Prevalence and Outcomes of Infection Among Patients in Intensive Care Units in 2017

Revealing quorum-sensing networks in Pseudomonas aeruginosa infections through internal and external signals to prevent new resistance trends

In the context of growing antibiotic resistance in bacteria, the quorum-sensing (QS) system of Pseudomonas aeruginosa (P. aeruginosa) has become a target for new therapeutic strategies. QS is a crucial communication process and an essential pathogenic mechanism. This comprehensive review explores the critical role of QS in the pathogenesis of P. aeruginosa infections, including lung, burn, bloodstream, gastrointestinal, corneal, and urinary tract infections. In addition, this review delves into the complexity of the bacterial QS communication network and highlights the intricate mechanisms underlying these pathological processes. Notably, in addition to the four main QS systems, bacterial QS can interact with various external and internal signaling networks, such as host environments and nutrients in the external microbiome, as well as internal virulence regulation systems within bacteria. These elements can significantly influence the behavior and virulence of microbial communities. Therefore, this review reveals that inhibitors targeting singular QS pathways may inadvertently promote virulence in other pathways, leading to new trends in drug resistance. In response to evolving resistance challenges, this study proposes more cautious treatment strategies, including multitarget interventions and combination therapies, aimed at combating the escalating issue of resistance.

Clinical Application of Metagenomic Next-Generation Sequencing in Sepsis Patients with Early Antibiotic Treatment

Purpose

This study aimed to evaluate the clinical utility of metagenomic next-generation sequencing (mNGS) in sepsis patients who received early empirical antibiotic treatment.

Patients and Methods

A retrospective analysis was conducted on clinical data from sepsis patients diagnosed in the Emergency Intensive Care Unit (EICU) between April 2019 and May 2023. All patients underwent standard conventional microbiological testing. Patients were categorized into either the mNGS group or the control group based on whether they underwent mNGS tests. Baseline variables were matched using propensity scores.

Results

Out of 461 sepsis patients screened, 130 were included after propensity matching, with 65 patients in each group. Despite prior antibiotic treatment, 57 cases (87.69%) in the mNGS group had positive mNGS results, exceeding the culture detection rate (52.31%). Besides, a higher proportion of patients in the mNGS group experienced antibiotic adjustments compared to the control group (72.31% vs 53.85%). Mortality rates were also compared based on the duration of antibiotic exposure before mNGS sampling. Patients exposed to antibiotics for less than 24 hours had a lower mortality rate compared to those exposed for over 8 days (22.22% vs 42.86%). COX multivariate analysis identified mNGS testing, underlying diseases, lymphocyte percentage, infection site (respiratory and bloodstream) as independent risk factors for mortality in sepsis patients.

Conclusion

With increased antibiotic exposure time, the positive rate of culture testing significantly decreased (44.44% vs 59.52% vs 35.71%, P = 0.031), whereas the positive rate of mNGS remained stable (77.78% vs 88.10% vs 92.86%, P = 0.557). mNGS demonstrated less susceptibility to antibiotic exposure. Early mNGS detection positively impacted the prognosis of sepsis patients.

Impact of Continuous Infusion Meropenem PK/PD Target Attainment on C-Reactive Protein Dynamics in Critically Ill Patients With Documented Gram-Negative Hospital-Acquired or Ventilator-Associated Pneumonia

BACKGROUND AND OBJECTIVE

Population pharmacokinetic/pharmacodynamic (PK/PD) modelling of antibiotics including C-reactive protein (C-RP) dynamics could be helpful in predicting the efficacy of antimicrobials. We developed a PK/PD model for assessing the impact of continuous infusion (CI) meropenem PK/PD target attainment on C-RP dynamics in critically ill patients with documented Gram-negative hospital- (HAP) or ventilator-acquired pneumonia (VAP).

METHODS

Patients were grouped according to the type of antibiotic treatment received [meropenem monotherapy; meropenem plus empirical anti-MRSA (methicillin-resistant Staphylococcus aureus) therapy; meropenem in combination with another anti-Gram-negative active agent; meropenem plus a targeted anti-MRSA therapy]. A one-compartment population PK model of CI meropenem was developed by including all patients. A full C-RP production inhibition model was developed for fitting the PD data by including only patients receiving meropenem monotherapy or meropenem plus empirical anti-MRSA therapy. Monte Carlo simulations explored the relationship between the type of PK/PD target attainment of CI meropenem, defined as optimal (steady-state plasma concentration [Css] to minimum inhibitory concentration [MIC] ratio = 4-8), quasi-optimal (Css/MIC = 1-4) and sub-optimal (Css/MIC < 1) and the magnitude of C-RP production inhibition over time.

RESULTS

A total of 64 patients providing 211 meropenem concentrations were included in the PK analysis, whereas 47 patients providing 328 C-RP data were included in the PD model. Simulations showed that optimal PK/PD target attainment was associated with the highest and most rapid C-RP production inhibition (44% and 56% at days 2 and 4, respectively). Conversely, sub-optimal PK/PD target attainment was shown to be almost ineffective (< 5% at day 4 and < 10% at day 10).

CONCLUSION

Our PK/PD model predicted that attaining optimal PK/PD target with CI meropenem may grant prompt and intense C-RP decrease among critically ill patients receiving targeted monotherapy for Gram-negative HAP/VAP, thus anticipating efficacy.

Mortality of patients with sepsis in intensive care units at tertiary hospitals in Jordan: Prospective cohort study

The aim of this study was to describe the 30-day mortality rate of adult patients with sepsis and septic shock in 6 intensive care units of 2 tertiary hospitals in Jordan. A prospective cohort design was used. Patients with sepsis and septic shock admitted to the medical and surgical intensive care units at 2 tertiary hospitals were followed up during the period between February 2022 and June 2022 (N = 148). Data were analyzed using SPSS, version 23. Moreover, descriptive statistics, chi-square, and binary logistic regression were used. Notably, 52.7% of patients with sepsis and septic shock died within 30 days of diagnosis of sepsis and septic shock. Sequential Organ Failure Assessment score and the history of having solid tumors significantly predicted the 30-day mortality rate. Moreover, 43 (29.0%) patients with sepsis and septic shock had positive blood cultures, and 46 (31.0%) had positive urine cultures. Patients with sepsis and septic shock have a notable mortality rate that can be predicted from total Sequential Organ Failure Assessment scores and from the history of having solid tumors. Early assessment and initiation of treatment for sepsis essentially would reduce the likelihood of progression of sepsis to septic shock and would reduce associated patients' mortality.

Investigation of hospital-acquired infections prevalence and analysis of influencing factors: a case study of a specialized infectious disease hospital in Chongqing, 2017-2023

Objective

This study aimed to investigate the prevalence of hospital-acquired infections (HAIs) and their main influencing factors in a specialized infectious disease hospital in Chongqing from 2017 to 2023, providing reference for the formulation of precise infection control measures.

Methods

A retrospective cross-sectional survey method was employed, combining bedside investigations with medical record reviews. Surveys were conducted on all hospitalized patients on a certain day of the last week of October each year from 2017 to 2023. Data collected included patients' basic information, diagnosis, and hospital infection status. Statistical analysis, including retrospective case-control and multivariable logistic regression analysis, was performed to identify the risk factors for hospital infections.

Results

The investigation compliance rate for the prevalence of HAIs in the specialized infectious disease hospital in Chongqing from 2017 to 2023 was greater than 96% each year. The prevalence rate of HAIs ranged from 0.89 to 2.52%. Hospital infection departments were mainly concentrated in general internal medicine, tuberculosis, and HIV/AIDS departments, accounting for 31.25, 26.25, and 23.75%, respectively. The most common infection site was the lower respiratory tract (54.22%), followed by bloodstream and urinary tract infections, each accounting for 9.64%. The predominant pathogens of hospital infections were Klebsiella pneumoniae and fungi. The utilization rate of antimicrobial drugs ranged from 20.75 to 33.25%, primarily for monotherapy. The rate of pathogen testing for therapeutic antimicrobial drug use was 82.84%, meeting national requirements. Multivariable logistic regression analysis revealed that the use of antibiotic (OR = 7.46, 95%CI 2.54-21.89, p < 0.001) and the presence of cardiovascular diseases (OR = 26.69, 95%CI 6.69-106.54, p < 0.001) increased the risk of HAIs.

Conclusion

The prevalence of HAIs in specialized infectious disease hospitals remains stable, primarily concentrated in departments such as general internal medicine, tuberculosis, and HIV/AIDS. The lower respiratory tract is the main infection site, and comorbid cardiovascular diseases and antibiotic use are risk factors for HAIs. Therefore, to reduce the risk of hospital infections, it is necessary to strengthen the daily monitoring of key departments and the care of key patients. Further implementation of precise and effective infection control measures, including rational antibiotic use, regular infection monitoring and pathogen culture is warranted.

Validation of Cefiderocol Package Insert Dosing Recommendation for Patients Receiving Continuous Renal Replacement Therapy: A Prospective Multicenter Pharmacokinetic Study

Background

Cefiderocol is the first antibiotic with effluent flow rate-based dosing recommendations outlined in the product label for patients receiving continuous renal replacement therapy (CRRT). We aimed to investigate the population pharmacokinetics of cefiderocol among patients receiving CRRT and validate these dosing recommendations.

Methods

A multicenter, prospective cefiderocol pharmacokinetic study among intensive care unit patients receiving CRRT was conducted (2022-2023). Blood sampling was performed at steady-state and cefiderocol concentrations were assayed by validated liquid chromatography-tandem mass spectrometry. Population pharmacokinetic analyses were conducted in Pmetrics using R software. The free time above the minimum inhibitory concentration (f T > MIC) and total daily area under the concentration time curve (AUCdaily) were calculated.

Results

Fourteen patients with effluent flow rates ranging from 2.1 to 5.1 L/h were enrolled. Cefiderocol concentrations best fitted a 2-compartment model. Mean ± standard deviation (SD) parameter estimates for clearance, central compartment volume, and intercompartment transfer constants (k12 and k21) were 3.5 ± 1.5 L/hour, 10.7 ± 8.4 L, 3.9 ± 1.8 hours-1, and 2.2 ± 2.2 hours-1, respectively. With simulations based on product label dosing recommendations, all patients achieved 100% fT > MIC up to MIC 8 mg/L with an AUCdaily (mean ± SD) of 1444 ± 423 mg × hour/L. Cefiderocol was well tolerated among the 14 patients.

Conclusions

The current package insert dosing recommendations resulted in pharmacodynamically optimized cefiderocol exposures. Cefiderocol concentrations exceeded relevant MIC breakpoints in all patients at each effluent flow rate, and AUCdaily was within the range observed in patients in the phase 3 clinical trials, suggestive of a safe and therapeutic drug profile.

Reduced mortality with antimicrobial stewardship guided by BioFire FilmArray Blood Culture Identification 2 panel in critically ill patients with bloodstream infection: A retrospective propensity score-matched study

OBJECTIVES

To investigate whether using the BioFire® FilmArray® Blood Culture Identification 2 panel (BCID2) leads to timely antimicrobial therapy and improves patient outcomes in critically ill patients with bloodstream infections (BSIs).

METHODS

This retrospective observational study included patients with BSIs admitted to the intensive care unit from July 1, 2021, to August 31, 2023. Patients were divided into groups receiving appropriate or inappropriate antimicrobial therapy. Those receiving inappropriate therapy underwent adjustments using standard-of-care (SOC) testing or BCID2. Propensity score matching (PSM) was performed on the original cohort (Model 1) and a time-window bias-adjusted cohort (Model 2). Clinical impact of BCID2-guided antimicrobial adjustment was analysed in both models.

RESULTS

A total of 181 patients received inappropriate antimicrobial therapy, with 33 undergoing BCID2 testing and 148 undergoing SOC testing. Following PSM and time-window bias adjustment, 66 patients were analysed in Model 1 and 46 patients in Model 2. BCID2 significantly reduced the median time to appropriate antimicrobial therapy (40.8 vs. 74.0 h in Model 1; 42.8 vs. 68.9 h in Model 2) and the day-28 mortality rate (27.8% vs. 77.1%, P < 0.001 in Model 1; 23.5% vs. 58.6%, P = 0.021 in Model 2). In multivariate regression analysis, BCID2-guided antimicrobial adjustment was an independent prognostic factor for day-28 mortality (adjusted odds ratio [aOR] 0.07 in Model 1 and aOR 0.12 in Model 2).

CONCLUSION

BCID2-guided antimicrobial stewardship was associated with a shorter time to appropriate antimicrobial therapy and reduced day-28 mortality in critically ill patients with BSIs receiving inappropriate antimicrobial therapy.

Candidemia Following Severe COVID-19 in Hospitalised and Critical Ill Patients: A Systematic Review and Meta-Analysis

RATIONALE

The epidemiology and clinical impact of COVID-19-associated candidemia (CAC) remained uncertain, leaving gaps in understanding its prevalence, risk factors and outcomes.

METHODS

A systematic review and meta-analysis were conducted by searching PubMed, Embase and Scopus for reports of CAC prevalence, risk factors and clinical outcomes up to June 18, 2024. The generalised linear mixed model was employed to determine the prevalence and 95% confidence intervals (CIs). The risk factors and clinical outcomes were compared between patients with and without CAC using the inverse variance method.

RESULTS

From 81 studies encompassing 29 countries and involving 351,268 patients, the global prevalence of CAC was 4.33% (95% Cl, 3.16%-5.90%) in intensive care unit (ICU) patients. In ICUs, the pooled prevalence of CAC in high-income countries was significantly higher than that of lower-middle-income countries (5.99% [95% Cl, 4.24%-8.40%] vs. 2.23% [95% Cl, 1.06%-4.61%], p = 0.02). Resistant Candida species, including C. auris, C. glabrata (Nakaseomyces glabratus) and C. krusei (Pichia kudriavzveii), constituted 2% of ICU cases. The mortality rate for CAC was 68.40% (95% Cl, 61.86%-74.28%) among ICU patients. Several risk factors were associated with CAC, including antibiotic use, central venous catheter placement, dialysis, mechanical ventilation, tocilizumab, extracorporeal membrane oxygenation and total parenteral nutrition. Notably, the pooled odds ratio of tocilizumab was 2.59 (95% CI, 1.44-4.65).

CONCLUSIONS

The prevalence of CAC is substantial in the ICU setting, particularly in high-income countries. Several risk factors associated with CAC were identified, including several that are modifiable, offering the opportunity to mitigate the risk of CAC.

COVID-19 vs. non-COVID-19 related nosocomial pneumonias: any differences in etiology, prevalence, and mortality?

PURPOSE OF REVIEW

This review explores the similarities and differences between coronavirus disease 2019 (COVID-19)-related and non-COVID-related nosocomial pneumonia, particularly hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). It critically assesses the etiology, prevalence, and mortality among hospitalized patients, emphasizing the burden of these infections during the period before and after the severe acute respiratory syndrome coronavirus 2 pandemic.

RECENT FINDINGS

Recent studies highlight an increase in nosocomial infections during the COVID-19 pandemic, with a significant rise in cases involving severe bacterial and fungal superinfections among mechanically ventilated patients. These infections include a higher incidence of multidrug-resistant organisms (MDROs), complicating treatment and recovery. Notably, COVID-19 patients have shown a higher prevalence of VAP than those with influenza or other respiratory viruses, influenced by extended mechanical ventilation and immunosuppressive treatments like corticosteroids.

SUMMARY

The findings suggest that COVID-19 has exacerbated the frequency and severity of nosocomial infections, particularly VAP. These complications not only extend hospital stays and increase healthcare costs but also lead to higher morbidity and mortality rates. Understanding these patterns is crucial for developing targeted preventive and therapeutic strategies to manage and mitigate nosocomial infections during regular or pandemic care.

Treatment of multidrug-resistant Gram-negative bloodstream infections in critically ill patients: an update

PURPOSE OF REVIEW

This review describes the latest information in the management of bloodstream infections caused by multidrug-resistant Gram-negative bacilli (MDRGNB) in critically ill patients.

RECENT FINDINGS

The prevalence of bloodstream infections due to MDRGNB is high, and they pose a significant risk in critically ill patients. Recently, novel antimicrobial agents, including new β-lactam/β-lactamase inhibitor combinations and cefiderocol, have been introduced for treating these infections. Concurrently, updated guidelines have been issued to aid in treatment decisions. Prompt diagnosis and identification of resistance patterns are crucial for initiating effective antibiotic therapy. Current studies, especially with observational design, and with limited sample sizes and patients with bacteremia, suggest that the use of these new antibiotics is associated with improved outcomes in critically ill patients with MDRGNB bloodstream infections.

SUMMARY

For critically ill patients with bloodstream infections caused by MDRGNB, the use of newly developed antibiotics is recommended based on limited observational evidence. Further randomized clinical trials are necessary to determine the most effective antimicrobial therapies among the available options.

Multifocal candidiasis can be considered a form of invasive candidiasis in critically non-neutropenic patients

Candida infections can be serious in intensive care unit (ICU) patients, as Candida is an organism that specially colonizes the digestive system. In immunocompromised patients, treatment is protocolized, but in non-neutropenic patients, it is not well established. On the other hand, the treatment of this type of infection is not absent of adverse effects. The prevalence of fungal infections, especially candidiasis, and its mortality in the ICU is high, mainly due to the lack of diagnosis and absence of treatment criteria, because they are often detected in the disseminated candidiasis phase, such as candidemia. One of the indicators of the progression of the disease is the presence of Candida in more than two different foci, named Candida multifocality, within the concept of invasive candidiasis. In fact, the invasive fungal diseases in adult patients i intensive care unit (FUNDICU) project was created to optimize the management of candidiasis. The management of candidiasis in ICU patients first requires the identification of patients at high risk of candidiasis, which must be performed based on the evidence of immune dysregulation, higher severity index (acute physiologic assessment and chronic health evaluation and multiple organ dysfunction syndrome), long ICU stays or other factors such as mechanical ventilation or us of broad-spectrum antibiotics. To increase detection and dispense the appropriate antifungal at an early stage, it is necessary to include the concept of multifocality in invasive candidiasis with screening of different foci. Antifungal treatment reduces mortality both overall and attributable to Candida. Detecting a high invasive candidiasis risk is a patient safety concept and should be treated as such. Identifying patients (critically non-neutropenic adult patients with severe multiple organ dysfunction syndrome and the first isolation of Candida spp. in a study sample of possible secondary infection) and demonstrating invasive candidiasis (multifocal or disseminated) require urgent initiation of antifungal treatment to minimize mortality attributable to invasive candidiasis in the ICU and eliminate mortality rates above 50%.

Cancer and sepsis: future challenges for long-term outcome

PURPOSE OF REVIEW

The purpose of this review is to investigate the long-term outcomes of cancer patients who experience sepsis or septic shock.

RECENT FINDINGS

Sepsis is a frequent cause of ICU admission in cancer patients, accounting for approximately 15% of such cases. Short-term mortality rates among these patients vary widely across studies, but they are consistently found to be slightly higher than those of noncancer patients. However, there is a lack of evidence regarding the long-term outcomes of cancer patients who have experienced sepsis or septic shock. The few available studies have reported relatively high mortality rates, reaching around 80% in a few cohort studies. Although several observational studies have noted a decrease in 1-year mortality rates over time, observational data also suggest that sepsis may increase the risk of cancer in the long run.

SUMMARY

As cancer is becoming a chronic disease, there is an urgent need for studies on the quality of life of cancer patients who have experienced sepsis. The relationship between sepsis and cancer extends beyond its impact on the progression of cancer, as sepsis might also contribute to the development of cancer.

18F-labelled gentiobiose as potential PET-radiotracer for specific bacterial imaging: precursor synthesis, radiolabelling and in vitro evaluation

AIM

Bacterial infections are a clinical challenge, requiring fast and specific diagnosis to ensure effective treatment. Therefore, this project is dedicated to development of positron emission tomography (PET) radiotracers specifically targeting bacteria. Unlike previously developed bacteria-specific radiotracers, which are successful in detecting Gram-negative bacteria, tracers capable of imaging Gram-positive infections are still lacking.

METHODS

The disaccharide gentiobiose as abundant part of the cell wall of Gram-positive bacteria could fill this gap. Herein, the synthesis and evaluation of 2'-deoxy-2'-[18F]fluorogentiobiose ([18F]FLA280) is reported. The precursor for radiolabelling was obtained from a convergent synthesis under application of a benzylidene/benzyl group protecting strategy.

RESULTS

The first catalytic hydrogenation in 18F-radiochemistry is reported as proof of concept. The deprotection was carried out without any side product formation, giving the final radiotracer [18F]FLA280 in good radiochemical yield and excellent radiochemical purity. [18F]FLA280 was proven to be stable in murine and human blood serum for 120 minutes and was subjected to in vitro bacterial uptake studies towards S. aureus and E. coli resulting in a low bacterial uptake.

CONCLUSION

The observed bacterial uptake indicates that [18F]FLA280 may be not a promising tracer candidate for in vivo translation and alternative candidates particularly for Gram-positive bacteria are required. However, further development on the concept of labelled carbohydrates and cell wall building blocks might be promising.

High-dose colistin pharmacokinetics in critically ill patients receiving continuous renal replacement therapy

BACKGROUND

Colistin, administered as intravenous colistimethate (CMS), is still used in the critical care setting and current guidelines recommend high dosage CMS in patients undergoing continuous renal replacement therapy (CRRT). Due to the paucity of real-life data, we aimed to describe colistin pharmacokinetic/pharmacodynamic (PK/PD) profile in a cohort of critically ill patients with infections due to carbapenem-resistant (CR) bacteria undergoing CRRT.

RESULTS

All consecutive patients admitted to three Intensive Care Units (ICUs) of a large metropolitan University Hospital, treated with colistin for at least 48 h at the dosage of 6.75 MUI q12, after 9 MIU loading dose, and undergoing CRRT were included. After the seventh dose, patients underwent blood serial sampling during a time frame of 24 h. We included 20 patients, who had CR-Acinetobacter baumannii ventilator-associated pneumonia and were characterized by a median SAPS II and SOFA score of 41 [34.5-59.3] and 9 [6.7-11], respectively. Fifteen patients died during ICU stay and six recovered renal function. Median peak and trough colistin concentrations were 16.6 mcg/mL [14.8-20.6] and 3.9 mcg/mL [3.3-4.4], respectively. Median area under the time-concentration curve (AUC0 - 24) and average steady-state concentration (Css, avg) were 193.9 mcg h/mL [170.6-208.6] and 8.07 mcg/mL [7.1-8.7]. Probability of target attainment of colistin pharmacodynamics according to the fAUC0 - 24/MIC target ≥ 12 was 100% for MIC ≤ 2 mcg/mL and 85% for MIC = 4 mcg/ML, although exceeding the toxicity limit of Css, avg 3-4 mcg/mL.

CONCLUSIONS

In critically ill patients with CR infections undergoing CRRT, recommended CMS dosage resulted in colistin plasmatic levels above bacterial MIC90, but exceeding the safety Css, avg. limit.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov on 23/07/2021 with the ID NCT04995133 (https//clinicaltrials.gov/study/NCT04995133).

Daily Chlorhexidine Bath for Health Care Associated Infection Prevention (CLEAN-IT): protocol for a multicenter cluster randomized crossover open-label trial

BACKGROUND

Critically ill patients are at increased risk of health care-associated infections due to various devices (central line-associated bloodstream infection, catheter-associated urinary tract infection, and ventilator-associated pneumonia), which pose a significant threat to this population. Among several strategies, daily bathing with chlorhexidine digluconate, a water-soluble antiseptic, has been studied as an intervention to decrease the incidence of health care-associated infections in the intensive care unit; however, its ability to reduce all health care-associated infections due to various devices is unclear. We designed the Daily Chlorhexidine Bath for Health Care Associated Infection Prevention (CLEAN-IT) trial to assess whether daily chlorhexidine digluconate bathing reduces the incidence of health care-associated infections in critically ill patients compared with soap and water bathing.

METHODS

The CLEAN-IT trial is a multicenter, open-label, cluster randomized crossover clinical trial. All adult patients admitted to the participating intensive care units will be included in the trial. Each cluster (intensive care unit) will be randomized to perform either initial chlorhexidine digluconate bathing or soap and water bathing with crossover for a period of 3 to 6 months, depending on the time of each center's entrance to the study, with a 1-month washout period between chlorhexidine digluconate bathing and soap and water bathing transitions. The primary outcome is the incidence of health care-associated infections due to devices. The secondary outcomes are the incidence of each specific health care-associated infection, rates of microbiological cultures positive for multidrug-resistant pathogens, antibiotic use, intensive care unit and hospital length of stay, and intensive care unit and hospital mortality.

CONCLUSION

The CLEAN-IT trial will be used to study feasible and affordable interventions that might reduce the health care-associated infection burden in critically ill patients.

Deep longitudinal lower respiratory tract microbiome profiling reveals genome-resolved functional and evolutionary dynamics in critical illness

The lower respiratory tract (LRT) microbiome impacts human health, especially among critically ill patients. However, comprehensive characterizations of the LRT microbiome remain challenging due to low microbial mass and host contamination. We develop a chelex100-based low-biomass microbial-enrichment method (CMEM) that enables deep metagenomic profiling of LRT samples to recover near-complete microbial genomes. We apply the method to 453 longitudinal LRT samples from 157 intensive care unit (ICU) patients in three geographically distant hospitals. We recover 120 high-quality metagenome-assembled genomes (MAGs) and associated plasmids without culturing. We detect divergent longitudinal microbiome dynamics and hospital-specific dominant opportunistic pathogens and resistomes in pneumonia patients. Diagnosed pneumonia and the ICU stay duration were associated with the abundance of specific antibiotic-resistance genes (ARGs). Moreover, CMEM can serve as a robust tool for genome-resolved analyses. MAG-based analyses reveal strain-specific resistome and virulome among opportunistic pathogen strains. Evolutionary analyses discover increased mobilome in prevailing opportunistic pathogens, highly conserved plasmids, and new recombination hotspots associated with conjugative elements and prophages. Integrative analysis with epidemiological data reveals frequent putative inter-patient strain transmissions in ICUs. In summary, we present a genome-resolved functional, transmission, and evolutionary landscape of the LRT microbiota in critically ill patients.

Relationship between SARS-CoV-2 infection and ICU-acquired candidemia in critically ill medical patients: a multicenter prospective cohort study

BACKGROUND

While SARS-CoV2 infection has been shown to be a significant risk-factor for several secondary bacterial, viral and Aspergillus infections, its impact on intensive care unit (ICU)-acquired candidemia (ICAC) remains poorly explored.

METHOD

Using the REA-REZO network (French surveillance network of ICU-acquired infections), we included all adult patients hospitalized for a medical reason of admission in participating ICUs for at least 48 h from January 2020 to January 2023. To account for confounders, a non-parsimonious propensity score matching was performed. Rates of ICAC according to SARS-CoV2 status were compared in matched patients. Factors associated with ICAC in COVID-19 patients were also assessed using a Fine-Gray model.

RESULTS

A total of 55,268 patients hospitalized at least 48 h for a medical reason in 101 ICUs were included along the study period. Of those, 13,472 were tested positive for a SARS-CoV2 infection while 284 patients developed an ICAC. ICAC rate was higher in COVID-19 patients in both the overall population and the matched patients' cohort (0.8% (107/13,472) versus 0.4% (173/41,796); p < 0.001 and 0.8% (93/12,241) versus 0.5% (57/12,241); p = 0.004, respectively). ICAC incidence rate was also higher in those patients (incidence rate 0.51 per 1000 patients-days in COVID-19 patients versus 0.32 per 1000 patients-days; incidence rate ratio: 1.58 [95% CI:1.08-2.35]; p = 0.018). Finally, patients with ICAC had a higher ICU mortality rate (49.6% versus 20.2%; p < 0.001).

CONCLUSION

In this large multicenter cohort of ICU patients, although remaining low, the rate of ICAC was higher among COVID-19 patients.

Effect of adequacy of empirical antibiotic therapy for hospital-acquired bloodstream infections on intensive care unit patient prognosis: a causal inference approach using data from the Eurobact2 study

OBJECTIVES

Hospital-acquired bloodstream infections (HA-BSI) in the intensive care unit (ICU) are common life-threatening events. We aimed to investigate the association between early adequate antibiotic therapy and 28-day mortality in ICU patients who survived at least 1 day after the onset of HA-BSI.

METHODS

We used individual data from a prospective, observational, multicentre, and intercontinental cohort study (Eurobact2). We included patients who were followed for ≥1 day and for whom time-to-appropriate treatment was available. We used an adjusted frailty Cox proportional-hazard model to assess the effect of time-to-treatment-adequacy on 28-day mortality. Infection- and patient-related variables identified as confounders by the Directed Acyclic Graph were used for adjustment. Adequate therapy within 24 hours was used for the primary analysis. Secondary analyses were performed for adequate therapy within 48 and 72 hours and for identified patient subgroups.

RESULTS

Among the 2418 patients included in 330 centres worldwide, 28-day mortality was 32.8% (n = 402/1226) in patients who were adequately treated within 24 hours after HA-BSI onset and 40% (n = 477/1192) in inadequately treated patients (p < 0.01). Adequacy within 24 hours was more common in young, immunosuppressed patients, and with HA-BSI due to Gram-negative pathogens. Antimicrobial adequacy was significantly associated with 28-day survival (adjusted Hazard Ratio (aHR), 0.83; 95% CI, 0.72-0.96; p 0.01). The estimated population attributable fraction of 28-day mortality of inadequate therapy was 9.15% (95% CI, 1.9-16.2%).

DISCUSSION

In patients with HA-BSI admitted to the ICU, the population attributable fraction of 28-day mortality of inadequate therapy within 24 hours was 9.15%. This estimate should be used when hypothesizing the possible benefit of any intervention aiming at reducing the time-to-appropriate antimicrobial therapy in HA-BSI.

Deciphering the gastrointestinal carriage of Klebsiella pneumoniae

Bacterial infections pose a significant global health threat, accounting for an estimated 7.7 million deaths. Hospital outbreaks driven by multi-drug-resistant pathogens, notably Klebsiella pneumoniae (K. pneumoniae), are of grave concern. This opportunistic pathogen causes pneumonia, urinary tract infections, and bacteremia, particularly in immunocompromised individuals. The rise of hypervirulent K. pneumoniae adds complexity, as it increasingly infects healthy individuals. Recent epidemiological data suggest that asymptomatic gastrointestinal carriage serves as a reservoir for infections in the same individual and allows for host-to-host transmission via the fecal-oral route. This review focuses on K. pneumoniae's gastrointestinal colonization, delving into epidemiological evidence, current animal models, molecular colonization mechanisms, and the protective role of the resident gut microbiota. Moreover, the review sheds light on in vivo high-throughput approaches that have been crucial for identifying K. pneumoniae factors in gut colonization. This comprehensive exploration aims to enhance our understanding of K. pneumoniae gut pathogenesis, guiding future intervention and prevention strategies.

Navigating Uncertainty: Managing Influenza-Associated Invasive Pulmonary Aspergillosis in an Intensive Care Unit

We present a challenging case of a patient admitted to an intensive care unit with influenza-associated pulmonary aspergillosis (IAPA). The clinical course was characterised by refractory fungal pneumonia and tracheobronchitis, suspected drug-induced liver injury due to triazole antifungals, and secondary bacterial infections with multidrug-resistant microorganisms, resulting in a fatal outcome despite the optimisation of antifungal treatment through therapeutic drug monitoring. This case underscores the complexity that clinicians face in managing critically ill patients with invasive fungal infections.

POCT Detection of Pseudomonas aeruginosa by PGM and Application of Preventing Nosocomial Infection of Bronchoscopy

Background

The primary pathogen responsible for bronchoscope contamination is Pseudomonas aeruginosa. Conventional techniques for bronchoscopy disinfection and pathogen identification methods are characterized by time-consuming and operation complexly. The objective of this research is to establish a prompt and precise method for the identification of Pseudomonas aeruginosa, with the ultimate goal of mitigating the risk of nosocomial infections linked to this pathogen.

Methods

The magnetic nanoparticles (MNPs) were synthesized in a single step, followed by the optimization of the coating process with antibodies and invertase to produce the bifunctionalized IMIc. Monoclonal antibodies were immobilized on microplates for the specific capture and enrichment of Pseudomonas aeruginosa. Upon the presence of Pseudomonas aeruginosa, the monoclonal antibodies, the test sample, and the IMIc formed sandwich structures. The subsequent addition of a sucrose solution allowed for the detection of glucose produced through invertase hydrolysis by a personal glucose meter, enabling quantitative assessment of Pseudomonas aeruginosa concentration.

Results

TEM image demonstrates that the MNPs exhibit a consistent spherical shape. NTA determined that the grain diameter of magnetic nanoparticles was 200 nm. FTIR spectrum revealed the successful modification of two carboxyl groups on the MNPs. The optimization of the incubation pH of the microplate-coated antibody was 7. The optimization of the incubation time of the microplate-coated antibody was 2 h. The optimization of the ligation pH for the polyclonal antibody was 5. Reaction times of polyclonal antibodies linked to magnetic beads was 1 h. The pH of invertase linked by magnetic beads was 4.

Conclusion

This article presents a novel qualitative and quantitative immunoassay for point-of-care monitoring of P. aeruginosa utilizing PGM as a readout. The PGM represents a convenient and accurate quantitative detection method suitable for potential clinical diagnostic applications.

A nomogram to predict 28-day mortality in patients with sepsis combined coronary artery disease: retrospective study based on the MIMIC-III database

Object

Establish a clinical prognosis model of coronary heart disease (CHD) to predict 28-day mortality in patients with sepsis.

Method

The data were collected retrospectively from septic patients with a previous history of coronary heart disease (CHD) from the Medical Information Mart for Intensive Care (MIMIC)-III database. The included patients were randomly divided into the training cohorts and validation cohorts. The variables were selected using the backward stepwise selection method of Cox regression, and a nomogram was subsequently constructed. The nomogram was compared to the Sequential Organ Failure Assessment (SOFA) model using the C-index, area under the receiver operating characteristic curve (AUC) over time, Net reclassification index (NRI), Integrated discrimination improvement index (IDI), calibration map, and decision curve analysis (DCA).

Result

A total of 800 patients were included in the study. We developed a nomogram based on age, diastolic blood pressure (DBP), pH, lactate, red blood cell distribution width (RDW), anion gap, valvular heart disease, peripheral vascular disease, and acute kidney injury (AKI) stage. The nomogram was evaluated using C-index, AUC, NRI, IDI, calibration plot, and DCA. Our findings revealed that this nomogram outperformed the SOFA score in predicting 28-day mortality in sepsis patients.

High adsorption capacity of hemoperfusion on imipenem in critically ill patients with septic shock: a case report

BACKGROUND

Sepsis is a life-threatening organ dysfunction caused by an excessive host response to infection, manifested by elevated levels of inflammatory cytokines. At present, the use of hemoperfusion to remove inflammatory cytokines from the bloodstream has been expanding. Meanwhile, the pharmacokinetics and pharmacodynamics characteristics of antibiotics in critically ill patients may be impacted by hemoperfusion.

CASE PRESENTATION

The patient was a 69-year-old male with poorly controlled type 2 diabetes. When admitted to the ICU, Multiple Organ Dysfunction Syndrome (MODS) appeared within 48 h, and he was suspected of septic shock due to acute granulocytopenia and significantly increased procalcitonin. Broad-spectrum antibiotics imipenem was administered according to Sepsis 3.0 bundle and hemoperfusion lasting 4 h with a neutron-macroporous resin device (HA-380, Jafron, China) five times was conducted to lower the extremely high value of serum inflammatory factors. Blood samples were collected to measure imipenem plasma concentration to investigate the effect of hemoperfusion quantitatively. This study showed that 4 h of hemoperfusion had a good adsorption ability on inflammatory factors and could remove about 75.2% of imipenem.

CONCLUSIONS

This case demonstrated the high adsorption capacity of hemoperfusion on imipenem in critically ill patients. It implies a timely imipenem supplement is required, especially before hemoperfusion.

Early identification and diagnosis, pathophysiology, and treatment of sepsis-related acute lung injury: a narrative review

Background and Objective

Sepsis is a life-threatening organ dysfunction, and the most common and vulnerable organ is the lungs, with sepsis-related acute respiratory distress syndrome (ARDS) increasing mortality. In recent years, an increasing number of studies have improved our understanding of sepsis-related ARDS in terms of epidemiology, risk factors, pathophysiology, prognosis, and other aspects, as well as our ability to prevent, detect, and treat sepsis-related ARDS. However, sepsis-related lung injury remains an important issue and clinical burden. Therefore, a literature review was conducted on sepsis-related lung injury in order to further guide clinical practice in reducing the acute and chronic consequences of this condition.

Methods

This study conducted a search of the MEDLINE and PubMed databases, among others for literature published from 1991 to 2023 using the following keywords: definition of sepsis, acute lung injury, sepsis-related acute lung injury, epidemiology, risk factors, early diagnosis of sepsis-related acute lung injury, sepsis, ARDS, pathology and physiology, inflammatory imbalance caused by sepsis, congenital immune response, and treatment.

Key Content and Findings

This review explored the risk factors of sepsis, sepsis-related ARDS, early screening and diagnosis, pathophysiology, and treatment and found that in view of the high mortality rate of ARDS associated with sepsis. In response to the high mortality rate of sepsis-related ARDS, some progress has been made, such as rapid identification of sepsis and effective antibiotic treatment, early fluid resuscitation, lung-protective ventilation, etc.

Conclusions

Sepsis remains a common and challenging critical illness to cure. In response to the high mortality rate of sepsis-related ARDS, progress has been made in rapid sepsis identification, effective antibiotic treatment, early fluid resuscitation, and lung-protective ventilation. However, further research is needed regarding long-term effects such as lung recruitment, prone ventilation, and the application of neuromuscular blocking agents and extracorporeal membrane oxygenation.

Septic shock in the immunocompromised cancer patient: a narrative review

Immunosuppressed patients, particularly those with cancer, represent a momentous and increasing portion of the population, especially as cancer incidence rises with population growth and aging. These patients are at a heightened risk of developing severe infections, including sepsis and septic shock, due to multiple immunologic defects such as neutropenia, lymphopenia, and T and B-cell impairment. The diverse and complex nature of these immunologic profiles, compounded by the concomitant use of immunosuppressive therapies (e.g., corticosteroids, cytotoxic drugs, and immunotherapy), superimposed by the breakage of natural protective barriers (e.g., mucosal damage, chronic indwelling catheters, and alterations of anatomical structures), increases the risk of various infections. These and other conditions that mimic sepsis pose substantial diagnostic and therapeutic challenges. Factors that elevate the risk of progression to septic shock in these patients include advanced age, pre-existing comorbidities, frailty, type of cancer, the severity of immunosuppression, hypoalbuminemia, hypophosphatemia, Gram-negative bacteremia, and type and timing of responses to initial treatment. The management of vulnerable cancer patients with sepsis or septic shock varies due to biased clinical practices that may result in delayed access to intensive care and worse outcomes. While septic shock is typically associated with poor outcomes in patients with malignancies, survival has significantly improved over time. Therefore, understanding and addressing the unique needs of cancer patients through a new paradigm, which includes the integration of innovative technologies into our healthcare system (e.g., wireless technologies, medical informatics, precision medicine), targeted management strategies, and robust clinical practices, including early identification and diagnosis, coupled with prompt admission to high-level care facilities that promote a multidisciplinary approach, is crucial for improving their prognosis and overall survival rates.

Multidrug-Resistant Bacteria in Immunocompromised Patients

The increasing incidence of antibiotic resistance in bacteria is a major problem in terms of therapeutic options, especially in immunocompromised patients, such as patients from intensive care units (ICUs), HIV-positive patients, patients with malignancies or transplant patients. Commensal bacteria, especially anaerobes, serve to maintain microbial stability by preventing overpopulation with pathogenic bacteria. In immunocompromised patients, microbiota imbalance caused by antibiotic therapy and decreased host immunity favors intestinal overpopulation with pathogenic species, leading to increased bacterial translocation and susceptibility to systemic infections. Infections with multidrug-resistant (MDR) bacteria pose major challenges to the establishment of appropriate treatment and lead to increased mortality. Asymptomatic colonization with MDR bacteria usually precedes infection and tends to persist for long periods of time, and in immunocompromised patients, colonization with MDR bacteria is a risk factor for systemic infections. This review aims to assess the relation between colonization and infection with MDR bacteria in immunocompromised patients such as ICU patients, HIV-positive patients and cancer patients and to identify the prevalence and patterns of MDR bacterial colonization and infection in this category of patients.

Acanthamoebae as a protective reservoir for Pseudomonas aeruginosa in a clinical environment

BACKGROUND

Pseudomonas aeruginosa is a growing concern in healthcare-associated infections and poses significant risk to those with serious underlying health conditions. The antimicrobial resistance traits of the pathogen and ability to form biofilms make effective mitigation and disinfection strategies difficult. Added to this challenge is the role that free-living amoebae such as Acanthamoeba play in the detection, disinfection and transmission of P. aeruginosa. P. aeruginosa can survive intracellularly within amoebae, which has the potential to limit detectability and permit transmission into high-risk areas.

METHODS/FINDINGS

We screened for the presence of Acanthamoeba spp. and P. aeruginosa within a functioning general hospital in Scotland using a culture and molecular approach, noting their presence at several sites over a four-month period, particularly within floor drains connecting patient rooms. In addition, microbiome analysis revealed that amoebae harbour a unique microbial community comprised primarily of Pseudomonas spp. that were not readily detected using microbiome sequencing techniques on environmental swabs. Having demonstrated that both organisms were consistently present in hospital settings, we investigated the relationship between acanthamoeba and P. aeruginosa in the laboratory, showing that (i) acanthamoeba growth rate is increased in the presence of pseudomonas biofilms and viable pseudomonas persist within the amoebae and (ii) hydrogen peroxide-based disinfectants are significantly less effective against an isolate of P. aeruginosa in the presence of acanthamoeba than when the bacteria are incubated alone.

CONCLUSIONS

These findings suggest that amoebae, and other protists, can influence the detection and persistence of P. aeruginosa in high-risk areas and should be considered when implementing mitigation strategies.

Antibiotic De-Escalation Practices in the Intensive Care Unit: A Multicenter Observational Study

BACKGROUND

There is little known about antibiotic de-escalation (ADE) practices in the intensive care unit (ICU).

OBJECTIVE

The objective was to determine the proportion of patients who received ADE within 24 hours of actionable cultures and identify predictors of timely ADE.

METHODS

Multicenter cohort study in ICUs of 15 hospitals in Australia and New Zealand. Adult patients were included if they were started on broad-spectrum antibiotics within 24 hours of ICU admission. The ADE was defined as switching from a broad-spectrum agent to a narrower-spectrum agent or antibiotic cessation. The primary outcome was ADE within 24 hours of an actionable culture, where ADE was possible.

RESULTS

The 446 patients included in the study had a mean age of 63 ± 16 years, 60% were male, 32% were mechanically ventilated, and 19% were immunocompromised. Of these, 161 (36.1%) were not eligible for ADE and 37 (8.3%) for whom ADE within 24 hours of actionable culture could not be determined. In the remaining 248 patients, ADE occurred ≤24 hours in 60.5% (n = 150/248) after actionable cultures. In the multivariable logistic regression analysis, ADE was less likely to occur within 24 hours for patients with negative cultures (odds ratio [OR] = 0.48, 95% confidence interval [CI] = 0.25-0.92, P = 0.03).

CONCLUSION AND RELEVANCE

Timely ADE may not occur in 40% of patients in the ICU and is less likely to occur in patients with negative cultures. Timely ADE can be improved, and patients with negative cultures should be targeted as part of antimicrobial stewardship efforts.

Retrospective ANalysis of multi-drug resistant Gram-nEgative bacteRia on veno-venous extracorporeal membrane oxygenation. The multicenter RANGER STUDY

BACKGROUND

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) is a rapidly expanding life-support technique worldwide. The most common indications are severe hypoxemia and/or hypercapnia, unresponsive to conventional treatments, primarily in cases of acute respiratory distress syndrome. Concerning potential contraindications, there is no mention of microbiological history, especially related to multi-drug resistant (MDR) bacteria isolated before V-V ECMO placement. Our study aims to investigate: (i) the prevalence and incidence of MDR Gram-negative (GN) bacteria in a cohort of V-V ECMOs; (ii) the risk of 1-year mortality, especially in the case of predetected MDR GN bacteria; and (iii) the impact of annual hospital V-V ECMO volume on the probability of acquiring MDR GN bacteria.

METHODS

All consecutive adults admitted to the Intensive Care Units of 5 Italian university-affiliated hospitals and requiring V-V ECMO were screened. Exclusion criteria were age < 18 years, pregnancy, veno-arterial or mixed ECMO-configuration, incomplete records, survival < 24 h after V-V ECMO. A standard protocol of microbiological surveillance was applied and MDR profiles were identified using in vitro susceptibility tests. Cox-proportional hazards models were applied for investigating mortality.

RESULTS

Two hundred and seventy-nine V-V ECMO patients (72% male) were enrolled. The overall MDR GN bacteria percentage was 50%: 21% (n.59) detected before and 29% (n.80) after V-V ECMO placement. The overall 1-year mortality was 42%, with a higher risk observed in predetected patients (aHR 2.14 [1.33-3.47], p value 0.002), while not in 'V-V ECMO-acquired MDR GN bacteria' group (aHR 1.51 [0.94-2.42], p value 0.090), as compared to 'non-MDR GN bacteria' group (reference). Same findings were found considering only infections. A larger annual hospital V-V ECMO volume was associated with a lower probability of acquiring MDR GN bacteria during V-V ECMO course (aOR 0.91 [0.86-0.97], p value 0.002).

CONCLUSIONS

21% of MDR GN bacteria were detected before; while 29% after V-V ECMO connection. A history of MDR GN bacteria, isolated before V-V ECMO, was an independent risk factor for mortality. The annual hospital V-V ECMO volume affected the probability of acquiring MDR GN bacteria. Trial Registration ClinicalTrial.gov Registration Number NCTNCT06199141, date 12.26.2023.

Predicting early appropriate therapy for patients infected by carbapenem-resistant Gram-negative pathogens in intensive care units in Italy

BACKGROUND

Antibiotic resistance among Gram-negative bacteria in intensive care units (ICUs) is linked with high morbidity and mortality in patients. In this study, we estimated the therapeutic coverage of various antibiotics, focusing on cefiderocol and comparators, administered empirically against an infection of unknown origin in the ICU.

METHODS

In the ARTEMIS surveillance study, susceptibilities of 624 Italian Gram-negative isolates to amikacin, aztreonam-avibactam, cefiderocol, ceftazidime-avibactam, ceftolozane-tazobactam, colistin, imipenem-relebactam, meropenem, and meropenem-vaborbactam were tested by broth microdilution, and results were interpreted by European Committee on Antimicrobial Susceptibility Testing breakpoints. The susceptibility rates from the ARTEMIS study were extrapolated to Gram-negative isolates obtained from 5,774 patients in Italian ICUs in 2021. The sum of the predicted susceptibilities of individual pathogens represented the overall likelihood of in vitro activity of each antibiotic as early targeted therapy for ICU patients.

RESULTS

A total of 624 Italian Gram-negative isolates included 206 Pseudomonas aeruginosa, 138 Acinetobacter baumannii, 187 Klebsiella pneumoniae, and 93 Escherichia coli. Against A. baumannii, K. pneumoniae, P. aeruginosa, and E. coli, the overall susceptibility rates for cefiderocol were 87.7%, 96.8%, 99%, and 100%, respectively; and for comparator agents, 8.7-96.4%, 25.7-100%, 73.3-100%, and 89.2-100%, respectively. Among the subset of meropenem-resistant isolates, susceptibility rates of A. baumannii, K. pneumoniae, and P. aeruginosa to cefiderocol were 86.4%, 96.2% and 100%, respectively. Corresponding susceptibility rates to comparator agents were 0-96.8%, 0-100%, and 6.4-100%, respectively. There were no meropenem-resistant isolates of E. coli. The extrapolation of data to isolates from Italian ICUs showed that the highest likelihood of therapeutic coverage, both overall and among meropenem-resistant isolates, was reported for colistin (96.8% and 72.2%, respectively) and cefiderocol (95.7% and 71.4%, respectively). All other antibiotics were associated with a likelihood below 73% overall and between 0% and 41.4% for meropenem-resistant isolates.

CONCLUSIONS

Based on confirmed susceptibility rates and reported ICU prevalence of multiple Gram-negative species, cefiderocol showed a higher predicted therapeutic coverage and utility in ICUs compared with comparator beta-lactam-beta-lactamase inhibitor antibiotics. Cefiderocol may be a promising early treatment option for patients at high risk of carbapenem-resistant Gram-negative bacterial infections in the ICU.

Sepsis Biomarkers: Advancements and Clinical Applications-A Narrative Review

Sepsis is now defined as a life-threatening syndrome of organ dysfunction triggered by a dysregulated host response to infection, posing significant challenges in critical care. The main objective of this review is to evaluate the potential of emerging biomarkers for early diagnosis and accurate prognosis in sepsis management, which are pivotal for enhancing patient outcomes. Despite advances in supportive care, traditional biomarkers like C-reactive protein and procalcitonin have limitations, and recent studies have identified novel biomarkers with increased sensitivity and specificity, including circular RNAs, HOXA distal transcript antisense RNA, microRNA-486-5p, protein C, triiodothyronine, and prokineticin 2. These emerging biomarkers hold promising potential for the early detection and prognostication of sepsis. They play a crucial role not only in diagnosis but also in guiding antibiotic therapy and evaluating treatment effectiveness. The introduction of point-of-care testing technologies has brought about a paradigm shift in biomarker application, enabling swift and real-time patient evaluation. Despite these advancements, challenges persist, notably concerning biomarker variability and the lack of standardized thresholds. This review summarizes the latest advancements in sepsis biomarker research, spotlighting the progress and clinical implications. It emphasizes the significance of multi-biomarker strategies and the feasibility of personalized medicine in sepsis management. Further verification of biomarkers on a large scale and their integration into clinical practice are advocated to maximize their efficacy in future sepsis treatment.

Infectious Foci, Comorbidities and Its Influence on the Outcomes of Septic Critically Ill Patients

Sepsis is among the most frequent diagnoses on admission to the intensive care unit (ICU). A systemic inflammatory response, activated by uncontrolled infection, fosters hypoperfusion and multiorgan failure and often leads to septic shock and mortality. These infections arise from a specific anatomic source, and how the infection foci influence the outcomes is unknown. All patients admitted to the ICU of Hospital de Vila Franca de Xira, between 1 January 2017 and 31 June 2023, were screened for sepsis and categorized according to their infection foci. During the study period, 1296 patients (32.2%) had sepsis on admission. Their mean age was 67.5 ± 15.3 and 58.1% were male; 73.0% had community-acquired infections. The lung was the main focus of infection. Septic shock was present in 37.9% of the patients and was associated with hospital mortality. Severe imbalances were noted in its incidence, and there was lower mortality in lung infections. The hospital-acquired infections had a slightly higher mortality but, after adjustment, this difference was non-significant. Patients with secondary bacteremia had a worse prognosis (one-year adjusted hazard ratio of 1.36, 95% confidence interval 1.06-1.74, p = 0.015), especially those with an isolated non-fermenting Gram-negative infection. Lung, skin, and skin structure infections and peritonitis had a worse prognosis, whilst urinary, biliary tract, and other intra-abdominal infections had a better one-year outcome.

Active fractions from Jingfang Baidu Powder alleviate Klebsiella-induced Pneumonia by inhibiting TLR4/Myd88-ERK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Jingfang Baidu Powder (JFBDP) is a classic traditional Chinese medicine prescription. Although Jingfang Baidu powder obtained a general consensus on clinical efficacy in treating pneumonia, there were many Chinese herbal drugs in formula, complex components, and large oral dosage, which brings certain obstacles to clinical application.

AIM OF THE STUDY

Therefore, screening of the active fraction that exerts anti-pneumonia helps improve the pharmaceutical preparation, improve the treatment compliance of patients, and further contribute to the clinical application, and the screening of the new active ingredients with anti-pneumonia. The histopathological observation, real-time quantitative PCR, western blotting, and immunofluorescence were applied to evaluate the anti-pneumonia efficacy of active fractions from JFBDP.

RESULTS

Three fractions from JFBDP inhibit the gene expression of IL-1β, IL-10, CCL3, CCL5, and CCL22 in lung tissue infected by Klebsiella at various degrees, and presented a good dose-response relationship. JF50 showed stronger anti-inflammatory effects among three fractions including JF30, JF50, and JF75. Besides, JF50 significantly reduced the protein expression of TLR4 and Myd88 in lung tissue infected with Klebsiella, and it also significantly inhibited p-ERK and p-NF-κB p65. JF50 significantly inhibits the protein expression of Caspase 3, Caspase 8, and Caspase 9 in lung tissue infected with Klebsiella at the dose of 25 mg/kg and 50 mg/kg.

CONCLUSION

JF50 improves lung pathological damage in Klebsiella pneumonia mice by inhibiting the TLR4/Myd88/NF-κB-ERK signaling pathway, and inhibiting apoptosis of lung tissue cells. These findings provide a reference for further exploring the active substance basis of Jingfang Baidu Powder in treating bacterial pneumonia.

The diagnostic value of bronchoalveolar lavage fluid metagenomic next-generation sequencing in critically ill patients with respiratory tract infections

Metagenomic next-generation sequencing (mNGS) is an unbiased and rapid method for detecting pathogens. This study enrolled 145 suspected severe pneumonia patients who were admitted to the Affiliated Hospital of Jining Medical University. This study primarily aimed to determine the diagnostic performance of mNGS and conventional microbiological tests (CMTs) using bronchoalveolar lavage fluid samples for detecting pathogens. Our findings indicated that mNGS performed significantly higher sensitivity (97.54% vs 28.68%, P < 0.001), coincidence (90.34% vs 35.17%, P < 0.001), and negative predictive value (80.00% vs 13.21%, P < 0.001) but performed lower specificity than CMTs (52.17% vs 87.5%, P < 0.001). Streptococcus pneumoniae as the most common bacterial pathogen had the largest proportion (22.90%, 30/131) in this study. In addition to bacteria, fungi, and virus, mNGS can detect a variety of atypical pathogens such as Mycobacterium tuberculosis and non-tuberculous. Mixed infections were common in patients with severe pneumonia, and bacterial-fungal-viral-atypical pathogens were the most complicated infection. After adjustments of antibiotics based on mNGS and CMTs, the clinical manifestation improved in 139 (95.86%, 139/145) patients. Our data demonstrated that mNGS had significant advantage in diagnosing respiratory tract infections, especially atypical pathogens and fungal infections. Pathogens were detected timely and comprehensively, contributing to the adjustments of antibiotic treatments timely and accurately, improving patient prognosis and decreasing mortality potentially.IMPORTANCEMetagenomic next-generation sequencing using bronchoalveolar lavage fluid can provide more comprehensive and accurate pathogens for respiratory tract infections, especially when considering the previous usage of empirical antibiotics before admission or complicated clinical presentation. This technology is expected to play an important role in the precise application of antimicrobial drugs in the future.

Think Globally, Adapt Locally: The ISCCM Guidelines and Position Statements

How to cite this article: Myatra SN, Peter JV, Juneja D, Kulkarni AP. Think Globally, Adapt Locally: The ISCCM Guidelines and Position Statements. Indian J Crit Care Med 2024;28(S2):S1-S3.

A retrospective study of the predictors of mortality among patients in intensive care units at North West-Bank hospitals in Palestine

OBJECTIVES

The intensive care unit (ICU) mortality rate remains high, especially in developing countries, regardless of the advances in critical management. There is a lack of studies about mortality causes in hospitals and particularly ICUs in Palestine.This study evaluated the demographic and clinical characteristics of critically ill patients and determined the predictors of mortality among patients in the ICU.

METHODS

A retrospective study assessed all patients who stayed in the ICU for more than 24 h from January 2017 to January 2019. Data were collected from the patient's files. Patient characteristics (background, clinical variables, and comorbidities) were recorded.

RESULTS

The study included 227 eligible ICU patients. The cases' mean age was 55.5 (SD ± 18.2) years. The overall ICU mortality rate was 31.7%. The following factors were associated with high adjusted mortality odds: admission from inside the hospital (adjusted odds ratio (aOR), 2.1, 95% CI: 1.1-3.9, p < 0.05), creatinine level ≥2 mg/dl on admission (aOR, 2.7, 95% CI: 1.3-5.8, p < 0.01), hematology malignancy patients (aOR, 3.4, 95% CI: 1.6-6.7, p = 0.001), immune-compromised (aOR, 2.5, 95% CI: 1.3-4.7, p < 0.01), septic shock (aOR, 27.1, 95% CI: 7.9-88.3, p < 0.001), hospital-acquired infections (aOR: 13.4, 95% CI: 4.1-57.1, p < 0.001), and patients with multiple-source infection (aOR: 16.3, 95% CI: 6.4-57.1, p < 0.001). Also, high SOFA and APACHE scores predicted morality (p < 0.001).

CONCLUSION

The mortality rate among ICU patients was high. It was higher among those admitted from the hospital wards, septic shock, hospital-acquired infection, multiple infection sources, and multi-drug resistance infections. Thus, strategies should be developed to enhance the ICU environment and provide sufficient resources to minimize the effects of these predictors.

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Definition and Epidemiology of Sepsis

Here we review the epidemiology of sepsis, focusing on its definition, incidence, and mortality, as well as the demographic insights and risk factors that influence its occurrence and outcomes. We address how age, sex, and racial/ethnic disparities impact upon incidence and mortality rates. Sepsis is more frequent and severe among the elderly, males, and certain racial and ethnic groups. Poor socioeconomic status, geographic location, and pre-existing comorbidities also elevate the risk of developing and dying from sepsis. Seasonal variations, with an increased incidence during winter months, is also apparent. We delve into the predictive value of disease severity scores such as the Sequential Organ Failure Assessment score. We also highlight issues relating to coding and administrative data that can generate erroneous and misleading information, and the need for greater consistency. The Sepsis-3 definitions, offering more precise clinical criteria, are a step in the right direction. This overview will, we hope, facilitate understanding of the multi-faceted epidemiological characteristics of sepsis and current challenges.

Quality control efforts of medical institutions: the impacts of a value-based payment system on medical staff and healthcare-associated infections

BACKGROUND

In South Korea, various quality assessments have been introduced to improve the quality of care; as such, the overall level of quality of medical institutions has improved. However, gaps still exist between institutions.

AIM

To evaluate the impact of quality management efforts of medical institutions on securing medical staff and healthcare-associated infections in intensive care units (ICUs).

METHODS

This study used data from the second and third ICU quality assessments conducted by the Health Insurance Review and Assessment Service, which included 265 hospitals and 39,096 inpatients. The continuous quality improvement efforts of medical institutions were measured according to changes in their grade based on quality assessment results. In addition, healthcare-associated infection rates were measured, including rates for ventilator-associated pneumonia and catheter-associated infections. The incidence rate ratio (IRR) was calculated using generalized estimating equation Poisson regression models that included hospital and patient characteristics.

RESULTS

Healthcare-associated infections occurred in approximately 2% of patients using ventilators or catheters. Ventilator-associated pneumonia increased significantly in institutions with a decline in grade [IRR 2.038, 95% confidence interval (CI) 1.426-2.915]. In institutions with an improvement in grade, infections associated with central venous catheters (IRR 0.484, 95% CI 0.330-0.711) and urinary catheters (IRR 0.587, 95% CI 0.398-0.866) decreased.

CONCLUSIONS

Although quality assessment has been introduced in ICUs in South Korea, some gaps remain between medical institutions. Differences in securing medical resources through the quality management efforts of medical institutions were observed, and the infection rate was low in hospitals with high-quality management and high in hospitals with low-quality management.

From Proteome to Potential Drugs: Integration of Subtractive Proteomics and Ensemble Docking for Drug Repurposing against Pseudomonas aeruginosa RND Superfamily Proteins

Pseudomonas aeruginosa (P. aeruginosa) poses a significant threat as a nosocomial pathogen due to its robust resistance mechanisms and virulence factors. This study integrates subtractive proteomics and ensemble docking to identify and characterize essential proteins in P. aeruginosa, aiming to discover therapeutic targets and repurpose commercial existing drugs. Using subtractive proteomics, we refined the dataset to discard redundant proteins and minimize potential cross-interactions with human proteins and the microbiome proteins. We identified 12 key proteins, including a histidine kinase and members of the RND efflux pump family, known for their roles in antibiotic resistance, virulence, and antigenicity. Predictive modeling of the three-dimensional structures of these RND proteins and subsequent molecular ensemble-docking simulations led to the identification of MK-3207, R-428, and Suramin as promising inhibitor candidates. These compounds demonstrated high binding affinities and effective inhibition across multiple metrics. Further refinement using non-covalent interaction index methods provided deeper insights into the electronic effects in protein-ligand interactions, with Suramin exhibiting superior binding energies, suggesting its broad-spectrum inhibitory potential. Our findings confirm the critical role of RND efflux pumps in antibiotic resistance and suggest that MK-3207, R-428, and Suramin could be effectively repurposed to target these proteins. This approach highlights the potential of drug repurposing as a viable strategy to combat P. aeruginosa infections.

Development of an eco-friendly capillary electrophoresis method for the simultaneous determination of piperacillin, tazobactam and ibuprofen in plasma samples: application to a pharmacokinetic study in rats

Piperacillin (PIP) and tazobactam (TAZ) are broad-spectrum beta-lactam antimicrobial agents, which are frequently co-prescribed in intensive care units (ICUs) worldwide. Ibuprofen (IBU) is a potent pain killer which is commonly co-prescribed with PIP and TAZ postoperatively. The combination therapy of PIP, TAZ, and IBU has been administered commonly after surgical procedures to combat aerobic and anaerobic microbes and exert anti-inflammatory and analgesic effects. This study describes, for the first time, the development of a new capillary electrophoresis (CE) method with a photodiode array detector for the simultaneous determination of PIP, TAZ, and IBU in plasma samples. The experimental factors affecting the elution of analytes were carefully optimized. The final analysis was achieved using a fused silica capillary (58 cm effective length and 75 μm ID) and a background electrolyte solution containing a methanol/borax buffer solution (15 mM and pH 9.3) in a ratio of (10 : 90 v/v) with a driving voltage of 30 kV and detection at 210 nm. The relationship between the peak area and concentration was linear from 1 to 200 μg mL-1 for both PIP and TAZ and from 3 to 200 μg mL-1 for TAZ. The method used was thoroughly validated in accordance with the validation requirements set out by the Food and Drug Administration (FDA) for bio-analytical processes. The proposed CE method was employed to conduct pharmacokinetic and bioavailability studies of the drugs in rat models. The pharmacokinetic results revealed that there is a significant impact upon prescribing this combination concurrently when compared to their single administration. To illustrate, the time required to reach their maximum concentrations (T max) was increased by 0.25 h for both PIP and TAZ, whereas it was increased by 0.5 for IBU. When it comes to their maximum concentration (C max), it was increased by 13.7%, 55.5%, and 44% for PIP, TAZ, and IBU, respectively. Furthermore, the bioavailabilities of PIP, TAZ, and IBU were significantly increased by 55.4%, 19.7%, and 35.6%, respectively. These findings require caution when these drugs are co-prescribed as there is a noticeable augmentation in their therapeutic impacts. Additionally, the greenness of the proposed method was assessed by three metric tools. In conclusion, the method is a valuable tool for further studies on drug-drug interaction in humans.

Patient-level cost analysis of intensive care unit acquired infections: A prospective cohort study

INTRODUCTION

Hospital-associated infections (HAIs) are associated with increased mortality and prolonged hospital length-of-stay (LOS). Although some studies have shown that HAIs are associated with increased costs, these studies only used cost estimates, were carried out in a small number of centres, or only in high-income countries.

METHODS

We carried out a prospective cohort study in ten Brazilian intensive care units (ICUs) selected from a collaborative platform study (IMPACTO MR). We included all patients aged 18 years or older admitted from October 2019 to December 2021 and who had an ICU LOS of at least two days. The costs were adjusted for official inflation until December 2022 and converted into international dollars using the 2021 purchasing power parity (PPP) conversion rate. We used a propensity score matching method to compare patients with HAIs and patients without HAIs, and patients with and without ventilator-associated pneumonia (VAP), central-line bloodstream infection (CLABSI), catheter-associated urinary tract infection (CA-UTI) and multidrug-resistant (MDR) HAIs.

RESULTS

We included 7,953 patients in the study, of whom 574 (7.2%) had an HAI during their ICU stay. After propensity-score matching, patients with HAIs had ICU costs that were more than three times higher than those of patients without HAIs [$ 19,642 (IQR; 12,884-35,134) vs. 6,086 (IQR; 3,268-12,550); p <0.001). Patients with VAP, CLABSI, and CA-UTI, but not with MDR-HAIs also had higher total ICU costs.

CONCLUSIONS

HAIs acquired in the ICU are associated with higher ICU costs. These findings were consistent across specific types of infection.

Molecular Genetic Analysis of Perioperative Colonization by Infection-Related Microorganisms in Patients Receiving Intraoral Microvascular Grafts

Background/Objectives: In oral and maxillofacial surgery, the reconstruction of defects often involves the transfer of skin tissue into the oral cavity utilizing microvascular grafts. This study investigates postoperative changes in microbial colonization following intraoral microvascular transplantation, as well as potential influencing factors. Methods: In 37 patients undergoing intraoral reconstructions, pre- and postoperative swabs were taken from the donor and recipient regions to quantify the seven selected marker bacteria using TaqMan PCRs. Patient-specific factors and clinical data were also recorded. Results: The infection-associated Acinetobacter baumannii tended to decrease postoperatively, while the infectious pathogens Pseudomonas aeruginosa, Enterococcus faecalis and the family of Enterobacteriaceae showed a postoperative increase without being directly associated with a clinical infection. Streptococcus mitis showed a significant postoperative decrease on buccal mucosa and increase on the graft surface (oral dysbiosis) and was significantly reduced or displaced by other bacteria (e.g., Mycoplasma salivarium, positive selection) when treated with ampicillin/sulbactam. Conclusions: The cutaneous microbiome of the graft adapts to the local intraoral environment. Postoperative shifts in oral bacterial colonization and an increase in infection-relevant bacteria were observed. These perioperative changes in colonization are also influenced by the administration of ampicillin/sulbactam. Consequently, single doses of antibiotics appear to be more beneficial compared to longer-term preventive use.

Phage Therapy in a Burn Patient Colonized with Extensively Drug-Resistant Pseudomonas aeruginosa Responsible for Relapsing Ventilator-Associated Pneumonia and Bacteriemia

Pseudomonas aeruginosa is one of the main causes of healthcare-associated infection in Europe that increases patient morbidity and mortality. Multi-resistant pathogens are a major public health issue in burn centers. Mortality increases when the initial antibiotic treatment is inappropriate, especially if the patient is infected with P. aeruginosa strains that are resistant to many antibiotics. Phage therapy is an emerging option to treat severe P. aeruginosa infections. It involves using natural viruses called bacteriophages, which have the ability to infect, replicate, and, theoretically, destroy the P. aeruginosa population in an infected patient. We report here the case of a severely burned patient who experienced relapsing ventilator-associated pneumonia associated with skin graft infection and bacteremia due to extensively drug-resistant P. aeruginosa. The patient was successfully treated with personalized nebulized and intravenous phage therapy in combination with immunostimulation (interferon-γ) and last-resort antimicrobial therapy (imipenem-relebactam).

Population pharmacokinetics of daptomycin in critically ill patients receiving extracorporeal membrane oxygenation

BACKGROUND

Daptomycin is widely used in critically ill patients for Gram-positive bacterial infections. Extracorporeal membrane oxygenation (ECMO) is increasingly used in this population and can potentially alter the pharmacokinetic (PK) behaviour of antibiotics. However, the effect of ECMO has not been evaluated in daptomycin. Our study aims to explore the effect of ECMO on daptomycin in critically ill patients through population pharmacokinetic (PopPK) analysis and to determine optimal dosage regimens based on both efficacy and safety considerations.

METHODS

A prospective, open-label PK study was carried out in critically ill patients with or without ECMO. The total concentration of daptomycin was determined by UPLC-MS/MS. NONMEM was used for PopPK analysis and Monte Carlo simulations.

RESULTS

Two hundred and ninety-three plasma samples were collected from 36 critically ill patients, 24 of whom received ECMO support. A two-compartment model with first-order elimination can best describe the PK of daptomycin. Creatinine clearance (CLCR) significantly affects the clearance of daptomycin while ECMO has no significant effect on the PK parameters. Monte Carlo simulations showed that, when the MICs for bacteria are  ≥1 mg/L, the currently recommended dosage regimen is insufficient for critically ill patients with CLCR > 30 mL/min. Our simulations suggest 10 mg/kg for patients with CLCR between 30 and 90 mL/min, and 12 mg/kg for patients with CLCR higher than 90 mL/min.

CONCLUSIONS

This is the first PopPK model of daptomycin in ECMO patients. Optimal dosage regimens considering efficacy, safety, and pathogens were provided for critical patients based on pharmacokinetic-pharmacodynamic analysis.

Pseudomonas aeruginosa in chronic lung disease: untangling the dysregulated host immune response

Pseudomonas aeruginosa is a highly adaptable opportunistic pathogen capable of exploiting barriers and immune defects to cause chronic lung infections in conditions such as cystic fibrosis. In these contexts, host immune responses are ineffective at clearing persistent bacterial infection, instead driving a cycle of inflammatory lung damage. This review outlines key components of the host immune response to chronic P. aeruginosa infection within the lung, beginning with initial pathogen recognition, followed by a robust yet maladaptive innate immune response, and an ineffective adaptive immune response that propagates lung damage while permitting bacterial persistence. Untangling the interplay between host immunity and chronic P. aeruginosa infection will allow for the development and refinement of strategies to modulate immune-associated lung damage and potentiate the immune system to combat chronic infection more effectively.

Automated surveillance of antimicrobial consumption in intensive care, northern Sweden: an observational case study

BACKGROUND

The digitalization of information systems allows automatic measurement of antimicrobial consumption (AMC), helping address antibiotic resistance from inappropriate drug use without compromising patient safety.

OBJECTIVES

Describe and characterize a new automated AMC surveillance service for intensive care units (ICUs), with data stratified by referral clinic and linked with individual patient risk factors, disease severity, and mortality.

METHODS

An automated service collecting data from the electronic medical record was developed, implemented, and validated in a healthcare region in northern Sweden. We performed an observational study from January 1, 2018, to December 31, 2021, encompassing general ICU care for all ≥18-years-olds in a catchment population of 270000 in secondary care and 900000 in tertiary care. We used descriptive analyses to associate ICU population characteristics with AMC outcomes over time, including days of therapy (DOT), length of therapy, defined daily doses, and mortality.

RESULTS

There were 5608 admissions among 5190 patients with a median age of 65 (IQR 48-75) years, 41.2% females. The 30-day mortality was 18.3%. Total AMC was 1177 DOTs in secondary and 1261 DOTs per 1000 patient days and tertiary care. AMC varied significantly among referral clinics, with the highest total among 810 general surgery admissions in tertiary care at 1486 DOTs per 1000 patient days. Case-mix effects on the AMC were apparent during COVID-19 waves highlighting the need to account for case-mix. Patients exposed to more than three antimicrobial drug classes (N = 242) had a 30-day mortality rate of 40.6%, with significant variability in their expected rates based on admission scores.

CONCLUSION

We introduce a new service and instructions for automating local ICU-AMC data collection. The versatile long-term ICU-AMC metrics presented, covering patient factors, referral clinics and mortality outcomes, are expected to be beneficial in refining antimicrobial drug use.

Activity of Aztreonam/Avibactam and Recently Approved β-Lactamase Inhibitor Combinations against Enterobacterales and Pseudomonas aeruginosa from Intensive Care Unit and Non-Intensive Care Unit Patients

We evaluated the activities of aztreonam/avibactam and recently approved β-lactamase inhibitor combinations (BLICs) to compare the antimicrobial susceptibility patterns of Enterobacterales and Pseudomonas aeruginosa isolated from intensive care unit (ICU) and non-ICU patients. Clinical isolates (1/patient) were consecutively collected from 72 United States medical centres in 2020-2022 and susceptibility tested by broth microdilution. The results for 5421 isolates from ICU patients were analysed and compared to those for 20,649 isolates from non-ICU patients. Isolates from ventilator-associated pneumonia patients were analysed separately. Aztreonam/avibactam inhibited 100.0%/>99.9% Enterobacterales and 100.0%/98.3% of carbapenem-resistant Enterobacterales (CRE) from ICU/non-ICU patients at ≤8 mg/L, respectively. The CRE susceptibility rates were 88.5%/82.9% for ceftazidime/avibactam, 82.1%/81.2% for meropenem/vaborbactam, and 78.2%/72.6% for imipenem/relebactam among ICU/non-ICU isolates. Among the P. aeruginosa isolates from ICU/non-ICU patients, the susceptibility rates were 96.3%/97.6% for ceftazidime/avibactam, 97.2/98.4% for ceftolozane/tazobactam, 97.1%/98.0% for imipenem/relebactam, 77.8%/84.6% for piperacillin/tazobactam, and 76.9%/85.8% for meropenem; aztreonam/avibactam inhibited 78.0%/81.9% of P. aeruginosa at ≤8 mg/L. In summary, lower susceptibility rates were observed among ICU than non-ICU isolates. Aztreonam/avibactam exhibited potent in vitro activity and broad-spectrum activity against Enterobacterales from ICU and non-ICU patients, including CRE and isolates non-susceptible to newer BLICs. Against P. aeruginosa, aztreonam/avibactam showed a spectrum of activity comparable to that of piperacillin/tazobactam, meropenem, and ceftazidime.