 of 36) for meropenem. 28-day all-cause mortality rates were 4% (12 of 282) for aztreonam-avibactam and 7% (ten of 140) for meropenem; in patients with complicated intra-abdominal infection, mortality was 2% (four of 208) and 3% (three of 104) for aztreonam-avibactam and meropenem, respectively, and in patients with HAP-VAP, mortality was 11% (eight of 74) and 19% (seven of 36), respectively. Aztreonam-avibactam was generally well tolerated, and safety findings were consistent with the known safety profile of aztreonam monotherapy. There were no treatment-related serious adverse events in the aztreonam-avibactam group. INTERPRETATION: These phase 3 efficacy and safety data provide support for aztreonam-avibactam as a potential therapeutic option for complicated intra-abdominal infection or HAP-VAP caused by Gram-negative bacteria. FUNDING: Pfizer.

Navigating the Current Treatment Landscape of Metallo-ß-Lactamase-Producing Gram-Negative Infections: What are the Limitations?

The spread of carbapenemase-producing gram-negative pathogens, especially those producing metallo-ß-lactamases (MBLs), has become a major health concern. MBLs are molecularly the most diverse carbapenemases, produced by a wide spectrum of gram-negative organisms, including the Enterobacterales, Pseudomonas spp., Acinetobacter baumannii, and Stenotrophomonas maltophilia, and can hydrolyze most ß-lactams using metal ion cofactors in their active sites. Over the years, the prevalence of MBL-carrying isolates has increased globally, particularly in Asia. MBL infections are associated with adverse clinical outcomes including longer length of hospital stay, ICU admission, and increased mortality across the globe. The optimal treatment for MBL infections not only depends on the pathogen but also on the underlying resistance mechanisms. Currently, there are only few drugs or drug combinations that can efficiently offset MBL-mediated resistance, which makes the treatment of MBL infections challenging. The rising concern of MBLs along with the limited treatment options has led to the need and development of drugs that are specifically targeted towards MBLs. This review discusses the prevalence of MBLs, their clinical impact, and the current treatment options for MBL infections and their limitations. Furthermore, this review will discuss agents currently in the pipeline for treatment of MBL infections.

Assessment of De-Escalation of Empirical Antimicrobial Therapy in Medical Wards with Recognized Prevalence of Multi-Drug-Resistant Pathogens: A Multicenter Prospective Cohort Study in Non-ICU Patients with Microbiologically Documented Infection.

Antimicrobial resistance poses a major threat to human health worldwide and the implementation of antimicrobial stewardship programs (ASPs), including antimicrobial de-escalation (ADE), is a multifaceted tool for minimizing unnecessary or inappropriate antibiotic exposure. This was a prospective observational study of 142 non-Intensive Care Unit (ICU) patients with microbiologically documented infection who were initially administered empirical antimicrobial therapy and admitted to the medical wards of 6 tertiary-care hospitals in Greece from January 2017 to December 2018. Patients were divided into two groups, the ADE and non-ADE group, based on whether ADE was applied or not, respectively. Exploratory end-points were ADE feasibility, safety and efficacy. ADE was applied in 76 patients at a median time of 4 days (IQR: 3, 5). An increased likelihood of ADE was observed in patients with urinary tract (OR: 10.04, 95% CI: 2.91, 34.57; p < 0.001), skin and soft tissue (OR: 16.28, 95% CI: 1.68, 158.08; p = 0.016) and bloodstream infections (OR: 2.52, 95% CI: 1, 6.36; p = 0.05). Factors significantly associated with higher rates of ADE were clarithromycin administration, diagnosis of urinary tract infection (UTI), isolation of E. coli, age and symptoms type on admission. Mortality was lower in the ADE group (18.4% vs. 30.3% p < 0.1) and ADE was not significantly associated with the probability of death (p = 0.432). ADE was associated with favorable clinical outcomes and can be performed even in settings with high prevalence of multi-drug resistant (MDR) pathogens without compromising safety.

Integration of individual preclinical and clinical anti-infective PKPD data to predict clinical study outcomes.

The AIDA randomized clinical trial found no significant difference in clinical failure or survival between colistin monotherapy and colistin-meropenem combination therapy in carbapenem-resistant Gram-negative infections. The aim of this reverse translational study was to integrate all individual preclinical and clinical pharmacokinetic-pharmacodynamic (PKPD) data from the AIDA trial in a pharmacometric framework to explore whether individualized predictions of bacterial burden were associated with the trial outcomes. The compiled dataset included for each of the 207 patients was (i) information on the infecting Acinetobacter baumannii isolate (minimum inhibitory concentration, checkerboard assay data, and fitness in a murine model), (ii) colistin plasma concentrations and colistin and meropenem dosing history, and (iii) disease scores and demographics. The individual information was integrated into PKPD models, and the predicted change in bacterial count at 24 h for each patient, as well as patient characteristics, was correlated with clinical outcomes using logistic regression. The in vivo fitness was the most important factor for change in bacterial count. A model-predicted growth at 24 h of ≥2-log10 (164/207) correlated positively with clinical failure (adjusted odds ratio, aOR = 2.01). The aOR for one unit increase of other significant predictors were 1.24 for SOFA score, 1.19 for Charlson comorbidity index, and 1.01 for age. This study exemplifies how preclinical and clinical anti-infective PKPD data can be integrated through pharmacodynamic modeling and identify patient- and pathogen-specific factors related to clinical outcomes - an approach that may improve understanding of study outcomes.

Visceral Leishmaniasis in a Twin Pregnancy: A Case Report and Review of the Literature.

Visceral leishmaniasis (VL), often referred to as kala-azar, is quite rare in developed countries during pregnancy. Only few studies have evaluated its impact on perinatal outcome. It is caused primarily by Leishmania donovani or Leishmania infantum and presents with a wide spectrum of clinical manifestations from cutaneous ulcers to multisystem disease. Differential diagnosis is challenging as symptoms and signs are insidious, mimicking other diseases. Misdiagnosis can result in severe adverse perinatal outcomes, even maternal/neonatal death. Early treatment with liposomal amphotericin-B (LAmB) is currently the first choice with adequate effectiveness. We report a rare case of VL in a twin pregnancy with onset at the second trimester, presenting with periodic fever with rigors, right flank pain, and gradual dysregulation of all three cell lines. The positive rK39 enzyme-linked immunosorbent assay test confirmed the diagnosis. Treatment with LAmB resulted in clinical improvement within 48 h and in the delivery of two late-preterm healthy neonates with no symptoms or signs of vertical transmission. The one-year follow-up, of the mother and the neonates, was negative for recurrence. To our knowledge, this is the first reported case of VL in a twin pregnancy, and consequently treatment and perinatal outcome are of great importance.

Attributable mortality of infections caused by carbapenem-resistant Enterobacterales: results from a prospective, multinational case-control-control matched cohorts study (EURECA).

OBJECTIVES: To assess the mortality attributable to infections caused by carbapenem-resistant Enterobacterales (CRE) and to investigate the effect of clinical management on differences in observed outcomes in a multinational matched cohort study. METHODS: A prospective matched-cohorts study (NCT02709408) was performed in 50 European hospitals from March 2016 to November 2018. The main outcome was 30-day mortality with an active post-discharge follow-up when applied. The CRE cohort included patients with complicated urinary tract infections, complicated intra-abdominal infections, pneumonia, or bacteraemia from other sources because of CRE. Two control cohorts were selected: patients with infection caused by carbapenem-susceptible Enterobacterales (CSE) and patients without infection. Matching criteria included type of infection for the CSE group, hospital ward of CRE detection, and duration of hospital admission up to CRE detection. Multivariable and stratified Cox regression was applied. RESULTS: The cohorts included 235 patients with CRE infection, 235 patients with CSE infection, and 705 non-infected patients. The 30-day mortality (95% CI) was 23.8% (18.8-29.6), 10.6% (7.2-15.2), and 8.4% (6.5-10.6), respectively. The difference in 30-day mortality rates between patients with CRE infection when compared with patients with CSE infection was 13.2% (95% CI, 6.3-20.0), (HR, 2.57; 95% CI, 1.55-4.26; p < 0.001), and 15.4% (95% CI, 10.5-20.2) when compared with non-infected patients (HR, 3.85; 95% CI, 2.57-5.77; p < 0.001). The population attributable fraction for 30-day mortality for CRE vs. CSE was 19.28%, and for CRE vs. non-infected patients was 9.61%. After adjustment for baseline variables, the HRs for mortality were 1.87 (95% CI, 0.99-3.50; p 0.06) and 3.65 (95% CI, 2.29-5.82; p < 0.001), respectively. However, when treatment-related time-dependent variables were added, the HR of CRE vs. CSE reduced to 1.44 (95% CI, 0.78-2.67; p 0.24). DISCUSSION: CRE infections are associated with significant attributable mortality and increased adjusted hazard of mortality when compared with CSE infections or patients without infection. Underlying patient characteristics and a delay in appropriate treatment play an important role in the CRE mortality.

Clinical and Economic Value of Reducing Antimicrobial Resistance in the Management of Hospital-Acquired Infections with Limited Treatment Options in Greece.

INTRODUCTION: Antimicrobial resistance (AMR) is a major public health threat worldwide. Greece has the highest burden of infections due to antibiotic-resistant bacteria among European Union/European Economic Area (EU/EEA) countries. One of the most serious AMR threats in Greece is hospital-acquired infections (HAIs) with limited treatment options (LTO) caused by resistant gram-negative pathogens. Thus, this study sought to estimate the current AMR burden in Greece and the value of reducing AMR to gram-negative pathogens for the Greek healthcare system. METHODS: The current model was adapted from a previously published and validated model of AMR to investigate the overall and AMR-specific burden of treating the most common HAIs with LTO in Greece and scenarios to demonstrate the benefits associated with reducing AMR levels from a third-party payer perspective. Clinical and economic outcomes were estimated over a 10-year time horizon; life years (LYs) and quality-adjusted life years (QALYs) were calculated over a lifetime (based on the annual number of infections over 10 years) at a willingness-to-pay of €30,000 per QALY gained and a 3.5% discount rate. RESULTS: In Greece, the current AMR levels in HAIs with LTO caused by four gram-negative pathogens account for > 316,000 hospital bed days, €73 million in hospitalisation costs, and > 580,000 LYs and 450,000 QALYs lost over 10 years. The monetary burden is estimated at €13.9 billion. A reduction in current AMR levels by 10-50% results in clinical and economic benefit; 29,264-151,699 bed days may be saved, leading to decreased hospitalisation costs (€6.8 million-€35.3 million) and a gain in LYs (85,328-366,162) and QALYs (67,421-289,331), associated with a monetary benefit of between €2.0 billion and €8.7 billion. CONCLUSION: This study shows the substantial clinical and economic burden AMR represents to the Greek healthcare system and the value that can be achieved by effectively reducing AMR levels.

HIV RNA/DNA Levels at Diagnosis Can Predict Immune Reconstitution: A Longitudinal Analysis.

BACKGROUND: HIV DNA mirrors the number of infected cells and the size of the HIV viral reservoir. The aim of this study was to evaluate the effect of pre-cART HIV DNA levels as a predictive marker of immune reconstitution and on the post-cART CD4 counts trends. METHODS: HIV DNA was isolated from PBMCs and quantified by real-time PCR. Immune reconstitution was assessed up to four years. Piecewise-linear mixed models were used to describe CD4 count changes. RESULTS: 148 people living with HIV (PLWH) were included. The highest rate of immune reconstitution was observed during the first trimester. There was a trend showing that high HIV RNA level resulted in greater increase in CD4 count, especially during the first trimester of cART (difference above vs. below median 15.1 cells/µL/month; 95% CI -1.4-31.5; p = 0.073). Likewise, higher HIV DNA level would predict greater CD4 increases, especially after the first trimester (difference above vs. below median 1.2 cells/µL/month; 95% CI -0.1-2.6; p = 0.071). Higher DNA and RNA levels combined were significantly associated with greater CD4 increase past the first trimester (difference high/high vs. low/low 2.1 cells/µL/month; 95% CI 0.3-4.0; p = 0.024). In multivariable analysis, lower baseline CD4 counts predicted a greater CD4 rise. CONCLUSIONS: In successfully treated PLWH, pre-cART HIV DNA and HIV RNA levels are predictors of immune reconstitution.

Prevalence and Clinical Consequences of Colistin Heteroresistance and Evolution into Full Resistance in Carbapenem-Resistant Acinetobacter baumannii.

Colistin heteroresistance (HR) refers to a bacterial population comprised of several subpopulations with different levels of resistance to colistin. In this study, we discuss the classic form of HR, in which a resistant subpopulation exists within a predominantly susceptible population. We investigated the prevalence of colistin HR and its evolution into full resistance among 173 clinical carbapenem-resistant Acinetobacter baumannii isolates and examined the effect of HR on clinical outcomes. To determine HR, we performed population analysis profiling. Our results showed a high prevalence of HR (67.1%). To examine evolution of HR strains into full resistance, the HR strains were grown in colistin-containing broth, transferred onto colistin-containing plates, and colonies on these plates were transferred into colistin-free broth. Many of the HR strains (80.2%) evolved into full resistance, 17.2% reverted to HR, and 2.6% were borderline. We used logistic regression to compare 14-day clinical failure and 14-day mortality between patients infected by HR versus susceptible non-HR carbapenem-resistant A. baumannii. In the subgroup of patients with bacteremia, HR was significantly associated with 14-day mortality. IMPORTANCE To our knowledge, this is the first large-scale study to report on HR in Gram-negative bacteria. We described the prevalence of colistin HR in a large sample of carbapenem-resistant A. baumannii isolates, the evolution of many colistin HR isolates to a resistant phenotype following colistin exposure and withdrawal, and the clinical consequences of colistin HR. We found a high prevalence of HR among clinical carbapenem-resistant A. baumannii isolates; most evolved into a resistant phenotype following colistin exposure and withdrawal. In patients treated with colistin, evolution of HR A. baumannii into full resistance could lead to higher rates of treatment failure and contribute to the reservoir of colistin-resistant pathogens in health care settings.

Risk factors for infections caused by carbapenem-resistant Enterobacterales: an international matched case-control-control study (EURECA).

Background: Data on risk factors for carbapenem-resistant Enterobacterales (CRE) with wider applicability are needed to inform preventive measures and efficient design of randomised trials. Methods: An international matched case-control-control study was performed in 50 hospitals with high CRE incidence from March 2016 to November 2018 to investigate different aspects of infections caused by CRE (NCT02709408). Cases were patients with complicated urinary tract infection (cUTI), complicated intraabdominal (cIAI), pneumonia or bacteraemia from other sources (BSI-OS) due to CRE; control groups were patients with infection caused by carbapenem-susceptible Enterobacterales (CSE), and by non-infected patients, respectively. Matching criteria included type of infection for CSE group, ward and duration of hospital admission. Conditional logistic regression was used to identify risk factors. Findings: Overall, 235 CRE case patients, 235 CSE controls and 705 non-infected controls were included. The CRE infections were cUTI (133, 56.7%), pneumonia (44, 18.7%), cIAI and BSI-OS (29, 12.3% each). Carbapenemase genes were found in 228 isolates: OXA-48/like, 112 (47.6%), KPC, 84 (35.7%), and metallo-ß-lactamases, 44 (18.7%); 13 produced two. The risk factors for CRE infection in both type of controls were (adjusted OR for CSE controls; 95% CI; p value) previous colonisation/infection by CRE (6.94; 2.74-15.53; <0.001), urinary catheter (1.78; 1.03-3.07; 0.038) and exposure to broad spectrum antibiotics, as categorical (2.20; 1.25-3.88; 0.006) and time-dependent (1.04 per day; 1.00-1.07; 0.014); chronic renal failure (2.81; 1.40-5.64; 0.004) and admission from home (0.44; 0.23-0.85; 0.014) were significant only for CSE controls. Subgroup analyses provided similar results. Interpretation: The main risk factors for CRE infections in hospitals with high incidence included previous colonization, urinary catheter and exposure to broad spectrum antibiotics. Funding: The study was funded by the Innovative Medicines Initiative Joint Undertaking (https://www.imi.europa.eu/) under Grant Agreement No. 115620 (COMBACTE-CARE).

Ex Vivo Evaluation of Glutamine Treatment in Sepsis and Trauma in a Human Peripheral Blood Mononuclear Cells Model.

We aimed to assess the lipopolysaccharide (LPS), or heat shock (HS) induction, and glutamine-modulating effects on heat shock protein-90α (HSP90α) and cytokines in an ex vivo model using peripheral blood mononuclear cells (PBMCs). The PBMCs of patients with septic shock, trauma-related systemic inflammatory response syndrome (SIRS), and healthy subjects were incubated with 1 µg/mL LPS at 43 °C (HS). Glutamine 10 mM was added 1 hour before or after induction or not at all. We measured mRNA HSP90α, monocyte (m) and lymphocyte (l) HSP90α proteins, interleukin (IL)-1b, -6, -8, -10, tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) supernatant levels. Heat shock increased the HSP90α mRNA and mHSP90α in all groups (10-fold in sepsis, p < 0.001 and p = 0.047, respectively). LPS induced the mHSP90α and lHSP90α in healthy (p < 0.001) and mHSP90α in SIRS (p = 0.004) but not in sepsis. LPS induced the cytokines at 24 and 48 h in all groups, especially in trauma (p < 0.001); HS only induced the IL-8 in healthy (p = 0.003) and septic subjects (p = 0.05). Glutamine at 10 mM before or after stimulation did not alter any induction effect of LPS or HS on HSP90α mRNA and mHSP90α protein in sepsis. In SIRS, glutamine before LPS decreased the mHSP90α but increased it when given after HS (p = 0.018). Before or after LPS (p = 0.049) and before HS (p = 0.018), glutamine decreased the lHSP90α expression in sepsis but increased it in SIRS when given after HS (p = 0.003). Regarding cytokines, glutamine enhanced the LPS-induced MCP-1 at 48 h in healthy (p = 0.011), SIRS (p < 0.001), and sepsis (p = 0.006). In conclusion, glutamine at 10 mM, before or after LPS and HS, modulates mHSP90α and lHSP90α in sepsis and SIRS differently and unpredictably. Although it does not alter the stimulation effect on interleukins, glutamine enhances the LPS induction effect on supernatant MCP-1 in all groups. Future research should seek to elucidate better the impact of glutamine and temperature modulation on HSP90α and MCP-1 pathways in sepsis and trauma.

Estimating the Clinical and Economic Impact of Introducing a New Antibacterial into Greek Clinical Practice for the Management of Hospital-Acquired Infections with Limited Treatment Options.

INTRODUCTION: Hospital-acquired infections (HAIs) and growing antimicrobial resistance (AMR) represent a significant healthcare burden globally. Especially in Greece, HAIs with limited treatment options (LTO) pose a serious threat due to increased morbidity and mortality. This study aimed to estimate the clinical and economic value of introducing a new antibacterial for HAIs with LTO in Greece. METHODS: A previously published and validated dynamic model of AMR was adapted to the Greek setting. The model estimated the clinical and economic outcomes of introducing a new antibacterial for the treatment of HAIs with LTO in Greece. The current treatment pathway was compared with introducing a new antibacterial to the treatment sequence. Outcomes were assessed from a third-party payer perspective, over a 10-year transmission period, with quality-adjusted life years (QALYs) and life years (LYs) gained considered over a lifetime horizon. RESULTS: Over the next 10 years, HAIs with LTO in Greece account for approximately 1.4 million hospital bed days, hospitalisation costs of more than €320 million and a loss of approximately 403,000 LYs (319,000 QALYs). Introduction of the new antibacterial as first-line treatment provided the largest clinical and economic benefit, with savings of up to 93,000 bed days, approximately €21 million in hospitalisation costs and an additional 286,000 LYs (226,000 QALYs) in comparison to the current treatment strategy. The introduction of a new antibacterial was linked to a monetary benefit of €6.8 billion at a willingness to pay threshold of €30,000 over 10 years. CONCLUSION: This study highlights the considerable clinical and economic benefit of introducing a new antibacterial for HAIs with LTO in Greece. This analysis shows the additional benefit when a new antibacterial is introduced to treatment sequences. These findings can be used to inform decision makers to implement policies to ensure timely access to new antibacterial treatments in Greece.

Antimicrobial resistance is a major issue for the Greek healthcare system. The overuse of antibacterial agents contributes to the growing resistance levels, making currently available treatment options less effective. As a result, there is an imperative need to address antimicrobial resistance in Greece. This study developed a mathematical model to investigate the clinical and economic benefits of introducing a new antibacterial to current treatment practice. The model uses regression equations to describe the relationships between inputs and outputs from a published and validated model, which describes the transmission and treatment of infections. The model is used to estimate the impact of a new treatment in Greece, considering differing treatment sequence scenarios. The largest health and financial benefits were seen when a new antibacterial was introduced at first line prior to currently used treatments. Over 10 years, savings of up to 93,000 hospital bed days and €21 million in hospitalisation costs could be achieved, as well as a gain of 286,000 patient life years and 226,000 patient quality-adjusted life years (QALYs), a measure of a patient's quality and length of life, over their remaining lifetime. The introduction of a new antibacterial into the current treatment pathway resulted in an overall monetary benefit of €6.8 billion over 10 years, when additional QALYs are valued at €30,000. This study demonstrates considerable health economic benefits of introducing a new antibacterial in Greece and can help inform decision makers when developing a national action plan to combat resistance and improve access to treatments.

Predictive score for patients with carbapenemase-producing enterobacterales colonization upon admission in a tertiary care hospital in an endemic area.

OBJECTIVES: Carbapenemase-producing Enterobacterales (CPE) comprise important nosocomial pathogens worldwide. Colonized patients are the source of further dissemination in healthcare settings. Considering that timely detection of CPE carriers is pivotal but universal screening is unfeasible, we aimed to develop and validate a prediction score to detect patients harbouring CPE on hospital admission. METHODS: The study was conducted in a tertiary care hospital located in a CPE endemic area. Rectal swabs were obtained from 2303 patients, screened shortly after hospital admission. The Enterobacterales isolated in cultures were examined for the presence of blaVIM, KPC, NDM, OXA-48 by PCR. Demographic data and patient history of the previous 6 months were recorded. Risk factors for CPE carriage were identified using a multivariable logistic regression model and a points-system risk score was developed. The discriminative ability of the risk score was assessed using the AUC and its predictive performance was validated in a second dataset of 1391 patients in a different time period. RESULTS: Seven predictors were identified: previous CPE colonization or infection, prior hospitalization, stay in a long-term health care facility, history of ≥2 interventions, renal replacement therapy, diabetes with end-organ damage and Karnofsky score. The developed risk score in the derivation dataset ranged between 0 and 79 points, with an AUC of 0.84 in the derivation and 0.85 in the validation dataset. CONCLUSIONS: This prediction tool may assist in identifying patients who are at risk of harbouring CPE on hospital admission in an endemic area and guide clinicians to implement prompt and appropriate infection control measures.

The Effect of Different Colistin Dosing Regimens on Nephrotoxicity: A Cohort Study.

(1) Background: It is not known whether different daily dosing schemes have different effects on colistin nephrotoxicity. We examined the effect of once- versus twice- or thrice-daily doses of colistin on renal function. (2) Methods: We performed a multicenter retrospective cohort study of hospitalized patients with a baseline glomerular filtration rate ≥ 50 mL/min who received intravenously the same colistin dose once (regimen A), twice (regimen B) or thrice daily (regimen C). The primary endpoint was acute kidney injury (AKI), defined as fulfilment of any of the RIFLE (Risk-Injury-Failure-Loss-End stage renal disease) criteria. (3) Results: We included 306 patients; 132 (43.1%) received regimen A, 151 (49.3%) regimen B, and 23 (7.5%) regimen C. Ninety-nine (32.4%) patients developed AKI; there was no difference between regimen A vs. B and C [45 (34.1%) vs. 54 (31.0%), p = 0.57]. In a propensity score−matched cohort, AKI was similar in patients receiving Regimen A, Regimen B, and Regimen C (31.6% vs. 33.3%, p = 0.78). On logistic regression analysis, diabetes was an independent predictor of AKI (OR = 4.59, 95% CI 2.03−10.39, p = 0.001) while eGFR > 80 mL/min (OR = 0.50, 95% CI 0.25−0.99, p = 0.048) was inversely associated with AKI. (4) Conclusions: Colistin once daily is not more nephrotoxic than the standard colistin regimens. The only independent predictor of nephrotoxicity was diabetes mellitus, while eGFR > 80 mL/min had a protective effect.

Molecular screening of cat and dog ectoparasites for the presence of Bartonella spp. in Attica, Greece.

The purpose of this study was the molecular detection of Bartonella spp. in fleas and ticks parasitizing cats and dogs from 39 locations in Attica, Greece. One hundred and forty five ectoparasites (104 fleas and 41 ticks) from 92 cats and 53 dogs were investigated individually using PCRs targeting the 16S-23S ribosomal RNA intergenic spacer (ITS) and the citrate synthase (gltA) genetic loci. Bartonella spp. were detected in 14 out of 104 fleas (13.5%) and in none of the ticks examined. Consequent sequence analysis of the amplicons from the two loci identified 3 strains as Bartonella henselae, and 11 as Bartonella clarridgeiae. Οur study demonstrates the presence of B. henselae and B. clarridgeiae in Ctenocephalides felis fleas from cat and dog in Greece. We also report a novel ITS sequence for B. clarridgeiae. Considering that fleas could pose a risk for human bartonellosis from their infected hosts, further studies on the public health risk of Bartonella presence in animal ectoparasites are warranted.

Oxidant/Antioxidant Status Is Impaired in Sepsis and Is Related to Anti-Apoptotic, Inflammatory, and Innate Immunity Alterations.

Oxidative stress is considered pivotal in the pathophysiology of sepsis. Oxidants modulate heat shock proteins (Hsp), interleukins (IL), and cell death pathways, including apoptosis. This multicenter prospective observational study was designed to ascertain whether an oxidant/antioxidant imbalance is an independent sepsis discriminator and mortality predictor in intensive care unit (ICU) patients with sepsis (n = 145), compared to non-infectious critically ill patients (n = 112) and healthy individuals (n = 89). Serum total oxidative status (TOS) and total antioxidant capacity (TAC) were measured by photometric testing. IL-6, -8, -10, -27, Hsp72/90 (ELISA), and selected antioxidant biomolecules (Ζn, glutathione) were correlated with apoptotic mediators (caspase-3, capsase-9) and the central anti-apoptotic survivin protein (ELISA, real-time PCR). A wide scattering of TOS, TAC, and TOS/TAC in all three groups was demonstrated. Septic patients had an elevated TOS/TAC, compared to non-infectious critically ill patients and healthy individuals (p = 0.001). TOS/TAC was associated with severity scores, procalcitonin, IL-6, -10, -27, IFN-γ, Hsp72, Hsp90, survivin protein, and survivin isoforms -2B, -ΔΕx3, -WT (p < 0.001). In a propensity probability (age-sex-adjusted) logistic regression model, only sepsis was independently associated with TOS/TAC (Exp(B) 25.4, p < 0.001). The AUCTOS/TAC (0.96 (95% CI = 0.93-0.99)) was higher than AUCTAC (z = 20, p < 0.001) or AUCTOS (z = 3.1, p = 0.002) in distinguishing sepsis. TOS/TAC, TOS, survivin isoforms -WT and -2B, Hsp90, IL-6, survivin protein, and repressed TAC were strong predictors of mortality (p < 0.01). Oxidant/antioxidant status is impaired in septic compared to critically ill patients with trauma or surgery and is related to anti-apoptotic, inflammatory, and innate immunity alterations. The unpredicted TOS/TAC imbalance might be related to undefined phenotypes in patients and healthy individuals.

Large-scale WGS of carbapenem-resistant Acinetobacter baumannii isolates reveals patterns of dissemination of ST clades associated with antibiotic resistance.

OBJECTIVES: To describe the population genetics and antibiotic resistance gene distribution of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates causing infections in three Mediterranean countries. METHODS: Isolates were collected during the 2013-17 AIDA clinical trial in six hospitals in Israel, Greece and Italy. WGS, bioinformatic characterization and antibiotic resistance profiling were performed. RESULTS: In the 247 CRAB isolates characterized in this study, ST distribution varied by country: 29/31 (93.5%) Greek isolates, 34/41 (82.9%) Italian isolates and 70/175 (40.0%) Israeli isolates belonged to ST2. The identified ST2 isolates included eight distinct clades: 2C, 2D and 2H were significantly more common in Italy, while 2F was unique to Greece. The uncommon ST3 was not present among Greek isolates and constituted only 5/41 (12%) Italian isolates. On the other hand, it was much more common among Israeli isolates: 78/175 (44.6%) belonged to ST3. The vast majority of isolates, 240/247 (97.2%), were found to harbour acquired carbapenemases, primarily blaOXA-23. The chromosomal oxaAb (blaOXA-51-like) and ampC genes characteristic of this organism were also ubiquitous. Most (96.4%) ST3 isolates carried a broad-host-range plasmid IncP1α. CONCLUSIONS: The geographical differences in CRAB populations support the theory that clonal spread of CRAB leads to endemicity in hospitals and regions. The close association between antibiotic resistance genes and clades, and between plasmids and STs, suggest that de novo creation of MDR A. baumannii is rare. The clustering of antibiotic resistance genes and plasmids that is unique to each clade/ST, and nearly uniform within clades/STs, suggests that horizontal transmission is rare but crucial to the clade's/ST's success.

European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidelines for the treatment of infections caused by multidrug-resistant Gram-negative bacilli (endorsed by European society of intensive care medicine).

SCOPE: These ESCMID guidelines address the targeted antibiotic treatment of third-generation cephalosporin-resistant Enterobacterales (3GCephRE) and carbapenem-resistant Gram-negative bacteria, focusing on the effectiveness of individual antibiotics and on combination versus monotherapy. METHODS: An expert panel was convened by ESCMID. A systematic review was performed including randomized controlled trials and observational studies, examining different antibiotic treatment regimens for the targeted treatment of infections caused by the 3GCephRE, carbapenem-resistant Enterobacterales, carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Acinetobacter baumannii. Treatments were classified as head-to-head comparisons between individual antibiotics and between monotherapy and combination therapy regimens, including defined monotherapy and combination regimens only. The primary outcome was all-cause mortality, preferably at 30 days and secondary outcomes included clinical failure, microbiological failure, development of resistance, relapse/recurrence, adverse events and length of hospital stay. The last search of all databases was conducted in December 2019, followed by a focused search for relevant studies up until ECCMID 2021. Data were summarized narratively. The certainty of the evidence for each comparison between antibiotics and between monotherapy and combination therapy regimens was classified by the GRADE recommendations. The strength of the recommendations for or against treatments was classified as strong or conditional (weak). RECOMMENDATIONS: The guideline panel reviewed the evidence per pathogen, preferably per site of infection, critically appraising the existing studies. Many of the comparisons were addressed in small observational studies at high risk of bias only. Notably, there was very little evidence on the effects of the new, recently approved, ß-lactam/ß-lactamase inhibitors on infections caused by carbapenem-resistant Gram-negative bacteria. Most recommendations are based on very-low- and low-certainty evidence. A high value was placed on antibiotic stewardship considerations in all recommendations, searching for carbapenem-sparing options for 3GCephRE and limiting the recommendations of the new antibiotics for severe infections, as defined by the sepsis-3 criteria. Research needs are addressed.

Pneumocystis jirovecii pneumonia in a X-linked chronic granulomatous disease female carrier.

The X-chromosome linked (XL) female carriers of chronic granulomatous disease (CGD) are considered to have no risk for infection. Herein we present a female CGD XL-carrier who developed Pneumocystis jirovecii pneumonia and Serratia marcescens infection associated with age-related skewing of X-chromosome inactivation.

Risk Factors for Surgical Site Infections in Patients Undergoing Emergency Surgery: A Single-centre Experience.

BACKGROUND/AIM: Surgical site infections (SSI) are associated with increased morbidity and mortality, and they occur more frequently during unplanned emergency surgical (ES) procedures rather than elective. Our aim was to determine the incidence of SSI within our ES cohort and to identify risk factors for SSI. PATIENTS AND METHODS: Data from consecutive patients undergoing ES in a single institution during a 5-year period were prospectively collected and analyzed. RESULTS: A total of 838 consecutive patients were included. The median age was 52 (IQR=25-71) years and some 368 (44%) were female. 157 (18.7%) of those patients developed SSI. The most commonly isolated pathogen was E. Coli (55.4%) followed by Staphylococcus Aureus (40.1%). The 30-day mortality rate of patients who presented SSIs was 14.6% compared to 6.8% of patients without SSI (p=0.002). Multivariable analysis showed that the type of wound, American Society of Anesthesiology score, severity and duration of surgery >90 min were independent risk factors for the occurrence of SSI. CONCLUSION: Identification of modifiable causative factors for SSI within an ES unit is paramount as they can critically impact postoperative outcomes.