The Pitt Bacteremia Score Predicts Mortality in Nonbacteremic Infections

Time to positivity of Klebsiella pneumoniae in blood cultures as prognostic marker in patients with intra-abdominal infection: A retrospective study

Klebsiella pneumoniae is a common causative pathogen of intra-abdominal infection with concomitant bacteraemia, leading to a significant mortality risk. The time to positivity (TTP) of blood culture is postulated to be a prognostic factor in bacteraemia caused by other species. Therefore, this study aimed to investigate the prognostic value of TTP in these patients. The single-centred, retrospective, observational cohort study was conducted between 1 July 2016 and 30 June 2021. All adult emergency department patients with diagnosis of intra-abdominal infection and underwent blood culture collection which yield K. pneumoniae during this period were enrolled. A total of 196 patients were included in the study. The overall 30-day mortality rate was 12.2% (24/196), and the median TTP of the studied cohort was 12.3 h (10.5-15.8 h). TTP revealed a moderate 30-day mortality discriminative ability (area under the curve 0.73, p < 0.001). Compared with the late TTP group (>12 h, N = 109), patients in the early TTP (≤12 h, N = 87) group had a significantly higher risk of 30-day morality (21.8% vs. 4.6%, p < 0.01) and other adverse outcomes. Furthermore, TTP (odds ratio [OR] = 0.79, p = 0.02), Pitt bacteraemia score (OR = 1.30, p = 0.03), and implementation of source control (OR = 0.06, p < 0.01) were identified as independent factors related to 30-day mortality risk in patients with intra-abdominal infection and K. pneumoniae bacteraemia. Therefore, physicians can use TTP for prognosis stratification in these patients.

Outcomes and Predictors of Mortality in Patients With KPC-Kp Infections Treated With Meropenem Vaborbactam: An Observational Multicenter Study

Background

Meropenem-vaborbactam is a recent and promising option for the treatment of KPC-producing Klebsiella pneumoniae (KPC-Kp) infections, including those resistant to ceftazidime-avibactam.

Methods

We conducted a retrospective analysis of observational data from 19 Italian hospitals on use and outcomes of patients treated with meropenem-vaborbactam for at least ≥24 hours for KPC-Kp infections. Crude and propensity-weighted multiple Cox regression models were performed to ascertain risk factors independently associated with 30-day mortality.

Results

The cohort included 342 adults with bloodstream infections (n = 172) and nonbacteremic infections (n = 170), of which 107 were lower respiratory tract infections, 30 were complicated urinary tract infections, and 33 were infections involving other sites. Most infections (62.3%) were managed with meropenem-vaborbactam monotherapy, or in combination with at least 1 other active drug (usually fosfomycin, tigecycline, or gentamicin) (37.7%). The 30-day mortality rate was 31.6% (108/342). In multiple Cox regression model, 30-day mortality was independently associated with septic shock at infection onset, Charlson comorbidity index ≥ 3, dialysis, concomitant COVID-19, and INCREMENT score ≥ 8. Administration of meropenem-vaborbactam within 48 hours from infection onset was a negative predictor of mortality. All predictors, except administration of meropenem-vaborbactam within 48 hours, remained significant when the multiple Cox regression model was repeated after adjustment for the propensity score for receipt of combination therapy.

Conclusions

Despite the limits of a retrospective study, the data derived from this multicenter cohort provide additional evidence on the efficacy of meropenem-vaborbactam in treating severe KPC-Kp infections, even when used as monotherapy.

Daptomycin and ceftaroline combination for the treatment of persistent methicillin-resistant Staphylococcus aureus bloodstream infections: a case series and literature review

Methicillin-resistant Staphylococcus aureus (MRSA) is challenging to treat due to a lack of guidance for clinicians. The daptomycin and ceftaroline combination is promising for treating persistent MRSA bloodstream infections (BSIs). In this report, we present a case series of 7 patients who failed vancomycin and then were treated with daptomycin and ceftaroline for persistent MRSA BSIs. The median age (IQR) of the included patients was 59 (48-67), with 5 male and 2 female patients. Six patients (85.7%) had a clinical cure for their persistent BSIs. The median time (IQR) for sterilization of MRSA BSIs after initiation of daptomycin and ceftaroline combination was 2 days (1-3). Among the patients who had clinical cures, the median time for clinical cures (IQR) was 6 weeks (4.5-6 weeks). The combination of daptomycin and ceftaroline could be an excellent treatment option for persistent MRSA BSIs.

A multi-species outbreak of VIM-producing carbapenem-resistant bacteria in a burn unit and subsequent investigation of rapid development of cefiderocol resistance

Carbapenem resistance due to metallo-β-lactamases (MBLs) such as the Verona integron-encoded metallo-β-lactamase (VIM) is particularly problematic due to the limited treatment options. We describe a case series of bacterial infections in a tertiary care hospital due to multi-species acquisition of a VIM gene along with our experience using novel β-lactam antibiotics and antibiotic combinations to treat these infections. Four patients were treated with the combination of ceftazidime-avibactam and aztreonam, with no resistance to the combination detected. However, cefiderocol-resistant Klebsiella pneumoniae isolates were detected in two out of the five patients who received cefiderocol within 3 weeks of having started the antibiotic. Strain pairs of sequential susceptible and resistant isolates from both patients were analyzed using whole-genome sequencing. This analysis revealed that the pairs of isolates independently acquired point mutations in both the cirA and fiu genes, which encode siderophore receptors. These point mutations were remade in a laboratory strain of K. pneumoniae and resulted in a significant increase in the MIC of cefiderocol, even in the absence of a beta-lactamase enzyme or a penicillin-binding protein 3 (PBP3) mutation. While newer β-lactam antibiotics remain an exciting addition to the antibiotic armamentarium, their use must be accompanied by diligent monitoring for the rapid development of resistance.

Real-World Experience of Ceftobiprole for Community- and Hospital-Acquired Pneumonia from a Stewardship Perspective

Ceftobiprole is a fifth-generation cephalosporin approved by European and American regulatory agencies for the treatment of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP). Ceftobiprole administration is useful in severe CAP as well as HAP where the potential is to save other β-lactams including carbapenems or linezolid/vancomycin in clinical practice. The aim of this study was to report the real-world evidence of ceftobiprole in patients with CAP and HAP in a single center. In this retrospective study, we included 159 patients with CAP or HAP: 105 (66%) had CAP and 54 (34%) had HAP. The median age was 70 years (IQR 60-77), the median Charlson Comorbidity Index was 5 (IQR 3-7.5) and baseline INCREMENT ESBL score was 8 (IQR 6-11). Ceftobiprole was mostly given as a combination treatment (77%) or as a carbapenem-sparing strategy (44%). There were no differences in mortality between shorter and longer duration of treatment (<7 days compared with ≥7 days (HR 1.02, C.I. 0.58-1.77, p = 0.93) or between first-line (HR 1.00, C.I. 0.46-2.17, p = 0.989) and second-line therapy. Ceftobiprole use in CAP or HAP in the real world is effective as a first- and second-line treatment as well as a carbapenem-sparing strategy. Further studies are needed to explore the full potential of ceftobiprole, including its real-world use in antimicrobial stewardship programs.

Comparison of bacteremic pneumonia caused by Escherichia coli and Klebsiella pneumoniae: A retrospective study

OBJECTIVES

To compare the prognosis of bacteremic pneumonia caused by Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli) pathogens.

METHODS

A retrospective analysis was carried out on the clinical data of 162 patients who were diagnosed with bacterial pneumonia caused by either K. pneumoniae or E. coli between 2016-2019. The primary outcome of the analysis was the patients' 30-day mortality rate.

RESULTS

There were 82 patients in the E. coli bacteremic pneumonia (E. coli-BP) group and 80 patients in the K. pneumoniae bacteremic pneumonia (KP-BP) group. The 30-day mortality rate was 43.75% (n=35/80) in the KP-BP group and 21.95% (n=18/82) in the E. coli-BP group (p<0.001). Following the adjustment for confounding variables in 4 distinct models, the hazard ratios for the primary outcome in KP-BP were determined to be 0.70 (95% confidence interval [CI]: [0.44-1.02]) in Model 1, 0.72 (95% CI: [0.46-1.14]) in Model 2, 0.99 (95% CI: [0.57-1.73]) in Model 3, and 1.22 (95% CI: [0.69-2.18]) in Model 4.

CONCLUSION

Patients diagnosed with KP-BP exhibited a similar prognosis as those diagnosed with E. coli-BP. For patients with KP-BP, the risk of mortality was significantly higher for those who were in the intensive care unit, were infected with carbapenem-resistant strains, or had a high sequential organ failure assessment score. In patients with E. coli-BP, the Pitt bacteremia score was strongly associated with the 30-day mortality rate.

To treat or not to treat: Assessing the role of anti-enterococcal therapy for intra-abdominal infections in patients with cancer

The clinical significance of enterococci in intra-abdominal infections, particularly those caused by multiple organisms, remains unclear. There are no definitive guidelines regarding the use of empiric therapy with antimicrobial agents targeting enterococci. In this study, we evaluated the impact of the initial antimicrobial therapy administration of anti-enterococcal agents on the treatment of intra-abdominal infections in patients with cancer in whom enterococci were isolated from ascitic fluid cultures. This retrospective study was conducted at Shizuoka Cancer Center between January 1, 2014, and December 31, 2020, on all adult patients with cancer with enterococci in their ascitic fluid cultures. The primary outcome was all-cause mortality, and the secondary outcomes were composite outcomes consisting of three components (mortality, recurrence, and treatment failure) and the risk factors associated with all-cause mortality and composite outcomes. In total, 103 patients were included: 61 received treatment covering enterococci, and 42 did not. The mortality rates did not differ significantly between the treated and untreated groups (treated: 8/61 [13.1%]; untreated: 5/42 [11.9%]; p = 1.00). Additionally, no significant difference was observed between the groups in terms of composite outcomes (treated group: 11/61 [18.0%]; untreated group: 9/42 [21.4%]; p = 0.80). Multivariate analysis showed that performance status (PS2-4; p < 0.0001) was an independent risk factor for mortality. The composite outcome was also significantly higher for PS2-4 (p = 0.007). Anti-enterococcal treatment was not associated with mortality or the composite outcome. In patients with cancer and intra-abdominal infections caused by enterococci, anti-enterococcal therapy was not associated with prognosis, whereas PS2 or higher was associated with prognosis. The results of this study suggest that the initial routine administration of anti-enterococcal agents for intra-abdominal infections may not be essential for all patients with cancer. To substantiate these findings, validation by a prospective randomized trial is warranted.

Carbapenem-resistant Enterobacterales in Children at 18 US Health Care System Study Sites: Clinical and Molecular Epidemiology From a Prospective Multicenter Cohort Study

Background

Carbapenem-resistant Enterobacterales (CRE) are an urgent public health threat in the United States.

Objective

Describe the clinical and molecular epidemiology of CRE in a multicenter pediatric cohort.

Methods

CRACKLE-1 and CRACKLE-2 are prospective cohort studies with consecutive enrollment of hospitalized patients with CRE infection or colonization between 24 December 2011 and 31 August 2017. Patients younger than age 18 years and enrolled in the CRACKLE studies were included in this analysis. Clinical data were obtained from the electronic health record. Carbapenemase genes were detected using polymerase chain reaction and whole-genome sequencing.

Results

Fifty-one children were identified at 18 healthcare system study sites representing all U.S. census regions. The median age was 8 months, with 67% younger than age 2 years. Median number of days from admission to culture collection was 11. Seventy-three percent of patients had required intensive care and 41% had a history of mechanical ventilation. More than half of children had no documented comorbidities (Q1, Q3 0, 2). Sixty-seven percent previously received antibiotics during their hospitalization. The most common species isolated were Enterobacter species (41%), Klebsiella pneumoniae (27%), and Escherichia coli (20%). Carbapenemase genes were detected in 29% of isolates tested, which was lower than previously described in adults from this cohort (61%). Thirty-four patients were empirically treated on the date of culture collection, but only 6 received an antibiotic to which the CRE isolate was confirmed susceptible in vitro. Thirty-day mortality was 13.7%.

Conclusions

CRE infection or colonization in U.S. children was geographically widespread, predominantly affected children younger than age 2 years, associated with significant mortality, and less commonly caused by carbapenemase-producing strains than in adults.

Risk Factors for 30-Day Mortality in Patients with Bacteremic Pneumonia Caused by Escherichia coli and Klebsiella pneumoniae: A Retrospective Study

Objective

Escherichia coli and Klebsiella pneumoniae are prevalent Gram-negative microorganisms responsible for pneumonia, as well as the primary Enterobacteriaceae pathogens causing bacteremic pneumonia. The objective of this research is to analyze the risk factors associated with bacteremic pneumonia caused by these pathogens and develop a predictive model.

Patients and Methods

This retrospective investigation encompassed a cohort of 252 patients diagnosed with Escherichia coli or Klebsiella pneumoniae-induced bacteremic pneumonia between 2018 and 2022. The primary endpoint was 30-day mortality, which was analyzed using multifactorial logistic regression, nomogram construction, and Bootstrap validation.

Results

Among the 252 patients diagnosed with Escherichia coli and Klebsiella pneumoniae, 65 succumbed to the disease while 187 survived. The overall 30-day mortality was found to be 25.8%. A multifactorial logistic regression analysis revealed that diastolic blood pressure, cerebrovascular diseases/transient ischemic attacks (TIA), immunosuppression, blood urea nitrogen, Pitt score, and CURB-65 score were statistically significant factors. The Nomogram model demonstrated an AUC of 0.954, which closely aligns with the Bootstrap-derived mean AUC of 0.953 (95% CI: 0.952-0.954).

Conclusion

In patients with bacteremic pneumonia caused by Escherichia coli and Klebsiella pneumoniae, Low diastolic blood pressure (≤61 mmHg), pre-existing cerebrovascular disease/ transient ischemic attacks (TIA), immunosuppression status, elevated blood urea nitrogen levels (≥8.39 mmol/L), high Pitt score (≥3), and a high CURB-65 score (≥2) are all independent risk factors for Escherichia coli and Klebsiella pneumoniae bacteremic pneumonia, among which the first three warrant particular attention.

Risk Factors and Mortality of Elderly Patients with Hospital-Acquired Pneumonia of Carbapenem-Resistant Klebsiella pneumoniae Infection

Purpose

Hospital-acquired pneumonia (HAP) caused by carbapenem-resistant K. pneumoniae (CRKP), especially in elderly patients, results in high morbidity and mortality. Studies on risk factors, mortality, and antimicrobial susceptibility of CRKP pulmonary infection among elderly patients are lacking.

Patients and Methods

A retrospective case-control study was conducted from January 2019 to December 2021. The elderly inpatients (≥65 years) who were diagnosed with HAP caused by K. pneumoniae were enrolled. Clinical data were collected. Univariate and multivariate logistic regression analyses were used to identify risk factors. Propensity score matching was used to minimize the effect of potential confounding variables. Kaplan-Meier analysis was used to compare survival.

Results

A total of 115 patients with CRKP infection and 78 patients with carbapenem-susceptible K. pneumoniae (CSKP) infection were recruited. There were four independent risk factors for CRKP infection: history of intensive care unit (ICU) stays from hospital admission to positive respiratory specimen culture for K. pneumoniae (odds ratio (OR)=2.530), Charlson comorbidity index score ≥3 (OR = 2.420), prior exposure to carbapenems (OR = 5.280), and prior K. pneumoniae infection or colonization in the preceding 3 years (OR = 18.529). The all-cause 30-day mortality was 22.3%, the mortality of CRKP and CSKP infection was 28.7% and 12.8%, respectively. Independent risk factors for mortality included: older age (OR = 1.107), immunocompromised patients (OR = 8.632), severe pneumonia (OR = 51.244), quick Sepsis-related Organ Failure Assessment (qSOFA) score ≥2 (OR = 6.187), exposure to tigecycline before infection (OR = 24.702), and prolonged ICU stay (OR = 0.987). Thirty-day mortality was significantly lower in patients receiving ceftazidime-avibactam (CAZ-AVI) containing regimens than patients receiving polymyxin B sulfate (PB) containing regimens (P = 0.048). qSOFA score had a good prognostic effect [area under receiver operating characteristic curve (AUROC) of 0.838].

Conclusion

Active screening of CRKP for the high-risk populations, especially elderly patients, is significant for early detection and successful management of CRKP infection.

Empirical vs pre-emptive broad-spectrum antifungal therapy for acute myelogenous leukaemia in the era of antimould prophylaxis

INTRODUCTION

This study compared clinical outcomes in patients with acute myelogenous leukaemia (AML) who developed prolonged (≥4 days) febrile neutropenia (FN) and received either empirical or pre-emptive antimould prophylaxis in order to evaluate the need for routine empirical antifungal therapy.

METHODS

This retrospective study reviewed adult patients (aged ≥18 years) with AML who developed prolonged FN and received antimould prophylaxis during induction or re-induction chemotherapy at a single centre between September 2016 and December 2020. Patients were categorized into pre-emptive or empirical groups based on whether or not there was clinical evidence of invasive fungal infection (IFI) at the start of antifungal treatment, respectively. Clinical outcomes were compared between the two groups after propensity score matching (PSM).

RESULTS

In total, 229 chemotherapy episodes (36 and 193 in the empirical and pre-emptive groups, respectively) were analysed. In the pre-emptive group, broad-spectrum antifungal therapy was administered in 45 (23.3%) episodes. After 1:3 PSM, there were no significant differences between the empirical and pre-emptive groups in terms of the incidence of proven or probable IFI [0/36 (0%) vs 5/97 (5.2%); P=0.323], all-cause mortality [3/36 (8.3%) vs 4/97 (4.1%); P=0.388] and IFI-related mortality [0/36 (0.0%) vs 1/45 (2.2%); P=0.556].

CONCLUSION

The differences in clinical outcomes between empirical and pre-emptive antifungal therapy in patients with AML who received antimould prophylaxis were not significant. Therefore, broad-spectrum antifungal therapy in patients receiving antimould prophylaxis may be delayed until there is clear evidence of IFI.

Weighing the Odds: Novel β-Lactam/β-Lactamase Inhibitor Use in Hospital-Acquired and Ventilator-Associated Pseudomonas aeruginosa Pneumonia for Patients Who Are Morbidly Obese

Background

Pseudomonas aeruginosa is a leading cause of hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP). Novel β-lactam/β-lactamase inhibitor (BL/BLI) combinations are often used for these infections; however, limited data exist to guide the dosing of BL/BLI in patients who are morbidly obese. Thus, we sought to evaluate the clinical and safety endpoints of patients who are morbidly obese (body mass index ≥35 kg/m2) and non-morbidly obese (<35 kg/m2) and receiving BL/BLI for P aeruginosa HABP/VABP.

Methods

This retrospective study was based on a cohort of patients hospitalized at 2 urban academic medical centers in Detroit, Michigan, from August 2014 through February 2021 with P aeruginosa HABP/VABP who were receiving BL/BLI (ceftazidime/avibactam, ceftolozane/tazobactam, or meropenem/vaborbactam) for ≥72 continuous hours. The primary endpoint was presumed treatment failure, defined as the presence of all-cause in-hospital mortality or the continuation of infectious symptoms. Analyses were adjusted for possible confounding with inverse probability of treatment weighting. Multivariable regression was used to identify predictors of treatment failure.

Results

In total, 285 patients with HABP (61.4%) and/or VABP (56.1%) were enrolled (morbidly obese, n = 95; non-morbidly obese, n = 190). The median Acute Physiology and Chronic Health Evaluation II score was 23 (IQR, 13-26), and 60% of patients were admitted to the intensive care unit at index culture collection. Patients who were morbidly obese demonstrated significantly greater odds of presumed treatment failure vs those who were non-morbidly obese (58.9% vs 37.9%, respectively; adjusted odds ratio, 1.675 [95% CI, 1.465-1.979]). In multivariable analysis, morbid obesity (1.06; 95% CI, 1.02-1.79), prolonged time to BL/BLI initiation (1.47; 95% CI, 1.28-2.66), renal dose-adjusted BL/BLI in the first 48 hours of therapy (1.12; 95% CI, 1.09-1.75), and continuous renal replacement therapy during BL/BLI therapy (1.35; 95% CI, 1.06-1.68) were independently associated with increased odds of presumed treatment failure.

Conclusions

Among hospitalized patients receiving BL/BLI for P aeruginosa HABP/VABP, those who were morbidly obese had significantly greater odds of presumed treatment failure when compared with those who were non-morbidly obese.

International Epidemiology of Carbapenemase-Producing Escherichia coli

BACKGROUND

Carbapenemase-producing (CP) Escherichia coli (CP-Ec) are a global public health threat. We aimed to describe the clinical and molecular epidemiology and outcomes of patients from several countries with CP-Ec isolates obtained from a prospective cohort.

METHODS

Patients with CP-Ec were enrolled from 26 hospitals in 6 countries. Clinical data were collected, and isolates underwent whole-genome sequencing. Clinical and molecular features and outcomes associated with isolates with or without metallo-β-lactamases (MBLs) were compared. The primary outcome was desirability of outcome ranking (DOOR) at 30 days after the index culture.

RESULTS

Of the 114 CP-Ec isolates in Consortium on resistance against carbapenems in Klebsiella and other Enterobacterales-2 (CRACKLE-2), 49 harbored an MBL, most commonly blaNDM-5 (38/49, 78%). Strong regional variations were noted with MBL-Ec predominantly found among patients in China (23/49). Clinically, MBL-Ec were more often from urine sources (49% vs 29%), less often met criteria for infection (39% vs 58%, P = .04), and had lower acuity of illness when compared with non-MBL-Ec. Among patients with infection, the probability of a better DOOR outcome for a randomly selected patient with MBL-Ec as compared with non-MBL-Ec was 62% (95% CI: 48.2-74.3%). Among infected patients, non-MBL-Ec had increased 30-day (26% vs 0%; P = .02) and 90-day (39% vs 0%; P = .001) mortality compared with MBL-Ec.

CONCLUSIONS

Emergence of CP-Ec was observed with important geographic variations. Bacterial characteristics, clinical presentations, and outcomes differed between MBL-Ec and non-MBL-Ec. Mortality was higher among non-MBL isolates, which were more frequently isolated from blood, but these findings may be confounded by regional variations.

Prediction of 30-Day Mortality Using the Quick Pitt Bacteremia Score in Hospitalized Patients with Klebsiella pneumoniae Infection

Purpose

Klebsiella pneumoniae is an important causative pathogen of nosocomial infections, resulting in poor prognosis owing to its hypervirulence and antibiotic resistance. A simplified quicker version of the Pitt bacteremia score (PBS) (qPitt) for acute illness severity measurement was developed recently. The goal of this study was to explore the prognostic value of qPitt in patients with K. pneumoniae infection.

Patients and Methods

Demographic information and management strategies were retrospectively collected from the records of all adult patients who visited the emergency department between January 1, 2021, and December 31, 2021, with culture-positive K. pneumoniae. The qPitt score was calculated based on: temperature <36°C, systolic blood pressure ≤90 mmHg or vasopressor administration, respiratory rate ≥25 times/min or need of mechanical ventilation, altered mental status, and cardiac arrest event. The 30-day mortality prediction abilities of the qPitt were compared with the PBS, the sequential organ failure assessment (SOFA), and the quick sequential organ failure assessment (qSOFA) using receiver operating characteristic curves.

Results

Data from 867 patients (57.8% men) with a mean age of 66.9 were compiled. The 30-day mortality rate of the enrolled patients was 13.4%, and the area under the curve (AUC) of the scoring systems were as follows: SOFA, 0.91 (95% confidence interval [CI]=0.89-0.93), qPitt, 0.87 (95% CI=0.84-0.89), PBS, 0.87 (95% CI=0.85-0.89), and qSOFA, 0.73 (95% CI=0.70-0.76). The AUC of qPitt was significantly higher than that of qSOFA (p<0.01) and similar to that of PBS (p=0.65).The qPitt also demonstrated excellent mortality discrimination ability in non-bacteremic patients, AUC= 0.85 (95% CI=0.82-0.88).

Conclusion

The qPitt revealed excellent 30-day mortality prediction ability and also predicted mortality in non-bacteremic patients with K. pneumoniae infection. Clinicians can use this simplified scoring system to stratify patients earlier and initiate prompt treatment in high-risk patients.

Treatment of Piperacillin-Tazobactam-Nonsusceptible/Ceftriaxone-Susceptible Infections With Carbapenem Versus Carbapenem-Sparing Antimicrobials

Background

Escherichia coli and Klebsiella pneumoniae with a piperacillin-tazobactam-nonsusceptible/ceftriaxone-susceptible (TZP-NS/CRO-S) phenotype have been increasingly identified, with limited available literature evaluating treatment strategies.

Methods

This was a retrospective study of noncritically ill adults hospitalized between 2013 and 2021 and treated at least 48 hours for TZP-NS/CRO-S E coli or K pneumoniae infections. The primary composite endpoint included escalation to intensive care unit, infection- or treatment-related readmission, mortality, and infection recurrence. Outcomes were compared between groups who received carbapenem (CG) versus carbapenem-sparing agents (CSG) as targeted gram-negative therapy.

Results

Of 1062 patients screened, 200 were included (CG, n = 51; CSG, n = 149). Baseline characteristics, including Charlson Comorbidity Index (CCI; median [interquartile range], 6 [3-9] vs 6 [4-9]; P = .704), were similar between groups, except for more immunocompromised CG patients (29% vs 11%, P = .001). The most common infection sources were urinary (31% vs 57%, P = .002) and bloodstream (18% vs 17%, P = .887). Eighty-eight percent of the CG received meropenem, while 58% of the CSG received ceftriaxone as targeted therapy. There was no statistical difference in the primary endpoint between overall groups (27% vs 17%, P = .123), nor when stratified by infection source. More patients in the CSG switched to oral therapy (15 [29%] vs 100 [67%], P < .001). In multivariate analysis, CCI was an independent predictor of the primary outcome (odds ratio [OR], 1.199 [95% confidence interval, 1.074-1.340]; P = .001), while treatment with carbapenem-sparing therapy was not.

Conclusions

Our study did not find improved clinical outcomes with targeted carbapenem therapy for TZP-NS/CRO-S infections. Carbapenem-sparing agents may be considered to spare carbapenems in noncritically ill patients similar to those included in our cohort.

Impact of antimicrobial stewardship with the Xpert MRSA/SA BC assay at a tertiary hospital in Japan

INTRODUCTION

Genetic testing is gaining increasing importance as a part of antimicrobial stewardship (AS). Rapid identification and determination of methicillin susceptibility using the Xpert MRSA/SA BC assay can improve the management of Staphylococcus aureus bacteremia (SAB) and reduce inappropriate antibiotic use. However, few reports have described the effectiveness of this approach.

METHODS

The present study aimed to assess the influence of AS using the Xpert MRSA/SA BC assay. Cases were classified into the pre-intervention group (n = 98 patients), in which SAB was identified by traditional culture (November 2017 to November 2019), and the post-intervention group (n = 97 patients), in which the Xpert MRSA/SA BC assay was performed when necessary (December 2019 to December 2021).

RESULTS

Patient characteristics, prognosis, duration of antimicrobial use, and length of hospital stay were compared between the groups. The Xpert assay was performed in 66 patients in the post-intervention group (68.0%). The two groups showed no significant differences in severity and mortality. The rate of cases treated with anti-MRSA agents reduced following the intervention (65.3% vs. 40.4%, p = 0.008). The number of cases involving definitive therapy within 24 h was higher in the post-intervention group (9.2% vs. 24.7%, p = 0.007). The hospitalization rate at >60 days was lower in Xpert implementation cases among MRSA bacteremia cases (28.6% vs. 0%, p = 0.01).

CONCLUSIONS

Thus, the Xpert MRSA/SA BC assay has potential as an AS tool, especially for early definitive treatment to SAB and reduction of long-term hospitalization in MRSA bacteremia cases.

Evaluation of clinical response to empirical antimicrobial therapy on day 7 and mortality in the intensive care unit: sub-analysis of the DIANA study Japanese data

It is not clear whether evaluating the clinical response to antibiotic use at day 7 among critically ill patients accurately predicts outcomes. We aimed to evaluate the relationship between clinical response to the initial empiric therapy on day 7 and mortality.

Methods

The determinants of antimicrobial use and de-escalation in critical care (DIANA) study was an international, multicenter, observational study on antibiotic use in the intensive care unit (ICU). ICU patients ages over 18 years in whom an empiric antimicrobial regimen in Japan was initiated were included. We compared patients who were evaluated as cured or improved ("effective") 7 days after starting antibiotic treatment with patients who were evaluated as deteriorated ("failure").

Results

Overall, 217 (83%) patients were in the effective group, and 45 (17%) were in the failure group. Both the infection-related mortality rate in the ICU and the in-hospital infection-related mortality rate in the effective group were lower than those in the failure group (0% versus 24.4%; P < 0.01 and 0.5% versus 28.9%; P < 0.01, respectively).

Conclusion

Assessment of efficacy of empiric antimicrobial treatment on day 7 may predict a favorable outcome among patients suffering from infection in the ICU.

Poor outcomes in both infection and colonization with carbapenem-resistant Enterobacterales

OBJECTIVES

To describe the epidemiology of patients with nonintestinal carbapenem-resistant Enterobacterales (CRE) colonization and to compare clinical outcomes of these patients to those with CRE infection.

DESIGN

A secondary analysis of Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae 2 (CRACKLE-2), a prospective observational cohort.

SETTING

A total of 49 US short-term acute-care hospitals.

PATIENTS

Patients hospitalized with CRE isolated from clinical cultures, April, 30, 2016, through August 31, 2017.

METHODS

We described characteristics of patients in CRACKLE-2 with nonintestinal CRE colonization and assessed the impact of site of colonization on clinical outcomes. We then compared outcomes of patients defined as having nonintestinal CRE colonization to all those defined as having infection. The primary outcome was a desirability of outcome ranking (DOOR) at 30 days. Secondary outcomes were 30-day mortality and 90-day readmission.

RESULTS

Of 547 patients with nonintestinal CRE colonization, 275 (50%) were from the urinary tract, 201 (37%) were from the respiratory tract, and 71 (13%) were from a wound. Patients with urinary tract colonization were more likely to have a more desirable clinical outcome at 30 days than those with respiratory tract colonization, with a DOOR probability of better outcome of 61% (95% confidence interval [CI], 53%-71%). When compared to 255 patients with CRE infection, patients with CRE colonization had a similar overall clinical outcome, as well as 30-day mortality and 90-day readmission rates when analyzed in aggregate or by culture site. Sensitivity analyses demonstrated similar results using different definitions of infection.

CONCLUSIONS

Patients with nonintestinal CRE colonization had outcomes similar to those with CRE infection. Clinical outcomes may be influenced more by culture site than classification as "colonized" or "infected."

qSOFA does not predict bacteremia in patients with severe manifestations of sepsis

BACKGROUND

Bloodstream infections in septic patients may be missed due to preceding antibiotic therapy prior to obtaining blood cultures. We leveraged the FABLED cohort study to determine if the quick Sequential Organ Failure Assessment (qSOFA) score could reliably identify patients at higher risk of bacteremia in patients who may have false negative blood cultures due to previously administered antibiotic therapy.

METHODS

We conducted a multi-centre diagnostic study among adult patients with severe manifestations of sepsis. Patients were enrolled in one of seven participating centres between November 2013 and September 2018. All patients from the FABLED cohort had two sets of blood cultures drawn prior to the administration of antimicrobial therapy, as well as additional blood cultures within 4 hours of treatment initiation. Participants were categorized according to qSOFA score, with a score ≥2 being considered positive.

RESULTS

Among 325 patients with severe manifestations of sepsis, a positive qSOFA score (defined as a score ≥2) on admission was 58% sensitive (95% CI 48% to 67%) and 41% specific (95% CI 34% to 48%) for predicting bacteremia. Among patients with negative post-antimicrobial blood cultures, a positive qSOFA score was 57% sensitive (95% CI 42% to 70%) and 42% specific (95% CI 35% to 49%) to detect patients who were originally bacteremic prior to the initiation of therapy.

CONCLUSIONS

Our results suggest that the qSOFA score cannot be used to identify patients at risk for occult bacteremia due to the administration of antibiotics pre-blood culture.

Clinical Impact of Ceftriaxone Resistance in Escherichia coli Bloodstream Infections: A Multicenter Prospective Cohort Study

Background

Ceftriaxone-resistant (CRO-R) Escherichia coli bloodstream infections (BSIs) are common.

Methods

This is a prospective cohort of patients with E coli BSI at 14 United States hospitals between November 2020 and April 2021. For each patient with a CRO-R E coli BSI enrolled, the next consecutive patient with a ceftriaxone-susceptible (CRO-S) E coli BSI was included. Primary outcome was desirability of outcome ranking (DOOR) at day 30, with 50% probability of worse outcomes in the CRO-R group as the null hypothesis. Inverse probability weighting (IPW) was used to reduce confounding.

Results

Notable differences between patients infected with CRO-R and CRO-S E coli BSI included the proportion with Pitt bacteremia score ≥4 (23% vs 15%, P = .079) and the median time to active antibiotic therapy (12 hours [interquartile range {IQR}, 1-35 hours] vs 1 hour [IQR, 0-6 hours]; P < .001). Unadjusted DOOR analyses indicated a 58% probability (95% confidence interval [CI], 52%-63%) for a worse clinical outcome in CRO-R versus CRO-S BSI. In the IPW-adjusted cohort, no difference was observed (54% [95% CI, 47%-61%]). Secondary outcomes included unadjusted and adjusted differences in the proportion of 30-day mortality between CRO-R and CRO-S BSIs (-5.3% [95% CI, -10.3% to -.4%] and -1.8 [95% CI, -6.7% to 3.2%], respectively), postculture median length of stay (8 days [IQR, 5-13 days] vs 6 days [IQR, 4-9 days]; P < .001), and incident admission to a long-term care facility (22% vs 12%, P = .045).

Conclusions

Patients with CRO-R E coli BSI generally have poorer outcomes compared to patients infected with CRO-S E coli BSI, even after adjusting for important confounders.

Towards survival prediction of cancer patients using medical images

Survival prediction of a patient is a critical task in clinical medicine for physicians and patients to make an informed decision. Several survival and risk scoring methods have been developed to estimate the survival score of patients using clinical information. For instance, the Global Registry of Acute Coronary Events (GRACE) and Thrombolysis in Myocardial Infarction (TIMI) risk scores are developed for the survival prediction of heart patients. Recently, state-of-the-art medical imaging and analysis techniques have paved the way for survival prediction of cancer patients by understanding key features extracted from Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scanned images with the help of image processing and machine learning techniques. However, survival prediction is a challenging task due to the complexity in benchmarking of image features, feature selection methods, and machine learning models. In this article, we evaluate the performance of 156 visual features from radiomic and hand-crafted feature classes, six feature selection methods, and 10 machine learning models to benchmark their performance. In addition, MRI scanned Brain Tumor Segmentation (BraTS) and CT scanned non-small cell lung cancer (NSCLC) datasets are used to train classification and regression models. Our results highlight that logistic regression outperforms for the classification with 66 and 54% accuracy for BraTS and NSCLC datasets, respectively. Moreover, our analysis of best-performing features shows that age is a common and significant feature for survival prediction. Also, gray level and shape-based features play a vital role in regression. We believe that the study can be helpful for oncologists, radiologists, and medical imaging researchers to understand and automate the procedure of decision-making and prognosis of cancer patients.

Predictive Value of a Quick Pitt Bacteremia Score for Prognosis of Patients with Bloodstream Infection Secondary to Urinary Tract Infection: A Retrospective Cohort Study

Purpose

To analyze the effect of a quick Pitt bacteremia score (qpitt) on the prognosis of patients with bloodstream infection (BSI) secondary to urinary tract infection (UTI) and to further explore its use in aiding appropriate selection of initial antibiotic treatment.

Methods

Medical records of patients with BSIs secondary to UTIs who were admitted to our hospital from January 2018 to December 2020 were retrospectively collected. To screen for independent risk factors, logistic analysis was conducted on statistically significant variables. The receiver operating characteristic (ROC) curve was drawn with prognosis and death as the state variables to evaluate the predictive value. Patients were grouped by qpitt 2-point cutoff, to explore the impact of initial antimicrobial treatment regimens on poor prognosis and death in different subgroups. Poor prognosis was defined as a hospital length of stay (HLOS) ≥14 days or death within 28 days from BSI onset (ie, 28-day death).

Results

A total of 266 patients were included in this study. In BSIs secondary to UTIs, we observed a pathogenic composition of 77.44% Gram-negative bacteria, 19.55% Gram-positive bacteria, and 3.01% fungi. The qpitt had poor predictive value for poor prognosis [area under ROC (AUROC) = 0.653, p < 0.001], while it had a high predictive value for death (AUROC = 0.890, p < 0.001). For patients with a qpitt ≥2, the poor prognosis and death rates of patients who were initially treated with carbapenem antibiotics were lower (p < 0.01). In comparison, initial treatment with carbapenem antibiotics had no significant effect on prognosis and death rates in patients with qpitt <2 (p > 0.1).

Conclusion

The qpitt is highly predictive for death in patients with BSIs secondary to UTIs and can be used to inform first-line antibiotic treatment strategy.

Comparison of quick Pitt to quick sofa and sofa scores for scoring of severity for patients with urinary tract infection

Quick Pitt (qPitt), which includes temperature, systolic blood pressure, respiratory rate, cardiac arrest, and mental status, is a new prognostic score derived from the Pitt Bacteremia score. The aim of our study is to compare qPitt with quick SOFA (qSOFA) and SOFA for scoring of severity in patients with urinary tract infection (UTI). Prospective observational study of patients diagnosed with UTI. Area under the ROC curve, sensibility, and specificity to predict 30-day mortality were calculated for qPitt, qSOFA and SOFA and compared. 382 UTI cases were analyzed. Thirty-day mortality (18.8% vs. 5.9%, p < 0.001) and longer hospital stay (6 [1-11] vs. 4 [1-7] days, p < 0.001) were associated with qPitt ≥ 2. However, qPitt had a worse performance to predict 30-day mortality compared to qSOFA and SOFA (AUROC 0.692 vs. 0.832 and 0.806, respectively, p = 0.010 and p = 0.041). The sensitivity of qPitt was lower than the sensitivity of qSOFA and SOFA (70.45 vs. 84.09 for both qSOFA and SOFA, p < 0.001), with a specificity lower than qSOFA and similar to SOFA (60.36 vs. 82.25 and 63.61, p < 0.001 and p = 0.742, respectively). Quick Pitt had moderate prognostic accuracy and performed worse than qSOFA and SOFA scores for predicting mortality in patients with UTI.

Multicenter Study of the Risk Factors and Outcomes of Bloodstream Infections Caused by Carbapenem-Non-Susceptible Acinetobacter baumannii in Indonesia

The prevalence of bacteremia caused by carbapenem-non-susceptible Acinetobacter baumannii (CNSAB) continues to increase, and it is associated with a high mortality rate. Early recognition of infection and mortality determinants risk factors is necessary for adequate antibiotic administration. We aimed to determine the risk factors and outcomes of CNSAB bacteremia in Indonesia. A multicenter case-control study was conducted in three referral hospitals in Indonesia. Data were collected retrospectively from January 2019 to December 2021. Cases were defined as patients with bacteremia where CNSAB was isolated from the blood, while the controls were patients with bacteremia caused by carbapenem-susceptible A. baumannii (CSAB). Risk factors for bacteremia and mortality associated with CNSAB bacteremia were determined using univariates analysis (chi-squared and Student's t-test or Mann-Whitney test) and multivariate logistic regression analysis. A total of 144 bacteremia patients were included, of whom 72 patients were for each case and control group. The final model of multivariate regression analysis revealed that bacteremia source from the lower respiratory tract (adjusted odds ratio (aOR): 3.24; 95% CI: 1.58-6.63, p = 0.001) and the use of central venous catheter (aOR: 2.56; 95% CI: 1.27-5.18; p = 0.009) were independent risk factors for CNSAB bacteremia. Charlson Comorbidity Index ≥ 4 (aOR: 28.56; 95% CI: 3.06-265.90, p = 0.003) and Pitt Bacteremia Score ≥ 4 (aOR: 6.44; 95% CI: 1.17-35.38; p = 0.032) were independent risk factors for mortality due to CNSAB bacteremia. Only high Pitt Bacteremia Score was an independent risk factor for mortality of CSAB bacteremia. In conclusion, we identified the risk factors for CNSAB-associated bacteremia and the risk factors for death, which are relevant for empiric therapy and infection control prevention, as well as prognosis evaluation of patients with bloodstream infections.

Bloodstream Infections in Hematologic Malignancy Patients with Fever and Neutropenia: Are Empirical Antibiotic Therapies in the United States Still Effective?

Background

Rising antimicrobial resistance rates may impact the efficacy of empirical antibiotic treatment for febrile neutropenia in high-risk cancer patients. Lacking contemporary data about the epidemiology, antibiotic resistance patterns, and clinical outcomes from bloodstream infections (BSI) in U.S. cancer patients, it is unclear if current guidelines remain relevant.

Methods

In a cross-sectional study, fourteen U.S. cancer centers prospectively identified BSIs in high-risk FN patients, including those receiving chemotherapy for hematologic malignancies or hematopoietic stem cell transplantation.

Results

Among 389 organsims causing BSI in 343 patients, there was an equal distribution of Gram-negative (GN) and Gram-positive (GP) bacteria, with variability across centers. Cefepime and piperacillin-tazobactam were the most commonly prescribed empirical antibiotics for FN, at 62% and 23% respectively; a GP-directed agent was empirically included in nearly half of all FN episodes within the first 24 hours. Susceptibility to fluoroquinolones, cefepime, piperacillin-tazobactam, and carbapenems was 49%, 84%, 88% and 96% respectively among GN isolates. Critical illness (CrI), defined as a new requirement for mechanical ventilation, vasopressor or death within 30 days, occurred in 15% and did not correlate with fluoroquinolone prophylaxis, organism type, initial antibiotics or adequacy of coverage. Only severity of illness at presentation, signified by a Pitt bacteremia score &gt; 2, predicted for critical illness within 30 days. Mortality was 4% by day 7 and 10% overall.

Conclusion

In accordance with U.S. guidelines, cefepime or piperacillin-tazobactam remain effective agents or empirical treatment for high risk cancer patients with FN who are stable at presentation, maintaining high GN pathogen susceptibility and yielding excellent outcomes.

Mortality prediction of patients in intensive care units using machine learning algorithms based on electronic health records

Improving predictive models for intensive care unit (ICU) inpatients requires a new strategy that periodically includes the latest clinical data and can be updated to reflect local characteristics. We extracted data from all adult patients admitted to the ICUs of two university hospitals with different characteristics from 2006 to 2020, and a total of 85,146 patients were included in this study. Machine learning algorithms were trained to predict in-hospital mortality. The predictive performance of conventional scoring models and machine learning algorithms was assessed by the area under the receiver operating characteristic curve (AUROC). The conventional scoring models had various predictive powers, with the SAPS III (AUROC 0.773 [0.766-0.779] for hospital S) and APACHE III (AUROC 0.803 [0.795-0.810] for hospital G) showing the highest AUROC among them. The best performing machine learning models achieved an AUROC of 0.977 (0.973-0.980) in hospital S and 0.955 (0.950-0.961) in hospital G. The use of ML models in conjunction with conventional scoring systems can provide more useful information for predicting the prognosis of critically ill patients. In this study, we suggest that the predictive model can be made more robust by training with the individual data of each hospital.

Superinfections caused by carbapenem-resistant Enterobacterales in hospitalized patients with COVID-19: a multicentre observational study from Italy (CREVID Study)

Objectives

To describe clinical characteristics and outcomes of COVID-19 patients who developed secondary infections due to carbapenem-resistant Enterobacterales (CRE).

Methods

Retrospective observational study including COVID-19 patients admitted to 12 Italian hospitals from March to December 2020 who developed a superinfection by CRE. Superinfection was defined as the occurrence of documented bacterial infection &gt;48 h from admission. Patients with polymicrobial infections were excluded. Demographic, clinical characteristics and outcome were collected. Isolates were classified as KPC, metallo-β-lactamase (MBL) and OXA-48-producing CRE. A Cox regression analysis was performed to identify factors independently associated with 30 day mortality.

Results

Overall, 123 patients (median age 66 years, IQR 59–75) were included. The majority of infections occurred in the ICU (81, 65.9%), while 42 (34.1%) in medical wards. The most common types of infection were bloodstream infections (BSI) (n = 64, 52%), followed by urinary-tract infections (UTI) (n = 28, 22.8%), hospital-acquired/ventilator-associated pneumonia (HAP/VAP) (n = 28, 22.8%), intra-abdominal infections (n = 2, 1.6%) and skin infections (n = 1, 0.8%). Sixty-three (51.2%) infections were caused by KPC-, 54 (43.9%) by MBL-, and 6 (4.8%) by OXA-48-producing CRE. Thirty-day mortality was 33.3% (41/123). On Cox regression analysis, HAP/VAP compared with UTI (HR 7.23, 95% CI 2.09–24.97, P = 0.004), BSI compared with UTI (HR 3.96, 95% CI, 1.33–11.77, P = 0.004), lymphopenia on admission (HR 3, 95% CI 1.44–6.26, P = 0.003) and age (HR 1.05, 95% CI 1.02–1.08, P = 0.002) were predictors of 30 day mortality.

Conclusions

Superinfections by CRE were associated with high risk of 30 day mortality in patients with COVID-19. HAP/VAP was the strongest predictor of death in these patients.

Carbapenem-Resistant Acinetobacter baumannii in U.S. Hospitals: Diversification of Circulating Lineages and Antimicrobial Resistance

Carbapenem-resistant Acinetobacter baumannii (CRAb) is a major cause of health care-associated infections. CRAb is typically multidrug resistant, and infection is difficult to treat. Despite the urgent threat that CRAb poses, few systematic studies of CRAb clinical and molecular epidemiology have been conducted. The Study Network of Acinetobacter as a Carbapenem-Resistant Pathogen (SNAP) is designed to investigate the clinical characteristics and contemporary population structure of CRAb circulating in U.S. hospital systems using whole-genome sequencing (WGS). Analysis of the initial 120 SNAP patients from four U.S. centers revealed that CRAb remains a significant threat to hospitalized patients, affecting the most vulnerable patients and resulting in 24% all-cause 30-day mortality. The majority of currently circulating isolates belonged to ST2Pas, a part of clonal complex 2 (CC2), which is the dominant drug-resistant lineage in the United States and Europe. We identified three distinct sublineages within CC2, which differed in their antibiotic resistance phenotypes and geographic distribution. Most concerning, colistin resistance (38%) and cefiderocol resistance (10%) were common within CC2 sublineage C (CC2C), where the majority of isolates belonged to ST2Pas/ST281Ox. Additionally, we identified ST499Pas as the most common non-CC2 lineage in our study. Our findings suggest a shift within the CRAb population in the United States during the past 10 years and emphasize the importance of real-time surveillance and molecular epidemiology in studying CRAb dissemination and clinical impact. IMPORTANCE Carbapenem-resistant Acinetobacter baumannii (CRAb) constitutes a major threat to public health. To elucidate the molecular and clinical epidemiology of CRAb in the United States, clinical CRAb isolates were collected along with data on patient characteristics and outcomes, and bacterial isolates underwent whole-genome sequencing and antibiotic susceptibility phenotyping. Key findings included emergence of new sublineages within the globally predominant clonal complex 2 (CC2), increased colistin and cefiderocol resistance within one of the CC2 sublineages, and emergence of ST499Pas as the dominant non-CC2 CRAb lineage in U.S. hospitals.

Clinical outcomes and bacterial characteristics of carbapenem-resistant Klebsiella pneumoniae complex among patients from different global regions (CRACKLE-2): a prospective, multicentre, cohort study

BACKGROUND

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a global threat. We therefore analysed the bacterial characteristics of CRKP infections and the clinical outcomes of patients with CRKP infections across different countries.

METHODS

In this prospective, multicentre, cohort study (CRACKLE-2), hospitalised patients with cultures positive for CRKP were recruited from 71 hospitals in Argentina, Australia, Chile, China, Colombia, Lebanon, Singapore, and the USA. The first culture positive for CRKP was included for each unique patient. Clinical data on post-hospitalisation death and readmission were collected from health records, and whole genome sequencing was done on all isolates. The primary outcome was a desirability of outcome ranking at 30 days after the index culture, and, along with bacterial characteristics and 30-day all-cause mortality (a key secondary outcome), was compared between patients from China, South America, and the USA. The desirability of outcome ranking was adjusted for location before admission, Charlson comorbidity index, age at culture, Pitt bacteremia score, and anatomical culture source through inverse probability weighting; mortality was adjusted for the same confounders, plus region where relevant, through multivariable logistic regression. This study is registered at ClinicalTrials.gov, NCT03646227, and is complete.

FINDINGS

Between June 13, 2017, and Nov 30, 2018, 991 patients were enrolled, of whom 502 (51%) met the criteria for CRKP infection and 489 (49%) had positive cultures that were considered colonisation. We observed little intra-country genetic variation in CRKP. Infected patients from the USA were more acutely ill than were patients from China or South America (median Pitt bacteremia score 3 [IQR 2-6] vs 2 [0-4] vs 2 [0-4]) and had more comorbidities (median Charlson comorbidity index 3 [IQR 2-5] vs 1 [0-3] vs 1 [0-2]). Adjusted desirability of outcome ranking outcomes were similar in infected patients from China (n=246), South America (n=109), and the USA (n=130); the estimates were 53% (95% CI 42-65) for China versus South America, 50% (41-61) for the USA versus China, and 53% (41-66) for the USA versus South America. In patients with CRKP infections, unadjusted 30-day mortality was lower in China (12%, 95% CI 8-16; 29 of 246) than in the USA (23%, 16-30; 30 of 130) and South America (28%, 20-37; 31 of 109). Adjusted 30-day all-cause mortality was higher in South America than in China (adjusted odds ratio [aOR] 4·82, 95% CI 2·22-10·50) and the USA (aOR 3·34, 1·50-7·47), with the mortality difference between the USA and China no longer being significant (aOR 1·44, 0·70-2·96).

INTERPRETATION

Global CRKP epidemics have important regional differences in patients' baseline characteristics and clinical outcomes, and in bacterial characteristics. Research findings from one region might not be generalisable to other regions.

FUNDING

The National Institutes of Health.

Moving from predicting hospital deaths by antibiotic-resistant bloodstream bacteremia toward actionable risk reduction using machine learning on electronic health records

Drug-resistant bacterial infections are a global health concern with high mortality and limited treatment options. Several clinical risk-severity scores are available, e.g. qPitt, but their predictive performance is moderate. Here, we leveraged machine learning and electronic health records (EHRs) to improve prediction of mortality due to bloodstream infection with Klebsiella pneumoniae. We tested the qPitt score and new EHR variables (either expert-chosen or the full set of diagnostic codes), fitting LASSO, boosted logistic regression (BLR), support vector machines, decision trees, and random forests. The qPitt score showed moderate discriminative ability (AUROC=0.63), whilst machine learning models significantly improved its performance (best AUROC by BLR 0.80 for expert-chosen and 0.88 for full code set). Similar results were obtained in critically ill patients, and when excluding potential non-causal variables to evaluate an actionable model. In conclusion, current risk scores for bacteremia mortality can be improved and, with opportune causal modelling, considered for deployment in clinical decision-making.

Contemporary Clinical and Molecular Epidemiology of Vancomycin-Resistant Enterococcal Bacteremia: A Prospective Multicenter Cohort Study (VENOUS I)

Background

Vancomycin-resistant enterococci (VRE) are major therapeutic challenges. Prospective contemporary data characterizing the clinical and molecular epidemiology of VRE bloodstream infections (BSIs) are lacking.

Methods

The Vancomycin-Resistant Enterococcal BSI Outcomes Study (VENOUS I) is a prospective observational cohort of adult patients with enterococcal BSI in 11 US hospitals. We included patients with Enterococcus faecalis or Enterococcus faecium BSI with ≥1 follow-up blood culture(s) within 7 days and availability of isolate(s) for further characterization. The primary study outcome was in-hospital mortality. Secondary outcomes were mortality at days 4, 7, 10, 12, and 15 after index blood culture. A desirability of outcome ranking was constructed to assess the association of vancomycin resistance with outcomes. All index isolates were subjected to whole genome sequencing.

Results

Forty-two of 232 (18%) patients died in hospital and 39 (17%) exhibited microbiological failure (lack of clearance in the first 4 days). Neutropenia (hazard ratio [HR], 3.13), microbiological failure (HR, 2.4), VRE BSI (HR, 2.13), use of urinary catheter (HR, 1.85), and Pitt BSI score ≥2 (HR, 1.83) were significant predictors of in-hospital mortality. Microbiological failure was the strongest predictor of in-hospital mortality in patients with E faecium bacteremia (HR, 5.03). The impact of vancomycin resistance on mortality in our cohort changed throughout the course of hospitalization. Enterococcus faecalis sequence type 6 was a predominant multidrug-resistant lineage, whereas a heterogeneous genomic population of E faecium was identified.

Conclusions

Failure of early eradication of VRE from the bloodstream is a major factor associated with poor outcomes.

Prediction of mortality in Staphylococcus aureus bloodstream infection using quick Pitt bacteremia score

OBJECTIVES

The quick Pitt bacteremia score (qPitt) predicts mortality in patients with serious infections due to gram-negative bacteria. This retrospective cohort study examines utility of qPitt to predict mortality in patients with Staphylococcus aureus bloodstream infection (SAB).

METHODS

Multivariate logistic regression was used to examine risk factors for 28-day mortality in hospitalized adults with SAB at four Prisma Health hospitals in South Carolina, USA from January 2015 to December 2017. Area under receiver operating characteristic curve (AUROC) was used to examine model discrimination.

RESULTS

Among 692 patients with SAB, 305 (44%) had methicillin-resistant S. aureus (MRSA), and 129 (19%) died within 28 days. After adjustment for age, comorbidities, and MRSA, each component of the qPitt was associated with 28-day mortality. There was a 3-fold increase in the risk of 28-day mortality for each one-point increase in qPitt. Predicted 28-day mortality was 3%, 9%, 22%, 45%, and 70% for qPitt of 0, 1, 2, 3, and ≥4, respectively. AUROC of the qPitt in predicting 28-day, 14-day, and in-hospital mortality were 0.80, 0.81, and 0.80, respectively.

CONCLUSIONS

The qPitt predicts mortality with good discrimination in SAB. These results support using qPitt as a measure of acute severity of illness in future studies.

Development and validation of a risk score for predicting positivity of blood cultures and mortality in patients with bacteremia and fungemia

INTRODUCTION

Bacteremia is a major cause of morbidity and mortality in hospitalized patients. Predictors of mortality are critical for the management and survival of hospitalized patients. The objective of this study was to determine the factors related to blood culture positivity and the risk factors for mortality in patients whose blood cultures were collected.

METHODS

A prospective 2-cohort study (derivation with 784 patients and validation with 380 patients) based on the Pitt bacteremia score for all patients undergoing blood culture collection. The score was obtained from multivariate analysis. The Kaplan-Meier survival curve of the cohort derivation and the cohort validation groups was calculated, and the difference was assessed using a log-rank test. Mortality-related factors were older age, extended hospitalization, > 10% of immature cells in the leukogram, lower mean blood pressure, elevated heart rate, elevated WBC count, and elevated respiratory rate. These continuous variables were dichotomized according to their significance level, and a cut-off limit was created.

RESULTS

The area under the ROC curve (AUC) was 0.789. The score was validated in a group of 380 patients who were prospectively evaluated.

CONCLUSION

Prolonged hospitalization, body temperature, and elevated heart rate were related to positive blood cultures. The Pitt score can be used to assess the risk of death; however it can be individualized according to the epidemiology of each hospital.

Place in Therapy of the Newly Available Armamentarium for Multi-Drug-Resistant Gram-Negative Pathogens: Proposal of a Prescription Algorithm

The worldwide propagation of antimicrobial resistance represents one of the biggest threats to global health and development. Multi-drug-resistant organisms (MDROs), including carbapenem-resistant non-fermenting Gram-negatives and Enterobacterales, present a heterogeneous and mutating spread. Infections by MDRO are often associated with an unfavorable outcome, especially among critically ill populations. The polymyxins represented the backbone of antibiotic regimens for Gram-negative MDROs in recent decades, but their use presents multiple pitfalls. Luckily, new agents with potent activity against MDROs have become available in recent times and more are yet to come. Now, we have the duty to make the best use of these new therapeutic tools in order not to prematurely compromise their effectiveness and at the same time improve patients’ outcomes. We reviewed the current literature on ceftazidime/avibactam, meropenem/vaborbactam and cefiderocol, focusing on antimicrobial spectrum, on the prevalence and mechanisms of resistance development and on the main in vitro and clinical experiences available so far. Subsequently, we performed a step-by-step construction of a speculative algorithm for a reasoned prescription of these new antibiotics, contemplating both empirical and targeted use. Attention was specifically posed on patients with life-risk conditions and in settings with elevated prevalence of MDRO.

Trend and Predictors of Short-term Mortality of Adult Bacteremia at Emergency Departments: A 14-Year Cohort Study of 14 625 Patients

BACKGROUND

Bacteremia is a life-threatening condition with a high mortality rate in critical care and emergency settings. The current study investigated the trend of mortality and developed predictive models of mortality for adults with bacteremia at emergency departments (EDs).

METHODS

We conducted a retrospective cohort study of adults with bacteremia at the ED of China Medical University Hospital. Patient data were obtained from the Clinical Research Data Repository, and mortality information was obtained from the National Death Registry. We developed a new model to predict 7-day mortality in the derivation population and compared the model performance of the new model with Pitt Bacteremia Score (PBS) and Bloodstream Infection Mortality Risk Score (BSIMRS) in the validation population.

RESULTS

We identified 14625 adult patients with first-time bacteremia at the ED, of whom 8.4% died within 7 days. From 2003 to 2016, both the cumulative incidence and 7-day mortality rate of bacteremia decreased significantly. The ED bacteremia mortality (ED-BM) model included PBS parameters, age, infection source, baseline steroid use, and biochemical profiles (estimated glomerular filtration rate, platelet, blood urea nitrogen, potassium, and hemoglobin) for predicting 7-day mortality. The discrimination performance of the ED-BM model (area under curve [AUC], 0.903) was significantly better than that of PBS (AUC, 0.848) or BSIMRS (AUC, 0.885).

CONCLUSIONS

Although the cumulative incidence and mortality of ED bacteremia decreased, its mortality burden remains critical. The proposed ED-BM model had significantly better model performance than other scoring systems in predicting short-term mortality for adult patients with bacteremia at EDs.

Comparison of Risk Factors and Outcomes in Carbapenem-Resistant and Carbapenem-Susceptible Gram-Negative Bacteremia

Background:

Carbapenem-resistant Gram-negative bacteremia (CR-GNB) is seen with increasing frequency and result in high mortality. The aim of this study was to compare the risk factors and results of carbapenem-resistant and carbapenem-susceptible Gram-negative bacteremia and to determine the factors related to mortality.

Methods:

The study was conducted as a retrospective observational comparative case series between June 2016 and November 2017 in Şişli Hamidiye Etfal Training and Research Hospital. The patients were divided into two groups as carbapenem-susceptible and carbapenem-resistant according to antibiotic susceptibility data of blood cultures. The risk factors for the development of carbapenem resistance, length of hospital stay, mortality rates, and mortality related factors were investigated between these two groups.

Results:

Two hundred and eleven cases were included in the study. Of these cases, 54 were resistant to carbapenem and 157 were susceptible to carbapenem. Mortality occurred in 60 (28.4%) patients. The 14 and 28 day mortality rates of patients with carbapenem resistance were significantly higher than those without carbapenem resistance. There was no statistically significant difference between two groups in length of stay in the hospital after bacteremia. Pittsburgh bacteremia score, cardiovascular disease, urinary catheterization, and inappropriate empirical antibiotic therapy were the most significant risk factors for mortality.

Conclusions:

Carbapenem resistance is associated with increased mortality and inappropriate empirical antibiotic treatment increases mortality. Therefore, patients should be evaluated for risk factors in predicting CR-GNB and treatment for resistant pathogens should be applied in appropriate patients.

Clinical characteristics, appropriateness of empiric antibiotic therapy, and outcome of Pseudomonas aeruginosa bacteremia across multiple community hospitals

There is relatively little contemporary information regarding clinical characteristics of patients with Pseudomonas aeruginosa bacteremia (PAB) in the community hospital setting. This was a retrospective, observational cohort study examining the clinical characteristics of patients with PAB across several community hospitals in the USA with a focus on the appropriateness of initial empirical therapy and impact on patient outcomes. Cases of PAB occurring between 2016 and 2019 were pulled from 8 community medical centers. Patients were classified as having either positive or negative outcome at hospital discharge. Several variables including receipt of active empiric therapy (AET) and the time to receiving AET were collected. Variables with a p value of < 0.05 in univariate analyses were included in a multivariable logistic regression model. Two hundred and eleven episodes of PAB were included in the analysis. AET was given to 81.5% of patients and there was no difference in regard to outcome (p = 0.62). There was no difference in the median time to AET in patients with a positive or negative outcome (p = 0.53). After controlling for other variables, age, Pitt bacteremia score ≥ 4, and septic shock were independently associated with a negative outcome. A high proportion of patients received timely, active antimicrobial therapy for PAB and time to AET did not have a significant impact on patient outcome.

Clinical characteristics and outcomes of 56 patients with pneumonia caused by carbapenem-resistant Klebsiella pneumoniae

OBJECTIVES

Pneumonia caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) is associated with high mortality. However, clinical studies on CRKP infections often exclusively involve bacteraemia, with only a few studies having focused on pneumonia. This retrospective study was conducted to investigate the clinical and microbiological characteristics of pneumonia caused by CRKP.

METHODS

Adult patients diagnosed with CRKP monomicrobial pneumonia treated with at least one active antimicrobial agent within 5 days of the pneumonia diagnosis were identified in a medical centre in Taiwan between January 2017 and April 2019. Clinical characteristics and outcomes of these patients were determined. Resistance mechanisms and capsular types of the CRKP isolates were determined by PCR.

RESULTS

A total of 56 patients with CRKP monomicrobial pneumonia were identified. The 7-day and 14-day mortality rates were 7.1% and 23.2%, respectively. Malignancy [adjusted odds ratio (aOR) = 8.87, 95% confidence interval (CI) 1.66-47.26; P = 0.011] and Acute Physiology and Chronic Health Evaluation (APACHE) II score (aOR = 1.12, 95% CI 1-1.25; P = 0.048) were independently associated with 14-day mortality. Most CRKP clinical isolates were carbapenemase-producers (39/44; 88.6%), of which K. pneumoniae carbapenemase type 2 (KPC-2)-producing isolates were most prevalent (30/39; 76.9%). The most prevalent capsular type in these isolates was K47 (30/44; 68.2%).

CONCLUSION

CRKP pneumonia is associated with high 14-day mortality. Malignancy and APACHE II score were independently associated with 14-day mortality.

Efficacy and safety of vancomycin loading doses in critically ill patients with methicillin-resistant Staphylococcus aureus infection

Background

While vancomycin loading doses may facilitate earlier pharmacokinetic-pharmacodynamic target attainment, the impact of loading doses on clinical outcomes remains understudied. Critically ill patients are at highest risk of morbidity and mortality from methicillin resistant Staphylococcus aureus (MRSA) infection and hypothesized to most likely benefit from a loading dose. We sought to determine the association between receipt of a vancomycin loading dose and clinical outcomes in a cohort of critically ill adults.

Methods

Four hundred and forty-nine critically ill patients with MRSA cultures isolated from blood or respiratory specimens were eligible for the study. Cohorts were established by receipt of a loading dose (⩾20 mg/kg actual body weight) or not. The primary outcome was clinical failure, a composite outcome of death within 30 days of first MRSA culture, blood cultures positive ⩾7 days, white blood cell count up to 5 days from vancomycin initiation, temperature up to 5 days from vancomycin initiation, or substitution (or addition) of another MRSA agent.

Results

There was no difference in the percentage of patients experiencing clinical failure between the loading dose and no loading dose groups (74.8% versus 72.8%; p = 0.698). Secondary outcomes were also similar between groups, including mortality and acute kidney injury, as was subgroup analysis based on site of infection. Exploratory analyses, including assessment of loading dose based on quartiles and a multivariable logistic regression model showed no differences.

Conclusion

Use of vancomycin loading doses was not associated with improved clinical outcomes in critically ill patients with MRSA infection.

Ceftazidime-avibactam use for KPC-Kp infections: a retrospective observational multicenter study

BACKGROUND

A growing body of observational evidence supports the value of ceftazidime-avibactam (CAZ-AVI) in managing infections caused by carbapenem-resistant Enterobacteriaceae (CRE).

METHODS

We retrospectively analyzed observational data on the use and outcomes of CAZ-AVI therapy for infections caused by KPC-producing K. pneumoniae (KPC-Kp) strains. Multivariate regression analysis was used to identify variables independently associated with 30-day mortality. Results were adjusted for propensity score for receipt of CAZ-AVI combination regimens vs. CAZ-AVI monotherapy.

RESULTS

The cohort comprised 577 adults with bloodstream infections (BSIs) (n=391) or non-bacteremic infections (nBSIs) involving mainly the urinary tract, lower respiratory tract, intra-abdominal structures. All received treatment with CAZ-AVI alone (n=165) or with one or more other active antimicrobials (n=412). The all-cause mortality rate 30 days after infection onset was 25% (146/577). There was no statistically significant difference in mortality between patients managed with CAZ-AVI alone and those treated with combination regimens (26.1% vs. 25.0%, P=0.79). In multivariate analysis, mortality was positively associated with the presence at infection onset of septic shock (P=0.002), neutropenia (P <0.001), or an INCREMENT score >8 (P=0.01); with LRTI (P=0.04); and with CAZ-AVI dose adjustment for renal function (P=0.01). Mortality was negatively associated with CAZ-AVI administration by prolonged infusion (P=0.006). All associations remained significant after propensity score adjustment.

CONCLUSIONS

CAZ-AVI is an important option for treating serious KPC-Kp infections, even when used alone. Further study is needed to explore the drug's seemingly more limited efficacy in LRTIs and the potential survival benefits of prolonging CAZ-AVI infusions to 3 hours or more.

Antibacterial Resistance Leadership Group 2.0 - Back to Business

In December 2019, the Antibacterial Resistance Leadership Group (ARLG) was awarded funding for another seven-year cycle to support a clinical research network on antibacterial resistance. ARLG 2.0 has three overarching research priorities: (1) infections caused by antibiotic resistant (AR) Gram-negative bacteria; (2) infections caused by AR Gram-positive bacteria, and (3) diagnostic tests to optimize use of antibiotics. To support the next generation of AR researchers, the ARLG offers three mentoring opportunities: the ARLG Fellowship, Early Stage Investigator Seed Grants, and the Trialists in Training Program. The purpose of this article is to update the scientific community on the progress made in the original funding period and to encourage submission of clinical research that addresses one or more of the research priority areas of ARLG 2.0.

Staphylococcus aureus Bacteremia in Patients Infected With COVID-19: A Case Series

Background

Previous viral pandemics have shown that secondary bacterial infections result in higher morbidity and mortality, with Staphylococcus aureus being the primary causative pathogen. The impact of secondary S. aureus bacteremia on mortality in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains unknown.

Methods

This was a retrospective observational case series of patients with coronavirus disease 2019 (COVID-19) who developed secondary S. aureus bacteremia across 2 New York City hospitals. The primary end point was to describe 14-day and 30-day hospital mortality rates of patients with COVID-19 and S. aureus bacteremia. Secondary end points included predictors of 14-day and 30-day hospital mortality in patients with COVID-19 and S. aureus bacteremia.

Results

A total of 42 patients hospitalized for COVID-19 with secondary S. aureus bacteremia were identified. Of these patients, 23 (54.8%) and 28 (66.7%) died at 14 days and 30 days, respectively, from their first positive blood culture. Multivariate analysis identified hospital-onset bacteremia (≥4 days from date of admission) and age as significant predictors of 14-day hospital mortality and Pitt bacteremia score as a significant predictor of 30-day hospital mortality (odds ratio [OR], 11.9; 95% CI, 2.03-114.7; P = .01; OR, 1.10; 95% CI, 1.03-1.20; P = .02; and OR, 1.56; 95% CI, 1.19-2.18; P = .003, respectively).

Conclusions

Bacteremia with S. aureus is associated with high mortality rates in patients hospitalized with COVID-19. Further investigation is warranted to understand the impact of COVID-19 and secondary S. aureus bacteremia.

Comparing Mortality Risk Predictive Ability of Different Scoring Systems in Cirrhotic Patients with Bacteremia

Patients with liver cirrhosis and bacteremia have substantially higher risk of mortality and morbidity. Our study aimed to investigate scoring systems that can predict the mortality risk in patients with cirrhosis and bacteremia. A single-center, retrospective cohort study was performed among adult patients who visited the emergency department from January 2015 to December 2018. All patients diagnosed with liver cirrhosis and bacteremia were enrolled and divided into survivor and nonsurvivor groups for comparison based on their 30-day in-hospital mortality event. The Pitt bacteremia score (PBS), model for end-stage liver disease (MELD) score, Child–Pugh score, and quick sequential Organ Failure Assessment (qSOFA) score were calculated and compared using the area under the receiver operating characteristic (AUROC) curves. A total of 127 patients (survivor: 86; nonsurvivor: 41) were eligible for this study. Compared with the nonsurvivor group, patients in the survivor group had significantly lower MELD score (22 ± 7 vs. 29 ± 5, p < 0.001), lower proportion of high qSOFA (score ≥ 2) (23.3% vs. 51.2%, p < 0.01), and high PBS (score ≥ 4) (7.0% vs. 34.1%, p < 0.001) category. There was also a significantly different distribution in Child–Pugh classification between the two groups (p < 0.01). The survivor group had significantly lower proportion of acute-on-chronic liver failure (27.9% vs. 68.3%, p < 0.001) and fewer number of organ failures (p < 0.001). In comparison of the discriminative ability in mortality risk prediction, PBS (AUROC = 0.83, 95% CI = 0.75–0.90, p < 0.001) and MELD scores (AUROC = 0.78, 95% CI = 0.70–0.86, p < 0.001) revealed a better predictive ability than Child–Pugh (AUROC = 0.69, 95% CI = 0.59–0.70, p < 0.01) and qSOFA scores (AUROC = 0.65, 95% CI = 0.54–0.75, p < 0.01). PBS and MELD scores both demonstrated a superior ability of predicting mortality risk in cirrhotic patients with bacteremia.

Time to positivity of Klebsiella pneumoniae in blood culture as prognostic indicator for pediatric bloodstream infections

The aim of this study is to explore the prognostic values and optimal cutoff point of time to positivity (TTP) of blood culture in children with Klebsiella pneumoniae (K. pneumoniae) bloodstream infection. Ninety-four children with K. pneumoniae bloodstream infection hospitalized in Children's Hospital of Chongqing Medical University from April 2014 to January 2019 were enrolled retrospectively. TTP and risk factors were determined and analyzed by receiver operating characteristic (ROC) analysis and logistic regression analysis. The standard cutoff point of TTP was 13 h. Patients in early TTP (≤ 13 h) group had significantly higher in-hospital mortality (37.93% vs 6.15%, P = 0.000), higher incidence of septic shock (44.83% vs 6.15%, P = 0.000), higher proportion of PRISM III scores ≥ 10 (48.28% vs 20.00%, P = 0.005), and higher proportion of hypoalbuminemia on admission (44.83% vs 18.46%, P = 0.008). Multivariate analysis indicated PRISM III scores ≥ 10, early TTP, and hypoalbuminemia on admission were independent risk factors of in-hospital mortality (OR 8.36, 95% CI 1.80-38.92, P = 0.007; OR 5.85, 95% CI 1.33-25.61, P = 0.019; OR 5.73, 95% CI 1.30-25.22, P = 0.021, respectively) and septic shock (OR 14.04, 95% CI 2.63-75.38, P = 0.002; OR 11.26, 95% CI 2.10-60.22, P = 0.005; OR 10.27, 95% CI 2.01-52.35, P = 0.005, respectively).Conclusion: Early TTP (TTP ≤ 13 h), PRISM III scores ≥ 10, and hypoalbuminemia on admission appeared to be associated with worse outcomes for K. pneumoniae bloodstream infection children. What is Known: • Klebsiella pneumoniae bloodstream infection is an important cause of infectious disease morbidity and mortality worldwide in children. • Short duration of time to positivity indicated poor clinical outcomes. What is New: • Time to positivity ≤ 13 h, along with PRISM III scores ≥ 10 and hypoalbuminemia on admission, indicated higher in-hospital mortality and incidence of septic shock in Klebsiella pneumoniae bloodstream infection children. • The cut-off point of TTP in this pediatric study was much longer than that reported in adult patients.

Predictors of Mortality in Patients with Carbapenem-Resistant Gram-Negative Bacilli or Vancomycin-Resistant Enterococci Bacteremia

Purpose

The incidences of carbapenem-resistant gram-negative bacilli (CRGNB) and vancomycin-resistant Enterococci (VRE) have increased rapidly in South Korea since 2000. The mortality rate for CRGNB or VRE bacteremia cases is higher than that for non-resistant bacteremia cases. The factors associated with higher mortality are unclear. We investigated the factors associated with mortality from CRGNB or VRE bacteremia and compared the relative risk of these factors.

Patients and Methods

We retrospectively collected data from adult patients with CRGNB or VRE bacteremia. Patients were grouped according to whether they survived or died. The data from both groups were compared.

Results

During the study period, 171 cases of CRGNB or VRE bacteremia were identified, of which 100 were CRGNB bacteremia cases and 71 were VRE bacteremia cases. Multivariate analysis revealed significant associations with Pitt bacteremia score (PBS) (odds ratio [OR] 1.329, 95% confidence interval [CI] 1.049-1.684). In the multivariate analysis, negative conversion of follow-up blood culture (FUBC) was related with one-week mortality from CRGNB or VRE bacteremia (OR 17.623, 95% CI 5.726-54.244). In the multivariate analysis of risk factors for 28-day mortality for CRGNB or VRE bacteremia, the significant risk factors were bacteremia of respiratory origin (OR 4.491, 95% CI 1.622-12.435) and positive FUBC (OR 4.082, 95% CI 1.626-10.204).

Conclusion

Despite the high mortality rate in patients with CRGNB or VRE bacteremia, the related mortality could be predicted by independent risk factors of PBS, positive FUBC, and bacteremia of respiratory origin.

Impact of Continuation of Parenteral Nutrition on Outcomes of Patients with Blood Stream Infections

Background: The impact of continuing parenteral nutrition (PN) in patients who develop blood stream infections (BSI) while receiving PN is largely unknown. Patients and Methods: Adult patients admitted to a large academic center over three consecutive years and seven months who had a positive blood culture while receiving PN were included in the study. The cohort was divided into those who had PN continued (PN-c) or discontinued (PN-dc) after the positive culture. We evaluated the effect of continuing PN on clinical outcomes by comparing a composite outcome of recurrent BSI, severe sepsis/septic shock, and death within 30 days between the two groups using a propensity score-weighting regression analysis. Results: Of 154 patients included in the study, approximately 70% of whom were surgical patients, 65 (42%) had PN discontinued whereas 89 (58%) had PN continued. Cohort characteristics were similar between the two groups including the Pitt bacteremia score and source control. There were more cases of candidemia (18% vs 6%, p = 0.03) and more cases of intra-abdominal infections (IAI; 42% vs 25%, p = 0.02) in the PN-c group compared with the PN-dc group. The most common sites of infection were endovascular and IAI in both groups. The median duration of bacteremia for both groups was one day. After applying propensity score weighting, the composite outcome of recurrent BSI, severe sepsis/septic shock, and death within 30 days was similar between the PN-dc and PN-c groups (43% and 49%, respectively; p = 0.61). Conclusions: Continuing PN in patients with bacteremia or candidemia was not associated with worse clinical outcomes.

Treatment of Bacteremia Caused by Enterobacter spp.: Should the Potential for AmpC Induction Dictate Therapy? A Retrospective Study

Objective: Carbapenems are considered treatment of choice for bacteremia caused by potential AmpC-producing bacteria, including Enterobacter spp. We aimed to compare mortality following carbapenem vs. alternative antibiotics for the treatment of Enterobacter spp. bacteremia. Patients and Methods: We conducted a retrospective study in two centers in Israel. We included hospitalized patients with Enterobacter bacteremia treated with third-generation cephalosporins (3GC), piperacillin/tazobactam, quinolones, or carbapenem monotherapy as the main antibiotic in the first week of treatment, between 2010 and 2017. Cefepime was excluded due to nonavailability during study years. The primary outcome was 30-day all-cause mortality. Univariate and multivariate analyses were conducted, introducing the main antibiotic as an independent variable. Results: Two hundred seventy-seven consecutive patients were included in the analyses. Of these, 73 were treated with 3GC, 39 with piperacillin/tazobactam, 104 with quinolones, and 61 with carbapenems. All-cause 30-day mortality was 16% (45 patients). The type of antibiotics was not significantly associated with mortality on univariate or multivariate analyses. With carbapenems as reference, adjusted odds ratios (ORs) for mortality were 0.708, 95% confidence interval (CI) 0.231-2.176 with 3GC; OR 1.172, 95% CI 0.388-3.537 with piperacillin/tazobactam; and OR 0.586, 95% CI 0.229-1.4 with quinolones. The main antibiotic was not associated with repeated growth of Entrobacter spp. in blood cultures or other clinical specimens. Resistance development was observed with 3GC and piperacillin/tazobactam. Conclusions: Carbapenem treatment was not advantageous to alternative antibiotics, including 3GC, among patients with Enterobacter spp. bacteremia in an observational study.

Early detection of infectious complications during induction therapy for acute leukemia with serial C-reactive protein biomarker assessment

Febrile neutropenia (FN) and blood stream infections (BSI) are major complications of induction treatment for acute leukemia. We assessed the predictive utility of C-reactive protein (CRP), an acute phase reactant, for FN and BSI during induction. CRP levels and dynamics were analyzed in 138 consecutive patients. FN and BSI occurred in 110 (80.3%) and 10 (7.5%) patients, respectively. Median peak CRP level in the 24-hours preceding FN was 7.5 mg/dl (0.2-38.1) vs. median peak CRP level of 5.11 mg/dl (0.2-23.1, p = .009) in patients without FN. CRP levels preceding BSI were 13.1 mg/dl (6.9-27.9) vs. 6.3 mg/dl (0.16-38.14, p = .011). CRP increase prior to event (ΔCRP) was higher among patients with BSI vs. patients without BSI (p = .013). CRP was predictive for FN (p = .009) and BSI (p = .01) on ROC curve analysis and was also independently associated with FN on multivariate analysis. In conclusion, CRP is a sensitive biomarker that precedes FN and BSI.

Fluoroquinolone Versus Nonfluoroquinolone Treatment of Bloodstream Infections Caused by Chromosomally Mediated AmpC-Producing Enterobacteriaceae

Objectives: Chromosomally mediated AmpC-producing Enterobacteriaceae (CAE) display high susceptibility to fluoroquinolones; minimal clinical data exist supporting comparative clinical outcomes. The objective of this study was to compare treatment outcomes between fluoroquinolone and nonfluoroquinolone definitive therapy of bloodstream infections caused by CAE. Methods: This retrospective cohort assessed adult patients with positive blood cultures for CAE that received inpatient treatment for ≥48 h. The primary outcome was difference in clinical failure between patients who received fluoroquinolone (FQ) versus non-FQ treatment. Secondary endpoints included microbiological cure, infection-related length of stay, 90-day readmission, and all-cause inpatient mortality. Results: 56 patients were included in the study (31 (55%) received a FQ as definitive therapy; 25 (45%) received non-FQ). All non-FQ patients received a beta-lactam (BL). Clinical failure occurred in 10 (18%) patients, with 4 (13%) in the FQ group and 6 (24%) in the BL group (p = 0.315). Microbiological cure occurred in 55 (98%) patients. Median infection-related length of stay was 10 (6–20) days, with a significantly longer stay occurring in the BL group (p = 0.002). There was no statistical difference in 90-day readmissions between groups (7% FQ vs. 17% BL; p = 0.387); one patient expired. Conclusion: These results suggest that fluoroquinolones do not adversely impact clinical outcomes in patients with CAE. When alternatives to beta-lactam therapy are needed, fluoroquinolones may provide an effective option.