Patient specific risk stratification for antimicrobial resistance and possible treatment strategies in gram-negative bacterial infections

Prevalence of Infections and Antimicrobial Resistance of ESKAPE Group Bacteria Isolated from Patients Admitted to the Intensive Care Unit of a County Emergency Hospital in Romania

The ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella Pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) is a group of bacteria very difficult to treat due to their high ability to acquire resistance to antibiotics and are the main cause of nosocomial infections worldwide, posing a threat to global public health. Nosocomial infections with MDR bacteria are found mainly in Intensive Care Units, due to the multitude of maneuvers and invasive medical devices used, the prolonged antibiotic treatments, the serious general condition of these critical patients, and the prolonged duration of hospitalization.

MATERIALS AND METHODS

During a period of one year, from January 2023 to December 2023, this cross-sectional study was conducted on patients diagnosed with sepsis admitted to the Intensive Care Unit of the Sibiu County Emergency Clinical Hospital. Samples taken were tracheal aspirate, catheter tip, pharyngeal exudate, wound secretion, urine culture, blood culture, and peritoneal fluid.

RESULTS

The most common bacteria isolated from patients admitted to our Intensive Care Unit was Klebsiella pneumoniae, followed by Acinetobacter baumanii and Pseudomonas aeruginosa. Gram-positive cocci (Enterococcus faecium and Staphilococcus aureus) were rarely isolated. Most of the bacteria isolated were MDR bacteria.

CONCLUSIONS

The rise of antibiotic and antimicrobial resistance among strains in the nosocomial environment and especially in Intensive Care Units raises serious concerns about limited treatment options.

TiO2 Nanocomposite Coatings and Inactivation of Carbapenemase-Producing Klebsiella Pneumoniae Biofilm-Opportunities and Challenges

The worldwide increase of multidrug-resistant Gram-negative bacteria is a global threat. The emergence and global spread of Klebsiella pneumoniae carbapenemase- (KPC-) producing Klebsiella pneumoniae represent a particular concern. This pathogen has increased resistance and abilities to persist in human reservoirs, in hospital environments, on medical devices, and to generate biofilms. Mortality related to this microorganism is high among immunosuppressed oncological patients and those with multiple hospitalizations and an extended stay in intensive care. There is a severe threat posed by the ability of biofilms to grow and resist antibiotics. Various nanotechnology-based strategies have been studied and developed to prevent and combat serious health problems caused by biofilm infections. The aim of this review was to evaluate the implications of nanotechnology in eradicating biofilms with KPC-producing Klebsiella pneumoniae, one of the bacteria most frequently associated with nosocomial infections in intensive care units, including in our department, and to highlight studies presenting the potential applicability of TiO2 nanocomposite materials in hospital practice. We also described the frequency of the presence of bacterial biofilms on medical surfaces, devices, and equipment. TiO2 nanocomposite coatings are one of the best long-term options for antimicrobial efficacy due to their biocompatibility, stability, corrosion resistance, and low cost; they find their applicability in hospital practice due to their critical antimicrobial role for surfaces and orthopedic and dental implants. The International Agency for Research on Cancer has recently classified titanium dioxide nanoparticles (TiO2 NPs) as possibly carcinogenic. Currently, there is an interest in the ecological, non-toxic synthesis of TiO2 nanoparticles via biological methods. Biogenic, non-toxic nanoparticles have remarkable properties due to their biocompatibility, stability, and size. Few studies have mentioned the use of nanoparticle-coated surfaces as antibiofilm agents. A literature review was performed to identify publications related to KPC-producing Klebsiella pneumoniae biofilms and antimicrobial TiO2 photocatalytic nanocomposite coatings. There are few reviews on the antibacterial and antibiofilm applications of TiO2 photocatalytic nanocomposite coatings. TiO2 nanoparticles demonstrated marked antibiofilm activity, but being nano in size, these nanoparticles can penetrate cell membranes and may initiate cellular toxicity and genotoxicity. Biogenic TiO2 nanoparticles obtained via green, ecological technology have less applicability but are actively investigated.

Antimicrobial Multidrug Resistance: Clinical Implications for Infection Management in Critically Ill Patients

The increasing incidence of antimicrobial resistance (AMR) worldwide represents a serious threat in the management of sepsis. Due to resistance to the most common antimicrobials prescribed, multidrug-resistant (MDR) pathogens have been associated with delays in adequate antimicrobial therapy leading to significant increases in mortality, along with prolonged hospital length of stay (LOS) and increases in healthcare costs. In response to MDR infections and the delay of microbiological results, broad-spectrum antibiotics are frequently used in empirical antimicrobial therapy. This can contribute to the overuse and misuse of antibiotics, further promoting the development of resistance. Multiple measures have been suggested to combat AMR. This review will focus on describing the epidemiology and trends concerning MDR pathogens. Additionally, it will explore the crucial aspects of identifying patients susceptible to MDR infections and optimizing antimicrobial drug dosing, which are both pivotal considerations in the fight against AMR. Expert commentary: The increasing AMR in ICUs worldwide makes the empirical antibiotic therapy challenging in septic patients. An AMR surveillance program together with improvements in MDR identification based on patient risk stratification and molecular rapid diagnostic tools may further help tailoring antimicrobial therapies and avoid unnecessary broad-spectrum antibiotics. Continuous infusions of antibiotics, therapeutic drug monitoring (TDM)-based dosing regimens and combination therapy may contribute to optimizing antimicrobial therapy and limiting the emergence of resistance.

Severe infections caused by difficult-to-treat Gram-negative bacteria

PURPOSE OF REVIEW

Antimicrobial resistance (AMR) in Gram-negative bacteria (GNB) poses a significant global health concern, contributing to increased infections, mortality rates, and healthcare costs. This review discusses the main clinical manifestations, therapeutic options, and recent findings in managing antibiotic-resistant GNB, with a focus on difficult-to-treat infections.

RECENT FINDINGS

Difficult-to-treat resistance (DTR) is a novel classification that identifies GNB exhibiting intermediate or resistant phenotypes to first-line agents in the carbapenem, beta-lactam, and fluoroquinolone categories. The main pathogens implicated in severe infections include DTR Enterobacterales, DTR Pseudomonas aeruginosa , and DTR Acinetobacter baumannii. Although the clinical implications of DTR strains are still under investigation, certain studies have linked them to prolonged hospital stays and poor patient outcomes.

SUMMARY

Severe infections caused by DTR-GNB pose a formidable challenge for healthcare providers and represent a growing global health issue. The proper administration and optimization of novel antibiotics at our disposal are of paramount importance for combating bacterial resistance and improving patient prognosis.

Recent Approaches for Downplaying Antibiotic Resistance: Molecular Mechanisms

Antimicrobial resistance (AMR) is a ubiquitous public health menace. AMR emergence causes complications in treating infections contributing to an upsurge in the mortality rate. The epidemic of AMR in sync with a high utilization rate of antimicrobial drugs signifies an alarming situation for the fleet recovery of both animals and humans. The emergence of resistant species calls for new treatments and therapeutics. Current records propose that health drug dependency, veterinary medicine, agricultural application, and vaccination reluctance are the primary etymology of AMR gene emergence and spread. Recently, several encouraging avenues have been presented to contest resistance, such as antivirulent therapy, passive immunization, antimicrobial peptides, vaccines, phage therapy, and botanical and liposomal nanoparticles. Most of these therapies are used as cutting-edge methodologies to downplay antibacterial drugs to subdue the resistance pressure, which is a featured motive of discussion in this review article. AMR can fade away through the potential use of current cutting-edge therapeutics, advancement in antimicrobial susceptibility testing, new diagnostic testing, prompt clinical response, and probing of new pharmacodynamic properties of antimicrobials. It also needs to promote future research on contemporary methods to maintain host homeostasis after infections caused by AMR. Referable to the microbial ability to break resistance, there is a great ultimatum for using not only appropriate and advanced antimicrobial drugs but also other neoteric diverse cutting-edge therapeutics.

Estimating the Clinical and Economic Impact of Introducing a New Antibacterial into Greek Clinical Practice for the Management of Hospital-Acquired Infections with Limited Treatment Options

INTRODUCTION

Hospital-acquired infections (HAIs) and growing antimicrobial resistance (AMR) represent a significant healthcare burden globally. Especially in Greece, HAIs with limited treatment options (LTO) pose a serious threat due to increased morbidity and mortality. This study aimed to estimate the clinical and economic value of introducing a new antibacterial for HAIs with LTO in Greece.

METHODS

A previously published and validated dynamic model of AMR was adapted to the Greek setting. The model estimated the clinical and economic outcomes of introducing a new antibacterial for the treatment of HAIs with LTO in Greece. The current treatment pathway was compared with introducing a new antibacterial to the treatment sequence. Outcomes were assessed from a third-party payer perspective, over a 10-year transmission period, with quality-adjusted life years (QALYs) and life years (LYs) gained considered over a lifetime horizon.

RESULTS

Over the next 10 years, HAIs with LTO in Greece account for approximately 1.4 million hospital bed days, hospitalisation costs of more than €320 million and a loss of approximately 403,000 LYs (319,000 QALYs). Introduction of the new antibacterial as first-line treatment provided the largest clinical and economic benefit, with savings of up to 93,000 bed days, approximately €21 million in hospitalisation costs and an additional 286,000 LYs (226,000 QALYs) in comparison to the current treatment strategy. The introduction of a new antibacterial was linked to a monetary benefit of €6.8 billion at a willingness to pay threshold of €30,000 over 10 years.

CONCLUSION

This study highlights the considerable clinical and economic benefit of introducing a new antibacterial for HAIs with LTO in Greece. This analysis shows the additional benefit when a new antibacterial is introduced to treatment sequences. These findings can be used to inform decision makers to implement policies to ensure timely access to new antibacterial treatments in Greece.

Empirical antibiotic therapy for difficult-to-treat Gram-negative infections: when, how, and how long?

PURPOSE OF REVIEW

To discuss empirical therapy for severe infections due to Gram-negative bacteria with difficult-to-treat resistance (GNB-DTR) in current clinical practice, focusing in particular on the positioning of novel therapeutic agents and rapid diagnostic tests.

RECENT FINDINGS

The current era of novel agents active against GNB-DTR and showing differential activity against specific determinants of resistance is an unprecedented scenario, in which the clinical reasoning leading to the choice of the empirical therapy for treating severe GNB-DTR infections is becoming more complex, but it also allows for enhanced treatment precision.

SUMMARY

Novel agents should be used in line with antimicrobial stewardship principles, aimed at reducing selective pressure for antimicrobial resistance. However, this does not mean that they should not be used. Indeed, excesses in restrictive uses may be unethical by precluding access to the most effective and less toxic treatments for patients with severe GNB-DTR infections. Given these premises (the 'how'), empirical treatment with novel agents should be considered in all patients with risk factors for GNB-DTR and severe clinical presentation of acute infection (the 'when'). Furthermore, empirical novel agents should preferably be continued only for a few hours, until de-escalation, modification, or confirmation (as targeted therapy) is made possible by the results of rapid diagnostic tests (the 'how long').

Best practices: Appropriate use of the new β-lactam/β-lactamase inhibitor combinations, ceftazidime-avibactam and ceftolozane-tazobactam in South Africa

Antibiotic stewardship of hospital-acquired infections because of difficult-to-treat resistant (DTR) Gram-negative bacteria is a global challenge. Their increasing prevalence in South Africa has required a shift in prescribing in recent years towards colistin, an antibiotic of last resort. High toxicity levels and developing resistance to colistin are narrowing treatment options further. Recently, two new β-lactam/β-lactamase inhibitor combinations, ceftazidime-avibactam and ceftolozane-tazobactam were registered in South Africa, bringing hope of new options for management of these life-threatening infections. However, with increased use in the private sector, increasing levels of resistance to ceftazidime-avibactam are already being witnessed, putting their long-term viability as treatment options of last resort, in jeopardy. This review focuses on how these two vital new antibiotics should be stewarded within a framework that recognises the resistance mechanisms currently predominant in South Africa's multi-drug and DTR Gram-negative bacteria. Moreover, the withholding of their use for resistant infections that can be treated with currently available antibiotics is a critical part of stewardship, if these antibiotics are to be conserved in the long term.

Molecular epidemiology and antimicrobial susceptibility of Pseudomonas spp. and Acinetobacter spp. from clinical samples at Jimma medical center, Ethiopia

Introduction

Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter baumannii (A. baumannii) can cause difficult-to-treat infections. We characterized molecular epidemiology of ceftazidime-resistant P. aeruginosa and carbapenem-resistant A. baumannii at a tertiary hospital in Ethiopia.

Materials and methods

Non-fermenting gram-negative bacilli (n = 80) isolated from admitted patients were subjected for species identification by MALDI-TOF. Pseudomonas species resistant to ceftazidime or meropenem, and Acinetobacter species resistant to meropenem, or imipenem were selected for whole genome sequencing. DNA extracted with EZ1 Advanced XL instrument (Qiagen, Hilden, Germany) was sequenced on Illumina (HiSeq2500) using libraries prepared by NEXTRA-kits (Illumina). Raw reads were assembled using SPAdes 3.13.0, and assembled genomes were used to query databases for resistome profile and sequence types.

Result

Among Pseudomonas species isolated, 31.7% (13/41), and 7.3% (3/41) were non-susceptible to ceftazidime, and meropenem, respectively. Carbapenem-resistance was 56.4% (22/39) among Acinetobacter species. Moreover, 92% (12/13) of Pseudomonas species non-susceptible to ceftazidime and/or meropenem, and 89.4% (17/19) of Acinetobacter species encoded multiple resistance genes for at least three classes of antimicrobials. The prevalent β - lactamase genes were bla_OXA–486 (53.8%, 7/13), bla_CTX–M–15 (23.0%, 3/13) among Pseudomonas, and bla_GES–11 (57.8%, 11/19) among Acinetobacter. The bla_OXA–51-like β - lactamase, bla_OXA–69 (63.1%, 12/19) was the most prevalent carbapenemase gene among Acinetobacter isolates. Single isolates from both P. aeruginosa, and A. baumannii were detected with the bla_NDM–1. Sequence type (ST)1 A. baumannii and ST274 P. aeruginosa were the prevalent sequence types. A cgMLST analysis of the ST1 A. baumannii isolates showed that they were closely related and belonged to the international clonal complex one (ICC1). Similarly, ST274 P. aeruginosa isolates were clonally related.

Conclusion

The prevalence of MDR isolates of Pseudomonas and Acinetobacter spp. was high. A. baumannii isolates were clonally spreading in the admission wards at the hospital. Emergence of bla_NDM–1 in the intensive care, and surgical wards of the hospital is a severe threat that requires urgent intervention.

Effectiveness of a Multifaced Antibiotic Stewardship Program: A Pre-Post Study in Seven Italian ICUs

Multidrug resistance has become a serious threat for health, particularly in hospital-acquired infections. To improve patients’ safety and outcomes while maintaining the efficacy of antimicrobials, complex interventions are needed involving infection control and appropriate pharmacological treatments in antibiotic stewardship programs. We conducted a multicenter pre-post study to assess the impact of a stewardship program in seven Italian intensive care units (ICUs). Each ICU was visited by a multidisciplinary team involving clinicians, microbiologists, pharmacologists, infectious disease specialists, and data scientists. Interventions were targeted according to the characteristics of each unit. The effect of the program was measured with a panel of indicators computed with data from the MargheritaTre electronic health record. The median duration of empirical therapy decreased from 5.6 to 4.6 days and the use of quinolones dropped from 15.3% to 6%, both p < 0.001. The proportion of multi-drug-resistant bacteria (MDR) in ICU-acquired infections fell from 57.7% to 48.8%. ICU mortality and length of stay remained unchanged, indicating that reducing antibiotic administration did not harm patients’ safety. This study shows that our stewardship program successfully improved the management of infections. This suggests that policy makers should tackle multidrug resistance with a multidisciplinary approach based on continuous monitoring and personalised interventions.

Ceftolozane/tazobactam for hospital-acquired/ventilator-associated bacterial pneumonia due to ESBL-producing Enterobacterales: a subgroup analysis of the ASPECT-NP clinical trial

BACKGROUND

After the MERINO trial with piperacillin/tazobactam, the efficacy of β-lactam/tazobactam combinations in serious infections involving extended-spectrum β-lactamase (ESBL)-producing pathogens merits special evaluation.

OBJECTIVES

To further confirm the efficacy of ceftolozane/tazobactam in treating hospital-acquired/ventilator-associated bacterial pneumonia (HABP/VABP) involving ESBL-positive and/or AmpC-producing Enterobacterales.

METHODS

Retrospective subgroup analysis of the ASPECT-NP trial comparing ceftolozane/tazobactam with meropenem for treating HABP/VABP in mechanically ventilated adults (ClinicalTrials.gov NCT02070757). ESBLs were identified using whole genome sequencing. Chromosomal AmpC production was quantified employing a high-sensitivity mRNA transcription assay.

RESULTS

Overall, 61/726 (8.4%) participants had all baseline lower respiratory tract (LRT) isolates susceptible to both study treatments and ≥1 baseline ESBL-positive/AmpC-overproducing Enterobacterales isolate. In this subgroup (ceftolozane/tazobactam n = 30, meropenem n = 31), baseline characteristics were generally comparable between treatment arms. The most frequent ESBL-positive and/or AmpC-overproducing Enterobacterales isolates (ceftolozane/tazobactam n = 31, meropenem n = 35) overall were Klebsiella pneumoniae (50.0%), Escherichia coli (22.7%), and Proteus mirabilis (7.6%). The most prevalent ESBLs were CTX-M-15 (75.8%), other CTX-M (19.7%), and SHV (4.5%); 10.6% of isolates overproduced chromosomal AmpC. Overall, 28 day all-cause mortality was 6.7% (2/30) with ceftolozane/tazobactam and 32.3% (10/31) with meropenem (25.6% difference, 95% CI: 5.54 to 43.84). Clinical cure rate at test-of-cure, 7-14 days after end of therapy, was 73.3% (22/30) with ceftolozane/tazobactam and 61.3% (19/31) with meropenem (12.0% difference, 95% CI: -11.21 to +33.51). Per-isolate microbiological response at test-of-cure was 64.5% (20/31) with ceftolozane/tazobactam and 74.3% (26/35) with meropenem (-9.8% difference, 95% CI: -30.80 to +12.00).

CONCLUSIONS

These data confirm ceftolozane/tazobactam as an effective treatment option for HABP/VABP involving ceftolozane/tazobactam-susceptible ESBL-positive and/or AmpC-producing Enterobacterales.

Bacteriological Profile and Antimicrobial Susceptibility Patterns of Gram-Negative Bloodstream Infection and Risk Factors Associated with Mortality and Drug Resistance: A Retrospective Study from Shanxi, China

Objective

The aim of this study was to analyze the epidemiological of gram-negative bloodstream infection (GNBSI) and establish a risk prediction model for mortality and acquiring multidrug resistant (MDR), the extended spectrum beta-lactamases (ESBLs) producing and carbapenem-resistant (CR) GNBSI.

Methods

This retrospective study covered five years from January 2015 to December 2019. Data were obtained from Hospital Information System (HIS) and microbiology department records. The risk factors for mortality and acquiring MDR, ESBLs-producing and CR GNBSI were analyzed by univariable and multivariable analysis.

Results

A total of 1018 GNBSI cases were collected. A majority of GNBSI patients were in hematology ward (23.77%). There were 38.61% patients who were assigned in the 41–60 age group. Escherichia coli was the most common gram-negative organism (49.90%). Among isolates of GNBSI, 40.47% were found to be MDR strains, 34.09% were found to be ESBLs-producing strains and 7.06% were found to be CR strains. Escherichia coli was the most common MDR (71.36%) and ESBLs-producing strain (77.81%). Acinetobacter baumannii was the most common CR isolate (46.15%). Multivariate analysis indicated that diabetes mellitus, solid organ tumor, non-fermentative bacteria, MDR strain, central venous cannula, urinary catheter, therapy with carbapenems or tigecycline prior 30 days of infection were independent mortality risk factors for GNBSIs. Over all, therapy with tigecycline prior 30 days of infection was the mutual predictor for mortality of GNBSI, acquiring MDR, ESBLs-producing and CR GNBSI (OR, 8.221, OR, 3.963, OR, 3.588, OR, 9.222, respectively, all p < 0.001).

Conclusion

Collectively, our study implies that patients who were diagnosed as GNBSI had a younger age. Therapy with tigecycline was the mutual and paramount predictor for mortality of GNBSI, acquiring MDR, ESBLs-producing and CR GNBSI. Our investigation had provided a theoretical basis for the use of antibiotics and prevention and control of hospital infection in our region.

The Interplay between Host Defense, Infection, and Clinical Status in Septic Patients: A Narrative Review

Sepsis is a life-threatening condition that arises when the body's response to an infection injures its own tissues and organs. Despite significant morbidity and mortality throughout the world, its pathogenesis and mechanisms are not clearly understood. In this narrative review, we aimed to summarize the recent developments in our understanding of the hallmarks of sepsis pathogenesis (immune and adaptive immune response, the complement system, the endothelial disfunction, and autophagy) and highlight novel laboratory diagnostic approaches. Clinical management is also discussed with pivotal consideration for antimicrobic therapy management in particular settings, such as intensive care unit, altered renal function, obesity, and burn patients.

Improving management and antimicrobial stewardship for bacterial and fungal infections in hospitalized patients with COVID-19

SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) infection is being one of the most significant challenges of health care systems worldwide. Bacterial and fungal infections in hospitalized patients with coronavirus disease 2019 (COVID-19) are uncommon but consumption of antibiotics and antifungals has increased dramatically during the ongoing pandemic resulting in increased selective pressure for global antimicrobial resistance. Nosocomial bacterial superinfections appear to be more frequent than community-acquired coinfections, particularly among patients admitted to the intensive care unit (ICU) and those receiving immunosuppressive treatment. Fungal infections associated with COVID-19 might be missed or misdiagnosed. Existing and new antimicrobial stewardship (AMS) programmes can be utilized directly in COVID-19 pandemic and are urgently needed to contain the high rates of misdiagnosis and antimicrobial prescription. The aim of this review is to describe the role of bacterial and fungal infections and possible strategies of AMS to use in daily practice for optimal management of COVID-19.

Management of Infections Caused by Multidrug-resistant Gram-negative Pathogens: Recent Advances and Future Directions

During the last decades, the isolation of multidrug-resistant Gram-negative (MDR-GN) bacteria has dramatically increased worldwide and has been associated with significant delays in the administration of adequate antibiotic treatment, resulting in increased morbidity and mortality rates. Given specific challenges to effective therapy with old antibiotics, there is the need to establish adequate clinical and therapeutic recommendations for antibiotic treatment of MDR-GN pathogens. Herein, we will review risk factors for harbouring infections due to MDR-GN bacteria, proposing an algorithm for the choice of empirical treatment when a MDR-GN pathogen is suspected. In addition, we will report our recommendations regarding the first- and second-line treatment options for hospitalized patients with serious infections caused by extended-spectrum β-lactamases producing Enterobacterales, carbapenem-resistant Enterobacterales, MDR Pseudomonas aeruginosa and MDR Acinetobacter baumannii. Recommendations have been specially focused, for each pathogen, on bloodstream infections, nosocomial pneumonia, and urinary tract infections.

Preparation and Antimicrobial Activity of Chitosan and Its Derivatives: A Concise Review

Despite the advantages presented by synthetic polymers such as strength and durability, the lack of biodegradability associated with the persistence in the environment for a long time turned the attention of researchers to natural polymers. Being biodegradable, biopolymers proved to be extremely beneficial to the environment. At present, they represent an important class of materials with applications in all economic sectors, but also in medicine. They find applications as absorbers, cosmetics, controlled drug delivery, tissue engineering, etc. Chitosan is one of the natural polymers which raised a strong interest for researchers due to some exceptional properties such as biodegradability, biocompatibility, nontoxicity, non-antigenicity, low-cost and numerous pharmacological properties as antimicrobial, antitumor, antioxidant, antidiabetic, immunoenhancing. In addition to this, the free amino and hydroxyl groups make it susceptible to a series of structural modulations, obtaining some derivatives with different biomedical applications. This review approaches the physico-chemical and pharmacological properties of chitosan and its derivatives, focusing on the antimicrobial potential including mechanism of action, factors that influence the antimicrobial activity and the activity against resistant strains, topics of great interest in the context of the concern raised by the available therapeutic options for infections, especially with resistant strains.

The Association Between High and Unnecessary Antibiotic Prescribing: A Cohort Study Using Family Physician Electronic Medical Records

BACKGROUND

Approximately 25% of outpatient antibiotic prescriptions are unnecessary among family physicians in Canada. Minimizing unnecessary antibiotics is key for community antibiotic stewardship. However, unnecessary antibiotic prescribing is much harder to measure than total antibiotic prescribing. We investigated the association between total and unnecessary antibiotic use by family physicians and evaluated inter-physician variability in unnecessary antibiotic prescribing.

METHODS

This was a cohort study based on electronic medical records of family physicians in Ontario, Canada, between April 2011 and March 2016. We used predefined expected antibiotic prescribing rates for 23 common primary care conditions to calculate unnecessary antibiotic prescribing rates. We used multilevel Poisson regression models to evaluate the association between total antibiotic volume (number of antibiotic prescriptions per patient visit), adjusted for multiple practice- and physician-level covariates, and unnecessary antibiotic prescribing.

RESULTS

There were 499 570 physician-patient encounters resulting in 152 853 antibiotic prescriptions from 341 physicians. Substantial inter-physician variability was observed. In the fully adjusted model, we observed a significant association between total antibiotic volume and unnecessary prescribing rate (adjusted rate ratio 2.11 per 10% increase in total use; 95% CI 2.05-2.17), and none of the practice- and physician-level variables were associated with unnecessary prescribing rate.

CONCLUSIONS

We demonstrated substantial inter-physician variability in unnecessary antibiotic prescribing in this cohort of family physicians. Total antibiotic use was strongly correlated with unnecessary antibiotic prescribing. Total antibiotic volume is a reasonable surrogate for unnecessary antibiotic use. These results can inform community antimicrobial stewardship efforts.

Epidemiology of Multidrug-Resistant Pseudomonas aeruginosa in the Middle East and North Africa Region

Over the last decades, there has been a dramatic global increase in multidrug-resistant (MDR) pathogens particularly among Gram-negative bacteria (GNB). Pseudomonas aeruginosa is responsible for various health care-associated infections, while MDR P. aeruginosa causes significant morbidity and mortality. Middle East and North Africa (MENA) represent an unexplored geographical region for the study of drug resistance since many of these countries are at crossroads of high volume of travel, diverse expatriate populations, as well as high antibiotic consumption despite attempts to implement antimicrobial stewardship programs. This minireview analyzes epidemiology, microbiological, and genomic characteristics of MDR P. aeruginosa in the MENA region. Published data on MDR P. aeruginosa prevalence, antimicrobial resistance patterns, and genetic profiles from studies published during the past 10 years from 19 MENA countries have been included in this minireview. There is wide variation in the epidemiology of MDR P. aeruginosa in the MENA region in terms of prevalence, antimicrobial characteristics, as well as genetic profiles. Overall, there is high prevalence of MDR P. aeruginosa seen in the majority of the countries in the MENA region with similarities between neighboring countries, which might reflect comparable population and antibiotic-prescribing cultures. Isolates from critical care units are significantly resistant particularly from certain countries such as Saudi Arabia, Egypt, Libya, Syria, and Lebanon with high-level resistance to cephalosporins, carbapenems, and aminoglycosides. Colistin susceptibility patterns remains high apart from countries with high-level antibiotic resistance such as Saudi Arabia, Syria, and Egypt.

Early prediction models for extended-spectrum β-lactamase-producing Escherichia coli infection in emergency department: A protocol for systematic review and meta analysis

BACKGROUND

Resistance in gram-negative bacteria has gained great importance in recent decades and one reason is the rapid increase of extended spectrum β-lactamase (ESBL)-producing bacteria as a growing problem worldwide. The increasing proportion of ESBL-producing Enterobacteriaceae (ESBL-E) infections acquired in the emergency community is a new feature of ESBLs epidemiology. Early recognition of patients with extended-spectrum β-lactamase-producing Escherichia coli infection is important in the emergency department. To mitigate the burden on the healthcare system, while also providing the best possible care for patients, early recognition of the infection is needed.

METHODS

For the acquisition of required data of eligible prospective/retrospective cohort study or randomized controlled trials (RCTs), we will search for publications from PubMed, Web of science, EMBASE, Cochrane Library, Google scholar. Two independent reviewers will read the full English text of the articles, screened and selected carefully, removing duplication. Then we evaluate the quality and analyses data by Review Manager (V.5.4). Results data will be pooled and meta-analysis will be conducted if there's 2 eligible studies considered.

RESULTS

This systematic review and meta-analysis will evaluate the value of the early prediction models for Extended-spectrum β-lactamase-producing E coli infection in emergency department.

CONCLUSIONS

This systematic review and meta-analysis will provide clinical evidence for predicting Extended-spectrum β-lactamase-producing E coli infection in emergency department, inform our understanding of the value of the predictive model in predicting Extended-spectrum β-lactamase-producing E coli infection in emergency department in the early stage. The conclusions drawn from this study may be beneficial to patients, clinicians, and health-related policy makers.

STUDY REGISTRATION NUMBER

INPLASY202130049.

Best practice: antibiotic decision-making in ICUs

PURPOSE OF REVIEW

A major challenge in the ICU is optimization of antibiotic use. This review assesses current understanding of core best practices supporting and promoting astute antibiotic decision-making.

RECENT FINDINGS

Limiting exposure to the shortest effective duration is the cornerstone of antibiotic decision-making. The decision to initiate antibiotics should include assessment of risk for resistance. This requires synthesis of patient-level data and environmental factors to determine whether delayed initiation could be considered in some patients with suspected sepsis until sensitivity data is available. Until improved stratification scores and clinically meaningful cut-off values to identify MDR are available and externally validated, decisions as to which empiric antibiotic is used should rely on syndromic antibiograms and institutional guidance. Optimization of initial and maintenance doses is another enabler of enhanced outcome. Stewardship practices must be streamlined by re-assessment to minimize negative effects, such as a potential increase in duration of therapy and increased risk of collateral damage from exposure to multiple, sequential antibiotics that may ensue from de-escalation.

SUMMARY

Multiple challenges and research priorities for antibiotic optimization remain; however, the best stewardship practices should be identified and entrenched in daily practice. Reducing unnecessary exposure remains a vital strategy to limit resistance development.

Gram-Negative Skin and Soft Tissue Infections

Skin and soft tissue infections (SSTIs) frequently are encountered in clinical practice, and gram-negative bacilli (GNB) constitute an underrated portion of their etiology. The rate of GNB-causing SSTIs is increasing, especially with the rise in antimicrobial resistance. Although the diagnosis of SSTIs mostly is clinical, rapid diagnostic modalities can shorten the time to initiating proper therapy and improving outcomes. Novel antibiotics are active against GNB SSTIs and can be of great value in the management. This review provides an overview of the role of GNB in SSTIs and summarizes their epidemiology, risk factors, outcome, and clinical management.

Burden of carbapenem non-susceptible infections in high-risk patients: systematic literature review and meta-analysis

Background

Owing to their resistance to an important class of antibiotics, the prevention and treatment of carbapenem-resistant (CR)/non-susceptible Gram-negative (GN) infections has become an important public health objective. We conducted a systematic review and meta-analysis of published literature to evaluate the burden of CR GN infections, focusing on high-risk patients such as transplant recipients, or patients with cancer, renal impairment, or sepsis.

Methods

MEDLINE®, Cochrane Central, and Embase® were searched between 2010 and March 2019. Abstracts and full-text articles were screened in duplicate. Random effects meta-analysis was conducted when reported outcomes were sufficiently similar.

Results

Twenty-six publications were eligible. Meta-analyses found increased mortality associated with CR infections among high-risk patients in both unadjusted analysis (8 studies; summary unadjusted odds ratio [OR]: 5.85; 95% confidence interval [CI]: 3.69, 9.26; I² = 19.8%) and adjusted analysis (5 studies; summary hazard ratio [HR]: 4.67; 95% CI: 2.18, 9.99; I² = 77.7%), compared to patients with carbapenem-susceptible (CS) infections or no infection. Increased mortality was also seen in subgroup analyses by length of follow-up (either short-term or long-term) or causative pathogen. A limited number of studies found that CR GN infections increased the risk for mechanical ventilation, adverse events such as graft failure or acute rejection in solid organ transplant recipients, increased renal failure or nephrotoxicity, and an increase in readmissions and costs, though the findings reported in the literature were not consistent.

Conclusion

This systematic literature review and meta-analysis indicates that CR GN infections in high-risk patients are associated with increased mortality, emphasizing the need for antimicrobial stewardship and infection control in hospitals which treat high-risk patients and for the development of effective antimicrobials with favorable efficacy and safety profiles for the treatment of CR GN infections.

Current choices of antibiotic treatment for Pseudomonas aeruginosa infections

PURPOSE OF REVIEW

Pseudomonas aeruginosa is one of the most feared nosocomial pathogens. Treatment of P. aeruginosa infections is challenging because of the limited choices of antibiotics and the emergent resistance of the pathogen. The present review aims at addressing the management of P. aeruginosa infections and highlighting the novel antibiotics that show a future promising role.

RECENT FINDINGS

Novel fluoroquinolones have been recently introduced and show favorable activity. New combinations of β-lactams/β-lactamase inhibitors have been studied in various indications of infections because of P. aeruginosa. Cefiderocol, a new cephalosporin, shows very promising results against P. aeruginosa. Currently, combination therapy is only recommended in limited scenarios. Extended-infusion of β-lactams exhibit clinical benefit. Bacteriophage therapy is a growing field of interest and may have an impactful effect on the treatment of resistant P. aeruginosa.

SUMMARY

Factors that guide clinical decisions for empiric and directed P. aeruginosa therapy include the epidemiology, the patient's risk factors, the site of infection, and the available treatment options. Conventional antipseudomonal antibiotics have been used successfully for a long time, but the increase in worldwide resistance necessitates the need for newer agents. Antimicrobial stewardship is essential to preserve the new drugs and prevent future development of resistance.

Treatment of Bloodstream Infections Due to Gram-Negative Bacteria with Difficult-to-Treat Resistance

The rising incidence of bloodstream infections (BSI) due to Gram-negative bacteria (GNB) with difficult-to-treat resistance (DTR) has been recognized as a global emergency. The aim of this review is to provide a comprehensive assessment of the mechanisms of antibiotic resistance, epidemiology and treatment options for BSI caused by GNB with DTR, namely extended-spectrum Beta-lactamase-producing Enterobacteriales; carbapenem-resistant Enterobacteriales; DTR Pseudomonas aeruginosa; and DTR Acinetobacter baumannii.

Risk stratification for multidrug-resistant Gram-negative infections in ICU patients

PURPOSE OF REVIEW

Antimicrobial resistance among Gram-negative microorganisms has alarmingly increased in the past 10 years worldwide. Infections caused by these microorganisms are difficult to treat, especially in critically ill patients.The present review examines how to accurately predict which patients carry a greater risk of colonization or infection on which to base the timely choice of an effective empirical antibiotic treatment regimen and avoid antibiotic overuse.

RECENT FINDINGS

There are many risk factors for acquiring one of many multidrug-resistant Gram-negative microorganisms (MDR-GN); however, scores anticipating colonization, infection among those colonized, or mortality among those infected have a variable accuracy. Accuracy of scores anticipating colonization is low. Scores predicting infections among colonized patients are, in general, better, and ICU patients infected with MDR-GN have a worse prognosis than those infected by non-resistant microorganisms. Scores are, in general, better at excluding patients.

SUMMARY

Despite these limitations, scores continue to gain popularity including those by Giannella, Tumbarello, Johnson, or the scores INCREMENT carbapenem-producing Enterobacteriaceae score, Cano, Tartof, or CarbaSCORE.

Development and validation of a scoring system for predicting cancer patients at risk of extended-spectrum b-lactamase-producing Enterobacteriaceae infections

Background

Extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE) infections are frequent and highly impact cancer patients. We developed and validated a scoring system to identify cancer patients harboring ESBL-PE at the National Institute of Cancer of Colombia.

Methods

We retrospectively analyzed medical records of 1695 cancer patients. Derivation phase included 710 patients admitted between 2013 to 2015, ESBL-PE positive culture (n = 265) paired by month and hospitalization ward with Non-ESBL-PE (n = 445). A crude and weighted score was developed by conditional logistic regression. The model was evaluated in a Validation cohort (n = 985) with the same eligibility criteria between 2016 to 2017.

Results

The score was based on eight variables (reported with Odds Ratio and 95% confidence interval): Hospitalization ≥7 days (5.39 [2.46–11.80]), Hospitalization during the previous year (4, 87 [2.99–7.93]), immunosuppressive therapy during the previous 3 months (2.97 [1.44–6.08]), Neutropenia (1.90 [1.12–3.24]), Exposure to Betalactams during previous month (1.61 [1.06–2.42]), Invasive devices (1.51 [1.012–2.25]), Neoplasia in remission (2.78 [1.25–1.17]), No chemotherapy during the previous 3 months (1.90 [1.22–2.97]). The model demonstrated an acceptable discriminatory capacity in the Derivation phase, but poor in the Validation phase (Recipient Operating Characteristic Curve: 0.68 and 0.55 respectively).

Conclusions

Cancer patients have a high prevalence of risk factors for ESBL-PE infection. The scoring system did not adequately discriminate patients with ESBL-PE. In a high-risk population, other strategies should be sought to identify patients at risk of resistant ESBL-PE infection.

Optimal Management of Complicated Infections in the Pediatric Patient: The Role and Utility of Ceftazidime/Avibactam

Antimicrobial resistance poses a substantial threat to global public health. The pursuit of new antibiotics has decreased and very few options have been investigated for the treatment of complicated multidrug-resistant Gram-negative (MDR-GN) infections in adult population and even less in pediatric patients. Ceftazidime-avibactam (CAZ-AVI) is novel cephalosporin/β-lactamase inhibitor (BL-BLI) combination with broad antibacterial spectrum. The aim of this review is to describe the current and future role CAZ-AVI in the pediatric population with suspected or confirmed MDR-GN infections.

How to manage KPC infections

Carbapenemase-producing Enterobacteriaceae represent an increasing global threat worldwide and Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) has become one of the most important contemporary pathogens, especially in endemic areas. Risk stratification and rapid diagnostics laboratory workflows are of paramount importance and indication for therapy of KPC-KP infection must be individualized according to the baseline characteristics of the patient and severity of infection. The optimal treatment of infection because of KPC-KP organisms is uncertain and antibiotic options are limited. The knowledge of the patient's pathophysiology, infection site, and application of the pharmacokinetic/pharmacodynamic principles on the basis of minimum inhibitory concentration (MIC) has progressively gained major relevance. Combination therapies including high-dose meropenem, colistin, fosfomycin, tigecycline, and aminoglycosides are widely used, with suboptimal results. In the past few years, new antimicrobials targeting KPC-KP have been developed and are now at various stages of clinical research. However, their optimal use should be guaranteed in the long term for delaying, as much as possible, the emergence of resistance. Strict infection control measures remain necessary. The aim of this review is to discuss the challenges in the management and treatment of patients with infections because KPC-KP and provide an expert opinion.

Effect of a "handshake" stewardship program versus a formulary restriction policy on High-End antibiotic use, expenditure, antibiotic resistance, and patient outcome

This study reports the effect of implementing an antibiotic stewardship program (ASP) based on the "handshake" strategy for 2 years on multiple endpoints compared with that in a preceding period when an antimicrobial restriction policy was only applied in the absence of a complete program in a tertiary-care Lebanese hospital. The studied endpoints were broad-spectrum antibiotic consumption, antibiotic expenditure, nosocomial bacteremia incidence rate, and patient outcome.An interrupted time series analysis was undertaken to assess the changes in the trend (ΔT) and level (ΔL) of the aforementioned endpoints among adult inpatients before (October 2013 to September 2015) and after the introduction of the ASP (October 2016 to September 2018).After the implementation of the "handshake" ASP, marked changes were observed in the consumption of broad-spectrum antibiotics. The mean use density levels for imipenem and meropenem decreased by 13.72% (P = 0.017), coupled with a decreasing rate of prescription (ΔT = -24.83 defined daily dose [DDD]/1,000 patient days [PD]/month; P = 0.02). Tigecycline use significantly decreased in level by 69.19% (P < 0.0001) and in trend (ΔT = -25.63 DDD/1,000 PD/month; P < 0.0001). A reduction in the use of colistin was also documented but did not reach statistical significance (ΔL = -8.71%, P = 0.56; ΔT = -5.51 DDD/1,000 PD/month = -5.5; P = 0.67). Antibiotic costs decreased by 24.6% after ASP implementation (P < 0.0001), and there was a distinct change from an increasing rate to a decreasing rate of expenditure (ΔT = -12.19 US dollars/PD/month; P = 0.002). The incidence rate of nosocomial bacteremia caused by carbapenem-resistant gram-negative bacteria (CRGNB) decreased by 34.84% (P = 0.13) coupled with a decreasing trend (ΔT = -0.23 cases/1,000 PD/month, P = 0.08). Specifically, a noticeable reduction in the incidence rate of bacteremia due to carbapenem-resistant Acinetobacter baumannii was documented (ΔL = -54.34%, P = 0.01; ΔT = -0.24 cases/1000 PD/month, P = 0.01). Regarding patient outcome, all-cause mortality rates did not increase in level or in rate (ΔL = -3.55%, P = 0.59; ΔT = -0.29 deaths/1000 PD/month, P = 0.6). The length of stay and 7-day readmission rate remained stable between the two periods.In conclusion, the "handshake" ASP succeeded in controlling the prescription rates of antibiotics and in decreasing the nosocomial bacteremia rates caused by CRGNB without compromising patient outcome in our facility. It also had an economic effect in reducing antibiotic costs compared with the previous restriction policy on antimicrobial dispensing.

An African perspective on the prevalence, fate and effects of carbapenem resistance genes in hospital effluents and wastewater treatment plant (WWTP) final effluents: A critical review

This article provides an overview of the antibiotic era and discovery of earliest antibiotics until the present day state of affairs, coupled with the emergence of carbapenem-resistant bacteria. The ways of response to challenges of antibiotic resistance (AR) such as the development of novel strategies in the search of new antibiotics, designing more effective preventive measures as well as the ecology of AR have been discussed. The applications of plant extract and chemical compounds like nanomaterials which are based on recent developments in the field of antimicrobials, antimicrobial resistance (AMR), and chemotherapy were briefly discussed. The agencies responsible for environmental protection have a role to play in dealing with the climate crisis which poses an existential threat to the planet, and contributes to ecological support towards pathogenic microorganisms. The environment serves as a reservoir and also a vehicle for transmission of antimicrobial resistance genes hence, as dominant inhabitants we have to gain a competitive advantage in the battle against AMR.

Rational approach in the management of Pseudomonas aeruginosa infections

PURPOSE OF REVIEW

This review details the management of Pseudomonas aeruginosa infections covering both current and future treatment options that are and may be available for the clinicians.

RECENT FINDINGS

Pseudomonas aeruginosa infections are a great concern in hospital-acquired infections with very limited therapeutic options. The increasing antibiotic resistance has led to a need for different treatment choices that range from the use of new antibiotics to new nonantibiotic alternative agents to kill or disarm the pathogen.

SUMMARY

New molecules such as ceftolozane-tazobactam, ceftazidime-avibactam, and imipenem-relebactam have shown an adequate activity against P. aeruginosa, especially against multidrug resistance strains. Other nonantibiotic alternative treatments, such as antibodies, bacteriocins or phage therapy, have shown promising results, but future clinical studies are needed.

Challenges and research priorities to progress the impact of antimicrobial stewardship

Antimicrobial stewardship programmes have been playing an important role in patient care and hospital policies. These programmes are now recognised as formal strategies for curbing the upward trend in antibiotic resistance and for improving the appropriate antimicrobial and antifungal use. The role of such programs in the era of antimicrobial resistance presents several unique challenges and opportunities, most notably in the diagnostic and therapeutic setting. Controversies remain regarding the most effective interventions and the appropriate design to evaluate their impact. In this review, based on rounds of discussion, we explain the most important challenges faced by antibiotic stewardship and antifungal stewardship programmes. We also try to suggest areas for further research.

Indian consensus on the management of CRE infection in critically ill patients (ICONIC) - India

Background: The increasing burden of carbapenem-resistant Enterobacteriaceae (CRE) carriage and infection in different patient settings in India has created an acute need for guidance for clinicians regarding optimal strategies for the management of CRE infection in critically ill patients. Research design and methods: A multidisciplinary panel of 11 Indian experts in CRE infection assembled for comprehensive discussion and consensus development. The experts developed clinical statements through a systematic review of key literature. Main outcome measures: The panel voted anonymously on 60 clinically relevant questions, through a modified Delphi process. Results: Forty-six key clinical consensus statements (CCS) were proposed. The panel reached a consensus on several important issues, providing recommendations on surveillance, diagnosis, prevention, pharmacokinetic challenges, combination therapy, and cornerstone molecules in CRE infections. The panel also proposed a treatment algorithm for NDM-prevalent settings. Conclusion: These consensus statements may offer clinicians expert guidance on the management of CRE infections. There is a dearth of high-/moderate-level evidence on managing CRE infections; the recommendations presented herein are based on expert opinion.

Bloodstream infections caused by carbapenem-resistant Acinetobacter baumannii: Clinical features, therapy and outcome from a multicenter study

OBJECTIVES

bloodstream infections (BSI) due to multidrug-resistant (MDR) Acinetobacter baumannii (AB) have been increasingly observed among hospitalized patients.

METHODS

prospective, observational study conducted among 12 large tertiary-care hospitals, across 7 Italian regions. From June 2017 to June 2018 all consecutive hospitalized patients with bacteremia due to MDR-AB were included and analyzed in the study.

RESULTS

During the study period 281 episodes of BSI due to MDR-AB were observed: 98 (34.8%) episodes were classified as primary bacteremias, and 183 (65.2%) as secondary bacteremias; 177 (62.9%) of them were associated with septic shock. Overall, 14-day mortality was observed in 172 (61.2%) patients, while 30-day mortality in 207 (73.6%) patients. On multivariate analysis, previous surgery, continuous renal replacement therapy, inadequate source control of infection, and pneumonia were independently associated with higher risk of septic shock. Instead, septic shock and Charlson Comorbidity Index >3 were associated with 14-day mortality, while adequate source control of infection and combination therapy with survival. Finally, septic shock, previous surgery, and aminoglycoside-containing regimen were associated with 30-day mortality, while colistin-containing regimen with survival.

CONCLUSIONS

BSI caused by MDR-AB represents a difficult challenge for physicians, considering the high rates of septic shock and mortality associated with this infection.

Prevalence of in vitro synergistic antibiotic interaction between fosfomycin and nonsusceptible antimicrobials in carbapenem-resistant Pseudomonas aeruginosa

PURPOSE

We assessed the synergistic potential of fosfomycin and parenteral antibiotics among carbapenem-resistant Pseudomonas aeruginosa (CRP).

METHODOLOGY

Minimum inhibitory concentrations (MICs) were determined by broth microdilution for all antibiotics except fosfomycin, for which the gradient diffusion strip (GDS) method was used. The GDS cross method was performed to assess interactions between fosfomycin and: aztreonam, cefepime, ceftazidime, ceftazidime/avibactam, ceftolozane/tazobactam, meropenem, piperacillin/tazobactam and tobramycin. Only organisms that were nonsusceptible to the second drug were assessed.

RESULTS

Among 153 clinical isolates, the fosfomycin MIC50/90 was 48/≥1024 mg l^-1 . Synergy was detected in 131/604 (21.7 %) fosfomycin-antibiotic combinations among 76 (49.7 %) isolates. Ceftazidime (42/81, 51.9%) and ceftolozane/tazobactam (7/14, 50.0%) displayed synergy most frequently. Meropenem susceptibility was restored in 21 (13.7 %) isolates. Antagonism was not observed.

CONCLUSION

Fosfomycin synergy was commonly observed in vitro among CRP. These data may guide the selection of combination antibiotic therapy. The susceptibility to other antibiotics was restored in combination with fosfomycin, warranting further in vivo evaluation.

Current trends in the treatment of pneumonia due to multidrug-resistant Gram-negative bacteria

Pneumonia is one of the most common infections worldwide. Morbidity, mortality, and healthcare costs increase substantially when pneumonia is caused by multidrug-resistant Gram-negative bacteria (MDR-GNB). The ongoing spread of antimicrobial resistance has made treating MDR-GNB pneumonia increasingly difficult. Fortunately, there have been some recent additions to our antibiotic armamentarium in the US and Europe for MDR-GNB, along with several agents that are in advanced stages of development. In this article, we review the risk factors for and current management of MDR-GNB pneumonia as well as novel agents with activity against these important and challenging pathogens.

Using local clinical and microbiological data to develop an institution specific carbapenem-sparing strategy in sepsis: a nested case-control study

Background

From a stewardship perspective it is recommended that antibiotic guidelines are adjusted to the local setting, accounting for the local epidemiology of pathogens. In many settings the prevalence of Gram-negative pathogens with resistance to empiric sepsis therapy is increasing. How and when to escalate standard sepsis therapy to a reserve antimicrobial agent, is a recurrent dilemma. The study objective was to develop decision strategies for empiric sepsis therapy based on local microbiological and clinical data, and estimate the number needed to treat with a carbapenem to avoid mismatch of empiric therapy in one patient (NNTC).

Methods

We performed a nested case control study in patients (> 18 years) with Gram-negative bacteremia in 2013-2016. Cases were defined as patients with Gram-negative bacteremia with in vitro resistance to the combination 2nd generation cephalosporin AND aminoglycoside (C-2GC + AG). Control patients had Gram-negative bacteremia with in vitro susceptibility to cefuroxime AND/OR gentamicin, 1:2 ratio. Univariate and multivariable analysis was performed for demographic and clinical predictors of resistance. The adequacy rates of empiric therapy and the NNTC were estimated for different strategies.

Results

The cohort consisted of 486 episodes of Gram-negative bacteremia in 450 patients. Median age was 66 years (IQR 56-74). In vitro resistance to C-2GC + AG was present in 44 patients (8.8%). Independent predictors for resistance to empiric sepsis therapy were hematologic malignancy (adjusted OR 4.09, 95%CI 1.43-11.62, p < 0.01), previously cultured drug resistant pathogen (adjusted OR 3.72. 95%CI 1.72-8.03, p < 0.01) and antibiotic therapy during the preceding 2 months (adjusted OR 12.5 4.08-38.48, p < 0.01). With risk-based strategies, an adequacy rate of empiric therapy of 95.2-99.3% could be achieved. Compared to treating all patients with a carbapenem, the NNTC could be reduced by 82.8% (95%CI 78.5-87.5%) using the targeted approaches.

Conclusions

A risk-based approach in empiric sepsis therapy has the potential to better target the use of reserve antimicrobial agents aimed at multi-resistant Gram-negative pathogens. A structured evaluation of the expected antimicrobial consumption and antibiotic adequacy rates is essential to be able to weigh the costs and benefits of potential antibiotic strategies and select the most appropriate approach.

Bacterial Infections in Patients with Liver Cirrhosis in an Internal Medicine Department

Background and Aims

Liver cirrhosis (LC) is the end stage of multiple processes that lead to hepatic failure and is the 10th most common cause of death in the Western world. Bacterial infections are one of the most important clinical problems in patients with LC, as their underlying immune status is compromised. Approximately 60% of bacterial infections in cirrhotic patients are community acquired (CA) and 40% are nosocomial. The most common infections in cirrhotic patients are spontaneous bacterial peritonitis (SBP) (25%), urinary tract infection (UTI) (20%), pneumonia (15%), bacteremia (12%), and cellulitis (2-11%). The aim of this study was to evaluate the most frequent infections in patients with LC and describe the evolution of the microbiology in these patients.

Material and Methods

This is a retrospective analysis of 4 interspersed years (2008, 2010, 2012, and 2014) that included 372 patients. Demographic characteristics were evaluated, including gender, age, type of infection, bacteria resistance profile, antibiotic use, Child-Pugh-Turcotte and Model for End-Stage Liver Disease scores, and mortality rate.

Results

The mean age of all patients enrolled in this study was 64.5 ± 12.2 years. Male patients were significantly more prevalent than female ones (72 vs. 28%). In the 4 analyzed years, the following numbers of infections occurred: 71 infections (49% CA and 51% nosocomial) in 2008; 86 infections (60.5% CA and 39.5% nosocomial) in 2010; 99 infections (56.6% CA and 43.4% nosocomial) in 2012; and 116 infections (70.7% CA and 29.3% nosocomial) in 2014. The most frequent infections were UTI (32.5%), respiratory tract infection (29.3%), SBP (26.1%), and cellulitis (6.2%). A microbiological agent was identified in 32.4, 59.3, 53.5, and 61.2% of infections in 2008, 2010, 2012, and 2014, respectively, with a predominance of gram-negative bacilli. In all series, a third-generation cephalosporin was the most frequent antibiotic used empirically. The majority of patients was in stage B (42.7%) of the Child-Pugh-Turcotte score, followed by stage C (39.3%) and stage A (18%). Mortality increased significantly over the years, from 7% in 2008 to 25% in 2014 (p = 0.016).

Conclusions

The present study showed a high prevalence of bacterial infections in patients with LC. A high rate of suspicion is needed for an infectious process in these patients, and an appropriate antibiotic treatment can decrease the morbidity and mortality in cirrhotic patients.

Ceftolozane/tazobactam for the treatment of multidrug resistant Pseudomonas aeruginosa: experience from the Balearic Islands

A prospective, descriptive observational study of consecutive patients treated with ceftolozane/tazobactam in the reference hospital of the Balearic Islands (Spain), between May 2016 and September 2017, was performed. Demographic, clinical, and microbiological variables were recorded. The later included resistance profile, molecular typing, and whole genome sequencing of isolates showing resistance development. Fifty-eight patients were treated with ceftolozane/tazobactam. Thirty-five (60.3%) showed respiratory tract infections, 21 (36.2%) received monotherapy, and 37 (63.8%) combined therapy for ≥ 72 h, mainly with colistin (45.9%). In 46.6% of the patients, a dose of 1/0.5 g/8 h was used, whereas 2/1 g/8 h was used in 41.4%. In 56 of the cases (96.6%), the initial Pseudomonas aeruginosa isolates recovered showed a multidrug resistant (MDR) phenotype, and 50 of them (86.2%) additionally met the extensively drug resistant (XDR) criteria and were only susceptible colistin and/or aminoglycosides (mostly amikacin). The epidemic high-risk clone ST175 was detected in 50% of the patients. Clinical cure was documented in 37 patients (63.8%) and resistance development in 8 (13.8%). Clinical failure was associated with disease severity (SOFA), ventilator-dependent respiratory failure, XDR profile, high-risk clone ST175, negative control culture, and resistance development. In 6 of the 8 cases, resistance development was caused by structural mutations in AmpC, including some mutations described for the first time in vivo, whereas in the other 2, by mutations in OXA-10 leading to the extended spectrum OXA-14. Although further clinical experience is still needed, our results suggest that ceftolozane/tazobactam is an attractive option for the treatment of MDR/XDR P. aeruginosa infections.

Choosing wisely: what is the actual role of antimicrobial stewardship in Intensive Care Units?

More than two-thirds of critically ill patients receive an antimicrobial therapy with a percentage between 30% and 50% of all prescribed antibiotics reported to be unnecessary, inappropriate or misused. Since inappropriate prescription of antibiotic drugs concurs to dissemination of the multidrug resistant organisms, a reasoned antibiotics use is crucial especially in Intensive Care Unit (ICU), where up to 60% of the admitted patients develops an infection during their ICU stay. Even if the concept of antimicrobial stewardship (AS) has been clearly described as a series of coordinated interventions designed to improve antimicrobial agents use, few studies are reporting about its effectiveness to improve outcomes, reduce adverse events and costs and decrease resistance rate spread. Moreover, although it is recognized that AS programs are particularly indicated in the critical setting due to the huge number of antimicrobial drugs used, the optimal characteristics of these interventions and the best system to evaluate their effectiveness are still unclear. Specific interventions, designed tacking into account the peculiarities of the ICU setting, are hence necessary to set-up an "in-ICU-stewardship," including prompt identification of infected patients, selection of appropriate empiric treatments, optimization of dosing and route of administration, improvement of diagnostic techniques, early de-escalation to achieve shorter duration and avoid unnecessary therapies. The present narrative review summarizes the "state of art" about AS programmes and discusses the effects of the interventions possibly applied in ICU setting to optimize the patient's treatment, reduce the micro-organisms resistance and contain the hospital resources utilization.

Rapid detection of carbapenemase activity of Enterobacteriaceae isolated from positive blood cultures by MALDI-TOF MS

Background

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been proved to be a useful tool for identification of pathogens directly isolated from blood cultures in clinical microbiology laboratories. β-Lactam antibiotics are commonly used for treatment of bloodstream infections caused by Enterobacteriaceae strains, and carbapenem is the superlative class of β-lactam antibiotics. Since the carbapenem resistance rate of Enterobacteriaceae strains raised year by year, efficient detection of carbapenemase activity and timely delivery of carbapenem susceptibility reports of Enterobacteriaceae strains isolated from blood cultures is important for clinicians.

Methods

We used 64 simulated blood cultures to establish the method of MALDI-TOF MS based ertapenem hydrolysis assay. The cutoff value of logRQ calculated from the peaks intensity of ertapenem and its hydrolysate was first set to identify the strains with carbapenemase activity. Then, we detected and calculated the logRQ values of 385 Enterobacteriaceae strains from positive clinical blood cultures to distinguish the carbapenemase producers and noncarbapenemase producers.

Results

The mean logRQ value of 32 noncarbapenemase producers was − 0.85 ± 0.14 in simulated blood cultures, while the logRQ value of 32 carbapenemase producers was 0.87 ± 0.55. Thus, the cutoff value of logRQ was set at − 0.45 with sensitivity of 100% and specificity of 100%. In 385 clinical positive blood cultures, the logRQ values of all carbapenem-susceptible Enterobacteriaceae strains (81.3%, 313/385) were < − 0.45. Comparing with the detection of carbapenemase genes, carbapenem-resistant Enterobacteriaceae strains (18.7%, 72/385) were well distinguished by MALDI-TOF MS based ertapenem hydrolysis assay with a sensitivity of 92.5% and specificity of 100%.

Conclusions

Our data show that MALDI-TOF MS based ertapenem hydrolysis assay is a rapid and accurate method to detect carbapenemase activity of Enterobacteriaceae strains from positive blood cultures, and can be routinely performed in clinical microbiology laboratories.

Patient, Provider, and Practice Characteristics Associated with Inappropriate Antimicrobial Prescribing in Ambulatory Practices

OBJECTIVE

To reduce inappropriate antimicrobial prescribing across ambulatory care, understanding the patient-, provider-, and practice-level characteristics associated with antibiotic prescribing is essential. In this study, we aimed to elucidate factors associated with inappropriate antimicrobial prescribing across urgent care, family medicine, and pediatric and internal medicine ambulatory practices.

DESIGN, SETTING, AND PARTICIPANTS

Data for this retrospective cohort study were collected from outpatient visits for common upper respiratory conditions that should not require antibiotics. The cohort included 448,990 visits between January 2014 and May 2016. Carolinas HealthCare System urgent care, family medicine, internal medicine and pediatric practices were included across 898 providers and 246 practices.

METHODS

Prescribing rates were reported per 1,000 visits. Indications were defined using the International Classification of Disease, Ninth and Tenth Revisions, Clinical Modification (ICD-9/10-CM) criteria. In multivariable models, the risk of receiving an antibiotic prescription was reported with adjustment for practice, provider, and patient characteristics.

RESULTS

The overall prescribing rate in the study cohort was 407 per 1,000 visits (95% confidence interval [CI], 405–408). After adjustment, adult patients seen by an advanced practice practitioner were 15% more likely to receive an antimicrobial than those seen by a physician provider (incident risk ratio [IRR], 1.15; 95% CI, 1.03–1.29). In the pediatric sample, older providers were 4 times more likely to prescribe an antimicrobial than providers aged ≤30 years (IRR, 4.21; 95% CI, 2.96–5.97).

CONCLUSIONS

Our results suggest that patient, practice, and provider characteristics are associated with inappropriate antimicrobial prescribing. Future research should target antibiotic stewardship programs to specific patient and provider populations to reduce inappropriate prescribing compared to a “one size fits all” approach.

Infect Control Hosp Epidemiol 2018;39:307–315

Antimicrobial resistance and antibiotic stewardship programs in the ICU: insistence and persistence in the fight against resistance. A position statement from ESICM/ESCMID/WAAAR round table on multi-drug resistance

Antimicrobial resistance (AMR) is a clear and present danger to patients in any intensive care unit (ICU) around the world. Whereas AMR may affect any patient in the hospital, patients in the ICU are particularly at risk of acquiring AMR infections due to the intensity of the treatment, use of invasive devices, increased risk of transmission and exposure to antibiotics. AMR is present in every ICU, although prevalence is geographically different and AMR pathogens encountered are variable. Intensive care and infectious disease specialists from the European Society of Intensive Care Medicine, European Society of Microbiology and Infectious Diseases and World Alliance Against Antimicrobial Resistance, united in the ANTARCTICA (Antimicrobial Resistance in Critical Care) coalition, call for increased awareness and action among health care professionals to reduce AMR development in critically ill patients, to improve treatment of AMR infections and to coordinate scientific research in this high-risk patient population. Close collaboration with other specialties, and combining these and other interventions in antibiotic stewardship programmes should be a priority in every ICU. Considerate antibiotic use and adopting strict infection control practices to halt AMR remains a responsibility shared by all healthcare workers, from physicians to maintenance personnel, from nurses to physiotherapists, from consultants to medical students. Together, we can reduce AMR in our ICUs and continue to treat our patients effectively.

Unmet needs in the management of intra-abdominal infections

INTRODUCTION

Intra-abdominal infections remain a leading cause of death, morbidity and resource use in surgical wards and intensive care units. The growing complexity of their management has led to new paradigms and unresolved issues in anti-infective therapy described in the current review. Areas covered: We analyzed the literature, recent guidelines, and expert opinions published over the last decade. Expert commentary: Prospective randomized trials are difficult to perform and observational studies or database analyses should be encouraged. Epidemiologic and microbiologic reports should be promoted, especially in developing/resource-limited countries and in specific subpopulations such as children, older people and patients with underlying diseases. The diagnostic process, including imaging procedures, could be improved. The value of biomarkers for diagnosis, monitoring and discontinuation of therapy should be clarified and improved. New microbiologic techniques are needed to speed up the diagnostic process and to improve the adequacy of anti-infective therapy. Very little progress has been made in the detection of clinical failures. Many aspects of anti-infective management, both for bacteria and fungi, remain unresolved, such as the high inoculum, the type of microorganisms to be treated, the timing of therapy, the value of de-escalation, drug monitoring and duration of therapy. New antibiotics are expected.

Antimicrobial resistance in the next 30 years, humankind, bugs and drugs: a visionary approach

PURPOSE

To describe the current standards of care and major recent advances with regard to antimicrobial resistance (AMR) and to give a prospective overview for the next 30 years in this field.

METHODS

Review of medical literature and expert opinion were used in the development of this review.

RESULTS

There is undoubtedly a large clinical and public health burden associated with AMR in ICU, but it is challenging to quantify the associated excess morbidity and mortality. In the last decade, antibiotic stewardship and infection prevention and control have been unable to prevent the rapid spread of resistant Gram-negative bacteria (GNB), in particular carbapenem-resistant Pseudomonas aeruginosa (and other non-fermenting GNB), extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant Enterobacteriaceae (CRE). The situation appears more optimistic currently for Gram-positive, where Staphylococcus aureus, and particularly methicillin-resistant S. aureus (MRSA), remains a cardinal cause of healthcare-associated infections worldwide. Recent advancements in laboratory techniques allow for a rapid identification of the infecting pathogen and antibiotic susceptibility testing. Their impact can be particularly relevant in settings with prevalence of MDR, since they may guide fine-tuning of empirically selected regimen, facilitate de-escalation of unnecessary antimicrobials, and support infection control decisions. Currently, antibiotics are the primary anti-infective solution for patients with known or suspected MDR bacteria in intensive care. Numerous incentives have been provided to encourage researchers to work on alternative strategies to reverse this trend and to provide a means to treat these pathogens. Although some promising antibiotics currently in phase 2 and 3 of development will soon be licensed and utilized in ICU, the continuous development of an alternative generation of compounds is extremely important. There are currently several promising avenues available to fight antibiotic resistance, such as faecal microbiota, and phage therapy.