Carbapenem therapy is associated with improved survival compared with piperacillin-tazobactam for patients with extended-spectrum β-lactamase bacteremia

No improvement in mortality among critically ill patients with carbapenems as initial empirical therapy and more detection of multi-drug resistant pathogens associated with longer use: a post hoc analysis of a prospective cohort study

Whether empirical therapy with carbapenems positively affects the outcomes of critically ill patients with bacterial infections remains unclear. This study aimed to investigate whether the use of carbapenems as the initial antimicrobial administration reduces mortality and whether the duration of carbapenem use affects the detection of multidrug-resistant (MDR) pathogens. This was a post hoc analysis of data acquired from Japanese participating sites from a multicenter, prospective observational study [Determinants of Antimicrobial Use and De-escalation in Critical Care (DIANA study)]. A total of 268 adult patients with clinically suspected or confirmed bacterial infections from 31 Japanese intensive care units (ICUs) were analyzed. The patients were divided into two groups: patients who were administered carbapenems as initial antimicrobials (initial carbapenem group, n = 99) and those who were not administered carbapenems (initial non-carbapenem group, n = 169). The primary outcomes were mortality at day 28 and detection of MDR pathogens. Multivariate logistic regression analysis revealed that mortality at day 28 did not differ between the two groups [18 (18%) vs 27 (16%), respectively; odds ratio: 1.25 (95% confidence interval (CI): 0.59-2.65), P = 0.564]. The subdistribution hazard ratio for detecting MDR pathogens on day 28 per additional day of carbapenem use is 1.08 (95% CI: 1.05-1.13, P < 0.001 using the Fine-Gray model with death regarded as a competing event). In conclusion, in-hospital mortality was similar between the groups, and a longer duration of carbapenem use as the initial antimicrobial therapy resulted in a higher risk of detection of new MDR pathogens.IMPORTANCEWe found no statistical difference in mortality with the empirical use of carbapenems as initial antimicrobial therapy among critically ill patients with bacterial infections. Our study revealed a lower proportion of inappropriate initial antimicrobial administrations than those reported in previous studies. This result suggests the importance of appropriate risk assessment for the involvement of multidrug-resistant (MDR) pathogens and the selection of suitable antibiotics based on risk. To the best of our knowledge, this study is the first to demonstrate that a longer duration of carbapenem use as initial therapy is associated with a higher risk of subsequent detection of MDR pathogens. This finding underscores the importance of efforts to minimize the duration of carbapenem use as initial antimicrobial therapy when it is necessary.

Carbapenem Versus Non-carbapenem Therapy in Hematology Patients: Extended-Spectrum Beta-Lactamase Positive Enterobacteriaceae Colonization Impact

BACKGROUND

Extended-spectrum beta-lactamase-producing Enterobacteriacea (ESBL-E) infections are a major source of mortality and morbidity in patients with hematologic cancers. One of the most significant risk factors for bacterial illness is prior colonization with resistant germs. Empiric usage of carbapenems is recommended for the treatment of infections in patients with a positive colonization history.

OBJECTIVES

We aimed to determine the outcome of empirical carbapenem (de-escalation) versus non-carbapenem (escalation) therapy in adult hematology patients who have rectal extended-spectrum beta-lactamase positive ESBL-E colonization.

METHODS

Two hundred three rectal swab cultures were collected from 130 patients, admission or during hospitalization between June 2014 and May 2015. Patients were followed till January 2016 for future infections due to ESBL-E. Empirical antibiotic treatment was started according to the patient's medical condition without consideration of previous colonization status. Stable patients received empirical escalation therapy. All-cause and early mortality of infections are analyzed.

RESULTS

Seventy-three (36%) swabs were positive for ESBL-E. Patients with rectal ESBL-E colonization were defined as cases; patients without colonization were defined as controls. Prospective infection due to ESBL-E in the case and control group was 6.8% and 2.3%, respectively. No statistically significant relation was found between colonization and prospective infection due to ESBL-E (p=0.110). There was no all-cause or early mortality in prospective infections with ESBL-E. Among case patients, one patient each died from all-cause mortality in the escalation (n=55) and de-escalation (n=3) group. The all-cause mortality in the antibiotic switch group (n=30) was eight, including five patients in the early mortality group although the bacteriologic agents were susceptible to the given antibiotics.

CONCLUSION

In our institution, rectal colonization with ESBL-E was high, but contracting an infection due to ESBL-E was surprisingly low. Colonization with ESBL-E may not necessarily end with an infection in some situations. In stable patients, disregarding colonization features before empirical therapy did not seem to be inappropriate.

Impact of a hospital sepsis management protocol on the selection of empirical antibiotics in infectious disease consultations

It is well-established that Infectious Diseases consultation (IDC) enhances the prognosis of bloodstream infections. However, it is unclear if adoption of an institutional sepsis protocol would lead to any further improvement in a setting where IDC and infectious diseases approval (IDA) - available throughout 7 days/24 hours -are mandatory for administering broad spectrum antibiotics. We aimed to evaluate the influence of the institutional sepsis protocol developed by Department of Infectious Diseases and Clinical Microbiology on the selection of appropriate empirical antibiotics by IDC through focusing on patients who had bloodstream infections caused by Extended-spectrum β-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae, which poses a therapeutic challenge. One hundred and fifty-three adult patients (58 patients in the pre-protocol period and 95 patients in the post-protocol period), who received empirical antibiotic treatment for ESBL-producing E. coli and K. pneumoniae, in whom at least one systemic antibiotic was started either on the day blood cultures were drawn or not later than 24 hours were included in the study, retrospectively. The primary outcome was whether the empirical treatment regimen included a carbapenem that was accepted as the appropriate treatment based on the results of the MERINO trial. Secondary outcomes included empirical treatment based on pre-defined risk factors suggesting multidrug resistance (MDR), 30-day inpatient mortality, and appropriate antibacterial treatment according to antimicrobial susceptibility test (AST) results. The median age (Interquartile range) was 61 (48-70.5) years and 76 (49.7%) out of 153 patients were male. The patients in the post-protocol period were older compared to the pre-protocol period (54 years vs 64 years, p = 0.045). The Charlson Comorbidity Index was higher during the post-protocol period compared to the pre-protocol period (4 vs 5, p=0.038). At least one risk factor for MDR bacteria infection was present in 147 (96.1%) of the 153 patients. While the rate of risk factors for MDR bacteria infections did not differ significantly between the pre-protocol and post-protocol periods, the post-protocol period showed a significantly higher level of appropriate antibiotic treatment according to the presence of MDR risk factors compared to the pre-protocol period (44.8% vs 64.2%, p=0.019). There was a significant increase in the use of carbapenems in the post-protocol period compared to the pre-protocol period (34.5% vs. 56.8%, p=0.007). When the subgroup of patients who were likely to have infection caused by ESBL-producing bacteria is taken into consideration, the carbapenem use was more frequent in the post-protocol period (37.8% vs 68.9%, p=0.002). The rate of appropriate empirical treatment according to AST was not statistically different between pre-protocol and post-protocol period. The 30-day mortality rates were similar in both periods (24.1% vs 31.5, p=0.33). However, the rate of susceptibility to piperacillin-tazobactam was statistically higher in the pre-protocol period (82.6% vs 46.2%, p=0.016) when 39.7% of the patients received piperacillin-tazobactam as the empirical treatment. This study highlights the significance of using a structured protocol to attain appropriate empirical treatment for patients suspected of sepsis, even in a setting where IDC is readily available.

Trends of antimicrobial susceptibilities and multidrug-resistant colonization rate in patients transferred from long-term care facilities during 2017-2022: a cross-sectional study

BACKGROUND

With the global increase in the older population, the proportion of those receiving care in long-term care facilities (LTCFs) has also been increasing. We assessed the epidemiology, antibiotic susceptibility, and colonization status of drug-resistant organisms in patients transferred from LTCFs.

METHODS

We retrospectively reviewed the medical records of patients transferred from LTCFs between 2017 and 2022. The reasons for admission, antimicrobial susceptibility, and colonization rates of carbapenem-resistant Enterobacterales (CRE), methicillin-resistant Staphylococcus aureus (MRSA), and carbapenem-resistant Acinetobacter baumannii (CRAB) were recorded. We analyzed the susceptibility and colonization rates by year to identify trends.

RESULTS

Of the 936 patients transferred from LTCFs, 54.3% were admitted to the intensive care unit and 12.5% died. The most common reason for admission was infection (n = 573, 61.2%), followed by gastrointestinal bleeding (n = 67, 7.2%) and cerebrovascular disorder (n = 65, 6.9%). A total of 452 Enterobacterales strains were isolated, and their susceptibility rates to ciprofloxacin and cefotaxime were 33.3% and 35.6%, respectively. A total of 54.9% were extended-spectrum beta-lactamase-producing strains, and 4.9% of them were carbapenem-resistant, both of which showed an increasing trend (P = 0.024 and P < 0.001, respectively). The prevalence rates of CRE, CRAB, and MRSA colonization were 9.2%, 7.1%, and 23.1%, respectively. CRE colonization showed a significant increase (P < 0.001), with carbapenemase-producing Enterobacterales accounting for 75.9% of cases.

CONCLUSIONS

Patients transferred from LTCFs are primarily affected by infections and exhibit high resistance rates. The increasing trend in CRE colonization rates each year highlights the need for the implementation of rigorous infection control measures for effective management.

Comparative analysis of a rapid diagnostic test and scoring tools for ESBL detection in Enterobacterales bloodstream infections for optimizing antimicrobial therapy

IMPORTANCE

Our study addresses a significant issue in the medical and scientific community-the delayed administration of appropriate antimicrobial treatments due to the time-consuming process of phenotypic susceptibility data collection in gram-negative bloodstream infections. Our research indicates that a multiplex PCR rapid diagnostic test (RDT) significantly outperformed two clinical scoring tools in predicting ceftriaxone susceptibility. Multiplex PCR also led to reduced instances of undertreatment with ceftriaxone and minimized overtreatment with carbapenems. Furthermore, multiplex PCR demonstrated high sensitivity and specificity in predicting ceftriaxone susceptibility. The results of our study underscore the potential RDTs to reduce the time to appropriate antimicrobial therapy, leading to improved patient outcomes and reduced healthcare costs.

Predictive Rule for Mortality of Inpatients With Escherichia coli Bacteremia: Chi-Square Automatic Interaction Detector Decision Tree Analysis Model

AIM

A predictive rule for risk factors for mortality due to Escherichia coli (E. coli)bacteremia has not been defined, especially using the chi-square automatic interaction detector (CHAID) decision tree analysis. Here we aimed to create the predictive rule for risk factors for in-hospital mortality due to E. coli bacteremia.

METHODS

The outcome of this retrospective cross-sectional survey was death in the hospital due to E. coli bacteremia. Factors potentially predictive of death in the hospital due to E. coli bacteremia were analyzed using the CHAID decision tree analysis.

RESULTS

A total of 420 patients (male:female=196:224; mean±standard deviation [SD] age, 75.81±13.13 years) were included in this study. 56 patients (13.3%) died in the hospital. The CHAID decision tree analysis revealed that patients with total protein level ≤5.10 g/dL (incidence, 46.2%), total protein level ≤5.90 g/dL with disturbance of consciousness (incidence, 39.4%), and total protein level >5.90 g/dL with hemoglobin level ≤11.10 g/dL and lactate dehydrogenase level ≥312.0 IU/L (incidence, 42.3%) were included in the high-risk group.

CONCLUSIONS

Appropriate preventative therapy should be facilitated in patients with E. coliat a high risk of mortality.

In vitro efficacy of humanized regimen of flomoxef against extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae

This study compared the efficacy of flomoxef with other β-lactam antibiotics against extended-spectrum β-lactamases (ESBL)-producing bacteria of clinical relevance. First, the prevalence and β-lactamase genotypes of ESBL-producing strains among Escherichia coli and Klebsiella pneumoniae isolates collected in Japan from 2004 to 2018 were investigated. High MIC90 values (>64 µg/mL) of ceftriaxone, cefepime, and ceftazidime and low MIC90 values (≤0.06-2 µg/mL) of flomoxef, cefmetazole, and meropenem against both species were observed. Second, a chemostat model was used to analyze the efficacy of humanized regimens of three oxacephem/cephamycin antibiotics (flomoxef, cefmetazole, cefoxitin) and two other antibiotics (meropenem and piperacillin/tazobactam) in suppressing the growth of five ESBL-producing E. coli and two K. pneumoniae strains. Flomoxef, piperacillin/tazobactam, and meropenem showed good bactericidal effects with >4 log10 CFU/mL reduction without bacterial regrowth at 24 h even when the MIC of test isolates was >MIC90. Cefmetazole and cefoxitin resulted in regrowth of test isolates with MIC ≥MIC90 at 24 h. Cefmetazole, cefoxitin, flomoxef, and meropenem showed increased MICs for regrown samples. A clear relationship between the proportion of time that the free drug concentration exceeded the MIC (%fT>MIC) and antibiotic efficacy was found for flomoxef, cefoxitin, and cefmetazole, and flomoxef had the highest %fT>MIC, whereas discrepancies between Clinical and Laboratory Standards Institute breakpoint and bactericidal activity were observed for cefmetazole. Flomoxef was effective in preventing the growth of all ESBL-producing strains, even those with an MIC eight times the MIC90. Thus, flomoxef may be a good alternative to meropenem in context of carbapenems sparing stewardship.

Efficacy of Carbapenems Compared With Noncarbapenem Broad-Spectrum Beta-Lactam Antibiotics as Initial Antibiotic Therapy Against Sepsis: A Nationwide Observational Study

OBJECTIVES

As causative pathogens are not usually identified at the time of initiating antibiotics in sepsis, carbapenems are commonly used as an initial treatment. To reduce indiscriminate use of carbapenems, the efficacy of alternative empiric regimens, such as piperacillin-tazobactam and the fourth-generation cephalosporins, should be elucidated. This study aimed to evaluate survival effect associated with carbapenems as initial therapy for sepsis compared with these antibiotics.

DESIGN

Multicenter retrospective observational study.

SETTING

Tertiary hospitals in Japan.

PATIENTS

Adult patients diagnosed as having sepsis from 2006 to 2019.

INTERVENTIONS

Administration of carbapenems as initial antibiotic therapy.

MEASUREMENTS AND MAIN RESULTS

This study used data of adult patients with sepsis extracted from a large-scale database in Japan. Patients were divided into two groups as follows: patients receiving carbapenems and patients receiving noncarbapenem broad-spectrum beta-lactam antibiotics as initial treatment. In-hospital mortality was compared between the groups by a logistic regression model adjusted by an inverse probability treatment weighting using propensity scores. To evaluate heterogeneity of effects according to patient characteristics, we also fitted logistic models in several subgroups. Among 7,392 patients with sepsis, 3,547 patients received carbapenems, and 3,845 patients received noncarbapenem agents. The logistic model showed no significant association between carbapenem therapy and lower mortality (adjusted OR 0.88, p = 0.108). Subgroup analyses suggested that there were significant survival benefits associated with carbapenem therapy in patients with septic shock, in ICUs, or with mechanical ventilation ( p for effect modifications: < 0.001, 0.014, and 0.105, respectively).

CONCLUSIONS

Compared with the noncarbapenem broad-spectrum antibiotics, carbapenems as an initial therapy for sepsis were not associated with significantly lower mortality.

Antimicrobial and antibiofilm activity of isoorientin against carbapenem non-sensitive Escherichia coli from raw milk of goats

Carbapenemase-producing E. coli is a grave public health concern as the potential emergence of resistant strains and their transmission. Isoorientin belongs to a potential antimicrobial flavonoid compound existing in several plants, while the research on the antimicrobial activity of isoorientin is limited thus far. We evaluated the antimicrobial and antibiofilm effects of isoorientin against biofilm-forming carbapenem non-sensitive Escherichia coli (E. coli) from raw milk of goats, and explored its molecular mechanisms. Isoorientin showed obvious antimicrobial ability with the minimum inhibitory concentration (MIC), and it exhibited synergistic activity with traditional antimicrobials against the carbapenem non-sensitive E. coli. Isoorientin could also significantly inhibit the carbapenem non-sensitive E. coli biofilm formation and destroy the established biofilms, with the percentage of inhibition ranging from 27.8% to 75% at MIC, and the corresponding percentage of eradication ranging from 15.3% to 61.6%, respectively. Confocal laser scanning microscopy (CLSM) observation and scanning electron microscopy (SEM) images indicated that the E. coli biofilm reduced in thickness with increasing concentrations of isoorientin. Dose-dependent decrease in eDNA revealed that isoorientin interacted with the extracellular polymeric substances (EPS) of the biofilm. qRT-PCR assay for the biofilm-forming associated genes further confirmed the above results. Overall, these results concluded that the isoorientin has significant antimicrobial and antibiofilm activity against carbapenem non-sensitive E. coli, and has potential application in prevention of food contamination and spoilage.

Pragmatic Comparison of Piperacillin/Tazobactam versus Carbapenems in Treating Patients with Nosocomial Pneumonia Caused by Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae

The effectiveness of piperacillin/tazobactam for managing nosocomial pneumonia caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is unknown. To answer this question, we conducted a retrospective cohort study in two tertiary teaching hospitals of patients admitted between January 2018 and July 2021 with a diagnosis of nosocomial pneumonia caused by ESBL-producing K. pneumoniae receiving either piperacillin/tazobactam or carbapenems within 24 h from the onset of pneumonia for at least 72 h. Clinical outcomes, including 28-day mortality and 14-day clinical and microbiological cure, were analyzed. Of the 136 total patients, 64 received piperacillin/tazobactam and 72 received carbapenems. The overall 28-day mortality was 19.1% (26/136). In the inverse probability of treatment weighted cohort, piperacillin/tazobactam therapy was not associated with worse clinical outcomes, as the 28-day mortality (OR, 0.82, 95% CI, 0.23–2.87, p = 0.748), clinical cure (OR, 0.94, 95% CI, 0.38–2.35, p = 0.894), and microbiological cure (OR, 1.10, 95% CI, 0.53–2.30, p = 0.798) were comparable to those of carbapenems. Subgroup analyses also did not demonstrate any statistical differences. In conclusion, piperacillin/tazobactam could be an effective alternative to carbapenems for treating nosocomial pneumonia due to ESBL-producing K. pneumoniae when the MICs are ≤8 mg/L.

A review of recent advances in the treatment of adults with complicated urinary tract infection

INTRODUCTION

Complicated urinary tract infections (cUTIs) entail diverse clinical conditions that could be managed differently and not necessarily with premature empiric therapy. Since multidrug-resistant organisms (MDROs) are widely spreading worldwide, the possibility of encountering these resistant bacteria is inevitably part of the daily life of physicians who manage cUTIs.

AREAS COVERED

The advances in the management of cUTIs are explored, illustrating: 1) a proposed therapeutical approach to cUTIs within the antimicrobial stewardship context; 2) evidence regarding novel antibiotics targeting MDROs. Evidence research has been performed through MEDLINE/PubMed using appropriate keywords and terms regarding cUTIs published before June 2022.

EXPERT OPINION

Novel antimicrobial drugs are available in the clinicians' armamentarium. Selecting the optimal therapy for suitable patients may be challenging given the multifaceted group of cUTIs. Carbapenems use is widely increasing, the role of old β-lactam/β-lactamase inhibitors is constantly revised, and novel drugs lack real-life studies. Understanding the different ranges of the complexity of patients affected by cUTIs may help select the most suitable antibiotic for every single case. More multicentric observational studies targeting cUTIs are needed to elucidate the appropriate drug based on patient characteristics and presentations, providing stronger recommendations for cases encountered in everyday clinical practice.

Therapeutic Options and Outcomes for the Treatment of Neonates and Preterms with Gram-Negative Multidrug-Resistant Bacteria: A Systematic Review

(1) Background: Infections caused by multidrug-resistant (MDR) or extensively drug-resistant (XDR) bacteria represent a challenge in the neonatal population due to disease severity and limited therapeutic possibilities compared to adults. The spread of antimicrobial resistance and drug availability differ significantly worldwide. The incidence of MDR bacteria has constantly risen, causing an increase in morbidity, mortality, and healthcare costs in both high-income (HIC) and low- and middle-income countries (LMIC). Therefore, more evidence is needed to define the possible use of newer molecules and to optimize combination regimens for the oldest antimicrobials in neonates. This systematic review aims to identify and critically appraise the current antimicrobial treatment options and the relative outcomes for MDR and XDR Gram-negative bacterial infections in the neonatal population. (2) Methods: A literature search for the treatment of MDR Gram-negative bacterial infections in neonates (term and preterm) was conducted in Embase, MEDLINE, and Cochrane Library. Studies reporting data on single-patient-level outcomes related to a specific antibiotic treatment for MDR Gram-negative bacterial infection in children were included. Studies reporting data from adults and children were included if single-neonate-level information could be identified. We focused our research on four MDROs: Enterobacterales producing extended-spectrum beta-lactamase (ESBL) or carbapenemase (CRE), Pseudomonas aeruginosa, and Acinetobacter baumannii. PROSPERO registration: CRD42022346739 (3) Results: The search identified 11,740 studies (since January 2000), of which 22 fulfilled both the inclusion and exclusion criteria and were included in the analysis. Twenty of these studies were conducted in LMIC. Colistin is the main studied and used molecule to treat Gram-negative MDR bacteria for neonate patients in the last two decades, especially in LMIC, with variable evidence of efficacy. Carbapenems are still the leading antibiotics for ESBL Enterobacterales, while newer molecules (i.e., beta-lactam agents/beta-lactamase inhibitor combination) are promising across all analyzed categories, but data are few and limited to HICs. (4) Conclusions: Data about the treatment of Gram-negative MDR bacteria in the neonatal population are heterogeneous and limited mainly to older antimicrobials. Newer drugs are promising but not affordable yet for many LMICs. Therefore, strategies cannot be generalized but will differ according to the country’s epidemiology and resources. More extensive studies are needed to include new antimicrobials and optimize the combination strategies for the older ones.

Comparison of the Treatment Outcome of Piperacillin-Tazobactam versus Carbapenems for Patients with Bacteremia Caused by Extended-Spectrum β-Lactamase-Producing Escherichia coli in Areas with Low Frequency of Coproduction of OXA-1: a Preliminary Analysis

Although piperacillin-tazobactam (TZP) was shown to be less effective than carbapenems in treating bacteremia due to extended-spectrum β-lactamase-producing (ESBL)-producing organisms in a randomized controlled trial, the fact that many of the causative organisms co-produced inhibitor-resistant OXA-1 along with ESBLs may have influenced the results. In this study, we compared the therapeutic effectiveness of TZP and carbapenem in treating ESBL-producing Escherichia coli bacteremia in areas with low frequency of OXA-1 co-production. Forty patients, 14 in the TZP treatment group and 26 in the carbapenem treatment group, were included in the analysis. There were no significant differences in patient background between the two groups. Urinary tract infection or cholangitis was the source of bacteremia in 26 patients (65%), and the Pitt bacteremia score was zero or one in 35 patients (87.5%). Only four (11.4%) of the 35 causative isolates available for microbiological analysis harbored bla_OXA-1, and only three (8.6%) were non-susceptible to TZP. Seventeen (48.6%) isolates carried bla_CTX-M-27, none of which carried other β-lactamase genes. No significant difference in the frequency of treatment failure on day 14 of bacteremia was documented between the TZP and carbapenem treatment groups in both the crude analysis and the inverse probability of treatment weighting-adjusted analysis. This study demonstrates that TZP may be a treatment option for non-severe cases of ESBL-producing E. coli bacteremia in areas with low frequency of OXA-1 co-production. IMPORTANCE Although carbapenems are considered the drug of choice for severe infections caused by extended-spectrum β-lactamase-producing (ESBL)-producing organisms, other therapeutic options are being explored to avoid increasing the selective pressure for carbapenem-resistant organisms. In this study, it was suggested that piperacillin-tazobactam may be as effective as carbapenems for the treatment of mild bacteremia caused by ESBL-producing Escherichia coli in areas where OXA-1 co-production by ESBL-producing E. coli is rare. The genetic background of each regional epidemic clone differs even among multidrug-resistant bacteria classified under the same name (e.g., ESBL-producing organisms), resulting in possible differences in the efficacy of therapeutic agents. Exploration of treatment options for multidrug-resistant organisms according to local epidemiology is worthwhile from the perspective of antimicrobial stewardship.

Extended-spectrum β-lactamase-producing and carbapenem-resistant Enterobacterales bloodstream infection after solid organ transplantation: Recent trends in epidemiology and therapeutic approaches

Background

Infections caused by multidrug‐resistant gram‐negative bacilli (MDR GNB), in particular extended‐spectrum β‐lactamase‐producing (ESBL‐E) and carbapenem‐resistant Enterobacterales (CRE), pose a major threat in solid organ transplantation (SOT). Outcome prediction and therapy are challenging due to the scarcity of randomized clinical trials (RCTs) or well‐designed observational studies focused on this population.

Methods

Narrative review with a focus on the contributions provided by the ongoing multinational INCREMENT‐SOT consortium (ClinicalTrials identifier NCT02852902) in the fields of epidemiology and clinical management.

Results

The Spanish Society of Transplantation (SET), the Group for Study of Infection in Transplantation of the Spanish Society of Infectious Diseases and Clinical Microbiology (GESITRA‐SEIMC), and the Spanish Network for Research in Infectious Diseases (REIPI) recently published their recommendations for the management of MDR GNB infections in SOT recipients. We revisit the SET/GESITRA‐SEIMC/REIPI document taking into consideration new evidence that emerged on the molecular epidemiology, prognostic stratification, and treatment of post‐transplant ESBL‐E and CRE infections. Results derived from the INCREMENT‐SOT consortium may support the therapeutic approach to post‐transplant bloodstream infection (BSI). The initiatives devoted to sparing the use of carbapenems in low‐risk ESBL‐E BSI or to repurposing existing non‐β‐lactam antibiotics for CRE in both non‐transplant and transplant patients are reviewed, as well as the eventual positioning in the specific SOT setting of recently approved antibiotics.

Conclusion

Due to the clinical complexity and relative rarity of ESBL‐E and CRE infections in SOT recipients, multinational cooperative efforts such as the INCREMENT‐SOT Project should be encouraged. In addition, RCTs focused on post‐transplant serious infection remain urgently needed.

Metabolic preference assay for rapid diagnosis of bloodstream infections

Bloodstream infections (BSIs) cause >500,000 infections and >80,000 deaths per year in North America. The length of time between the onset of symptoms and administration of appropriate antimicrobials is directly linked to mortality rates. It currently takes 2–5 days to identify BSI pathogens and measure their susceptibility to antimicrobials – a timeline that directly contributes to preventable deaths. To address this, we demonstrate a rapid metabolic preference assay (MPA) that uses the pattern of metabolic fluxes observed in ex-vivo microbial cultures to identify common pathogens and determine their antimicrobial susceptibility profiles. In a head-to-head race with a leading platform (VITEK 2, BioMérieux) used in diagnostic laboratories, MPA decreases testing timelines from 40 hours to under 20. If put into practice, this assay could reduce septic shock mortality and reduce the use of broad spectrum antibiotics.

It is currently slow to identify bloodstream infection pathogens. Here the authors report a rapid metabolic preference assay that uses the pattern of metabolic fluxes observed in ex-vivo microbial cultures to identify common pathogens and determine their antimicrobial susceptibility profiles.

Efficacy of Noncarbapenem β-Lactams Compared to Carbapenems for Extended-Spectrum β-Lactamase-Producing Enterobacterales Urinary Tract Infections

Background

Extended-spectrum β-lactamase (ESBL)-producing Enterobacterales are frequent causes of urinary tract infections (UTIs). Severe infections caused by ESBL Enterobacterales are often treated with carbapenems, but optimal treatment for less severe infections such as UTIs is unclear.

Methods

This retrospective cohort study included patients admitted to 4 hospitals in an academic healthcare system with an ESBL UTI treated with either a noncarbapenem β-lactam (NCBL) or a carbapenem for at least 48 hours from 1 April 2014 to 30 April 2018. Those who received an NCBL were compared to those receiving a carbapenem, with a primary outcome of hospital length of stay (LOS) and secondary outcomes of clinical and microbiological response, days until transition to oral therapy, rate of relapsed infection, and rate of secondary infections with a multidrug-resistant organism.

Results

Characteristics were similar among patients who received carbapenems (n = 321) and NCBLs (n = 171). There was no difference in LOS for the NCBL group compared to the carbapenem group (13 days vs 15 days, P = .66). The NCBL group had higher rates of microbiologic eradication (98% vs 92%, P = .002), shorter time to transition to oral therapy (5 days vs 9 days, P < .001), shorter overall durations of therapy (7 days vs 10 days, P < .001), and lower rates of relapsed infections (5% vs 42%, P = .0003).

Conclusions

Patients treated with NCBLs had similar LOS, higher rates of culture clearance, and shorter durations of antibiotic therapy compared to patients treated with carbapenems, suggesting that treatment for ESBL UTIs should not be selected solely based on phenotypic resistance.

Infections in Hospitalized Cancer Patients

Cancer patients are at an increased risk of developing infections that are primarily treatment-driven but may also be malignancy-driven. While cancer treatments such as chemotherapy, radiotherapy, and surgery have been known to improve malignancy morbidity and mortality, they also have the potential to weaken immune defenses and induce periods of severe cytopenia. These adverse effects pave the way for opportunistic infections to complicate a hospitalized cancer patient's clinical course. Understanding the risk each patient inherently has for developing a bacterial, fungal, or viral infection is critical to choosing the correct prophylactic treatment in conjunction with their scheduled cancer therapy. This review discusses the most common types of infections found in hospitalized cancer patients as well as the current guidelines for prophylactic and antimicrobial treatment in cancer patients. In addition, it describes the interaction between antibiotics and cancer therapies for consideration when treating infection in a cancer patient.

Predictive value of surveillance cultures for bacteremia caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales among patients with hematological diseases

PURPOSE

Due to the increasing prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales, empirical therapies with cefepime or piperacillin/tazobactam for hematology patients with febrile neutropenia have become ineffective. Carbapenems should be administered as soon as possible in such patients with ESBL bacteremia. If the surveillance culture results are consistent with the blood culture findings, the time to adequate treatment initiation can be shortened.

METHODS

All consecutive patients with Enterobacterales bacteraemia who were admitted from January 2013 to December 2018 at the hematology wards were enrolled in this study. Surveillance rectal swab and blood culture results were compared.

RESULTS

In total, 67 patients with Enterobacterales bacteremia underwent surveillance culture prior to the onset of infection. Regarding the presence or absence of ESBL-producing Enterobacterales, 64 (95.5%) patients had surveillance results concordant with blood culture results. The positive predictive value of surveillance culture for bacteremia caused by ESBL-producing Enterobacterales was 95.0%. Moreover, the negative predictive value of surveillance culture for bacteremia caused by non-ESBL-producing Enterobacterales was 95.7%.

CONCLUSION

The concordance rate between the surveillance rectal swab and blood cultures was highly acceptable. Surveillance rectal swab cultures are useful for identifying patients at high risk for ESBL bacteremia.

Distribution and Antibiotic Susceptibility Pattern of Multidrug-Resistant Bacteria and Risk Factors Among Kidney Transplantation Recipients with Infections Over 13 Years: A Retrospective Study

Background

Infection ranks as the most common complication after kidney transplantation (KT) and threatens outcomes of kidney transplantation recipients (KTR). This study aimed to investigate the microbiological profile of infection, assess bacterial resistance and identify risk factors for multidrug-resistant (MDR) bacterial infection among KTR.

Methods

During the study period, 866 recipients underwent kidney transplant surgery. We studied the distribution of pathogens, resistance rate of MDR bacteria and the risk factors of MDR bacterial infection.

Results

Totally, 214 species of pathogens (110 species were MDR bacteria) were isolated in 119 KTR. Escherichia coli (E. coli) was the most common bacteria of the infection. MDR extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) were most resistant to ampicillin, cefazolin, ciprofloxacin and complex sulfamethoxazole, while quite sensitive to imipenem, amikacin and piperacillin/tazobactam (PIT). All MDR gram-positive bacteria were quite sensitive to linezolid and vancomycin, except that MDR Staphylococcus was also susceptible to rifampicin. Female gender (OR = 3.497, 95% CI = 1.445–8.467, P = 0.006), pathogen types > 1 (OR = 3.832, 95% CI = 1.429–10.273, P = 0.008) and postoperative time < 3 months (OR = 0.331, 95% CI = 0.137–0.799, P = 0.014) were independent risk factors for MDR bacterial infection.

Conclusion

PIT and amikacin may be an alternative choice of ESBL-E infection. Rifampicin can also be prescribed for MDR Staphylococcus infection. MDR bacterial infection was associated with female gender, pathogen types more than 1 and 3 months postoperative period.

Timing in antibiotic therapy: when and how to start, de-escalate and stop antibiotic therapy. Proposals from a stablished antimicrobial stewardship program

The current morbimortality of serious infections is unacceptable and there is a need to promote the increase in the efficacy of empirical and targeted antibiotherapy. This could be achieved by initiatives coming from ASP teams aimed at promoting increased efficacy of antibiotic therapy .In the optimization of the antibiotic therapy there are several critical points in which an adequate timing could achieve benefits in the survival of patients with severe infections: prompt initiation of empirical treatment; de-escalation performance, appropriate targeted treatment; and finally, curtail antibiotic duration.

Controversies in the management of ESBL-producing Enterabacterales. Clinical Implications

Extended-spectrum β-lactamases (ESBL)-producing organisms currently represent a major health problem. Although recently published guidelines still consider carbapenems as the treatment of choice for ESBL-producing infections, it is necessary to find non-carbapenem β-lactams as alternatives to reduce the effects associated with their overutilization. In this review we focus on these alternatives to carbepenem use. It is possible that piperacillin-tazobactam may be an alternative in clinical settings with "low inoculum" infections like urinary tract infections. Newer β-lactam-β-lactamase inhibitors (BLBLIs) are potential options too. The current available data support the efficacy of both ceftazidime-avibactam and ceftolozane-tazobactam against susceptible ESBL-producing Enterobacterales (ESBL-E). We are waiting for the results of MERINO-3 study to confirm whether ceftolozane-tazobactam is a good option versus meropenem for treating bloodstream infections caused by ESBL- or AmpC-producing Enterobacterales.

In Vitro Activities of Ceftazidime-Avibactam and Aztreonam-Avibactam at Different Inoculum Sizes of Extended-Spectrum β-Lactam-Resistant Enterobacterales Blood Isolates

β-lactam–avibactam combinations have been proposed as carbapenem-sparing therapies, but little data exist on their in vitro activities in infections with high bacterial inocula. We investigated the in vitro efficacies and the inoculum effects of ceftazidime–avibactam and aztreonam–avibactam against extended-spectrum β-lactam-resistant Enterobacterales blood isolates. A total of 228 non-repetitive extended-spectrum β-lactam-resistant Escherichia coli and Klebsiella pneumoniae blood isolates were prospectively collected in a tertiary center. In vitro susceptibilities to ceftazidime, aztreonam, meropenem, ceftazidime–avibactam, and aztreonam–avibactam were evaluated by broth microdilution method using standard and high inocula. An inoculum effect was defined as an eightfold or greater increase in MIC when tested with the high inoculum. Of the 228 isolates, 99% were susceptible to ceftazidime–avibactam and 99% had low aztreonam–avibactam MICs (≤8 mg/L). Ceftazidime–avibactam and aztreonam–avibactam exhibited good in vitro activities; MIC₅₀/MIC₉₀ values were 0.5/2 mg/L, 0.125/0.5 mg/L, and ≤0.03/0.25 mg/L, respectively, and aztreonam–avibactam was more active than ceftazidime–avibactam. The frequencies of the inoculum effect with ceftazidime–avibactam and aztreonam–avibactam were lower than with meropenem (14% vs. 38%, p < 0.001 and 30% vs. 38%, p = 0.03, respectively). The β-lactam-avibactam combinations could be useful as carbapenem-sparing strategies, and aztreonam–avibactam has the better in vitro activity but is more subject to the inoculum effect than ceftazidime–avibactam.

Performance of the eazyplex® BloodScreen GN as a simple and rapid molecular test for identification of Gram-negative bacteria from positive blood cultures

The LAMP-based eazyplex® BloodScreen GN was evaluated for the detection of frequent Gram-negatives directly from positive blood culture (BC) bottles. A total of 449 BCs were analyzed. Sensitivities and specificities were 100% and 100% for Escherichia coli, 95.7% and 100% for Klebsiella pneumoniae, 100% and 100% for bla_CTX-M, 100% and 100% for Klebsiella oxytoca, 100% and 99% for Proteus mirabilis, and 100% and 99.8% for Pseudomonas aeruginosa, respectively. The time to result ranged from 8 to 16 min, plus about 6 min for sample preparation. The eazyplex® BloodScreen GN is a reliable molecular assay for rapid BC testing.

Clinical characteristics and prognosis of immunosuppressed inpatients with COVID-19 in Japan

Introduction

We aimed to analyze the clinical characteristics and outcomes of immunosuppressed inpatients with coronavirus disease 2019 (COVID-19).

Methods

In this observational study, we utilized a large nationwide registry of hospitalized patients with COVID-19 in Japan. Patients’ baseline characteristics and outcomes were compared according to the immunosuppressed states of the patients. The impact of different therapeutic agents on the clinical courses of the patients was evaluated.

Results

Data of 14,760 patients were included, and 887 (5.9%) were immunosuppressed. The immunosuppressed state of the patient resulted from solid tumor (43.3%, n = 384), chemotherapy within 3 months (15.6%, n = 138), collagen disease (16.9%, n = 150), use of immunosuppressive agents (16.0%, n = 142), and metastatic solid tumor (13.5%, n = 120). Immunosuppressed patients were older and had a higher severity of illness at admission and during hospitalization than non-immunosuppressed patients. The mortality rates for major diseases causing immunosuppression were as follows: solid tumor, 12.5% (48/384; P < 0.001; relative risk [RR], 3.41); metastatic solid tumor, 31.7% (38/120; P < 0.001; RR, 8.43); leukemia, 23.1% (9/39; P < 0.001; RR, 5.87); lymphoma, 33.3% (20/60; P < 0.001; RR, 8.63); and collagen disease, 15.3% (23/150; P < 0.001; RR 3.97). Underlying diseases with high mortality rates were not necessarily associated with high rates of invasive supportive care.

Conclusions

The prognosis of immunosuppressed COVID-19 inpatients varied according to the different immunosuppressed states. Multiple factors, including the severity of the underlying diseases, might have affected their invasive supportive care indications.

High-Level Carbapenem Resistance among OXA-48-Producing Klebsiellapneumoniae with Functional OmpK36 Alterations: Maintenance of Ceftazidime/Avibactam Susceptibility

The aim of this work was to analyze outer membrane porin-encoding genes (ompK35 and ompK36) in a collection of OXA-48 producing Klebsiella pneumoniae, to assess the effect of porin alterations on the susceptibility to ceftazidime/avibactam, and to describe a screening methodology for phenotypic detection of OXA-48-producing K. pneumoniae with disrupted porins. Antimicrobial susceptibility was tested by Microscan and Etest. The genomes of 81 OXA-48-producing K. pneumoniae were sequenced. MLST, detection of antimicrobial resistance genes, and analysis of ompK35 and ompK36 were performed in silico. Tridimensional structures of the OmpK36 variants were assessed. Receiver operating characteristics curves were built to visualize the performance ability of a disk diffusion assay using carbapenems and cefoxitin to detect OmpK36 functional alterations. A wide variety of OmpK36 alterations were detected in 17 OXA-48-producing K. pneumoniae isolates. All displayed a high-level meropenem resistance (MIC ≥ 8 mg/L), and some belonged to high-risk clones, such as ST15 and ST147. Alterations in ompK35 were also observed, but they did not correlate with high-level meropenem resistance. All isolates were susceptible to ceftazidime/avibactam and porin alterations did not affect the MICs of the latter combination. Cefoxitin together with ertapenem/meropenem low inhibition zone diameters (equal or lower than 16 mm) could strongly suggest alterations affecting OmpK36 in OXA-48-producing K. pneumoniae. OXA-48-producing K. pneumoniae with porin disruptions are a cause of concern; ceftazidime/avibactam showed good in vitro activity against them, so this combination could be positioned as the choice therapy to combat the infections caused by this difficult-to-treat isolates.

Genetic characterization of Carbapenem-Resistant Escherichia coli from China, 2015-2017

BACKGROUND

The molecular characteristics of carbapenem-resistant Escherichia coli (CREco) remain unclear.

METHODS

We conducted a multi-center bacterial resistance monitoring project from 2015 to 2017.The minimum inhibitory concentrations ofCREco were determined bybroth microdilution method. The genome sequencing of CREcoisolates was performed, and single-nucleotide polymorphism (SNP) was analyzed.

RESULTS

A total of 144CREcoisolatescollected from 10 cities in China were involved in this study. ST167 (n = 43) is the most popular type, followed by ST410(n = 14), ST131(n = 9). There were 102 (70.83%) CREco isolates that produced various NDMs, including NDM-1 (n = 16), NDM-4(n = 1), NDM-5(n = 79), NDM-6(n = 2) and NDM-9(n = 4). In addition, 15 isolates produced KPC-2, three isolates wereIMP-4 positive, and three isolates produced OXA-48. Genetic relatedness and phylogenetic analysis showed that isolates with the same ST had a high degree of homology. Some STs (including ST167, ST410, ST131, ST46, ST405 and ST617) exhibited a trend of outbreak.

CONCLUSIONS

The majority of CREco belonged to ST167, followed by ST410 and ST131, and most of them carried various NDM-coding genes. The spread of high-risk clones of CREco has occurred in different regions of China.

Comparison of therapy with β-lactam/β-lactamase inhibitor combinations or carbapenems for bacteraemia of nonurinary source caused by ESBL-producing Escherichia coli or Klebsiella pneumoniae

Background

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae has become a public health concern. This study aimed to compare the clinical outcomes of patients with nonurinary source bacteraemia caused by ESBL-producing Escherichia coli (E. coli) or Klebsiella pneumoniae (ESBL-producing EK) receiving β-lactam/β-lactamase inhibitor combinations (BLICs) versus carbapenem treatment and assess the risk factors of mortality with these two drugs.

Methods

We conducted a retrospective single-centre study of adult hospitalised patients with ESBL-producing EK bloodstream infection (BSI) from nonurinary source at our centre over a 4-year period. One hundred and eighty patients who received BLICs or carbapenems were included in the analysis. The outcome variables were 14-day treatment failure and 30-day mortality. For more reliable results, propensity score analysis was performed to compare the efficacy of the two drugs and analyse their risk factors for 30-day mortality.

Results

Out of 180 patients, 114 received BLICs, and 66 received carbapenem therapy. Compared to carbapenem-treated patients, those treated with BLICs were older and had higher age-adjusted Charlson comorbidity index, but they had shorter stay in the hospital. Additionally, their Pitt bacteraemia score, SOFA score, rate of leukaemia, and immune compromise were lower. After propensity score matching (PSM), the baseline characteristics of patients in the two treatment groups were balanced. BLICs were associated with a higher 14-day treatment failure rate (20.6%, 13/63) than carbapenems (16.3%, 7/43), although the difference was not significant in either univariate analysis (P = 0.429) or multivariate analysis (P = 0.122). And the 30-day mortality rate in BTG (11.1%, 7/63) and CTG (11.6%, 5/43) did not significantly differ (univariate analysis, P = 0.926; multivariate analysis, P = 0.420). In the multivariate analysis, after PSM, leukaemia was the only independent predictor of mortality in both BTG and CTG.

Conclusions

Our study showed that BLICs had higher 14-day treatment failure rate compared with carbapenems, although there were no statistically significant differences because of the small number of patients, therefore, further evaluation of the efficacy of BLICs is needed.

Insights into multidrug-resistant K. pneumoniae urinary tract infections: From susceptibility to mortality

The incidence of urinary tract infections (UTIs) caused by Klebsiella pneumoniae has exhibited an increasing trend and has become a high burden for many public health systems, especially in hospital settings. Multidrug resistance associated with the production of extended-spectrum β-lactamases (ESBL) among K. pneumoniae isolates is endemic in Southeastern Europe. We retrospectively analyzed 75 cases admitted to ‘St. Parascheva’ Clinical Hospital of Infectious Diseases in Iasi, Romania, during the first 6 months of 2019 (January 1 to June 30), who had a confirmed diagnosis of K. pneumoniae UTI at discharge. From a total of 75 patients, 34 (45.3%) presented ESBL⁺K. pneumoniae. The mean age was 66 years (70.1 for the ESBL⁺ patients vs. 62.6 for the ESBL^- patients, P=0.0365). There was a symmetrical sex distribution (37 men vs. 38 women). Of these, 22 men had ESBL⁺K. pneumoniae UTIs, compared to only 15 with an ESBL^- strain, P=0.0087. Another risk factor for ESBL⁺K. pneumoniae UTIs was the presence of hospitalization in the past 6 months; 20 (58.82%) patients with ESBL⁺ infections were previously hospitalized, compared to only 5 (12.19%) patients with ESBL^- strains, P<0.0001. The urinary catheter carriers presented an increased prevalence of ESBL⁺ infections (15/34 vs. 5/41, P=0.0012). Regarding mortality, ESBL⁺ infections caused 6 fatalities, compared to only 1 death in the ESBL^- group, P=0.0166. ESBL⁺K. pneumoniae strains represent an important cause of healthcare-related UTIs, with a significantly higher mortality rate compared to ESBL^- strains. Early identification and adequate management of the risk factors incriminated in ESBL⁺ UTIs should be a priority for physicians in order to limit the dissemination of the ESBL-producing strains and thus to improve the outcome of these patients.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members.As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

Hyperoncotic Albumin Solution in Continuous Renal Replacement Therapy Patients

Aim

The aim of this study was to investigate the association of hyperoncotic (20%) human albumin solution (HAS) with outcomes among critically ill patients receiving continuous renal replacement therapy (RRT).

Methods

Analysis of the Randomized Evaluation of Normal versus Augmented Level (RENAL) RRT trial data.

Results

Of 1,508 patients, 771 (51%) received albumin. Of these, 345 (45%) received 4% HAS only, 155 (20%) received 20% HAS only, and 271 (35%) received both. Patients who received combined 4% and 20% HAS were more severely ill, received more days of RENAL trial therapy and required mechanical ventilation for longer. Mean daily fluid balance was −288 mL (−904 to 261) with 20% HAS only versus 245 mL (−248 to 1,050) with 4% HAS only (p < 0.001). On Cox proportional hazards regression, 20% HAS exposure was not associated with greater 90-day mortality (odds ratio 1.12, 95% confidence interval [CI]: 0.77–1.62; p = 0.55) or longer recovery to RRT independence (sub-hazard ratio 1.04, 95% CI: 0.84–1.30; p = 0.70) compared to those who received 4% HAS only.

Conclusions

RENAL trial patients commonly received albumin in varying concentrations. The administration of 20% HAS was associated with a more negative fluid balance but was not independently associated with increased mortality or RRT dependence when compared to 4% HAS only.

An Evidence-Based Multidisciplinary Approach Focused at Creating Algorithms for Targeted Therapy of BSIs, cUTIs, and cIAIs Caused by Enterobacterales in Critically Ill Adult Patients

Prompt implementation of appropriate targeted antibiotic therapy represents a valuable approach in improving clinical and ecological outcome in critically septic patients. This multidisciplinary opinion article focused at developing evidence-based algorithms for targeted antibiotic therapy of bloodstream (BSIs), complicated urinary tract (cUTIs), and complicated intrabdominal infections (cIAIs) caused by Enterobacterales. The aim was to provide a guidance for intensive care physicians either in appropriately placing novel antibiotics or in considering strategies for sparing the broadest-spectrum antibiotics. A multidisciplinary team of experts (one intensive care physician, one infectious disease consultant, one clinical microbiologist and one MD clinical pharmacologist), performed several rounds of assessment to reach agreement in developing six different algorithms according to the susceptibility pattern (one each for multi-susceptible, extended-spectrum beta-lactamase-producing, AmpC beta-lactamase-producing, Klebsiella pneumoniae carbapenemase (KPC)-producing, OXA-48-producing, and Metallo-beta-lactamase (MBL)-producing Enterobacterales). Whenever multiple therapeutic options were feasible, a hierarchical scale was established. Recommendations on antibiotic dosing optimization were also provided. In order to retrieve evidence-based support for the therapeutic choices proposed in the algorithms, a comprehensive literature search was performed by a researcher on PubMed-MEDLINE from inception until March 2021. Quality and strength of evidence was established according to a hierarchical scale of the study design. Only articles published in English were included. It is expected that these algorithms, by allowing prompt revision of antibiotic regimens whenever feasible, appropriate place in therapy of novel beta-lactams, implementation of strategies for sparing the broadest-spectrum antibiotics, and pharmacokinetic/pharmacodynamic optimization of antibiotic dosing regimens, may be helpful either in improving clinical outcome or in containing the spread of antimicrobial resistance.

Validation of Available Extended-Spectrum-Beta-Lactamase Clinical Scoring Models in Predicting Drug Resistance in Patients with Enteric Gram-Negative Bacteremia Treated at South Texas Veterans Health Care System

Extended-spectrum-beta-lactamase (ESBL)-producing Enterobacteriaceae are increasingly common; however, predicting which patients are likely to be infected with an ESBL pathogen is challenging, leading to increased use of carbapenems. To date, five prediction models have been developed to distinguish between patients infected with ESBL pathogens. The aim of this study was to validate and compare each of these models to better inform antimicrobial stewardship. This was a retrospective cohort study of patients with Gram-negative bacteremia treated at the South Texas Veterans Health Care System over 3 months from 2018 to 2019. We evaluated isolate, clinical syndrome, and score variables for the five published prediction models/scores: Italian "Tumbarello," Duke, University of South Carolina (USC), Hopkins clinical decision tree, and modified Hopkins. Each model was assessed using the area under the receiver operating characteristic curve (AUROC) and Pearson correlation. One hundred forty-five patients were included for analysis, of which 20 (13.8%) were infected with an ESBL Escherichia coli or Klebsiella spp. The most common sources of infection were genitourinary (55.8%) and gastrointestinal/intraabdominal (24.1%), and the most common pathogen was E. coli (75.2%). The prediction model with the strongest discriminatory ability (AUROC) was Tumbarello (0.7556). The correlation between prediction model score and percent ESBL was strongest with the modified Hopkins model (R ² = 0.74). In this veteran population, the modified Hopkins and Duke prediction models were most accurate in discriminating between Gram-negative bacteremia patients when considering both AUROC and correlation. However, given the moderate discriminatory ability, many patients with ESBL Enterobacteriaceae (at least 25%) may still be missed empirically.

Recent molecules in the treatment of severe infections caused by ESBL-producing bacteria

Introduction: The widespread increase in resistance to β-lactam antibiotics in Enterobacterales currently represents one of the main threats to human health worldwide. The primary mechanisms of resistance are the production of β-lactamase enzymes that are able to hydrolyze β-lactams.Areas covered: we summarize the most recent advances regarding the main characteristics and spectrum of activity of new available antibiotics and strategies for the treatment of ESBL-producing Enterobacterales infections.Expert opinion: ESBL-producing strains are recognized as a worldwide challenge in the treatment of both hospital- and community-acquired infections. Data from the literature point out the high mortality associated with severe infections due to ESBL strains, especially in patients who developed severe sepsis or septic shock, together with the importance of the source of infection and indicators of severity, as determinants of the patient's outcome. Carbapenems are currently considered the first-line therapy, although the diffusion of resistant strains is an evolving problem and is mandatory the introduction in clinical practice of new drug regimens and treatment strategies, based on clinical data, local epidemiology, and microbiology. As a possible carbapenem-sparing strategy, ceftolozane-tazobactam and ceftazidime-avibactam appear the best-available carbapenem-sparing therapies. The definitive role of new drugs should be definitively assessed.

Magnetic resonance imaging-guided prostate biopsy-A review of literature

Objective

Multiparametric magnetic resonance imaging (MP-MRI) helps to identify lesion of prostate with reasonable accuracy. We aim to describe the various uses of MP-MRI for prostate biopsy comparing different techniques of MP-MRI guided biopsy.

Materials and methods

A literature search was performed for "multiparametric MRI", "MRI fusion biopsy", "MRI guided biopsy", "prostate biopsy", "MRI cognitive biopsy", "MRI fusion biopsy systems", "prostate biopsy" and "cost analysis". The search operation was performed using the operator "OR" and "AND" with the above key words. All relevant systematic reviews, original articles, case series, and case reports were selected for this review.

Results

The sensitivity of MRI targeted biopsy (MRI-TB) is between 91%-93%, and the specificity is between 36%-41% in various studies. It also has a high negative predictive value (NPV) of 89%-92% and a positive predictive value (PPV) of 51%-52%. The yield of MRI fusion biopsy (MRI-FB) is similar, if not superior to MR cognitive biopsy. In-bore MRI-TB had better detection rates compared to MR cognitive biopsy, but were similar to MR fusion biopsy.

Conclusions

The use of MRI guidance in prostate biopsy is inevitable, subject to availability, cost, and experience. Any one of the three modalities (i.e. MRI cognitive, MRI fusion and MRI in-bore approach) can be used. MRI-FB has a fine balance with regards to accuracy, practicality and affordability.

Piperacillin-tazobactam versus meropenem for treatment of bloodstream infections caused by third-generation cephalosporin-resistant Enterobacteriaceae: a study protocol for a non-inferiority open-label randomised controlled trial (PeterPen)

INTRODUCTION

The optimal treatment for extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae bloodstream infections has yet to be defined. Retrospective studies have shown conflicting results, with most data suggesting the non-inferiority of beta-lactam-beta-lactamase inhibitor combinations compared with carbapenems. However, the recently published MERINO trial failed to demonstrate the non-inferiority of piperacillin-tazobactam to meropenem. The potential implications of the MERINO trial are profound, as widespread adoption of carbapenem treatment will have detrimental effects on antimicrobial stewardship in areas endemic for ESBL and carbapenem-resistant bacteria. Therefore, we believe that it is justified to re-examine the comparison in a second randomised controlled trial prior to changing clinical practice.

METHODS AND ANALYSIS

PeterPen is a multicentre, investigator-initiated, open-label, randomised controlled non-inferiority trial, comparing piperacillin-tazobactam with meropenem for third-generation cephalosporin-resistant Escherichia coli and Klebsiella bloodstream infections. The study is currently being conducted in six centres in Israel and one in Canada with other centres from Israel, Italy and Canada expected to join. The two primary outcomes are all-cause mortality at day 30 from enrolment and treatment failure at day seven (death, fever above 38°C in the last 48 hours, continuous symptoms, increasing Sequential Organ Failure Assessment Score or persistent blood cultures with the index pathogen). A sample size of 1084 patients was calculated for the mortality endpoint assuming a 12.5% mortality rate in the control group with a 5% non-inferiority margin and assuming 100% follow-up for this outcome.

ETHICS AND DISSEMINATION

The study is approved by local and national ethics committees as required. Results will be published, and trial data will be made available.

TRIAL REGISTRATION NUMBERS

ClinicalTrials.gov Registry (NCT03671967); Israeli Ministry of Health Trials Registry (MOH_2018-12-25_004857).

Emergence of Resistance in Klebsiella aerogenes to Piperacillin-Tazobactam and Ceftriaxone

We examined the effects of piperacillin-tazobactam (TZP) concentration and bacterial inoculum on in vitro killing and the emergence of resistance in Klebsiella aerogenes The MICs for 15 clinical respiratory isolates were determined by broth microdilution for TZP and by Etest for ceftriaxone (CRO) and cefepime (FEP). The presence of resistance in TZP-susceptible isolates (n = 10) was determined by serial passes over increasing concentrations of TZP-containing and CRO-containing agar plates. Isolates with growth on TZP 16/4-μg/ml and CRO 8-μg/ml plates (n = 5) were tested in high-inoculum (HI; 7.0 log10 CFU/ml) and low-inoculum (LI; 5.0 log10 CFU/ml) time-kill studies. Antibiotic concentrations were selected to approximate TZP 3.375 g every 8 h (q8h) via a 4-h prolonged-infusion free peak concentration (40 μg/ml [TZP40]), peak epithelial lining fluid (ELF) concentrations, and average AUC0-24 values for TZP (20 μg/ml [TZP20] and 10 μg/ml [TZP10], respectively), the ELF FEP concentration (14 μg/ml), and the average AUC0-24 CRO concentration (6 μg/ml). For HI, FEP exposure significantly reduced 24-h inocula against all comparators (P ≤ 0.05) with a reduction of 4.93 ± 0.64 log10 CFU/ml. Exposure to TZP40, TZP20, and TZP10 reduced inocula by 0.81 ± 0.43, 0.21 ± 0.18, and 0.05 ± 0.16 log10 CFU/ml, respectively. CRO-exposed isolates demonstrated an increase of 0.42 ± 0.39 log10 CFU/ml compared to the starting inocula, with four of five CRO-exposed isolates demonstrating TZP-nonsusceptibility. At LI after 24 h of exposure to TZP20 and TZP10, the starting inoculum decreased by averages of 2.24 ± 1.98 and 2.91 ± 0.50 log10 CFU/ml, respectively. TZP demonstrated significant inoculum-dependent killing, warranting dose optimization studies.

The impact of nephrostomy drainage prior to mini-percutaneous nephrolithotomy in patients with ESBL-positive Escherichia coli

OBJECTIVE

Extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) is one of the most frightening multidrug-resistant bacteria that usually causes sepsis. Herein we explored the benefits of nephrostomy drainage prior to percutaneous nephrolithotomy (PCNL) on infection outcomes in patients with ESBL-EC.

PATIENTS AND METHODS

Between June 2016 and April 2019, 43 consecutive patients with ESBL-EC who received nephrostomy drainage for > 24 h prior to PCNL were retrospectively evaluated as group 1. 86 patients were randomly selected from patients with ESBL-EC who received concurrent percutaneous access during PCNL as group 2. The postoperative infection complications were compared.

RESULTS

Although the total infection complications were not statistically different (11.6% vs. 25.6%, p = 0.066), the severity seemed to be worse among group 2 subjects. Severe infections, including urosepsis (4.7% vs.13.9%) and septic shock (2.3% vs 4.6%), were observed at twice or greater rates in group 2. Blood transfusions were also more frequent (2.3% vs. 13.9%, p = 0.039). Multivariate analysis demonstrated that preoperative drainage was an independent risk factor for postoperative infection events (OR 2.31 CI 1.14-3.48, p = 0.017). Subgroup analyses indicated that preoperative drainage may largely reduce the incidence of urosepsis in patients with hydronephrosis or without receiving preoperative carbapenem therapy.

CONCLUSION

Because of the high rate of severe infection after PCNL in patients with ESBL‑positive E. coli, preoperative nephrostomy drainage for > 24 h is an effective measure to reduce the risk of severe infection complications, especially in patients with hydronephrosis or those without preoperative carbapenem therapy.

Is Piperacillin-Tazobactam Effective for the Treatment of Pyelonephritis Caused by Extended-Spectrum β-Lactamase-Producing Organisms?

BACKGROUND

Limited data exist regarding the efficacy of piperacillin-tazobactam (TZP) for the management of nonbacteremic pyelonephritis caused by extended-spectrum β-lactamase (ESBL)-producing organisms.

METHODS

We conducted a multicenter observational study comparing clinical outcomes of adults hospitalized with ESBL-producing pyelonephritis who were receiving TZP versus carbapenems, using an inverse probability of treatment weighted propensity score analysis. Patients were eligible for inclusion if all of the following criteria were met: (1) urine cultures growing Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, or Proteus mirabilis at ≥50 000 colony-forming units/mL; (2) identification of an ESBL gene; (3) pyuria (≥10 white blood cells per high powered field in the urine); and (4) dysuria and fever plus at least 1 of the following symptoms: emesis, rigors, hypotension, or flank pain.

RESULTS

There were 186 patients included in the propensity score-weighted cohort; 45 (24%) received TZP and 141 (76%) received a carbapenem. Of these 186 patients, 27% were admitted to the intensive care unit, 48% were immunocompromised, and 45% had underlying urologic abnormalities. There were no differences between the 2 groups in the proportion of patients (20% vs 25%) with recurrent cystitis or pyelonephritis with the same ESBL-producing organism within 30 days (odds ratio, 0.75; 95% confidence interval, .31-1.81; P = .52). There were no differences in the resolution of clinical symptoms by Day 7 or in 30-day mortality. There was 1 (2%) patient in the TZP arm and 11 (8%) patients in the carbapenem arm who had incident carbapenem-resistant organisms isolated within 30 days (P = .09).

CONCLUSIONS

TZP may be a reasonable alternative to carbapenems for the management of ESBL-producing pyelonephritis and may mitigate the risk of emergence of carbapenem-resistant organisms, compared with carbapenem therapy.

Metapopulation ecology links antibiotic resistance, consumption, and patient transfers in a network of hospital wards

Antimicrobial resistance (AMR) is a global threat. A better understanding of how antibiotic use and between-ward patient transfers (or connectivity) impact population-level AMR in hospital networks can help optimize antibiotic stewardship and infection control strategies. Here, we used a metapopulation framework to explain variations in the incidence of infections caused by seven major bacterial species and their drug-resistant variants in a network of 357 hospital wards. We found that ward-level antibiotic consumption volume had a stronger influence on the incidence of the more resistant pathogens, while connectivity had the most influence on hospital-endemic species and carbapenem-resistant pathogens. Piperacillin-tazobactam consumption was the strongest predictor of the cumulative incidence of infections resistant to empirical sepsis therapy. Our data provide evidence that both antibiotic use and connectivity measurably influence hospital AMR. Finally, we provide a ranking of key antibiotics by their estimated population-level impact on AMR that might help inform antimicrobial stewardship strategies.

In Vivo Activity of QPX7728, an Ultrabroad-Spectrum Beta-Lactamase Inhibitor, in Combination with Beta-Lactams against Carbapenem-Resistant Klebsiella pneumoniae

Resistance to beta-lactams has created a major clinical issue. QPX7728 is a novel ultrabroad-spectrum cyclic boronic acid beta-lactamase inhibitor with activity against both serine and metallo-beta-lactamases developed to address this resistance for use in combination with beta-lactam antibiotics. The objective of these studies was to evaluate the activity of QPX7728 in combination with multiple beta-lactams against carbapenem-resistant Klebsiella pneumoniae isolates in a neutropenic mouse thigh infection model. Neutropenic mice were infected with strains with potentiated beta-lactam MICs of ≤2 mg/liter in the presence of 8 mg/liter QPX7728. Two strains of carbapenem-resistant K. pneumoniae were tested with aztreonam, biapenem, cefepime, ceftazidime, ceftolozane, and meropenem alone or in combination with 12.5, 25, or 50 mg/kg of body weight of QPX7728 every 2 hours for 24 hours. Treatment with all beta-lactams alone either was bacteriostatic or allowed for bacterial growth. The combination of QPX7728 plus each of these beta-lactams produced bacterial killing at all QPX7728 doses tested. Overall, these data suggest that QPX7728 administered in combination with different partner beta-lactam antibiotics may have utility in the treatment of bacterial infections due to carbapenem-resistant K. pneumoniae.

[Infections due to multidrug-resistant pathogens : Pathogens, resistance mechanisms and established treatment options]

The increase in resistant pathogens has long been a global problem. Complicated life-threatening infections due to multidrug-resistant pathogens (MRD) meanwhile occur regularly in intensive care medicine. An important and also potentially modifiable factor of the rapid spread of resistance is the irrational use of broad spectrum antibiotics in human medicine. In addition to many other resistance mechanisms, beta-lactamases play an important role in Gram-negative pathogens. They are not uncommonly the leading reason of difficult to treat infections and the failure of known routinely used broad spectrum antibiotics, such as cephalosporins, (acylamino)penicillins and carbapenems. Strategies for containment of MRDs primaríly target the rational use of antibiotics. In this respect interdisciplinary treatment teams, e.g. antibiotic stewardship (ABS) and infectious diseases stewardship (IDS) play a major role.

Early Treatment with Human Albumin Solution in Continuous Renal Replacement Patients

AIMS

To study the impact of early human albumin solution (HAS) in continuous renal replacement therapy (RRT) patients.

METHODS

Analysis of Randomized Evaluation of Normal versus Augmented Level (RENAL) RRT trial data.

RESULTS

Of 1,464 patients, 500 (34%) received early albumin. These patients had higher illness severity scores, greater use of mechanical ventilation, and 90-day mortality (51 vs. 41%; p < 0.001). However, early albumin carried similar RRT dependence risk among survivors at day 90 (4.9 vs. 5.8%; p = 0.62). On Cox proportional hazards regression, with standardized inverse probability of treatment weighting, early albumin was not associated with increased mortality (hazard ratio [HR]: 1.23, 95% CI: 0.97-1.55; p = 0.09) or recovery to RRT independence (HR: 0.92, 95% CI: 0.78-1.10; p = 0.38).

CONCLUSIONS

Early albumin was administered to one-third of RENAL trial patients and in those with greater illness severity. Early albumin was not independently associated with mortality risk or rate of recovery to RRT independence.

Gram-negative Organisms from Patients with Community-Acquired Urinary Tract Infections and Associated Risk Factors for Antimicrobial Resistance: A Single-Center Retrospective Observational Study in Japan

A specific antibiogram is necessary for the empiric antibiotic treatment of community-acquired urinary tract infections (UTI) because of the global spread of antimicrobial resistance. This study aimed to develop an antibiogram specific for community-acquired UTI and assess the risk factors associated with community-acquired UTI caused by antimicrobial-resistant organisms. This cross-sectional observational retrospective study included patients with community-acquired UTI caused by Gram-negative rods (GNR) who were admitted to the emergency department at a tertiary care hospital in Ibaraki, Japan, in 2017–2018. A total of 172 patients were enrolled (including 38 nursing home residents). Of the 181 GNR strains considered as causative agents, 135 (75%) were Escherichia coli, and 40 (22%) exhibited third-generation cephalosporin resistance. Extended-spectrum β-lactamase (ESBL)-producing E. coli accounted for 25/40 (63%) of resistant GNR. Overall susceptibility rate of Enterobacterales was 92%, 81%, 100%, 75%, and 89% for cefmetazole, ceftriaxone, meropenem, levofloxacin, and trimethoprim–sulfamethoxazole, respectively. Residence in a nursing home (odds ratio (OR), 2.83; 95% confidence interval (CI), 1.18–6.79) and recent antibiotic use (OR, 4.52; 95% CI, 1.02–19.97) were independent risk factors for UTI with resistant GNR. ESBL-producing E. coli was revealed to have a strong impact on antimicrobial resistance pattern. Therefore, an antibiotic strategy based on a disease-specific antibiogram is required.

Inoculum effect of β-lactam antibiotics

The phenomenon of attenuated antibacterial activity at inocula above those utilized for susceptibility testing is referred to as the inoculum effect. Although the inoculum effect has been reported for several decades, it is currently debatable whether the inoculum effect is clinically significant. The aim of the present review was to consolidate currently available evidence to summarize which β-lactam drug classes demonstrate an inoculum effect against specific bacterial pathogens. Review of the literature showed that the majority of studies that evaluated the inoculum effect of β-lactams were in vitro investigations of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Haemophilus influenzae and Staphylococcus aureus. Across all five pathogens, cephalosporins consistently displayed observable inoculum effects in vitro, whereas carbapenems were less susceptible to an inoculum effect. A handful of animal studies were available that validated that the in vitro inoculum effect translates into attenuated pharmacodynamics of β-lactams in vivo. Only a few clinical investigations were available and suggested that an in vitro inoculum effect of cefazolin against MSSA may correspond to an increased likeliness of adverse clinical outcomes in patients receiving cefazolin for bacteraemia. The presence of β-lactamase enzymes was the primary mechanism responsible for an inoculum effect, but the observation of an inoculum effect in multiple pathogens lacking β-lactamase enzymes indicates that there are likely multiple mechanisms that may result in an inoculum effect. Further clinical studies are needed to better define whether interventions made in the clinic in response to organisms displaying an in vitro inoculum effect will optimize clinical outcomes.

Performance and impact of a multiplex PCR in ICU patients with ventilator-associated pneumonia or ventilated hospital-acquired pneumonia

BACKGROUND

Early appropriate antibiotic therapy reduces morbidity and mortality of severe pneumonia. However, the emergence of bacterial resistance requires the earliest use of antibiotics with the narrowest possible spectrum. The Unyvero Hospitalized Pneumonia (HPN, Curetis) test is a multiplex PCR (M-PCR) system detecting 21 bacteria and 19 resistance genes on respiratory samples within 5 h. We assessed the performance and the potential impact of the M-PCR on the antibiotic therapy of ICU patients.

METHODS

In this prospective study, we performed a M-PCR on bronchoalveolar lavage (BAL) or plugged telescoping catheter (PTC) samples of patients with ventilated HAP or VAP with Gram-negative bacilli or clustered Gram-positive cocci. This study was conducted in 3 ICUs in a French academic hospital: the medical and infectious diseases ICU, the surgical ICU, and the cardio-surgical ICU. A multidisciplinary expert panel simulated the antibiotic changes they would have made if the M-PCR results had been available.

RESULTS

We analyzed 95 clinical samples of ventilated HAP or VAP (72 BAL and 23 PTC) from 85 patients (62 males, median age 64 years). The median turnaround time of the M-PCR was 4.6 h (IQR 4.4-5). A total of 90/112 bacteria were detected by the M-PCR system with a global sensitivity of 80% (95% CI, 73-88%) and specificity of 99% (95% CI 99-100). The sensitivity was better for Gram-negative bacteria (90%) than for Gram-positive cocci (62%) (p = 0.005). Moreover, 5/8 extended-spectrum beta-lactamases (CTX-M gene) and 4/4 carbapenemases genes (3 NDM, one oxa-48) were detected. The M-PCR could have led to the earlier initiation of an effective antibiotic in 20/95 patients (21%) and to early de-escalation in 37 patients (39%) but could also have led to one (1%) inadequate antimicrobial therapy. Among 17 empiric antibiotic treatments with carbapenems, 10 could have been de-escalated in the following hours according to the M-PCR results. The M-PCR also led to 2 unexpected diagnosis of severe legionellosis confirmed by culture methods.

CONCLUSIONS

Our results suggest that the use of a M-PCR system for respiratory samples of patients with VAP and ventilated HAP could improve empirical antimicrobial therapy and reduce the use of broad-spectrum antibiotics.

Management of children with fever and neutropenia: results of a survey in 51 pediatric cancer centers in Germany, Austria, and Switzerland

Purpose

Investigation of the current practice of diagnostics and treatment in pediatric cancer patients with febrile neutropenia.

Methods

On behalf of the German Society for Pediatric Oncology and Hematology and the German Society for Pediatric Infectious Diseases, an Internet-based survey was conducted in 2016 concerning the management of febrile neutropenia in pediatric oncology centers (POC). This survey accompanied the release of the corresponding German guideline to document current practice before its implementation in clinical practice.

Results

In total, 51 POCs participated (response rate 73%; 43 from Germany, and 4 each from Austria and Switzerland). Identified targets for antimicrobial stewardship concerned blood culture diagnostics, documentation of the time to antibiotics, the use of empirical combination therapy, drug monitoring of aminoglycosides, the time to escalation in patients with persisting fever, minimal duration of IV treatment, sequential oral treatment in patients with persisting neutropenia, indication for and choice of empirical antifungal treatment, and the local availability of a pediatric infectious diseases consultation service.

Conclusion

This survey provides useful information for local antibiotic stewardship teams to improve the current practice referring to the corresponding national and international guidelines.

Electronic supplementary material

The online version of this article (10.1007/s15010-020-01462-z) contains supplementary material, which is available to authorized users.

Ceftolozane/Tazobactam for Treatment of Severe ESBL-Producing Enterobacterales Infections: A Multicenter Nationwide Clinical Experience (CEFTABUSE II Study)

Background

Few data are reported in the literature about the outcome of patients with severe extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) infections treated with ceftolozane/tazobactam (C/T), in empiric or definitive therapy.

Methods

A multicenter retrospective study was performed in Italy (June 2016-June 2019). Successful clinical outcome was defined as complete resolution of clinical signs/symptoms related to ESBL-E infection and lack of microbiological evidence of infection. The primary end point was to identify predictors of clinical failure of C/T therapy.

Results

C/T treatment was documented in 153 patients: pneumonia was the most common diagnosis (n = 46, 30%), followed by 34 cases of complicated urinary tract infections (22.2%). Septic shock was observed in 42 (27.5%) patients. C/T was used as empiric therapy in 46 (30%) patients and as monotherapy in 127 (83%) patients. Favorable clinical outcome was observed in 128 (83.7%) patients; 25 patients were considered to have failed C/T therapy. Overall, 30-day mortality was reported for 15 (9.8%) patients. At multivariate analysis, Charlson comorbidity index >4 (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.9-3.5; P = .02), septic shock (OR, 6.2; 95% CI, 3.8-7.9; P < .001), and continuous renal replacement therapy (OR, 3.1; 95% CI, 1.9-5.3; P = .001) were independently associated with clinical failure, whereas empiric therapy displaying in vitro activity (OR, 0.12; 95% CI, 0.01-0.34; P < .001) and adequate source control of infection (OR, 0.42; 95% CI, 0.14-0.55; P < .001) were associated with clinical success.

Conclusions

Data show that C/T could be a valid option in empiric and/or targeted therapy in patients with severe infections caused by ESBL-producing Enterobacterales. Clinicians should be aware of the risk of clinical failure with standard-dose C/T therapy in septic patients receiving CRRT.

Clinical and Microbiological Characteristics of Patients with Complicated Intra-abdominal Infections in Intensive Care Unit

In order to investigate the clinical and microbiological characteristics of patients with complicated intra-abdominal infections (cIAIs) in intensive care unit (ICU), the clinical data of 612 cIAIs patients from January 2016 to December 2018 were retrospectively collected. Clinical characteristics, distribution of pathogens and drug resistance were statistically analyzed. It was found that patients with community-acquired intra-abdominal infections (CA-IAIs) made up a majority of cIAIs patients. The positive rate of abdominal drainage fluid culture was 55.56%. Gramnegative bacteria accounted for the majority, the most commonly isolated bacteria of which were Escherichia coli (20.96%), Klebsiella pneumoniae (10.20%) and Pseudomonas aeruginosa (5.57%). The most commonly isolated gram-positive bacteria were Enterococcus (16.88%) and Methicillin-resistant staphylococcus aureus (MRSA, 3.90%). Enterobacter isolates showed high resistance rate to most cephalosporins and low resistance rate to piperacillin/tazobactam and carbapenems. Extended spectrum beta-lactamase (ESBL) screen positive isolates from CA-IAIs patients showed an increasing trend in past three years. Enterococcus and MRSA showed high resistance rate to clindamycin, quinolone, erythromycin and tetracycline, while they showed high sensitivity rate to linezolid, tegacycline, teicoplanin and vancomycin. Our results indicate that isolated bacteria from abdominal drainage fluid show high resistance rates to commonly used antibiotics in ICU patients with cIAIs. The curative effects on diseases should be monitored continuously when antibiotics are used. Meanwhile, we should always keep eyes on drug-resistant bacteria, especially when the treatment efficacy is not good.

Molecular Mechanisms and Epidemiology of Carbapenem-Resistant Escherichia coli Isolated from Chinese Patients During 2002-2017

Background

The emergence and spread of carbapenem-resistant Escherichia coli (E. coli) pose a serious threat to human health worldwide. This study aimed to investigate the molecular mechanisms underlying carbapenem resistance and their prevalence among E. coli in China.

Methods

A collection of 5796 E. coli clinical isolates were collected from the First Affiliated Hospital of Wenzhou Medical University from 2002 to 2017. Sensitivity to antibiotics was determined using the agar dilution method. The detection of carbapenemases production and the prevalence of resistance-associated genes were investigated through modified carbapenem inactivation method (mCIM), PCR and sequencing. The mutations in outer membrane porins genes (ompC and ompF) were also analyzed by PCR and sequencing assays. The effect of efflux pump mechanism on carbapenem resistance was also tested. E. coli were typed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).

Results

A total of 58 strains (1.0%) of carbapenem-resistant E. coli were identified. The strains carrying bla_KPC-2 and bla_NDM accounted for 22.4% (13/58) and 51.7% (30/58), respectively. Among bla_NDM- positive strains, 27 bla_NDM genes were assigned to bla_NDM-5, while the remaining three strains were bla_NDM-1, whereas bla_VIM, bla_IMP, bla_OXA-48, and bla_SHV were not found. The CTX-M-type β-lactamase genes accounted for 96.6% (56/58). In addition, bla_TEM-1 genes were identified in 58.6% of tested strains. In carbapenem-resistant isolates, mutations in OmpC (the majority of mutated sites were D192G and Q104_F141del, accounting for 54.5%) and OmpF (large deletions S75_V127del, W83_D135del and Q88_D135del) were detected. Of note, the antibiotic resistance was not associated with overexpression of efflux pump. Moreover, MLST categorized the 58 carbapenem-resistant isolates into 19 different sequence types. PFGE analysis revealed that homology among the carbapenem-resistant isolates was low and sporadic.

Conclusion

The bla_NDM was the principal resistance mechanism of carbapenem-resistant E. coli in the hospital. bla_NDM-5 is becoming a new threat to public health and the alteration of outer membrane porins might help further increase the MIC of carbapenem.

Carbapenem-Sparing Strategies for ESBL Producers: When and How

Extended spectrum β-lactamase (ESBL)-producing bacteria are prevalent worldwide and correlated with hospital infections, but they have been evolving as an increasing cause of community acquired infections. The spread of ESBL constitutes a major threat for public health, and infections with ESBL-producing organisms have been associated with poor outcomes. Established therapeutic options for severe infections caused by ESBL-producing organisms are considered the carbapenems. However, under the pressure of carbapenem overuse and the emergence of resistance, carbapenem-sparing strategies have been implemented. The administration of carbapenem-sparing antibiotics for the treatment of ESBL infections has yielded conflicting results. Herein, the current available knowledge regarding carbapenem-sparing strategies for ESBL producers is reviewed, and the optimal conditions for the "when and how" of carbapenem-sparing agents is discussed. An important point of the review focuses on piperacillin-tazobactam as the agent arousing the most debate. The most available data regarding non-carbapenem β-lactams (i.e., ceftolozane-tazobactam, ceftazidime-avibactam, temocillin, cephamycins and cefepime) are also thoroughly presented as well as non β-lactams (i.e., aminoglycosides, quinolones, tigecycline, eravacycline and fosfomycin).