Determinants of inappropriate empirical antibiotic treatment: systematic review and meta-analysis

Coinfections and antimicrobial treatment in a cohort of falciparum malaria in a non-endemic country: a 10-year experience

INTRODUCTION

Falciparum malaria remains one of the deadliest infectious diseases worldwide. In Germany, it is mainly an imported infection among travellers. Rates of coinfection are often unknown, and a clinical rationale for the beneficial use of calculated antibiotic therapy in patients with malaria and suspected coinfection is lacking.

METHODS

We conducted an analysis of all in-patients treated with falciparum malaria at a German infectious diseases centre in vicinity to one of Europe's major airports for 2010-2019. Logistic regression and time-to-event analysis were used to evaluate predictors for bacterial coinfection, the use of antibacterial substances, as well as their influence on clinical course.

RESULTS

In total, 264 patients were included. Of those, 64% received an additional antibacterial therapy (n = 169). Twenty-nine patients (11.0%) were found to have suffered from a relevant bacterial coinfection, while only a small fraction had relevant bacteremia (n = 3, 1.4%). However, patients with severe malaria did not suffer from coinfections more frequently (p = 0.283). CRP levels were not a reliable predictor for a bacterial coinfection (OR 0.99, 95% CI 0.94-1.06, p = 0.850), while another clinical focus of infection was positively associated (OR 3.86, 95% CI 1.45-11.55, p  = 0.010).

CONCLUSION

Although bacterial coinfections were rare in patients with malaria at our centre, the risk does not seem negligible. These data point rather towards individual risk assessment in respective patients than to general empiric antibiotic use.

Risk of multi-drug-resistant organism acquisition from prior bed occupants in the intensive care unit: a meta-analysis

Multi-drug-resistant organisms (MDROs) have become a global threat to human health. Prior bed occupancy with MDRO infection/colonization is an exposure factor that is closely associated with the MDRO acquisition rates in subsequent bed patients in intensive care units (ICUs). A meta-analysis was conducted to investigate the risk of MDRO acquisition from prior bed occupants in the ICU. PubMed, Cochrane Library, Web of Science, and Embase databases and reference lists were searched for articles published up to December 2021. The Newcastle-Ottawa scale was used for quality assessment. The risk measure was calculated as the odds ratio (OR) and corresponding 95% confidence interval (CI), and the heterogeneity was tested using I2 method and Q test. Eight articles were analysed using a random-effects model. Of the 8147 patients exposed to prior bed occupants infected or colonized with MDROs, 421 had acquired MDROs. The control group consisted of 55,933 patients without exposure factors, of which 1768 had been infected/colonized with MDROs. The pooled acquisition OR for MDROs was 1.80 (95% CI: 1.42, 2.29), P<0.00001. Subgroup analysis based on multi-drug-resistant Gram-positive and Gram-negative organisms was conducted using a fixed-effects model. The results significantly varied between the groups. Heterogeneity was partially explained by the MDRO type. In conclusion, exposure of bed occupants to infected/colonized MDROs significantly increased the risk of MDRO acquisition in subsequent bed occupants.

Determinants of Inadequate Empiric Antimicrobial Therapy in ICU Sepsis Patients in Al-Madinah Al-Munawwarah, Saudi Arabia: A Comparison of Artificial Neural Network and Regression Analysis

In the management of sepsis, providing adequate empiric antimicrobial therapy is one of the most important pillars of sepsis management. Therefore, it is important to evaluate the adequacy of empiric antimicrobial therapy (EAMT) in sepsis patients admitted to intensive care units (ICU) and to identify the determinants of inadequate EAMT. The aim of this study was to evaluate the adequacy of empiric antimicrobial therapy in patients admitted to the ICU with sepsis or septic shock, and the determinants of inadequate EAMT. The data of patients admitted to the ICU units due to sepsis or septic shock in two tertiary healthcare facilities in Al-Madinah Al-Munawwarah were retrospectively reviewed. The current study used logistic regression analysis and artificial neural network (ANN) analysis to identify determinants of inadequate empiric antimicrobial therapy, and evaluated the performance of these two approaches in predicting the inadequacy of EAMT. The findings of this study showed that fifty-three per cent of patients received inadequate EAMT. Determinants for inadequate EAMT were APACHE II score, multidrug-resistance organism (MDRO) infections, surgical history (lower limb amputation), and comorbidity (coronary artery disease). ANN performed as well as or better than logistic regression in predicating inadequate EAMT, as the receiver operating characteristic area under the curve (ROC-AUC) of the ANN model was higher when compared with the logistic regression model (LRM): 0.895 vs. 0.854. In addition, the ANN model performed better than LRM in predicting inadequate EAMT in terms of classification accuracy. In addition, ANN analysis revealed that the most important determinants of EAMT adequacy were the APACHE II score and MDRO. In conclusion, more than half of the patients received inadequate EAMT. Determinants of inadequate EAMT were APACHE II score, MDRO infections, comorbidity, and surgical history. This provides valuable inputs to improve the prescription of empiric antimicrobials in Saudi Arabia going forward. In addition, our study demonstrated the potential utility of applying artificial neural network analysis in the prediction of outcomes in healthcare research.

Appropriateness of Empirical Antibiotic Therapy in Hospitalized Patients with Bacterial Infection: A Retrospective Cohort Study

Objective

The incidence of inappropriate and excessive empirical antibiotic therapy is unclear. The aim of this study was to determine the prevalence of different empirical antibiotic therapy prescriptions, related factors, and outcomes in hospitalized patients with bacterial infection.

Methods

A retrospective cohort study was performed and patients with bacterial infection who were admitted between October 1, 2019, and September 30, 2020, were included. Multivariable analysis was performed by the logistic regression model.

Results

A total of 536 (42.6%) of the 1257 included patients received inappropriate empirical antibiotic therapy (IEAT), and 368 (29.3%) patients received appropriate but unnecessarily broad-spectrum empirical antibiotic therapy (AUEAT). MDRO (adjusted OR 2.932 [95% CI 2.201~3.905]; p < 0.001) and fever on admission (adjusted OR 0.592 [95% CI 0.415~0.844]; p = 0.004) were correlates of IEAT; sepsis (adjusted OR 2.342 [95% CI 1.371~3.999]; p = 0.002), age (adjusted OR 1.019 [95% CI 1.008~1.030]; p < 0.001), MDRO (adjusted OR 0.664 [95% CI 0.469~0.941]; p = 0.021), and urinary tract infection (adjusted OR 0.352 [95% CI 0.203~0.611]; p < 0.001) were correlates of AUEAT. Patients who received AUEAT were more likely to have a poor prognosis (63 [17.8%] vs 101 [27.4%]; p = 0.002). Both IEAT (median [IQR], 24,971 [13,135-70,155] vs 31,489 [14,894-101,082] CNY; p = 0.007) and AUEAT (median [IQR], 24,971 [13,135-70,155] vs 30,960 [16,475-90,881] CNY; p = 0.002) increased hospital costs. 45.3% (570/1257) of patients were infected with MDRO and 62.9% of them received IEAT.

Conclusion

Inappropriate and excessive empirical antibiotic use was widely prevalent among hospitalized patients. Either inappropriate or excessive use of antibiotics may increase the burden of healthcare costs, the latter of which may be associated with poor prognosis. Clinicians need to be more judicious in choosing antibiotic(s). The MDRO epidemic was severe, especially in patients who received IEAT. It is imperative to take effective measures to improve the current situation of antibiotic abuse and antimicrobial resistance.

Prediction of ciprofloxacin resistance in hospitalized patients using machine learning

BACKGROUND

Ciprofloxacin is a widely used antibiotic that has lost efficiency due to extensive resistance. We developed machine learning (ML) models that predict the probability of ciprofloxacin resistance in hospitalized patients.

METHODS

Data were collected from electronic records of hospitalized patients with positive bacterial cultures, during 2016-2019. Susceptibility results to ciprofloxacin (n = 10,053 cultures) were obtained for Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus. An ensemble model, combining several base models, was developed to predict ciprofloxacin resistant cultures, either with (gnostic) or without (agnostic) information on the infecting bacterial species.

RESULTS

The ensemble models' predictions are well-calibrated, and yield ROC-AUCs (area under the receiver operating characteristic curve) of 0.737 (95%CI 0.715-0.758) and 0.837 (95%CI 0.821-0.854) on independent test-sets for the agnostic and gnostic datasets, respectively. Shapley additive explanations analysis identifies that influential variables are related to resistance of previous infections, where patients arrived from (hospital, nursing home, etc.), and recent resistance frequencies in the hospital. A decision curve analysis reveals that implementing our models can be beneficial in a wide range of cost-benefits considerations of ciprofloxacin administration.

CONCLUSIONS

This study develops ML models to predict ciprofloxacin resistance in hospitalized patients. The models achieve high predictive ability, are well calibrated, have substantial net-benefit across a wide range of conditions, and rely on predictors consistent with the literature. This is a further step on the way to inclusion of ML decision support systems into clinical practice.

Risk factors associated with inappropriate empirical antimicrobial treatment in bloodstream infections. A cohort study

Introduction: Bloodstream infections (BSI) are a major cause of mortality all over the world. Inappropriate empirical antimicrobial treatment (i-EAT) impact on mortality has been largely reported. However, information on related factors for the election of i-EAT in the treatment of BSI in adults is lacking. The aim of the study was the identification of risk-factors associated with the use of i-EAT in BSI. Methods: A retrospective, observational cohort study, from a prospective database was conducted in a 400-bed acute-care teaching hospital including all BSI episodes in adult patients between January and December 2018. The main outcome variable was EAT appropriation. Multivariate analysis using logistic regression was performed. Results: 599 BSI episodes were included, 146 (24%) received i-EAT. Male gender, nosocomial and healthcare-associated acquisition of infection, a high Charlson Comorbidity Index (CCI) score and the isolation of multidrug resistant (MDR) microorganisms were more frequent in the i-EAT group. Adequation to local guidelines' recommendations on EAT resulted in 91% of appropriate empirical antimicrobial treatment (a-EAT). Patients receiving i-EAT presented higher mortality rates at day 14 and 30 when compared to patients with a-EAT (14% vs. 6%, p = 0.002 and 22% vs. 9%, p < 0.001 respectively). In the multivariate analysis, a CCI score ≥3 (OR 1.90 (95% CI 1.16-3.12) p = 0.01) and the isolation of a multidrug resistant (MDR) microorganism (OR 3.79 (95% CI 2.28-6.30), p < 0.001) were found as independent risk factors for i-EAT. In contrast, female gender (OR 0.59 (95% CI 0.35-0.98), p = 0.04), a correct identification of clinical syndrome prior to antibiotics administration (OR 0.26 (95% CI 0.16-0.44), p < 0.001) and adherence to local guidelines (OR 0.22 (95% CI 0.13-0.38), p < 0.001) were identified as protective factors against i-EAT. Conclusion: One quarter of BSI episodes received i-EAT. Some of the i-EAT related factors were unmodifiable (male gender, CCI score ≥3 and isolation of a MDR microorganism) but others (incorrect identification of clinical syndrome before starting EAT or the use of local guidelines for EAT) could be addressed to optimize the use of antimicrobials.

The time-varying association between previous antibiotic use and antibiotic resistance

OBJECTIVES

The objective of the study was to estimate how the time elapsed from previous antibiotic use is associated with antibiotic resistance.

METHODS

Data comprised electronic medical records of all patients in an Israeli hospital who had a positive bacterial culture from 2016 to 2019. These included susceptibility testing results and clinical and demographic data. Mixed-effects time-varying logistic models were fitted to estimate the association between the time elapsed since the last use of aminoglycosides and gentamicin resistance (n = 13 095), cephalosporins and ceftazidime resistance (n = 13 051), and fluoroquinolones and ciprofloxacin resistance (n = 15 364) while adjusting for multiple covariates.

RESULTS

For all examined antibiotics, previous antibiotic use had a statistically significant association with resistance (p < 0.001). These associations exhibited a clear decreasing pattern over time, which we present as a flexible function of time. Nonetheless, previous antibiotic use remained a significant risk factor for resistance for at least 180 days when the adjusted ORs were 1.94 (95% CI, 1.40-2.69), 1.33 (95% CI, 1.10-1.61), and 2.25 (95% CI, 1.49-3.41) for gentamicin, ceftazidime, and ciprofloxacin, respectively.

DISCUSSION

The association between prior antibiotic use and resistance decreases over time. Commonly used cut-offs for prior antibiotic use can either misclassify patients still at higher risk when too recent or provide a diluted estimate of the effects of antibiotic use on future resistance when too distant. Hence, prior antibiotic use should be considered a time-dependent risk factor for resistance in both epidemiological research and clinical practice.

New antimicrobial treatment options for severe Gram-negative infections

PURPOSE OF REVIEW

This review will provide rationale for the development of new antibiotics to treat severe or multidrug-resistant (MDR) Gram-negative infections. It will also provide an overview of recently approved and pipeline antibiotics for severe/MDR Gram-negative infections.

RECENT FINDINGS

MDR Gram-negative infections are recognized as critical threats by global and national organizations and carry a significant morbidity and mortality risk. Increasing antibiotic resistance amongst Gram-negative bacteria, including carbapenem-resistant Acinetobacter baumannii , extended-spectrum β-lactamase-producing Enterobacterales, carbapenem-resistant Enterobacterales and Pseudomonas aeruginosa , with difficult-to-treat-resistance has made both empiric and definitive treatment of these infections increasingly problematic. In recent years, several antibiotics have been approved for treatment of MDR Gram-negative infections and ongoing clinical trials are poised to provide additional options to clinicians' armamentarium. These agents include various β-lactam/β-lactamase inhibitor combinations, eravacycline, plazomicin and cefiderocol.

SUMMARY

Severe/MDR Gram-negative infections continue to be important infections due to their impact on patient outcomes, especially in critically ill and immunocompromised hosts. The availability of new antibiotics offers an opportunity to improve empiric and definitive treatment of these infections.

Plethora of Antibiotics Usage and Evaluation of Carbapenem Prescribing Pattern in Intensive Care Units: A Single-Center Experience of Malaysian Academic Hospital

Excessive antibiotic consumption is still common among critically ill patients admitted to intensive care units (ICU), especially during the coronavirus disease 2019 (COVID-19) period. Moreover, information regarding antimicrobial consumption among ICUs in South-East Asia remains scarce and limited. This study aims to determine antibiotics utilization in ICUs by measuring antibiotics consumption over the past six years (2016−2021) and specifically evaluating carbapenems prescribed in a COVID-19 ICU and a general intensive care unit (GICU) during the second year of the COVID-19 pandemic. (2) Methods: This is a retrospective cross-sectional observational analysis of antibiotics consumption and carbapenems prescriptions. Antibiotic utilization data were estimated using the WHO Defined Daily Doses (DDD). Carbapenems prescription information was extracted from the audits conducted by ward pharmacists. Patients who were prescribed carbapenems during their admission to COVID-19 ICU and GICU were included. Patients who passed away before being reviewed by the pharmacists were excluded. (3) Results: In general, antibiotics consumption increased markedly in the year 2021 when compared to previous years. Majority of carbapenems were prescribed empirically (86.8%). Comparing COVID-19 ICU and GICU, the reasons for empirical carbapenems therapy in COVID-19 ICU was predominantly for therapy escalation (64.7% COVID-19 ICU vs. 34% GICU, p < 0.001), whereas empirical prescription in GICU was for coverage of extended-spectrum beta-lactamases (ESBL) gram-negative bacteria (GNB) (45.3% GICU vs. 22.4% COVID-19 ICU, p = 0.005). Despite microbiological evidence, the empirical carbapenems were continued for a median (interquartile range (IQR)) of seven (5−8) days. This implies the need for a rapid diagnostic assay on direct specimens, together with comprehensive antimicrobial stewardship (AMS) discourse with intensivists to address this issue.

The 2021 Dutch Working Party on Antibiotic Policy (SWAB) guidelines for empirical antibacterial therapy of sepsis in adults

BACKGROUND

The Dutch Working Party on Antibiotic Policy (SWAB) in collaboration with relevant professional societies, has updated their evidence-based guidelines on empiric antibacterial therapy of sepsis in adults.

METHODS

Our multidisciplinary guideline committee generated ten population, intervention, comparison, and outcome (PICO) questions relevant for adult patients with sepsis. For each question, a literature search was performed to obtain the best available evidence and assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The quality of evidence for clinically relevant outcomes was graded from high to very low. In structured consensus meetings, the committee formulated recommendations as strong or weak. When evidence could not be obtained, recommendations were provided based on expert opinion and experience (good practice statements).

RESULTS

Fifty-five recommendations on the antibacterial therapy of sepsis were generated. Recommendations on empiric antibacterial therapy choices were differentiated for sepsis according to the source of infection, the potential causative pathogen and its resistance pattern. One important revision was the distinction between low, increased and high risk of infection with Enterobacterales resistant to third generation cephalosporins (3GRC-E) to guide the choice of empirical therapy. Other new topics included empirical antibacterial therapy in patients with a reported penicillin allergy and the role of pharmacokinetics and pharmacodynamics to guide dosing in sepsis. We also established recommendations on timing and duration of antibacterial treatment.

CONCLUSIONS

Our multidisciplinary committee formulated evidence-based recommendations for the empiric antibacterial therapy of adults with sepsis in The Netherlands.

Cross-roads for meta-analysis and network meta-analysis of H. pylori therapy

Helicobacter pylori infections are responsible for tremendous morbidity and mortality worldwide, leading to efforts to eradicate the organism. However, the effectiveness of antimicrobial therapy has been undermined by the progressive development of antimicrobial resistance. Treatments and treatment guidelines have been based on traditional pairwise meta-analyses of randomised controlled trials. More recently, network meta-analyses have also been used in an attempt to provide useful information to the clinician regarding which therapies appear best and which to avoid as the least efficacious. However, both forms of meta-analysis have been undermined by the same problems including the poor quality of the clinical trials using unoptimised regimens and incomparable comparisons related to marked geographic and ethnic genotypic and phenotypic heterogeneity. In addition, the comparator regimens often consist of invalid strawman comparisons. New approaches concerning H. pylori treatment and analysis of therapies are needed. H. pylori therapies should be based on antimicrobial stewardship, as in other infectious diseases. This approach requires the use of only optimised therapies proven to be reliably highly effective in the local population (eg, a cure rate of >90%) for both the study and the comparator regimens. Meta-analyses should be restricted to regimens that meet these criteria and must take into account the presence of marked geographical and host genetic and phenotypic heterogeneity. In addition, to provide clinically relevant results, treatment outcomes should focus on, and present, actual cure rates in addition to odd ratios.

Characteristics and Outcomes of Bloodstream Infections in a Tertiary-Care Pediatric Hematology-Oncology Unit: A 10-Year Study

Bloodstream infections (BSIs) after chemotherapy or hematopoietic stem cell transplantation (HSCT) are a leading cause of morbidity and mortality. Data on 154 BSIs that occurred in 111 onco-hematological patients (57 hematological malignancies, 28 solid tumors, and 26 non-malignant hematological diseases) were retrospectively collected and analyzed. Monomicrobial Gram-positive (GP), Gram-negative (GN), and fungal BSIs accounted for 50% (77/154), 38.3% (59/144), and 3.2% (5/154) of all episodes. Polymicrobial infections were 7.8% (12/154), while mixed bacterial-fungal infections were 0.6% (1/154). The most frequent GN isolates were Escherichia coli (46.9%), followed by Pseudomonas aeruginosa (21.9%), Klebsiella species (18.8%), and Enterobacter species (6.3%). Overall, 18.8% (12/64) of GN organisms were multidrug-resistant (seven Escherichia coli, three Klebsiella pneumoniae, and two Enterobacter cloacae), whereas GP resistance to glycopeptides was observed in 1% (1/97). Initial empirical antibiotic therapy was deemed inappropriate in 12.3% of BSIs (19/154). The 30-day mortality was 7.1% (11/154), while the bacteremia-attributable mortality was 3.9% (6/154). In multivariate analysis, septic shock was significantly associated with 30-day mortality (p = 0.0001). Attentive analysis of epidemiology and continuous microbiological surveillance are essential for the appropriate treatment of bacterial infections in pediatric onco-hematological patients.

A Multicenter Clinical Study To Demonstrate the Diagnostic Accuracy of the GenMark Dx ePlex Blood Culture Identification Gram-Negative Panel

Bacteremia can progress to septic shock and death without appropriate medical intervention. Increasing evidence supports the role of molecular diagnostic panels in reducing the clinical impact of these infections through rapid identification of the infecting organism and associated antimicrobial resistance genes. We report the results of a multicenter clinical study assessing the performance of the GenMark Dx ePlex investigational-use-only blood culture identification Gram-negative panel (BCID-GN), a rapid diagnostic assay for detection of bloodstream pathogens in positive blood culture (PBC) bottles. Prospective, retrospective, and contrived samples were tested. Results from the BCID-GN were compared to standard-of-care bacterial identification methods. Antimicrobial resistance genes (ARGs) were identified using PCR and sequence analysis. The final BCID-GN analysis included 2,444 PBC samples, of which 926 were clinical samples with negative Gram stain results. Of these, 109 samples had false-negative and/or -positive results, resulting in an overall sample accuracy of 88.2% (817/926). After discordant resolution, overall sample accuracy increased to 92.9% (860/926). Pre- and postdiscordant resolution sample accuracy excludes 37 Gram-negative organisms representing 20 uncommon genera, 10 Gram-positive organisms, and 1 Candida species present in 5% of samples that are not targeted by the BCID-GN. The overall weighted positive percent agreement (PPA), which averages the individual PPAs from the 27 targets (Gram-negative and ARG), was 94.9%. The limit of detection ranged from 10⁴ to 10⁷ CFU/ml, except for one strain of Fusobacterium necrophorum at 10⁸ CFU/ml.

Nosocomial Infection

OBJECTIVE

The first 70 years of critical care can be considered a period of "industrial revolution-like" advancement in terms of progressing the understanding and care of critical illness. Unfortunately, like the industrial revolution's impact on the environment, advancing ICU care of increasingly elderly, immunosuppressed, and debilitated individuals has resulted in a greater overall burden and complexity of nosocomial infections within modern ICUs. Given the rapid evolution of nosocomial infections, the authors provide an updated review.

DATA SOURCES AND STUDY SELECTION

We searched PubMed and OVID for peer-reviewed literature dealing with nosocomial infections in the critically ill, as well as the websites of government agencies involved with the reporting and prevention of nosocomial infections. Search terms included nosocomial infection, antibiotic resistance, microbiome, antibiotics, and intensive care.

DATA EXTRACTION AND DATA SYNTHESIS

Nosocomial infections in the ICU setting are evolving in multiple domains including etiologic pathogens plus novel or emerging pathogens, prevalence, host risk factors, antimicrobial resistance, interactions of the host microbiome with nosocomial infection occurrence, and understanding of pathogenesis and prevention strategies. Increasing virulence and antimicrobial resistance of nosocomial infections mandate increasing efforts toward their prevention.

CONCLUSIONS

Nosocomial infections are an important determinant of outcome for patients in the ICU setting. Systematic research aimed at improving the prevention and treatment of nosocomial infections is still needed.

The role of combination therapy in the treatment of severe infections caused by carbapenem resistant gram-negatives: a systematic review of clinical studies

BACKGROUND

Effective treatment of sepsis due to carbapenem-resistant Gram-negative bacteria (CR-GNB) remains a challenge for clinicians worldwide. In recent years, the combination of antibiotics has become the preferred treatment strategy for CR-GNB infection. However, robust evidence to support this approach is lacking. This systematic review aimed at critically evaluating all available antibiotic options for CR-GNB sepsis with particular focus on combination.

METHODS

We systematically searched published literature from January 1945 until December 2018 for observational comparative and non-comparative studies and randomized trials examining any antibiotic option for CR-GNB. Studies were included if reporting microbiologically-confirmed infection caused by Acinetobacter baumannii, Enterobacteriaceae/Klebsiella spp., or Pseudomonas aeruginosa, reporting at least one of the study outcomes, and definitive antibiotic treatment. Carbapenem-resistance was defined as phenotypically-detected in vitro resistance to at least one of the following carbapenems: doripenem, ertapenem, imipenem, meropenem. Each antibiotic regimen was classified as "defined" when at least the molecular class(es) composing the regimen was detailed. Primary outcomes were 30-day and attributable mortality. Bayesian network meta-analysis (NMA) approach was selected for quantitative synthesis to explore feasibility of pooling data on antibiotic regimens.

RESULTS

A total of 6306 records were retrieved and 134 studies including 11,546 patients were included: 54 studies were on Acinetobacter, 52 on Enterobacteriaceae/Klebsiella, 21 on mixed Gram-negative, and 7 on Pseudomonas. Nine (7%) were RCTs; 19 prospective cohorts (14%), 89 (66%) retrospective, and 17 (13%) case series. Forty-one studies (31%) were multicentric. Qualitative synthesis showed an heterogeneous and scattered reporting of key-clinical and microbiological variables across studies. Ninety-two distinct antibiotic regimens were identified with 47 of them (51%, 5863 patients) not reporting any details on numbers, type, dosage and in vitro activity of the included antibiotic molecules. The NMAs could not be performed for any of the selected outcome given the presence of too many disconnected components.

CONCLUSION

The existing evidence is insufficient to allowing for the formulation of any evidence-based therapeutic recommendation for CR-GNB sepsis. Future studies must provide a standardized definition of antibiotic regimen to drive recommendations for using combination of antibiotics that can be reliably applied to clinical practice.

Impact of Sepsis Flow Chip, a novelty fast microbiology method, in the treatment of bacteremia caused by Gram-negative bacilli

Objective

The aim of this study was to assess the impact of the information provided by the new Sepsis Chip Flow system (SFC) and other fast microbiological techniques on the selection of the appropriate antimicrobial treatment by the clinical researchers of an antimicrobial stewardship team.

Methods

Two experienced clinical researchers performed the theoretical exercise of independently selecting the treatment for patients diagnosed by bacteremia due to bacilli gram negative (BGN). At first, the clinicians had only available the clinical characteristics of 74 real patients. Sequentially, information regarding the Gram stain, MALDI-TOF, and SFC from Vitro were provided. Initially, the researchers prescribed an antimicrobial therapy based on the clinical data, later these data were complementing with information from microbiological techniques, and the clinicians made their decisions again.

Results

The data provided by the Gram stain reduced the number of patients prescribed with combined treatments (for clinician 1, from 23 to 7, and for clinician 2, from 28 to 12), but the use of carbapenems remained constant. In line with this, the data obtained by the MALDI-TOF also decreased the combined treatment, and the use of carbapenems remained unchanged. By contrast, the data on antimicrobial resistance provided by the SFC reduced the carbapenems treatment.

Conclusions

From the theoretical model the Gram stain and the MALDI-TOF results achieved a reduction in the combined treatment. However, the new system tested (SFC), due to the resistance mechanism data provided, not only reduced the combined treatment, it also decreased the prescription of the carbapenems.

Mortality review as a tool to assess the contribution of healthcare-associated infections to death: results of a multicentre validity and reproducibility study, 11 European Union countries, 2017 to 2018

IntroductionThe contribution of healthcare-associated infections (HAI) to mortality can be estimated using statistical methods, but mortality review (MR) is better suited for routine use in clinical settings. The European Centre for Disease Prevention and Control recently introduced MR into its HAI surveillance.AimWe evaluate validity and reproducibility of three MR measures.MethodsThe on-site investigator, usually an infection prevention and control doctor, and the clinician in charge of the patient independently reviewed records of deceased patients with bloodstream infection (BSI), pneumonia, Clostridioides difficile infection (CDI) or surgical site infection (SSI), and assessed the contribution to death using 3CAT: definitely/possibly/no contribution to death; WHOCAT: sole cause/part of causal sequence but not sufficient on its own/contributory cause but unrelated to condition causing death/no contribution, based on the World Health Organization's death certificate; QUANT: Likert scale: 0 (no contribution) to 10 (definitely cause of death). Inter-rater reliability was assessed with weighted kappa (wk) and intra-cluster correlation coefficient (ICC). Reviewers rated the fit of the measures.ResultsFrom 2017 to 2018, 24 hospitals (11 countries) recorded 291 cases: 87 BSI, 113 pneumonia , 71 CDI and 20 SSI. The inter-rater reliability was: 3CAT wk 0.68 (95% confidence interval (CI): 0.61-0.75); WHOCAT wk 0.65 (95% CI: 0.58-0.73); QUANT ICC 0.76 (95% CI: 0.71-0.81). Inter-rater reliability ranged from 0.72 for pneumonia to 0.52 for CDI. All three measures fitted 'reasonably' or 'well' in > 88%.ConclusionFeasibility, validity and reproducibility of these MR measures was acceptable for use in HAI surveillance.

Antimicrobial Lessons From a Large Observational Cohort on Intra-abdominal Infections in Intensive Care Units

Severe intra-abdominal infection commonly requires intensive care. Mortality is high and is mainly determined by disease-specific characteristics, i.e. setting of infection onset, anatomical barrier disruption, and severity of disease expression. Recent observations revealed that antimicrobial resistance appears equally common in community-acquired and late-onset hospital-acquired infection. This challenges basic principles in anti-infective therapy guidelines, including the paradigm that pathogens involved in community-acquired infection are covered by standard empiric antimicrobial regimens, and second, the concept of nosocomial acquisition as the main driver for resistance involvement. In this study, we report on resistance profiles of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecalis and Enterococcus faecium in distinct European geographic regions based on an observational cohort study on intra-abdominal infections in intensive care unit (ICU) patients. Resistance against aminopenicillins, fluoroquinolones, and third-generation cephalosporins in E. coli, K. pneumoniae and P. aeruginosa is problematic, as is carbapenem-resistance in the latter pathogen. For E. coli and K. pneumoniae, resistance is mainly an issue in Central Europe, Eastern and South-East Europe, and Southern Europe, while resistance in P. aeruginosa is additionally problematic in Western Europe. Vancomycin-resistance in E. faecalis is of lesser concern but requires vigilance in E. faecium in Central and Eastern and South-East Europe. In the subcohort of patients with secondary peritonitis presenting with either sepsis or septic shock, the appropriateness of empiric antimicrobial therapy was not associated with mortality. In contrast, failure of source control was strongly associated with mortality. The relevance of these new insights for future recommendations regarding empiric antimicrobial therapy in intra-abdominal infections is discussed.

Local audit of empiric antibiotic therapy in bacteremia: A retrospective cohort study

Background

It is unclear if a local audit would be useful in providing guidance on how to improve local practice of empiric antibiotic therapy. We performed an audit of antibiotic therapy in bacteremia to evaluate the proportion and risk factors for inadequate empiric antibiotic coverage.

Methods

This retrospective cohort study included patients with positive blood cultures across 3 hospitals in Hamilton, Ontario, Canada during October of 2019. Antibiotic therapy was considered empiric if it was administered within 24 hours after blood culture collection. Adequate coverage was defined as when the isolate from blood culture was tested to be susceptible to the empiric antibiotic. A multivariable logistic regression model was used to predict inadequate empiric coverage. Diagnostic accuracy of a clinical pathway based on patient risk factors was compared to clinician’s decision in predicting which bacteria to empirically cover.

Results

Of 201 bacteremia cases, empiric coverage was inadequate in 56 (27.9%) cases. Risk factors for inadequate empiric coverage included unknown source at initiation of antibiotic therapy (adjusted odds ratio (aOR) of 2.76 95% CI 1.27–6.01, P = 0.010) and prior antibiotic therapy within 90 days (aOR of 2.46 95% CI 1.30–4.74, P = 0.006). A clinical pathway that considered community-associated infection as low risk for Pseudomonas was better at ruling out Pseudomonas bacteremia with a negative likelihood ratio of 0.17 (95% CI 0.03–1.10) compared to clinician’s decision with negative likelihood ratio of 0.34 (95% CI 0.10–1.22).

Conclusions

An audit of antibiotic therapy in bacteremia is feasible and may provide useful feedback on how to locally improve empiric antibiotic therapy.

Effect on 30-day mortality and duration of hospitalization of empirical antibiotic therapy in CRGNB-infected pneumonia

BACKGROUND

The objective of this study was to investigate whether unreasonable empirical antibiotic treatment (UEAT) had an impact on 30-day mortality and duration of hospitalization in bacterial pneumonia caused by carbapenem-resistant gram-negative bacteria (CRGNB).

METHODS

This was a retrospective cohort study involving CRGNB-infected pneumonia. All CRGNB-infected pneumonia patients received empirical and targeted antibiotic treatment (TAT), and they were divided into reasonable empirical antibiotic treatment (REAT) and UEAT according to whether the empirical antibiotic treatment (EAT) was reasonable. The data of the two groups were compared to analyze their influence on the 30-day mortality and hospitalization time in CRGNB-infected pneumonia patients. Moreover, we also considered other variables that might be relevant and conducted multivariable regression analysis of 30-day mortality and duration of hospitalization in CRGNB-infected pneumonia patients.

RESULTS

The study collected 310 CRGNB-infected pneumonia patients, the most common bacterium is Acinetobacter baumannii (211/310 [68%]), the rest were Klebsiella pneumoniae (46/310 [15%]), Pseudomonas aeruginosa and others (53/310 [17%]). Among them, 76/310 (24.5%) patients received REAT. In the analysis of risk factors, dementia, consciousness were risk factors of 30-day mortality, pulmonary disease, hemodynamic support at culture taken day and recent surgery were risk factors for longer hospital stay. The analysis of 30-day mortality showed that UEAT was not associated with 30-day mortality for the 30-day mortality of REAT and UEAT were 9 of 76 (11.84%) and 36 of 234 (15.38%) (P = 0.447), respectively. Meanwhile, there was difference between REAT and UEAT (P = 0.023) in the analysis of EAT on hospitalization time in CRGNB-infected pneumonia patients.

CONCLUSIONS

UEAT was not associated with 30-day mortality while was related to duration of hospitalization in CRGNB-infected pneumonia patients, in which Acinetobacter baumanniii accouned for the majority.

A game theoretic approach reveals that discretizing clinical information can reduce antibiotic misuse

The overuse of antibiotics is exacerbating the antibiotic resistance crisis. Since this problem is a classic common-goods dilemma, it naturally lends itself to a game-theoretic analysis. Hence, we designed a model wherein physicians weigh whether antibiotics should be prescribed, given that antibiotic usage depletes its future effectiveness. The physicians' decisions rely on the probability of a bacterial infection before definitive laboratory results are available. We show that the physicians' equilibrium decision rule of antibiotic prescription is not socially optimal. However, we prove that discretizing the information provided to physicians can mitigate the gap between their equilibrium decisions and the social optimum of antibiotic prescription. Despite this problem's complexity, the effectiveness of the discretization solely depends on the type of information available to the physician to determine the nature of infection. This is demonstrated on theoretic distributions and a clinical dataset. Our results provide a game-theory based guide for optimal output of current and future decision support systems of antibiotic prescription.

Impact of an Antimicrobial Stewardship Program-bundled initiative utilizing Accelerate Pheno™ system in the management of patients with aerobic Gram-negative bacilli bacteremia

Purpose

Gram-negative bacteria (GNB) are a leading cause of bloodstream infections (BSI) and management is complicated by antibiotic resistance. The Accelerate Pheno™ system (ACC) can provide rapid organism identification and antimicrobial susceptibility testing (AST).

Methods

A retrospective, pre-intervention/post-intervention study was conducted to compare management of non-critically ill patients with GNB BSI before and after implementation of a bundled initiative. This bundled initiative included dissemination of a clinical decision algorithm, ACC testing on all GNB isolated from blood cultures, real-time communication of results to the Antimicrobial Stewardship Program (ASP), and prospective audit with feedback by the ASP. The pre-intervention period was January 2018 through December 2018, and the post-intervention period was May 2019 through February 2020.

Results

Seventy-seven and 129 patients were included in the pre-intervention and post-intervention cohorts, respectively. When compared with the pre-intervention group, the time from Gram stain to AST decreased from 46.1 to 6.9 h (p < 0.001), and the time to definitive therapy (TTDT) improved from 32.6 to 10.5 h (p < 0.001). Implementation led to shorter median total duration of antibiotic therapy (14.2 vs 9.5 days; p < 0.001) and mean hospital length of stay (7.9 vs 5.3 days; p = 0.047) without an increase in 30-day readmissions (22.1% vs 14%; p = 0.13).

Conclusion

Implementation of an ASP-bundled approach incorporating the ACC aimed at optimizing antibiotic therapy in the management GNB BSI in non-critically ill patients led to reduced TTDT, shorter duration of antibiotic therapy, and shorter hospital length of stay without adversely affecting readmission rates.

Microbiological profiles and antimicrobial resistance patterns of pediatric bloodstream pathogens in China, 2016-2018

OBJECTIVES

This study aimed to investigate the microbiological profiles and antimicrobial resistance patterns of bloodstream pathogens in Chinese children.

METHODS

This retrospective study was conducted at 13 tertiary hospitals in China during 2016-2018. The first bloodstream isolates of the same species from one pediatric patient < 18 years were included to this study for analysis. Antimicrobial susceptibility testing was determined based on minimum inhibitory concentrations or Kirby-Bauer disk diffusion methods according to the 2018 Clinical and Laboratory Standards Institute guidelines.

RESULTS

Overall, 9345 nonduplicate bloodstream isolates were collected. Top 10 pathogens included Coagulase-negative staphylococcus (CoNS) (44.4%), Escherichia coli (10.2%), Klebsiella pneumoniae (5.9%), Staphylococcus aureus (5.0%), Streptococcus pneumoniae (4.9%), Pseudomonas aeruginosa(2.8%), Enterococcus faecium (2.7%), Stenotrophomonas maltophilia (2.4%), Salmonella spp. (2.3%), and Streptococcus agalactiae (2.0%). The commonest pathogens apart from CoNS in age group 0-28 days, 29 days-2 months, 3-11 months, 1-5 years, and ≥ 5 years were Escherichia coli (17.2%), Escherichia coli (14.0%), Escherichia coli (7.9%), Streptococcus pneumoniae (10.7%) ,and Staphylococcus aureus (13.6%), respectively. The overall prevalence of extended-spectrum β-lactamases-producing Enterobacteriaceae, carbapenem-resistant Klebsiella pneumoniae, carbapenem-resistant Acinetobacter baumannii, and carbapenem-resistant Pseudomonas aeruginosa were 41.4, 28.4, 31.7, and 5.6%, respectively. The overall prevalence of methicillin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae and vancomycin-resistant Enterococcus was 38.1, 28.3, and 0.7%, respectively.

CONCLUSIONS

The major bacterial pathogens have differences in different age groups, ward types, and regions in Chinese children, and the commonest causing microorganism was the Escherichia coli, especially in neonates and infants. High prevalence of important resistant phenotypes is of a serious concern.

Predicting antibiotic resistance in hospitalized patients by applying machine learning to electronic medical records

BACKGROUND

Computerized decision support systems are becoming increasingly prevalent with advances in data collection and machine learning algorithms. However, they are scarcely used for empiric antibiotic therapy. Here we accurately predict the antibiotic resistance profiles of bacterial infections of hospitalized patients using machine learning algorithms applied to patients' electronic medical records (EMR).

METHODS

The data included antibiotic resistance results of bacterial cultures from hospitalized patients, alongside their electronic medical records. Five antibiotics were examined: Ceftazidime (n=2942), Gentamicin (n=4360), Imipenem (n=2235), Ofloxacin (n=3117) and Sulfamethoxazole-Trimethoprim (n=3544). We applied lasso logistic regression, neural networks, gradient boosted trees, and an ensemble combining all three algorithms, to predict antibiotic resistance. Variable influence was gauged by permutation tests and Shapely Additive Explanations analysis.

RESULTS

The ensemble model outperformed the separate models and produced accurate predictions on a test set data. When no knowledge regarding the infecting bacterial species was assumed, the ensemble model yielded area under the receiver-operating-characteristic (auROC) scores of 0.73-0.79, for different antibiotics. Including information regarding the bacterial species improved the auROCs to 0.8-0.88. The effects of different variables on the predictions were assessed and found consistent with previously identified risk factors for antibiotic resistance.

CONCLUSIONS

Our study demonstrates the potential of machine learning models to accurately predict antibiotic resistance of bacterial infections of hospitalized patients. Moreover, we show that rapid information regarding the infecting bacterial species can improve predictions substantially. The implementation of such systems should be seriously considered by clinicians to aid correct empiric therapy and to potentially reduce antibiotic misuse.

Perfil microbiologico y de resistencia antimicrobiana en infecciones adquiridas en la comunidad. Hospital Universitario San José de Popayán

Objetivo. Describir el perfil microbiológico y de resistencia bacteriana de los aislamientos en adultos con infecciones adquiridas en comunidad en el Hospital Universitario San José de junio 2016 a diciembre 2019. Metodología. Se realizó un estudio descriptivo de corte transversal, análisis retrospectivo de los aislamientos microbiológicos en adultos desde junio 2016 a diciembre 2019, basado en la data institucional. Se analizó la información con STATA15,0. Se obtuvo la aprobación del comité de ética del hospital. Resultados. Se incluyeron 5121 aislamientos microbiológicos, el 61% en el servicio de urgencias. El urocultivo fue la muestra más frecuente. E. coli fue el germen más común tanto a nivel general como en urocultivos, hemocultivos y cultivos de líquido peritoneal. La resistencia a ampicilina y amp/sul fue elevada, hasta del 68% para E. coli. El 20% de los S. aureus fueron resistentes a meticilina. Se observó una resistencia inusual a carbapenémicos por parte de P. aeruginosa. Discusión. El perfil microbiológico concuerda con la literatura mundial y nacional, sin embargo, el HUSJ tiene un comportamiento microbiológico que debe ser estudiado a profundidad. Conclusión. Los porcentajes de resistencia a antibióticos de uso frecuente son elevados. Se requiere ajustes de las guías de manejo institucionales y nacionales.

In vitro efficacy of ceftazidime-avibactam, aztreonam-avibactam and other rescue antibiotics against carbapenem-resistant Enterobacterales from the Arabian Peninsula

OBJECTIVES

Our aim was to assess the susceptibility of carbapenem-resistant Enterobacterales (CRE) from the Arabian Peninsula to a broad spectrum of antibiotics, including fosfomycin, ceftazidime-avibactam, and aztreonam-avibactam.

METHODS

1192 non-repeat CRE isolated in 2009-2017 from 33 hospitals in five countries of the Arabian Peninsula were tested. The minimum inhibitory concentration of 14 antibiotics was determined. Carbapenemase and 16S methylase genes were detected by PCR. Clonality was assessed by PFGE.

RESULTS

The highest rate of susceptibility was detected to aztreonam-avibactam (95.5%) followed by colistin (79.8%), fosfomycin (71.8%) and tigecycline (59.9%). Isolates co-producing two carbapenemases (12.4%) were the least susceptible. Aminoglycoside susceptibility was affected by the frequent production of a 16S methylase. Susceptibility to ceftazidime-avibactam was impacted by the high rate of metallo-beta-lactamase producers (46.3%), while aztreonam-avibactam resistance occurred mostly in clonally unrelated, carbapenemase non-producing Escherichia coli.

CONCLUSION

Of the currently available drugs: colistin, tigecycline, and ceftazidime-avibactam co-administered with aztreonam appear to be the most effective to treat CRE infections. However, the presence of non-clonal CRE isolates, in which avibactam does not lower the aztreonam MIC below the clinical breakpoint, is of notable concern. Based on the relatively high rate of fosfomycin susceptibility, it would be desirable to license parenteral fosfomycin in the region.

Paving the Way for the Implementation of a Decision Support System for Antibiotic Prescribing in Primary Care in West Africa: Preimplementation and Co-Design Workshop With Physicians

Background

Suboptimal use of antibiotics is a driver of antimicrobial resistance (AMR). Clinical decision support systems (CDSS) can assist prescribers with rapid access to up-to-date information. In low- and middle-income countries (LMIC), the introduction of CDSS for antibiotic prescribing could have a measurable impact. However, interventions to implement them are challenging because of cultural and structural constraints, and their adoption and sustainability in routine clinical care are often limited. Preimplementation research is needed to ensure relevant adaptation and fit within the context of primary care in West Africa.

Objective

This study examined the requirements for a CDSS adapted to the context of primary care in West Africa, to analyze the barriers and facilitators of its implementation and adaptation, and to ensure co-designed solutions for its adaptation and sustainable use.

Methods

We organized a workshop in Burkina Faso in June 2019 with 47 health care professionals representing 9 West African countries and 6 medical specialties. The workshop began with a presentation of Antibioclic, a publicly funded CDSS for antibiotic prescribing in primary care that provides personalized antibiotic recommendations for 37 infectious diseases. Antibioclic is freely available on the web and as a smartphone app (iOS, Android). The presentation was followed by a roundtable discussion and completion of a questionnaire with open-ended questions by participants. Qualitative data were analyzed using thematic analysis.

Results

Most of the participants had access to a smartphone during their clinical consultations (35/47, 74%), but only 49% (23/47) had access to a computer and none used CDSS for antibiotic prescribing. The participants considered that CDSS could have a number of benefits including updating the knowledge of practitioners on antibiotic prescribing, improving clinical care and reducing AMR, encouraging the establishment of national guidelines, and developing surveillance capabilities in primary care. The most frequently mentioned contextual barrier to implementing a CDSS was the potential risk of increasing self-medication in West Africa, where antibiotics can be bought without a prescription. The need for the CDSS to be tailored to the local epidemiology of infectious diseases and AMR was highlighted along with the availability of diagnostic tests and antibiotics using national guidelines where available. Participants endorsed co-design involving all stakeholders, including nurses, midwives, and pharmacists, as central to any introduction of CDSS. A phased approach was suggested by initiating and evaluating CDSS at a pilot site, followed by dissemination using professional networks and social media. The lack of widespread internet access and computers could be circumvented by a mobile app with an offline mode.

Conclusions

Our study provides valuable information for the development and implementation of a CDSS for antibiotic prescribing among primary care prescribers in LMICs and may, in turn, contribute to improving antibiotic use, clinical outcomes and decreasing AMR.

In vitro evaluation of double carbapenem and colistin combinations against OXA-48, NDM carbapenemase-producing colistin-resistant Klebsiella pneumoniae strains

BACKGROUND

Treatment of pandrug-resistant isolates often necessitates combination therapy. Checkerboard synergy and time-killing assay tests were performed to evaluate the benefits of a triple combination with meropenem, ertapenem, and colistin against 10 colistin-resistant K. pneumoniae clinical isolates harboring different β-lactamases. (bla_OXA-48, bla_NDM).

MATERIALS AND METHODS

In this study, ertapenem and meropenem (ERT/MEM), meropenem and colistin (MEM/COL), ertapenem, meropenem and colistin (ERT/MEM/COL) combinations were tested using checkerboard techniques and time-kill assays of each antibiotic alone and in combination against 10 colistin-resistant clinical K. pneumoniae isolates. An analysis of K. pneumoniae isolate B6 using a scanning electron microscope revealed morphologic changes in the cell surface after treatment with each antibiotic both alone and in combination. The whole genome of K. pneumoniae KPNB1 was sequenced using an Ion Torrent PGM sequencer.

RESULTS

According to the checkboard results, synergistic combinations were observed with ertapenem/meropenem (5/10 isolates), meropenem/colistin (7/10) and ertapenem/meropenem/colistin (9/10); no antagonism was observed for all combinations. For the time-kill assay results; synergism and bactericidal effects were observed with meropenem/colistin (10/10) and with ertapenem/meropenem/colistin (10/10) combinations, and an indifference effect was observed with the ertapenem and meropenem (10/10) combination. Strain number 1 was found 100% identical to Klebsiella pneumoniae subsp. pneumoniae HS11286 according to the outcomes of complete genome sequence analysis, and the strain carried the genes bla_OXA-181, bla_CTXM-15, blaNDM, arr-3, aac (6')-Ib-cr, rmtF, and catB1.

CONCLUSION

Using double carbapenem antibiotics with colistin could be a potential alternative to treat colistin and carbapenem-resistant K. pneumoniae. The present study is the first Turkish report of OXA-181-type carbapenemase causing colistin resistance.

Variation of effect estimates in the analysis of mortality and length of hospital stay in patients with infections caused by bacteria-producing extended-spectrum beta-lactamases: a systematic review and meta-analysis

OBJECTIVE

To assess the variation of effect estimates in the analysis of mortality and length of stay (LOS) in patients with infections caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae.

DESIGN

Systematic review and meta-analysis METHODS: Literature search for clinical studies from 1 January 1960 to 1 October 2018 was conducted in PubMed. Primary outcomes were risk ratios (RRs) of all-cause and attributable mortality and weighted mean differences (WMDs) in LOS in patients with bloodstream infections (BSIs) and non-invasive infections. Any change in the effect estimates was assessed by grouping studies according to design, setting, economy-based country classification, reporting period, microbiological aetiology, infection type and adjustment for appropriateness of empirical treatment. The impact of ESBL production was calculated using random-effect meta-analysis and heterogeneity was evaluated by I² statistics and metaregression.

RESULTS

Eighty-four studies including 22 030 patients and 149 outcome measures were included in the meta-analysis. Most studies were retrospective cohorts from high-income countries, providing unadjusted estimates. ESBL production in patients with BSIs (56 studies) increased the RR for all-cause mortality by a factor of 1.70 (95% CI 1.52 to 1.90; p<0.001), attributable mortality (16 studies) by 1.75 (95% CI 1.448 to 2.108; p<0.001) and WMD in the intensive care unit by 3.07 days (95% CI 1.61 to 4.54; p<0.001). WMD in hospital LOS was significantly higher in BSIs (4.41 days; 95% CI 3.37 to 5.46; p<0.001) and non-invasive (2.19 days; 95% CI 1.56 to 2.81; p<0.001). Subgroup analyses showed variation of estimates by study design, population, strain and assessment of appropriateness of empiric treatment. High heterogeneity was observed in all analyses.

CONCLUSIONS

Current evidence of the clinical burden of infections caused by ESBL-producing bacteria is highly heterogeneous and based mainly on unadjusted estimates derived from retrospective studies. Despite these limitations, ESBL production in strains causing BSIs seems associated with higher all-cause and attributable mortality and longer hospitalisation.

The Association Between Empirical Antibiotic Treatment and Mortality in Severe Infections Caused by Carbapenem-resistant Gram-negative Bacteria: A Prospective Study

Background

Empirical colistin should be avoided. We aimed to evaluate the association between covering empirical antibiotics (EAT) and mortality for infections caused by carbapenem-resistant gram-negative bacteria (CRGNB).

Methods

This was a secondary analysis of a randomized controlled trial, including adults with bloodstream infections, pneumonia, or urosepsis caused by CRGNB. All patients received EAT followed by covering targeted therapy. The exposure variable was covering EAT in the first 48 hours. The outcome was 28-day mortality. We adjusted the analyses by multivariable regression analysis and propensity score matching.

Results

The study included 406 inpatients with severe CRGNB infections, mostly Acinetobacter baumannii (312/406 [77%]). Covering EAT was given to 209 (51.5%) patients, mostly colistin (n = 200). Patients receiving noncovering EAT were older, more frequently unconscious and dependent, carrying catheters, and mechanically ventilated with pneumonia. Mortality was 84 of 197 (42.6%) with noncovering vs 96 of 209 (45.9%) with covering EAT (P = .504). Covering EAT was not associated with survival in the adjusted analysis; rather, there was a weak association with mortality (odds ratio [OR], 1.37; 95% confidence interval [CI], 1.02-1.84). Results were similar for colistin monotherapy and colistin-carbapenem combination EAT. In the propensity score-matched cohort (n = 338) covering antibiotics were not significantly associated with mortality (OR, 1.42; 95% CI, .91-2.22). Similar results were obtained in an analysis of 14-day mortality.

Conclusions

Empirical use of colistin before pathogen identification, with or without a carbapenem, was not associated with survival following severe infections caused by CRGNBs, mainly A. baumannii.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

This comprehensive review of the 2018 dental literature is provided to inform busy dentists about progress in the profession. Developed by the Committee on Scientific Investigation of the American Academy of Restorative Dentistry, each author brings discipline-specific expertise to one of the 8 sections of the report including (1) prosthodontics; (2) periodontics, alveolar bone, and peri-implant tissues; (3) implant dentistry; (4) dental materials and therapeutics; (5) occlusion and temporomandibular disorders; (6) sleep-related breathing disorders; (7) oral medicine and oral and maxillofacial surgery; and (8) dental caries and cariology. The report targets important information that will likely influence day-to-day treatment decisions. Each review is not intended to stand alone but to update interested readers so that they may visit source materials if greater detail is desired. As the profession continues its march toward evidence-based clinical decision-making, an already voluminous library of potentially valuable dental literature continues to grow. It is the intention of this review and its authors to provide assistance in navigating the extensive dental literature published in 2018. It is our hope that readers find this work useful in the clinical management of patients moving forward.

Influence of antibiotic treatment on the detection of S. aureus in whole blood following pathogen enrichment

Background

Early pathogen detection and identification are crucial for an effective and targeted antibiotic therapy in patients suffering from blood stream infection. Molecular diagnostic methods can accelerate pathogen identification as compared to blood culture, but frequently suffer from the inhibition of polymerase chain reation (PCR) by sample matrix components, such as host DNA, anticoagulants, or plasma proteins. To overcome this limitation, molecular diagnostic methods commonly rely on pathogen enrichment by selective lysis of blood cells and pelleting of intact pathogens prior to analysis.

Results

Here, we investigated the impact of antibiotic treatment on the recovery of pathogen DNA using an established pathogen enrichment protocol. Based on the hypothesis that induction of bacterial cell wall disintegration following antibiotic administration leads to incomplete pelleting of pathogen DNA, S. aureus was grown in human whole blood with or without addition of cell wall active (vancomycin, piperacillin) or non cell wall active (ciprofloxacin, clindamycin) antibiotics at clinically relevant concentrations. Pathogen detection remained unaffected by non cell wall active antibiotics or even increased in the presence of cell wall active antibiotics, indicating improved accessibility of pathogen DNA. Likewise, mechanical lysis of S. aureus prior to pathogen enrichment resulted in increased recovery of pathogen DNA. Quantification of pathogen and human DNA after selective lysis of blood cells and pathogen enrichment confirmed partial depletion of human DNA, leading to a net enrichment of pathogen DNA over human DNA.

Conclusion

Concurrent antibiotic administration does not reduce the recovery of pathogen DNA during pathogen enrichment by selective lysis and centrifugation.

Leads to a 10-fold human DNA depletion as compared to pathogen DNA. Moreover, we confirm that the recovery of pathogen DNA after pathogen enrichment is not negatively influenced by concurrent antibiotic administration.

Electronic supplementary material

The online version of this article (10.1186/s12866-019-1559-7) contains supplementary material, which is available to authorized users.

What we know about media communication on antibiotics and antimicrobial resistance: A systematic review of the scientific literature

OBJECTIVE

Systematically review the literature regarding media communication about antibiotics and anti-microbial resistance (AMR) to synthesise its key characteristics and impact effectiveness, identifying gaps and areas for further research.

METHODS

A comprehensive systematic review covering five international databases for articles published between 1^st September 2008 and 1^st September 2018 was performed using the registered protocol (PROSPERO: CRD42018116464). The search using terms related to media communication and antibiotics or AMR yielded 19 eligible studies, which were analysed and qualitatively synthesised.

RESULTS

Research on media communication regarding antibiotics or AMR has rapidly increased in the last decade. 74% of studies used a media content analysis method, while the remaining studies collected data via surveys. Print media were examined in 53% (n = 10), with 74% (n = 14) focused on English language media.

CONCLUSION

Currently, knowledge regarding media communication of antibiotics and AMR is very restricted to English-speaking print media. Further research is required to understand communication on this topic from other media (types and geographical regions) as well as how media effects attitude and behaviour change.

PRACTICE IMPLICATIONS

Better understanding of media communication regarding antibiotics and AMR may be crucial for policymakers and public health experts when planning strategies to tackle this issue.

Rates, predictors and mortality of community-onset bloodstream infections due to Pseudomonas aeruginosa: systematic review and meta-analysis

BACKGROUND

Pseudomonas aeruginosa is mostly a nosocomial pathogen affecting predisposed patients. However, community-onset bloodstream infections (CO-BSI) caused by this organism are not exceptional.

OBJECTIVES

To assess the predisposing factors for CO-BSI due to P. aeruginosa (CO-BSI-PA) and the impact in mortality of inappropriate empirical antimicrobial therapy.

DATA SOURCE

A systematic literature search was performed in the Medline, Embase, Cochrane Library, Scopus and Web of Science databases. Study eligibility criteria and participants: Articles published between 1 January 2002 and 31 January 2018 reporting at least of 20 adult patients with CO-BSI due to P. aeruginosa were considered.

INTERVENTION

Empiric antimicrobial therapy for CO-BSI-PA.

METHODS

A systematic review and a meta-analysis were conducted for risk factors and to evaluate if inappropriate empiric antimicrobial therapy increased mortality in CO-BSI-PA using a Mantel-Haenszel effects model.

RESULTS

Twelve studies assessing data of 1120 patients were included in the systematic review. Solid tumour (33.1%), haematologic malignancy (26.4%), neutropenia (31.7%) and previous antibiotic use (44.8%) were the most prevalent predisposing factors. Septic shock was present in 42.3% of cases, and 30-day crude mortality was 33.8%. Mortality in meta-analysis (four studies) was associated with septic shock at presentation (odds ratio, 22.31; 95% confidence interval, 3.52-141.35; p 0.001) and with inappropriate empiric antibiotic therapy (odds ratio, 1.83; 95% confidence interval, 1.12-2.98l p 0.02).

CONCLUSIONS

CO-BSI-PA mostly occurred in patients with predisposing factors and had a 30-day mortality comparable to hospital-acquired cases. Inappropriate empirical antibiotic therapy was associated with increased mortality. Appropriate identification of patients at risk for CO-BSI-PA is needed for empirical treatment decisions.

Role of place of acquisition and inappropriate empirical antibiotic therapy on the outcome of extended-spectrum β-lactamase-producing Enterobacteriaceae infections

The impact of inappropriate empirical antibiotic therapy (IEAT) on the outcome of severe infections due to extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-Ent) remains unclear. Current evidence is limited by study design and lack of confounder control. The main objective of this study was to define the outcome of severe infections due to ESBL-Ent according to clinical parameters and place of infection acquisition. Adult hospitalised patients with ESBL-Ent infections were included in a 3-year multicentre prospective study. Primary outcomes were IEAT rates and crude mortality of severe infections, adjusted by place of acquisition [community-acquired infection (CAI), healthcare-associated infection (HCAI) and hospital-acquired infection (HAI)]. Among 729 patients, 519 (71.2%) were diagnosed with HAI, 176 (24.1%) with HCAI and 34 (4.7%) with CAI. Moreover, 32.9% of patients received IEAT; higher rates of IEAT were observed in pneumonia (23%) and deep surgical site infections (19%). HCAIs were more frequently associated with IEAT than HAIs (48.3% vs. 27.9%; OR = 1.7, 95% CI 1.2-2.4). The overall mortality rate for severe infections (n = 264) was 12.1% and was significantly higher in HCAIs (20%) than HAIs (10%) (RR = 2.3, 95% CI 1.01-5.3). IEAT significantly increased the risk of mortality in bloodstream infections (RR = 8.3, 95% CI 2-46.3). Rates of IEAT and overall mortality of ESBL-Ent severe infections were higher in HCAIs than HAIs. Prompt diagnosis of patients with severe HCAIs due to ESBL-Ent is essential since these infections receive high rates of IEAT and significantly higher mortality than HAIs [ClinicalTrials.gov Identifier: NCT00404625].

[Current status of antibiotic therapy for Staphylococcus aureus sepsis in children]

OBJECTIVE

To investigate the current status of empirical antibiotic therapy for children with Staphylococcus aureus sepsis and the effect of therapeutic paradigm on prognosis based on a retrospective analysis.

METHODS

A total of 78 children with Staphylococcus aureus sepsis who were admitted from January 2014 to August 2017 were enrolled. According to the preferred empirical antibiotics before the detection of Staphylococcus aureus by blood culture, these children were divided into a carbapenem group with 16 children, a β-lactam group with 37 children, a vancomycin group with 15 children and a vancomycin+β-lactam group with 10 children. A retrospective analysis was performed for related clinical data including general status, underlying diseases, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, history of use of immunosuppressant, drug resistance to methicillin and prognosis. A logistic regression analysis was used to investigate the effect of empirical antibiotic therapy on the clinical outcome and prognosis of children with Staphylococcus aureus sepsis.

RESULTS

There were no significant differences among these groups in general status, underlying diseases, history of use of immunosuppressant, APACHE II score, nosocomial infection and detection rate of methicillin-resistant Staphylococcus aureus (P>0.05). There were significant differences in the incidence rate of septic shock and in-hospital mortality among these four groups (P<0.05). The carbapenem group had the highest incidence rate of septic shock and in-hospital mortality (69% and 50% respectively). The multivariate logistic regression analysis showed that empirical antibiotic therapy with different antibiotics had different risks for septic shock and in-hospital death in children with Staphylococcus aureus sepsis (P<0.05), and that an APACHE II score of ≥15 was an independent risk factor for septic shock in these children (P<0.05). The carbapenem group had significantly higher risks of septic shock and in-hospital death than the vancomycin group (P<0.05).

CONCLUSIONS

Inappropriate empirical use of antibiotics may lead to a poor prognosis in children with Staphylococcus aureus sepsis. Empirical use of carbapenems is not recommended for children suspected of Staphylococcus aureus sepsis.

The Hypothetical Impact of Accelerate Pheno on Time to Effective Therapy and Time to Definitive Therapy for Bloodstream Infections Due to Drug-Resistant Gram-Negative Bacilli

Strategies are needed to improve time to optimal therapy in patients with bloodstream infections (BSI) due to resistant Gram-negative (GN) pathogens. Accelerate Pheno (ACC) can provide antimicrobial susceptibility results within 7 h of a positive culture and may more rapidly optimize therapy. The primary objective of this study was to evaluate the hypothetical impact of ACC on time to effective therapy (TTET) and time to definitive therapy (TTDT) among patients with BSI due to resistant GN pathogens. ACC was performed on resistant GN BSI isolates, and results were not available to clinicians in real time. A potential benefit of having ACC on TTET or TTDT was determined if modifications to antimicrobial regimens could have been made sooner with ACC. Comparisons on the impact of ACC in the presence or absence of testing by the Verigene Gram-negative blood culture test (Verigene GN-BC) were performed. Sixty-one patients with resistant GN BSI were evaluated. The median actual TTET and TTDT in the cohort were 25.9 h (interquartile range [IQR], 18.5, 42.1) and 47.6 h (IQR, 24.9, 79.6), respectively. Almost half of the patients had potential improvement in TTET and/or TTDT with ACC. In patients who would have had a benefit the median potential decreases in TTET and TTDT were 16.6 h (IQR, 5.5 to 30.6) and 29.8 h (IQR, 13.6 to 43), respectively. The largest potential improvements were seen in patients for whom Verigene results were not available. In conclusion, among patients with resistant GN BSI in a setting where other rapid diagnostic technologies are utilized, ACC results could have further improved TTET and TTDT.