The role of antimicrobial stewardship in curbing carbapenem resistance

A Retrospective Single-Center Analysis from Southern Italy on the Use of T2 Magnetic Resonance Assays as a Point-of-Care Method for Patients with Sepsis

Background: The rapid and accurate identification of the pathogens responsible for sepsis is essential for prompt and effective antimicrobial therapy. The T2Bacteria® Panel (T2B) and T2Candida® Panel (T2C) are rapid molecular tests performed on whole blood that exploit T2 Magnetic Resonance (T2MRsup®) technology. Objectives: This study evaluates the impact of the T2MR system as a point-of-care device for managing sepsis and septic shock patients. Methods: This single-center retrospective study was conducted at the Sant' Elia Hospital of Caltanissetta from 1 January 2023 to 31 July 2023. The study population was composed of patients with suspected sepsis and septic shock according to the Sepsis-3 criteria and for whom concurrent T2MR and BC samples were requested for diagnosis. Results: A total of 81 consecutive patients were enrolled in this study. Concordant T2/BC results were obtained in 69/81 (85.2%) patients; 58/81 (71.6%) were concordant-negative and 11/81 (13.6%) were concordant-positive. Discordant T2MR+/BC- results were observed in 9/81 patients (11.1%), while T2MR-/BC+ results were detected in 3/81 patients (3.7%). Furthermore, the median time for reporting positive T2MR test results (5.2 h) was significantly shorter than that for BC (122 h). Conclusions: Due to its high reliability, faster detection time, and simple workflow, T2MR in combination with BC improved the etiological diagnosis of sepsis in the enrolled patients.

Emergence of carbapenemase-producing Enterobacterales (CPE) in patients with severe COVID-19 infection and successful control in intensive care

Objective

We aim to highlight the risks of acquiring carbapenemase-producing Enterobacterales (CPE) resistance genes in patients with severe coronavirus disease 2019 (COVID-19) in intensive care.

Design

Outbreak analysis to assess for a transmission risk area (TRA) conducted after identification of potential CPE outbreak within shared room spaces in intensive care.

Setting

Analysis conducted within a 24-bed single-room model intensive-care department within a level-3 tertiary center public hospital in regional Victoria, Australia.

Patients

3 patients, with severe COVID-19 admitted to intensive care over a 3-month period with shared room spaces requiring prolonged mechanical ventilation and broad-spectrum antimicrobials, identified and were managed for CPE isolated from sputum. Overlap carbapenemase genes were identified among different organisms raising suspicion of transmitted resistance genes. A subsequent case managed for severe community-acquired pneumonia isolated CPE 3 months beyond these cases.

Methods

Outbreak analysis via weekly cross-sectional point prevalence screening of fecal samples or rectal swabs for CPE from patients admitted to the intensive-care department over a 4-week period.

Results

34 patients were included in the analysis with 51 tests for CPE screening conducted. No further cases of CPE were identified. Statewide Infection Surveillance team and the Department of Health and Human Services did not find the cases to derive from a TRA. No further action including environmental screening was indicated.

Conclusions

These cases highlight the independent acquisition of CPE genes in patients with severe COVID-19 and antimicrobial selective pressures resulting in significant morbidity and mortality. Increasing awareness, robust antimicrobial stewardship, and infection prevention measures could reduce pressures driving CPE resistance mutations and the risk of CPE transmission.

The Impact of Antimicrobial Stewardship and Infection Control Interventions on Acinetobacter baumannii Resistance Rates in the ICU of a Tertiary Care Center in Lebanon

Antimicrobial resistance is a serious threat to global health, causing increased mortality and morbidity especially among critically ill patients. This toll is expected to rise following the COVID-19 pandemic. Carbapenem-resistant Acinetobacter baumannii (CRAb) is among the Gram-negative pathogens leading antimicrobial resistance globally; it is listed as a critical priority pathogen by the WHO and is implicated in hospital-acquired infections and outbreaks, particularly in critically ill patients. Recent reports from Lebanon describe increasing rates of infection with CRAb, hence the need to develop concerted interventions to control its spread. We set to describe the impact of combining antimicrobial stewardship and infection control measures on resistance rates and colonization pressure of CRAb in the intensive care units of a tertiary care center in Lebanon before the COVID-19 pandemic. The antimicrobial stewardship program introduced a carbapenem-sparing initiative in April 2019. During the same period, infection control interventions involved focused screening, monitoring, and tracking of CRAb, as well as compliance with specific measures. From January 2018 to January 2020, we report a statistically significant decrease in carbapenem consumption and a decrease in resistance rates of isolated A. baumannii. The colonization pressure of CRAb also decreased significantly, reaching record low levels at the end of the intervention period. The results indicate that a multidisciplinary approach and combined interventions between the stewardship and infection control teams can lead to a sustained reduction in resistance rates and CRAb spread in ICUs.

Risk Factors for a Hospital-Acquired Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infection: A Five-Year Retrospective Study

Purpose

This study aimed to describe trends in Klebsiella pneumoniae (KP) resistance in bloodstream infections (BSI) and to identify risk factors for a hospital-acquired carbapenem-resistant Klebsiella pneumoniae (CRKP) BSI and 28-day mortality from a hospital-acquired KP BSI.

Patients and Methods

We recorded the results of antimicrobial susceptibility testing of 396 KP-positive blood cultures from January 2016 to December 2020. A total of 277 patients with a KP BSI were included in this study, of which 171 had a hospital-acquired infection and 84 had a hospital-acquired CRKP BSI. Multivariate logistic regression analysis was used to identify risk factors for a hospital-acquired CRKP BSI and 28-day mortality from a hospital-acquired KP BSI.

Results

The proportion of hospital-acquired infections among KP BSI patients increased from 53.1% in 2016 to 72.8% in 2020. The detection rate of CRKP among KP BSI patients increased from 18.8% in 2016 to 37.7% in 2020. Multivariate logistic regression showed that β-lactam/β-lactamase inhibitor combinations (BLBLIs) exposure (P  = 0.022, OR 2.863), carbapenems exposure (P  = 0.007, OR 3.831) and solid organ transplantation (P   <0.001, OR 19.454) were independent risk factors for a hospital-acquired CRKP BSI. Risk factors for a 28-day mortality from hospital-acquired KP BSI were CRKP BSI (P  =0.009, OR 5.562), septic shock (P  =0.002, OR 4.862), mechanical ventilation>96 hours (P =0.020, OR 8.765), and platelet counts <100×10⁹/L (P  =0.003, OR 4.464).

Conclusion

The incidence of hospital-acquired KP BSI continues to rise and the proportion of CRKP BSI is also increasing. We believe that the use of the BLBLIs needs to be carefully evaluated in hospital-acquired infection. Hospital-acquired KP BSI Patients with CRKP BSI, septic shock, mechanical ventilation and deficiency of platelets are more likely to have a poor prognosis.

Multidrug-Resistant Gram-Negative Bacteria: Infection Prevention and Control Update

Multidrug-resistant gram-negative bacteria (MDR-GNB) pose one of the greatest challenges to health care today because of their propensity for human-to-human transmission and lack of therapeutic options. Containing the spread of MDR-GNB is challenging, and the application of multifaceted infection control bundles during an evolving outbreak makes it difficult to measure the relative impact of each measure. This article will review the utility of various infection control measures in containing the spread of various MDR-GNB and will provide the supporting evidence for these interventions.

Accuracy and Impact on Patient Management of New Tools for Diagnosis of Sepsis: Experience with the T2 Magnetic Resonance Bacteria Panel

The rapid and accurate identification of pathogens responsible for sepsis is essential for prompt and effective antimicrobial therapy. Molecular technologies have been developed to detect the most common causative agents, with high sensitivity and short time to result (TTR). T2 Bacteria Panel (T2), based on a combination of PCR and T2 magnetic resonance, can identify directly in blood samples Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecium, and Acinetobacter baumannii pathogens. This study evaluates the role of T2 in the diagnosis of sepsis and its impact on patient management, specifically in terms of TTR and the switch from empirical to directed therapy, comparing results of blood culture (BC) and T2 assay in 82 patients with sepsis. T2 significantly improved the detection of the causative agents of sepsis. For pathogens included in the panel, T2 sensitivity was 100% (95% CI 86.3–100.0), significantly higher than that of BC (54.8%, 95% CI 36.0–72.7). The TTR (median, IQR) of positive T2 (3.66 h, 3.59–4.31) was significantly shorter than that of the positive BC (37.58 h, 20.10–47.32). A significant reduction in the duration of empiric therapy and an increase in the percentage of patients with switched therapy was observed in patients with a positive T2 result. In conclusion, T2 can shorten and improve the etiological diagnosis of sepsis with a positive impact on patient management.

A "resistance calculator": Simple stewardship intervention for refining empiric practices of antimicrobials in acute-care hospitals

Objective:

In the era of widespread resistance, there are 2 time points at which most empiric prescription errors occur among hospitalized adults: (1) upon admission (UA) when treating patients at risk of multidrug-resistant organisms (MDROs) and (2) during hospitalization, when treating patients at risk of extensively drug-resistant organisms (XDROs). These errors adversely influence patient outcomes and the hospital’s ecology.

Design and setting:

Retrospective cohort study, Shamir Medical Center, Israel, 2016.

Patients:

Adult patients (aged >18 years) hospitalized with sepsis.

Methods:

Logistic regressions were used to develop predictive models for (1) MDRO UA and (2) nosocomial XDRO. Their performances on the derivation data sets, and on 7 other validation data sets, were assessed using the area under the receiver operating characteristic curve (ROC AUC).

Results:

In total, 4,114 patients were included: 2,472 patients with sepsis UA and 1,642 with nosocomial sepsis. The MDRO UA score included 10 parameters, and with a cutoff of ≥22 points, it had an ROC AUC of 0.85. The nosocomial XDRO score included 7 parameters, and with a cutoff of ≥36 points, it had an ROC AUC of 0.87. The range of ROC AUCs for the validation data sets was 0.7–0.88 for the MDRO UA score and was 0.66–0.75 for nosocomial XDRO score. We created a free web calculator (https://assafharofe.azurewebsites.net).

Conclusions:

A simple electronic calculator could aid with empiric prescription during an encounter with a septic patient. Future implementation studies are needed to evaluate its utility in improving patient outcomes and in reducing overall resistances.

The Continuing Plague of Extended-Spectrum β-Lactamase Producing Enterbacterales Infections: An Update

Antimicrobial resistance is a common iatrogenic complication of modern life and medical care. One of the most demonstrative examples is the exponential increase in the incidence of extended-spectrum β-lactamases (ESBLs) production among Enterobacteriaceae, that is, the most common human pathogens outside of the hospital setting. Infections resulting from ESBL-producing bacteria are associated with devastating outcomes, now affecting even previously healthy individuals. This poses an enormous burden and threat to public health. This article aims to narrate the evolving epidemiology of ESBL infections and highlights current challenges in terms of management and prevention of these common infections.

Incidence and risk factors of carbapenem-resistant Enterobacteriaceae infection in intensive care units: a matched case-control study

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) infection is associated with intensive care admissions, morbidity, and mortality. Our study aimed to determine the incidence, risk factors, and patient outcomes of CRE in the ICU units.

METHODS

This was a retrospective matched case-control study of patients admitted to ICUs. Patients who have positive cultures of CRE and carbapenem-susceptible Enterobacteriaceae (CSE) were included in the study. Patients were randomly selected from a pool of CSE subjects in a ratio of 1:1 of CRE to CSE as control patients.

RESULTS

The infection rate with CRE among all patients admitted to ICUs was 7.6% and the incidence of CRE infection was 5.6 per 1,000 person-day. The risk factors independently associated with CRE infection were: Higher Sequential Organ Failure Assessment (SOFA) and Nutrition Risk in Critically ill (NUTRIC) scores, prolonged ICU length of stay (LOS), previous surgery, dialysis and mechanical ventilation during ICU stay, and previous use of aminoglycoside and carbapenems.

CONCLUSION

In this retrospective study, the incidence of CRE infection was relatively elevated in patients admitted to ICU. Patients with high SOFA and NUTRIC scores, prolonged ICU LOS, previous surgery, dialysis and mechanical ventilation, and prior aminoglycosides and carbapenems use, may have an increased risk of CRE infection.

Implementation of an antimicrobial stewardship programme and reduction in carbapenemase-producing Enterobacterales in an Australian local health district

Background

Carbapenemase-producing Enterobacterales (CPE) are increasingly seen in Australian hospitals. Antimicrobial stewardship (AMS) interventions have been shown to reduce rates of carbapenem-resistant organisms; data on their effect on CPE rates are limited.

Objectives

To explore the effect of a multi-site computer-supported AMS programme on the rates of CPE in an Australian local health district.

Methods

All laboratory CPE isolates between 2008 and 2018 were identified. Microbiological and demographic data, CPE risk factors and outcomes were collected. Monthly carbapenem use was expressed as DDD per 1000 occupied bed days (OBD). Hand hygiene compliance rates among healthcare workers were analysed. A computer-supported AMS programme was implemented district-wide in 2012. Bivariate relationships were examined using Pearson's r and predictors of CPE isolates using time series linear regression.

Results

We identified 120 isolates from 110 patients. Numbers of CPE isolates and carbapenem use both showed a strong downward trend during the study period; the decreases were strongly correlated (r = 0.80, P = 0.006). The positive relationship between carbapenem use and CPE isolation was maintained while adjusting for time (b = 0.05, P < 0.001). Average yearly consumption of carbapenems fell by 20%, from 18.4 to 14.7 DDD/1000 OBD following implementation of the AMS programme. Hand hygiene compliance rates remained high throughout.

Conclusions

We demonstrated a reduction of CPE isolates in conjunction with reduced carbapenem use, longitudinally consolidated by a formal AMS programme. Prospective studies are needed to validate the effect of AMS on carbapenem resistance, especially in high-prevalence settings.

Infection control and risk factors for acquisition of carbapenemase-producing enterobacteriaceae. A 5 year (2011-2016) case-control study

Background

Carbapenemase-producing enterobacteriaceae (CPE) are a major threat for severely ill patients. However, only limited data on the epidemiology and on evidence-based infection prevention and control measures are available. The aim of this study was to investigate the epidemiology of patients with CPE, characterizing the CPE isolates by their resistance mechanisms and genetic similarity, to explore risk factors for their acquisition, and to evaluate the effectiveness of the current CPE infection control measures.

Methods

A retrospective case-control study was performed using data from 2011 to 2016 in a 1800-bed academic hospital in Central Europe, where risk-based screening at patients´ admission is performed. Carbapenem resistance mechanisms of all carbapenem resistant enterobacteriaceae from patients admitted during this period were investigated. Clinical data of the CPE-positive patients were analysed and compared to a matched control group (case-control ratio of 1:3). We performed univariate and multivariate statistical analysis to identify risk factors for CPE acquisition.

Results

Of 621,623 admitted patients in the study period, 75 patients with carriage of carbapenem resistant enterobacteriaceae were included (0.12/1000 admittances). Carbapenemase-encoding genes were detected in 77.3% (58/75) of patients with carbapenem-resistant enterobacteriaceae. The enzyme blaOXA-48 was found in 34.5% (20/58), blaKPC in 29.3% (17/58), blaNDM enzymes in 20.7% (12/58) and blaVIM in 8.6% (5/58) of the isolates. The overall mortality among CPE patients was 25.9% (15/58) and attributable mortality of CPE was 53.3% (8/15). Multivariate analysis revealed four risk factors to be independent predictors of CPE carriage: the length of hospital admission > 20 days (AOR: 4.9, 95% CI: 1.4–15.5; P <  0.001), hospital admission within the previous year (AOR: 22.3, 95% CI: 3.9–88.4; P <  0.001), exposure to a healthcare facility in a country with high or unknown carbapenem-resistant enterobacteriaceae prevalence 3 months before admission (AOR: 11.8, 95% CI: 2.2–63.2; P <  0.01) and the use of antibiotics longer than 10 days (AOR: 5.2, 95% CI: 1.4–35.9; P <  0.05). The current risk-based screening strategy at hospital admission could not identify 37 (63.8%) of the 58 CPE-positive patients. Epidemiological investigation and genotyping revealed that no outbreaks due to CPE occurred during this period.

Conclusion

Overall, the CPE carriage rate in patients was very low, the attributable mortality, however, is alarming (53%). BlaOXA-48 and blaKPC were the main cause of carbapenem resistance in enterobacteriaceae. Although the strict application of standard infection control measures was effective for prevention of outbreaks in this setting, an enlarged risk based targeted screening strategy has to be implemented.

Evaluating a Pharmacy-Driven 72-Hour Antibiotic Monitoring Program Implemented in a Community Hospital

Background: Antimicrobial stewardship programs commonly utilize infectious diseases pharmacists to guide appropriate utilization of broad-spectrum antimicrobials. Strategies should be developed to increase staff pharmacist's participation in decreasing broad-spectrum antibiotic use. Objective: The purpose of this study was to determine the effectiveness of a pharmacy-driven 72-hour antimicrobial stewardship initiative. Methods: A pharmacy-driven 72-hour antibiotic review policy was implemented at a community hospital. Targeted antibiotics included ertapenem, meropenem, and daptomycin. The hospital's infectious diseases pharmacist provided policy education to staff pharmacists. All pharmacists provided prospective audit and feedback to physicians. Preimplementation and postimplementation data were collected through a retrospective chart review to analyze the impact of the initiative. Results: There were a total of 570 targeted antibiotic orders for review, of which 155 antibiotic orders met criteria for inclusion; 97 in the preimplementation group and 58 in the postimplementation group. Targeted antibiotic orders decreased postimplementation during the study period. Days of therapy per 1000 patient days decreased between the 2 groups, although this was statistically significant neither for the pooled targeted antibiotics nor for each individual antibiotic. There was a statistically significant increase in the number of appropriately prescribed targeted antibiotics from preimplementation compared to postimplementation (from 35% to 64%, P < .01). Pharmacist interventions documented for patients receiving the targeted antibiotics increased significantly during the intervention period (P < .01). In addition, there was a total of $28 795.96 in cost avoidance based on the difference in antibiotic use between the 2 groups. Conclusion: Implementation of a pharmacy-driven 72-hour broad-spectrum antibiotic review in a large community-based hospital resulted in a reduction in utilization and hospital spending and a significant increase in appropriate use of targeted antibiotics, while also increasing pharmacist engagement with antimicrobial stewardship.

Impact of individualized active surveillance of carbapenem-resistant enterobacteriaceae on the infection rate in intensive care units: a 3-year retrospective study in a teaching hospital of People's Republic of China

Purpose: Active surveillance of carbapenem-resistant Enterobacteriaceae (CRE) may contribute to the decline of the infection rate. Individualized active surveillance of CRE could cost less than screening all patients. However, the impact of individualized active surveillance on the CRE infection rate in intensive care units (ICUs) has not been well described.

Patients and methods: We retrospectively studied the clinical data of all patients admitted in the ICUs of a tertiary-care hospital in China from 2015 to 2017 during two periods, before and after the implementation of individualized active surveillance. During period 1 (January 2015–April 2016), no screening protocol was used. During period 2 (May 2016–December 2017), we implemented active CRE screening for selected patients according to their clinical characteristics. The trend of CRE rate infection was analyzed by a joinpoint regression model, and multivariate analysis was performed to analyze the association of active surveillance, Acute Physiology and Chronic Health Evaluation (APACHE) II score, prior antimicrobial use, length of mechanical ventilation (MV) before infection, and other risk factors with CRE infection rate.

Results: A total of 5,372 patients were included. After assessing the patients’ clinical characteristics, 72.3% (3,882/5,372) were considered to be at high risk of CRE infection. During period 1, the infection percent of CRE increased by 13.04% every month (95% CI: 5.2–21.5). During period 2, the infection rate decreased (monthly percent change, −3.57%; 95% CI −6.9 to −0.1, P<0.05). Multivariate analysis showed that individualized active surveillance (odds ratio, 0.146; 95% CI, 0.061–0.347; P<0.001) was associated with a reduction of the CRE infection rate, whereas APACHE II score, prior antimicrobial use, and length of MV before infection were independent risk factors.

Conclusion: Individualized active surveillance may be associated with a reduction of the overall CRE infection rate in ICUs.

Evaluation of the Impact of Antimicrobial Stewardship Program (ASP) on Unrestricted Use of Meropenem at an Academic Medical Center

Objective The primary objectives were to evaluate the prescriber acceptance rate of Antimicrobial Stewardship Program (ASP) pharmacist recommendation to de-escalate/discontinue meropenem, and estimate the difference in duration of meropenem therapy. The secondary objective was to determine incidence of adverse events in the two groups. Methods It was a retrospective study. All patients admitted to Gwinnett Medical Center and receiving meropenem from January–November 2015 were included in the study. Exclusion criteria were: patients admitted to intensive care unit, one-time dose, infectious disease consultation, and age <18 years. Electronic medical records were reviewed for data collection. The control group consisted of patients from January–July 2015 when there was no ASP pharmacist. The intervention group consisted of patients from August–November 2015 during which period the ASP pharmacist recommended de-escalation/discontinuation of meropenem based on culture and sensitivity results. Results A total of 41 patients were studied, 21 in the control group and 20 in the intervention group. There was no significant difference in baseline characteristics in the two groups and in terms of prior hospitalization or antibiotic use (within 90 days) and documented or suspected MDRO infection at the time of admission. De-escalation/discontinuation was suggested in 16/20 patients in the intervention group (80%), and intervention was accepted in 68%. The mean duration of therapy was significantly decreased in the intervention group (5.6 days vs. 8.1 days, p =0.0175). Two patients had thrombocytopenia (unrelated to meropenem), and none of the patients had seizure. Conclusion Targeted antibiotic review is an effective ASP strategy, which significantly decreases the duration of meropenem therapy.

Use of Colistin in Critically Ill Patients

Due to lack of better therapeutic options, colistin use for extensively drug-resistant Gram-negative organisms was revived in the past two decades, including in patients in intensive-care units (ICU). There are multiple knowledge gaps pertaining to the clinical use and utility of colistin in critically-ill patients, but due to lack of options, it is used in these high risk patients. In this chapter, we critically review the various topics pertaining to colistin use in critically-ill patients, while highlighting the (lack of) controlled evidence supporting common current practices pertaining to colistin use by clinicians.

Impact of clinical pharmacist intervention on antimicrobial use in a small 164-bed hospital

Objectives

To study the impact of clinical pharmacist interventions (PIs) on antimicrobial prescriptions in terms of physician acceptance rates, clinical benefits and antimicrobial use/cost outcomes.

Methods

This study retrospectively analysed the impact of antimicrobial PIs over a 2-year period (October 2012 to October 2014) in a private non-teaching 164-bed hospital without a formal antimicrobial stewardship programme. Excluded from the study were outpatients and patients admitted to the intensive care unit or the emergency department. The PIs focused on appropriate indication and appropriate dosage; drug adverse events, allergies, intolerance and interactions; sequential therapy; therapeutic de-escalation; excessive duration of treatment and therapeutic drug monitoring. Carbapenems and linezolid were classified as special-vigilance drugs. Amoxicillin-clavulanic, piperacillin-tazobactam and vancomycin were classified as preferred drugs. Clinical benefits evaluated in accordance with internal guidelines, were classified as enhancing appropriate antimicrobial prescription or potentially reducing toxicity. Antimicrobial use and expenditure were compared with that of the previous 2-year period.

Results

386 PIs were implemented in 303 patients. The overall acceptance rate was 83.4%. The acceptance rate for appropriate prescription PIs was significantly lower than for toxicity PIs (73.7% vs 90.9%; p<0.0001). Significant reductions in the use of special-vigilance drugs (from 39.9 (22.2-86.0) to 28.0 (6.0-43.4) defined daily doses (DDD)/1000 patient-days; p=0.0003) were seen and increases in the use of piperacillin-tazobactam (from 13.2 (0-22.9) to 17.2 (6.9-44.8) DDD/1000 patient-days; p=0.007) and of cephalosporins (from 123.5 (61.8-196.6) to 149.1 (80.3-228.2) DDD/1000 patient-days; p=0.027). Overall cost savings were 5.1%.

Conclusions

PIs on antimicrobial prescriptions may be effective in enhancing appropriate use of antimicrobials, reducing their toxicity, reducing the use of special-vigilance drugs and reducing overall antimicrobial cost.

The Continuing Plague of Extended-spectrum β-lactamase-producing Enterobacteriaceae Infections

Antimicrobial resistance is a common iatrogenic complication of modern life and medical care. One of the most demonstrative examples is the exponential increase in the incidence of extended-spectrum β-lactamases (ESBLs) production among Enterobacteriaceae, which is the most common human pathogens outside of the hospital settings. Infections resulting from ESBL-producing bacteria are associated with devastating outcomes, now affecting even previously healthy individuals. This development poses an enormous burden and threat to public health. This paper aims to narrate the evolving epidemiology of ESBL infections, and highlight current challenges in terms of management and prevention of these common infections.

Evaluation of effects of an operational multidisciplinary team on antibiotic use in the medium to long term at a French university hospital

Background Antibiotic-resistant bacteria are a major public health problem throughout the world. In 2006, in accordance with the national guidelines for antibiotic use, the CHRU of Nancy created an operational multidisciplinary antibiotic team at one of its sites. In 2011, a cluster-controlled trial showed that the operational multidisciplinary antibiotic team (the intervention) had a favourable short-term effect on antibiotic use and costs. Objective Our objective was to determine whether these effects continued over the medium to long term (that is, 2-7 years after creation of the operational multidisciplinary antibiotic team, 2009-2014). Setting The 1800-bed University Hospital of Nancy (France). Method The effect in the medium to long term is measured according to the same criteria and assessed by the same methods as the first study. A cluster controlled trial was performed on the period 2009-2014. The intervention group comprised 11 medical and surgical wards in settings where the operational multidisciplinary antibiotic team was implemented and the control group comprised 6 wards without this operational team. Main outcome measure Consumption of antibiotics overall and by therapeutic class (in defined daily doses per 1000 patient-days) and costs savings (in €). Results The reduction in antibiotic use and costs continued, but at a lower rate than in the short term (11% between 2009 and 2014 compared with 33% between 2007 and 2009) at the site of the intervention. The principal decreases concerned fluoroquinolones and glycopeptides. At the site without an operational multidisciplinary antibiotic team (the control group), total antibiotic use remained stable. Between 2009 and 2014, costs fell 10.5% in the intervention group and 5.7% in the control group. Conclusion This study shows that it is possible to maintain the effectiveness over time of such an intervention and demonstrates its role in defining a hospital's antibiotic policy.

Screening for carbapenem-resistant Enterobacteriaceae: Who, When, and How?

The global spread of carbapenem-resistant Enterobacteriaceae (CRE) has been fostered by the lack of preemptive screening of patients in healthcare facilities that could prevent patient-to-patient transmission. Outbreaks of CRE infections have led some institutions to implement rigorous screening programs, although controlled comparative data are frequently lacking. Resource limitations and uncertainty regarding the optimal approach has kept many facilities from enacting more active routine surveillance policies that could reduce the prevalence of CRE. The ideal population to target for screening, the frequency of testing, and the preferred test method are components of surveillance programs that remain open to debate. This review discusses the rationale for different screening policies in use and the performance characteristics of laboratory methods available to detect CRE carriage.

Clinical and molecular epidemiology of Acinetobacter baumannii bloodstream infections in an endemic setting

AIM

The transmission dynamics of Acinetobacter baumannii in endemic settings, and the relation between microbial properties and patients' clinical outcomes, are yet obscure and hampered by insufficient metadata.

METHODS & RESULTS

Of 20 consecutive patients with A. baumannii bloodstream infection that were thoroughly analyzed at a single center, at least one transmission opportunity was evident for 85% of patients. This implies that patient-to-patient transmission is the major mode of A. baumannii acquisitions in health facilities. Moreover, all patients who died immediately (<24 h of admission) were infected with a single clone (ST457; relative risk = 1.6; p = 0.05).

CONCLUSION

This preliminary analysis should prompt further investigation by mapping genomic virulence determinants among A. baumannii ST457 lineage compared with other strains.

Multidrug-Resistant Gram-Negative Bacilli: Infection Control Implications

Antimicrobial resistance is a common iatrogenic complication of both modern life and medical care. Certain multidrug resistant and extensively drug resistant Gram-negative organisms pose the biggest challenges to health care today, predominantly owing to a lack of therapeutic options. Containing the spread of these organisms is challenging, and in reality, the application of multiple control measures during an evolving outbreak makes it difficult to measure the relative impact of each measure. This article reviews the usefulness of various infection control measures in containing the spread of multidrug-resistant Gram-negative bacilli.

Clinical and Epidemiological Significance of Carbapenem Resistance in Acinetobacter baumannii Infections

Carbapenems are considered the treatment of choice for Acinetobacter baumannii infections. Many facilities implement preventive measures toward only carbapenem-resistant A. baumannii (CRAB). However, the independent role of the carbapenem resistance determinant on patient outcomes remains controversial. In a 6-year analysis of adults with A. baumannii bloodstream infection (BSI), the outcomes of 149 CRAB isolates were compared to those of 91 patients with carbapenem-susceptible A. baumannii In bivariable analyses, CRAB BSIs were significantly associated with worse outcomes and with a delay in the initiation of appropriate antimicrobial therapy (DAAT). However, in multivariable analyses, carbapenem resistance status was no longer associated with poor outcomes, while DAAT remained an independent predictor. The epidemiological significance of A. baumannii should not be determined by its resistance to carbapenems.

The complex epidemiology of extended-spectrum β-lactamase-producing Enterobacteriaceae

ABSTRACT 

Antimicrobial resistance is a growing worldwide iatrogenic complication of modern medical care. Extended-spectrum β-lactamases have emerged as one of the most successful resistance mechanisms, limiting our therapeutic options to treat various human infections. The dissemination of these enzymes to the community probably signifies an irreversible step. This paper will review the evolution of human infections associated with extended-spectrum β-lactamase-producing organisms in the past 20 years, and will present and discuss the current challenges, controversies, debates and knowledge gaps in this research field.

Epidemiology and prevention of carbapenem-resistant Enterobacteriaceae in the United States

Carbapenem-resistant Enterobacteriaceae (CRE) are multidrug-resistant organisms with few treatment options that cause infections associated with substantial morbidity and mortality. CRE outbreaks have been increasingly reported worldwide and are mainly due to the emergence and spread of strains that produce carbapenemases. In the United States, transmission of CRE is primarily driven by the spread of organisms carrying the Klebsiella pneumoniae carbapenemase enzyme, but other carbapenemase enzymes, such as the New-Delhi metallo-β-lactamase, have also emerged. Currently recommended control strategies for healthcare facilities include the detection of patients infected or colonized with CRE and implementation of measures to prevent further spread. In addition to efforts in individual facilities, effective CRE control requires coordination across all healthcare facilities in a region. This review describes the current epidemiology and surveillance of CRE in the United States and the recommended approach to prevention.