Correlation between antimicrobial consumption and antimicrobial resistance of Pseudomonas aeruginosa in a hospital setting: a 10-year study

The challenge of antimicrobial resistance (AMR): current status and future prospects

Antimicrobial resistance (AMR) represents a critical global threat, compromising the effectiveness of antibacterial drugs as bacteria adapt and survive exposure to many classes of these drugs. This phenomenon is primarily fueled by the widespread overuse and misuse of antibacterial drugs, exerting selective pressure on bacteria and promoting the emergence of multi-resistant strains. AMR poses a top-priority challenge to public health due to its widespread epidemiological and economic implications, exacerbated not only by the diminishing effectiveness of currently available antimicrobial agents but also by the limited development of genuinely effective new molecules. In addressing this issue, our research aimed to examine the scientific literature narrating the Italian situation in the common European context of combating AMR. We sought to delineate the current state of AMR and explore future prospects through an analysis of strategies to counter antibacterial drug resistance. Adopting the "One Health" model, our objective was to comprehensively engage diverse sectors, integrate various disciplines, and propose programs, policies, and regulations. This narrative review, based on PubMed research related to antibiotic resistance, emphasizes the urgent need for a coordinated and proactive approach at both national and European levels to mitigate the impact of AMR and pave the way for effective strategies to counter this global health challenge.

Modification of the Antibiotic, Colistin, with Dextrin Causes Enhanced Cytotoxicity and Triggers Apoptosis in Myeloid Leukemia

Introduction

Acute myeloid leukemia (AML) remains difficult to treat due to its heterogeneity in molecular landscape, epigenetics and cell signaling alterations. Precision medicine is a major goal in AML therapy towards developing agents that can be used to treat patients with different 'subtypes' in combination with current chemotherapies. We have previously developed dextrin-colistin conjugates to combat the rise in multi-drug resistant bacterial infections and overcome dose-limiting nephrotoxicity. Recent evidence of colistin's anticancer activity, mediated through inhibition of intracellular lysine-specific histone demethylase 1 (LSD1/KDM1A), suggests that dextrin-colistin conjugates could be used to treat cancer cells, including AML. This study aimed to evaluate whether dextrin conjugation (which reduces in vivo toxicity and prolongs plasma half-life) could enhance colistin's cytotoxic effects in myeloid leukemia cell lines and compare the intracellular uptake and localization of the free and conjugated antibiotic.

Results

Our results identified a conjugate (containing 8000 g/mol dextrin with 1 mol% succinoylation) that caused significantly increased toxicity in myeloid leukemia cells, compared to free colistin. Dextrin conjugation altered the mechanism of cell death by colistin, from necrosis to caspase 3/7-dependent apoptosis. In contrast, conjugation via a reversible ester linker, instead of an amide, had no effect on the mechanism of the colistin-induced cell death. Live cell confocal microscopy of fluorescently labelled compounds showed both free and dextrin-conjugated colistins were endocytosed and co-localized in lysosomes, and increasing the degree of modification by succinoylation of dextrin significantly reduced colistin internalization.

Discussion

Whilst clinical translation of dextrin-colistin conjugates for the treatment of AML is unlikely due to the potential to promote antimicrobial resistance (AMR) and the relatively high colistin concentrations required for anticancer activity, the ability to potentiate the effectiveness of an anticancer drug by polymer conjugation, while reducing side effects and improving biodistribution of the drug, is very attractive, and this approach warrants further investigation.

Evaluation of long-term pharmacist-led prospective audit and feedback in antimicrobial stewardship: An 8-year study

BACKGROUND

Limited research has evaluated the long-term outcomes of prospective audit and feedback (PAF) led by pharmacists. We assessed pharmacist-led PAF processes and outcome measures over 8 years.

METHODS

This study was conducted at a single public hospital in Japan. Between 2014 and 2021, pharmacists conducted weekday PAFs for hospitalized patients and annually evaluated the process and outcome measures. The endpoints included detection of drug-resistant bacteria, drug susceptibility rates, duration of antimicrobial therapy, and proportion of long-term administration.

RESULTS

Among inpatients, methicillin-resistant Staphylococcus aureus significantly decreased from 50.9% in 2014 to 32.8% in 2021 (P < .001). The susceptibility rate of Pseudomonas aeruginosa to meropenem significantly increased from 91.2% in 2014 to 94.4% in 2021 (P < .001) and levofloxacin increased from 84.9% in 2014 to 89.3% in 2021 (P < .001). Antimicrobial therapy duration did not differ significantly between 2014 and 2016, but decreased significantly from 2017 onwards (P < .001), except in 2018. The number of patients receiving intravenous antimicrobials for >10 days decreased significantly between 2014 and 2021 (P < .001).

CONCLUSIONS

Long-term continuous PAF interventions by pharmacists contribute to improving and maintaining process and outcome indicators and prevent the spread of drug-resistant bacteria.

Relationship between Antibiotic Consumption and Resistance: A Systematic Review

Background

Unreserved use of antibiotics exerted selective pressure on susceptible bacteria, resulting in the survival of resistant strains. Despite this, the relationship between antibiotic resistance (ABR) and antibiotic consumption (ABC) is rarely studied. This systematic review aims to review the relationship between ABC and ABR from 2016 to 2022.

Methods

Articles published over 7 years (2016-2022) were searched from December 23 to 31, 2022. The search strategy was developed by using keywords for ABC and ABR. From 3367 articles, 58 eligible articles were included in the final review.

Results

The pooled ABC was 948017.9 DPDs and 4108.6 DIDs where over 70% of antibiotics were from the Watch and Reserve category based on the WHO AWaRe classification. The average pooled prevalence of ABR was 38.4%. Enterococcus faecium (59.4%), A. baumannii (52.6%), and P. aeruginosa (48.6%) were the most common antibiotic-resistant bacteria. Cephalosporins (76.8%), penicillin (58.3%), and aminoglycosides (52%) were commonly involved antibiotics in ABR. The positive correlation between ABR and consumption accounted for 311 (81%). The correlation between ABR P. aeruginosa and ABC accounted for 87 (22.7%), followed by 78 (20.3%) and 77 (20.1%) for ABR E. coli and K. pneumoniae with ABCs, respectively. Consumption of carbapenems and fluoroquinolones was most commonly correlated with resistance rates of P. aeruginosa, K. pneumoniae, E. coli, and A. baumannii.

Conclusion

There is a positive correlation between ABC and the rate of ABR. The review also revealed a cross-resistance between the consumption of different antibiotics and ABR. Optimizing antibiotic therapy and reducing unnecessary ABC will prevent the emergence and spread of ABR. Thus, advocating the implementation of stewardship programs plays a pivotal role in containing ABR.

Perceptions of antibiotic stewardship programmes and determinants of antibiotic prescribing patterns among physicians in tertiary hospitals in Bangladesh: implications for future policy and practice

BACKGROUND

The concerning growth of antimicrobial resistance (AMR) renders common infections life-threatening due to irrational antibiotic use and a lack of effective antimicrobial stewardship programmes (ASPs).

AIM

To investigate the awareness, perceptions and practices of physicians regarding ASPs, AMR and antibiotic prescribing in tertiary care hospitals in Bangladesh.

METHODS

This hospital-based cross-sectional survey was conducted in 11 tertiary care hospitals across Bangladesh between September 2020 and January 2021. A semi-structured questionnaire was administered through face-to-face interviews for data collection. Descriptive and multi-variate analyses were performed using STATA Version 13.

RESULTS

In total, 559 physicians were enrolled in this survey. Overall, 40.6% [95% confidence interval (CI) 36.5-44.8] of physicians reported being aware of ASPs, and this figure was higher in public hospitals compared with private hospitals (43.8% vs 27.1%). None of the study hospitals had any ASP initiatives. More than half (55.1%) of the participants were willing to receive feedback from an ASP on their antibiotic selection. Only 30.9% of respondents stated that they wait for the findings of microbiological tests before prescribing antibiotics, although challenges included empiric use of broad-spectrum antibiotics, delayed laboratory results and the existence of drug-resistant patients. In contrast, physicians aware of ASPs were 33% (adjusted odds ratio 0.67, 95% CI 0.45-0.98; P=0.033) less likely to wait for laboratory results before prescribing antibiotics. However, 42.5% of physicians considered patient affordability of purchasing antibiotics when prescribing.

CONCLUSIONS

Physicians' fundamental knowledge of ASPs and rational antibiotic prescription were found to fall short of the standard. Context-specific and integrated ASP activities, availability and use of guidelines, and improved laboratory facilities are required to battle AMR in Bangladesh.

Ceftazidime-avibactam and comparators against Pseudomonas aeruginosa isolates collected globally and in each geographical region between 2017-2020

OBJECTIVES

The objective of this study was to assess the distribution and antimicrobial susceptibility of Pseudomonas aeruginosa isolates against ceftazidime-avibactam (CAZ-AVI) and a panel of comparator agents collected globally and in each region from 2017-2020 from the Antimicrobial Testing Leadership and Surveillance program.

METHODS

Susceptibility and minimum inhibitory concentration of all P. aeruginosa isolates were determined using broth microdilution methodology according to the Clinical and Laboratory Standards Institute guidelines.

RESULTS

Of the total 29746 isolates of P. aeruginosa collected, 20.9% were multidrug resistant (MDR), 20.7% were extremely drug resistant (XDR), 8.4% were CAZ-AVI-resistant (CAZ-AVI-R), and 3.0% were MBL-positive. Amongst the MBL-positive isolates, the proportion of VIM-positive isolates was highest (77.8%). The highest proportion of MDR (25.5%), XDR (25.0%), MBL-positive (5.7%), and CAZ-AVI-R (12.3%) isolates were in Latin America. Amongst the sources, the highest proportion of isolates were from respiratory sources (43.0%), and the majority of isolates were from non-intensive care unit wards (71.2%). Overall, all P. aeruginosa isolates (90.9%) showed high susceptibility to CAZ-AVI. However, MDR and XDR isolates were less susceptible to CAZ-AVI (≤60.7). The only comparators to which all isolates of P. aeruginosa showed good overall susceptibility were colistin (99.1%) and amikacin (90.5%). However, only colistin was active (≥98.3%) against all the resistant isolates.

CONCLUSION

CAZ-AVI presents a potential treatment option against P. aeruginosa infections. However, active monitoring and surveillance, especially of the resistant phenotypes, is warranted for effective treatment of infections caused by P. aeruginosa.

Correlation between antibiotic use and resistance of gram-negative bacteria at a university hospital in Japan from 2013 to 2021: a study using the Japan Surveillance for Infection Prevention and Healthcare Epidemiology system

OBJECTIVES

The Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system aggregates information related to antimicrobial resistance (AMR) measures. We aimed to investigate the correlation between antibiotic use and AMR at a university hospital from 2013 to 2021 in a time series analysis using the J-SIPHE system. We also studied this correlation in each ward (inter-ward analysis).

METHODS

Data on antibiotic use and resistance rates were collected from the J-SIPHE system, except for the resistance rate in each ward, which was calculated from the source data prepared for this system.

RESULTS

Piperacillin/tazobactam use was positively correlated with piperacillin/tazobactam resistance in Escherichia coli and Klebsiella pneumoniae in the inter-ward analysis, and in Pseudomonas aeruginosa in both analyses. Carbapenem use was positively correlated with meropenem resistance in Enterobacter cloacae in the time series analysis and in P. aeruginosa in both analyses, and imipenem/cilastatin resistance in P. aeruginosa in inter-ward analysis. Quinolone use was positively correlated with levofloxacin resistance in E. coli in both analyses, and in K. pneumoniae in inter-ward analysis.

CONCLUSIONS

This is the first study to investigate the correlation between antibiotic use and AMR at a single hospital in time series and inter-ward analyses using the J-SIPHE system and data prepared for this system, suggesting that this system may be useful for promoting AMR measures.

Antimicrobial Resistance (AMR)

Antimicrobial resistance (AMR) has now emerged as a chronic public health problem globally, with the forecast of 10 million deaths per year globally by 2050. AMR occurs when viruses, bacteria, fungi and parasites do not respond to antimicrobial treatments in humans and animals, thus allowing the survival of the microorganism within the host. The prominent cause contributing to the current crisis remains to be the overuse and misuse of antimicrobials, particularly the inappropriate usage of antibiotics, increasing the global burden of antimicrobial resistance. The global consumption and usage of antibiotics are therefore closely monitored at all times. This review provides a current overview of the implications of strategies used by international governmental organisations, including the UN's 17 Sustainable Development Goals (SDGs), to address the problem of antibiotic resistance, as well as the "One Health Approach," a system incorporating a multidisciplinary effort to achieve the best possible health outcome by acknowledging the clear connections between humans, animals and their shared environment. The importance of public awareness and health literacy of lay audiences still needs to be further emphasised as part of global and local action plans. Antimicrobial resistance continues to be a major global public health dilemma of the 21st century. Already this topic is receiving substantial political input from the G7 countries and continues to be on the agenda of numerous political conferences. The consequences of failure to adequately address AMR are profound, with estimations of a return to the pre-antibiotic era, where everyday infections relating to childbirth, surgery and open fractured limbs could be potentially life-threatening. AMR itself represents a microcosm of factors, including social anthropology, civil unrest/war, diasporas, ethnic displacement, political systems, healthcare, economics, societal behaviour both at a population and individual level, health literacy, geoclimatic events, global travel and pharmaceutical innovation and investment, thus finding a solution that adequately addresses AMR and which helps stem further AMR emergence is complicated. Success will involve individuals, communities and nations all working together to ensure that the world continues to possess a sufficient armamentarium of effective antimicrobials that will sustain human and animal health, both now and in the future.

Antimicrobial utilization and resistance in Pseudomonas aeruginosa using segmented regression analysis: a comparative study between Serbia and eight European Countries

BACKGROUND

In Europe, Serbia occupies a high position in antibiotic utilization and antimicrobial resistance (AMR).

AIM

The aim was to analyse utilization trends of meropenem, ceftazidime, aminoglycosides, piperacillin/tazobactam and fluoroquinolones (2006-2020), and the reported AMR in Pseudomonas aeruginosa (2013-2020) in Serbia and to compare with data from eight European countries (2015-2020).

METHOD

Joinpoint regression was used to analyse antibiotic utilization data (2006-2020) and the reported AMR in Pseudomonas aeruginosa (2013-2020). Data sources were relevant national and international institutions. Antibiotic utilization and AMR in Pseudomonas aeruginosa data in Serbia were compared with eight European countries.

RESULTS

There was a significantly increased trend for ceftazidime utilization and reported resistance in Pseudomonas aeruginosa, Serbia (p < 0.05) (2018-2020). For ceftazidime, piperacillin/tazobactam, and fluoroquinolones resistances in Pseudomonas aeruginosa an increased trend was observed, Serbia (2013-2020). A decrease in both the utilization of aminoglycosides, Serbia (p < 0.05) (2006-2018) and contemporaneous Pseudomonas aeruginosa resistance (p > 0.05) was detected. Fluoroquinolone utilization (2015-2020) was highest in Serbia compared to Netherlands and Finland, 310 and 305% higher, similar compared to Romania, and 2% less compared to Montenegro. Aminoglycosides (2015-2020) were 2550 and 783% more used in Serbia compared to Finland and Netherlands, and 38% less regarding Montenegro. The highest percentage of Pseudomonas aeruginosa resistance was in Romania and Serbia (2015-2020).

CONCLUSION

The use of piperacillin/tazobactam, ceftazidime and fluoroquinolones should be carefully monitored in clinical practice due to increased Pseudomonas aeruginosa resistance. The level of utilization and AMR in Pseudomonas aeruginosa is still high in Serbia compared to other European countries.

'If you want to go far, go together'-community-based behaviour change interventions to improve antibiotic use: a systematic review of quantitative and qualitative evidence

INTRODUCTION

A large proportion of the burden of infections with antibiotic-resistant bacteria is linked to community-associated infections. This suggests that interventions set in community settings are needed. Currently there is a gap in understanding the potential of such interventions across all geographies. This systematic review aimed to synthesize the evidence on the value of community-based behaviour change interventions to improve antibiotic use. These are any interventions or innovations to services intended to stimulate behaviour changes among the public towards correct antibiotic use, delivered in a community setting and online.

METHODS

Systematic searches of studies published after 2001 were performed in several databases. Of 14 319 articles identified, 73 articles comprising quantitative, qualitative and mixed-methods studies met the inclusion criteria.

RESULTS

Findings showed positive emerging evidence of the benefits of community-based behaviour change interventions to improve antibiotic use, with multifaceted interventions offering the highest benefit. Interventions that combine educational aspects with persuasion may be more effective than solely educational interventions. The review uncovered difficulties in assessing this type of research and highlights the need for standardized approaches in study design and outcomes measurements. There is emerging, but limited, indication on these interventions' cost-effectiveness.

CONCLUSIONS

Policy makers should consider the potential of community-based behaviour change interventions to tackle antimicrobial resistance (AMR), complementing the clinical-based approaches. In addition to the direct AMR benefits, these could serve also as a means of (re)building trust, due to their inclusive participation leading to greater public ownership and use of community channels.

Correlation between antibiotic use and antibiotic resistance: A multicenter study using the Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system in Hokkaido, Japan

BACKGROUND

The Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system aggregates information related to antimicrobial resistance (AMR) measures in participating medical institutions nationwide and is intended to be used for promotion of AMR measures in participating facilities and their communities. This multicenter study aimed to determine the usefulness of the J-SIPHE system for evaluating the correlation between antibiotic use and antibiotic resistance in Hokkaido, Japan.

METHODS

Data on antibiotic use and detection rate of major resistant Gram-negative bacteria at 19 hospitals in 2020 were collected from the J-SIPHE system, and data correlations were analyzed using JMP Pro.

RESULTS

The detection rate of carbapenem-resistant Pseudomonas aeruginosa was significantly positively correlated with carbapenem use (Spearman's ρ = 0.551; P = .015). There were significant positive correlations between the detection rate of fluoroquinolone-resistant Escherichia coli and the use of piperacillin/tazobactam, carbapenems, and quinolones [ρ = 0.518 (P = .023), ρ = 0.76 (P < .001), and ρ = 0.502 (P = .029), respectively].

CONCLUSIONS

This is the first multicenter study to investigate the correlation between antibiotic use and antibiotic resistance using the J-SIPHE system. The results suggest that using this system may be beneficial for promoting AMR measures.

Clinical predictors of mortality in patients with pseudomonas aeruginosa infection

BACKGROUND

Infections caused by Pseudomonas aeruginosa are difficult to treat with a significant cost and burden. In Lebanon, P. aeruginosa is one of the most common organisms in ventilator-associated pneumonia (VAP). P. aeruginosa has developed widespread resistance to multiple antimicrobial agents such as fluoroquinolones and carbapenems. We aimed at identifying risk factors associated for P. aeruginosa infections as well as identifying independent risk factors for developing septic shock and in-hospital mortality.

METHODS

We used a cross-sectional study design where we included patients with documented P. aeruginosa cultures who developed an infection after obtaining written consent. Two multivariable regression models were used to determine independent predictors of septic shock and mortality.

RESULTS

During the observed period of 30 months 196 patients were recruited. The most common predisposing factor was antibiotic use for more than 48 hours within 30 days (55%). The prevalence of multi-drug resistant (MDR) P. aeruginosa was 10%. The strongest predictors of mortality were steroid use (aOR = 3.4), respiratory failure (aOR = 7.3), identified respiratory cultures (aOR = 6.0), malignancy (aOR = 9.8), septic shock (aOR = 18.6), and hemodialysis (aOR = 30.9).

CONCLUSION

Understanding resistance patterns and risk factors associated with mortality is crucial to personalize treatment based on risk level and to decrease the emerging threat of antimicrobial resistance.

Trends and Correlation Between Antimicrobial Resistance and Antibiotics Consumption in a Specialist Children’s Hospital from 2016 to 2021

Purpose

To explore the trends and correlation between antibiotics consumption and antimicrobial resistance in children in a specialist hospital from 2016–2021 in China.

Patients and Methods

This retrospective study investigated data on the consumption of antibiotics and antimicrobial resistance in children. Antibiotics consumption was expressed as defined daily doses (DDDs)/1000 patient-days based on the Guidelines for Anatomical Therapeutic Chemical. The trends in antibiotics consumption and antimicrobial resistance rates were analyzed by linear regression, while Spearman correlation analysis was employed to evaluate their correlations.

Results

An increasing trend in the annual consumption of carbapenems and monobactams was detected (all P<0.05). A significant upward trend was detected in the annual resistance rates of Enterococcus faecium to ciprofloxacin, Streptococcus pneumonia to ceftriaxone, Acinetobacter baumannii to carbapenems, Enterobacter cloacae to carbapenems, Pseudomonas aeruginosa to ceftazidime, and Escherichia coli to cefepime, while the annual resistance rates of Escherichia coli to carbapenems had a significant downward trend (all P<0.05). The consumption of cephalosporin/β-lactamase inhibitor (C/BLI) combinations and carbapenems had significant positive correlations with the resistance rates of Acinetobacter baumannii to carbapenems (r=0.763, P<0.001; r=0.806, P<0.001), Enterobacter cloacae to carbapenems (r=0.675, P<0.001; r=0.417, P=0.043), and Pseudomonas aeruginosa to ceftazidime (r=0.625, P=0.001; r=0.753, P<0.001), respectively. Also, increasing consumption of monobactams was related to the upward resistance rates of Acinetobacter baumannii to carbapenems (r=0.557, P=0.005) and Enterobacter cloacae to carbapenems (r=0.507, P= 0.011).

Conclusion

This study demonstrated significant positive associations between antibiotics consumption and specific antimicrobial resistance rates. The current findings pointed out some directions to pursue in controlling the prevalence of certain resistant bacterial strains in children.

OUP accepted manuscript

Introduction

Antimicrobial stewardship interventions (ASIs) aim to reduce the emergence of antimicrobial resistance. We sought to systematically evaluate how microbiological outcomes have been handled and analysed in randomized controlled trials (RCTs) evaluating ASIs.

Methods

We searched PubMed and Embase from 2011–21. Studies were selected if they were RCTs evaluating ASIs. A narrative synthesis approach was taken, identifying whether the study reported any microbiological data (bacterial genus/species; bacterial colony counts; prevalence of bacterial, microbiologically defined infections; and antibiotic susceptibility, measured pre-randomization or post-randomization in one arm only) or outcomes (post-randomization data compared between arms). Studies with or without microbiological data/outcomes were summarized in terms of study characteristics, methods of reporting and analysis of these outcomes.

Results

We identified 117 studies, with 34 (29.1%) collecting microbiological data and 18 (15.4%) reporting microbiological outcomes. Most studies with microbiological outcomes were conducted in secondary care (12/18, 66.7%) and targeted adult populations (14/18, 77.8%), and the intervention involved biomarker-guided rapid diagnostic testing (7/18, 38.9%). The overall quality of reporting and analysing microbiological outcomes was low and inconsistent. The selected study population in analyses and methods of handling missing data were unclear.

Conclusions

This review demonstrates that the quality of handling and reporting microbiological outcomes in RCTs of ASIs was low. The lack of consistency and clarity made it difficult to compare the findings across studies, limiting policy- and clinical decision-making. Therefore, there is a clear need for the development of guidance for handling microbiological outcomes in RCTs and adopting appropriate methods to evaluate these data carefully.

Trends in antimicrobial resistance in bloodstream infections at a large tertiary-care hospital in China: a 10-year retrospective study (2010-2019)

OBJECTIVES

Bloodstream infections (BSIs) are considered as a major cause of morbidity and mortality all over the world. The purpose of this study was to explore the distribution and antimicrobial resistance trends of pathogens causing BSIs at a large tertiary-care hospital in Henan province, east-central China.

METHODS

In this surveillance study, blood culture specimens were routinely taken from patients with fever or suspicion of sepsis from 2010 to 2019 at the First Affiliated Hospital of Zhengzhou University. Identification of organisms was carried out using the VITEK 2 Compact system and/or the VITEK MS system. Antimicrobial susceptibility tests were carried out by the minimum inhibitory concentration (MIC) method and/or the disk diffusion according to Clinical & Laboratory Standards Institute guidelines.

RESULTS

A total of 18180 strains were isolated from blood culture specimens, the most common pathogen was E. coli (21.6%), followed by CoNS (coagulase negative staphylococci, 18.8%), K. pneumoniae (13.0%), S. aureus (6.6%), E. faecium (5.0%), A. baumannii (4.4%), and P. aeruginosa (3.8%). The resistance rates of E. coli to ceftazidime, cefotaxime, cefepime and aztreonam showed a significant declined trend, and the frequency of carbapenem-resistant E. coli was below 6.0% over time. It is noteworthy that the proportion of carbapenem-resistant K. pneumoniae exhibited sharp upward trend during the ten years (from 6.7% to 56.7%). The prevalence of carbapenem-resistant A.baumannii has remained at a high level (>75%). In contrast, the resistance rates for P. aeruginosa against all tested agents were lower than 25%, and the resistance rates to aminoglycosides and fluoroquinolones showed a significant downward trend. The frequency of methicillin-resistant CoNS maintained a high level over the past decade (>70%), however, the isolation rate of MRSA ranged from 58.0% to 34.9%, showed a significant decline.

CONCLUSIONS

It was particularly noteworthy that the dramatic and consistent increase in carbapenem-resistance in K. pneumoniae during the 10-year surveillance period and effective infection control measures and stewardship efforts should be taken to prevent the spread. Our results indicate the the importance of active surveillance for bacterial etiology and their antibiotic resistance causing BSIs.

Secrets of the Hospital Underbelly: Patterns of Abundance of Antimicrobial Resistance Genes in Hospital Wastewater Vary by Specific Antimicrobial and Bacterial Family

Background: Hospital wastewater is a major source of antimicrobial resistance (AMR) outflow into the environment. This study uses metagenomics to study how hospital clinical activity impacts antimicrobial resistance genes (ARGs) abundances in hospital wastewater. Methods: Sewage was collected over a 24-h period from multiple wastewater collection points (CPs) representing different specialties within a tertiary hospital site and simultaneously from community sewage works. High throughput shotgun sequencing was performed using Illumina HiSeq4000. ARG abundances were correlated to hospital antimicrobial usage (AMU), data on clinical activity and resistance prevalence in clinical isolates. Results: Microbiota and ARG composition varied between CPs and overall ARG abundance was higher in hospital wastewater than in community influent. ARG and microbiota compositions were correlated (Procrustes analysis, p=0.014). Total antimicrobial usage was not associated with higher ARG abundance in wastewater. However, there was a small positive association between resistance genes and antimicrobial usage matched to ARG phenotype (IRR 1.11, CI 1.06-1.16, p<0.001). Furthermore, analyzing carbapenem and vancomycin resistance separately indicated that counts of ARGs to these antimicrobials were positively associated with their increased usage [carbapenem rate ratio (RR) 1.91, 95% CI 1.01-3.72, p=0.07, and vancomycin RR 10.25, CI 2.32-49.10, p<0.01]. Overall, ARG abundance within hospital wastewater did not reflect resistance patterns in clinical isolates from concurrent hospital inpatients. However, for clinical isolates of the family Enterococcaceae and Staphylococcaceae, there was a positive relationship with wastewater ARG abundance [odds ratio (OR) 1.62, CI 1.33-2.00, p<0.001, and OR 1.65, CI 1.21-2.30, p=0.006 respectively]. Conclusion: We found that the relationship between hospital wastewater ARGs and antimicrobial usage or clinical isolate resistance varies by specific antimicrobial and bacterial family studied. One explanation, we consider is that relationships observed from multiple departments within a single hospital site will be detectable only for ARGs against parenteral antimicrobials uniquely used in the hospital setting. Our work highlights that using metagenomics to identify the full range of ARGs in hospital wastewater is a useful surveillance tool to monitor hospital ARG carriage and outflow and guide environmental policy on AMR.

Impact of cascade reporting of antimicrobial susceptibility on fluoroquinolone and meropenem consumption at a Veterans' Affairs medical center

OBJECTIVE

To determine whether cascade reporting is associated with a change in meropenem and fluoroquinolone consumption.

DESIGN

A quasi-experimental study was conducted using an interrupted time series to compare antimicrobial consumption before and after the implementation of cascade reporting.

SETTING

A 399-bed, tertiary-care, Veterans' Affairs medical center.

PARTICIPANTS

Antimicrobial consumption data across 8 inpatient units were extracted from the Center for Disease Control and Prevention (CDC) National Health Safety Network (NHSN) antimicrobial use (AU) module from April 2017 through March 2019, reported as antimicrobial days of therapy (DOT) per 1,000 days present (DP).

INTERVENTION

Cascade reporting is a strategy of reporting antimicrobial susceptibility test results in which secondary agents are only reported if an organism is resistant to primary, narrow-spectrum agents. A multidisciplinary team developed cascade reporting algorithms for gram-negative bacteria based on local antibiogram and infectious diseases practice guidelines, aimed at restricting the use of fluoroquinolones and carbapenems. The algorithms were implemented in March 2018.

RESULTS

Following the implementation of cascade reporting, mean monthly meropenem (P =.005) and piperacillin/tazobactam (P = .002) consumption decreased and cefepime consumption increased (P < .001). Ciprofloxacin consumption decreased by 2.16 DOT per 1,000 DP per month (SE, 0.25; P < .001). Clostridioides difficile rates did not significantly change.

CONCLUSION

Ciprofloxacin consumption significantly decreased after the implementation of cascade reporting. Mean meropenem consumption decreased after cascade reporting was implemented, but we observed no significant change in the slope of consumption. cascade reporting may be a useful strategy to optimize antimicrobial prescribing.

Implementation of Antibiotic Stewardship in a University Hospital Setting

The article describes activities of an antibiotic center at a university hospital in the Czech Republic and presents the results of antibiotic stewardship program implementation over a period of 10 years. It provides data on the development of resistance of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus to selected antibiotic agents as well as consumption data for various antibiotic classes. The genetic basis of resistance to beta-lactam antibiotics and its clonal spread were also assessed. The study showed significant correlations between aminoglycoside consumption and resistance of Escherichia coli and Klebsiella pneumoniae to gentamicin (r = 0.712, r = 0.869), fluoroquinolone consumption and resistance of Klebsiella pneumoniae to ciprofloxacin (r = 0.896), aminoglycoside consumption and resistance of Pseudomonas aeruginosa to amikacin (r = 0.716), as well as carbapenem consumption and resistance of Pseudomonas aeruginosa to meropenem (r = 0.855). Genotyping of ESBL- positive isolates of Klebsiella pneumoniae and Escherichia coli showed a predominance of CTX-M-type; in AmpC-positive strains, DHA, EBC and CIT enzymes prevailed. Of 19 meropenem-resistant strains of Klebsiella pneumoniae, two were identified as NDM-positive. Clonal spread of these strains was not detected. The results suggest that comprehensive antibiotic stewardship implementation in a healthcare facility may help to maintain the effectiveness of antibiotics against bacterial pathogens. Particularly beneficial is the work of clinical microbiologists who, among other things, approve administration of antibiotics to patients with bacterial infections and directly participate in their antibiotic therapy.

The role of vaccines in combatting antimicrobial resistance

The use of antibiotics has enabled the successful treatment of bacterial infections, saving the lives and improving the health of many patients worldwide. However, the emergence and spread of antimicrobial resistance (AMR) has been highlighted as a global threat by different health organizations, and pathogens resistant to antimicrobials cause substantial morbidity and death. As resistance to multiple drugs increases, novel and effective therapies as well as prevention strategies are needed. In this Review, we discuss evidence that vaccines can have a major role in fighting AMR. Vaccines are used prophylactically, decreasing the number of infectious disease cases, and thus antibiotic use and the emergence and spread of AMR. We also describe the current state of development of vaccines against resistant bacterial pathogens that cause a substantial disease burden both in high-income countries and in low- and medium-income countries, discuss possible obstacles that hinder progress in vaccine development and speculate on the impact of next-generation vaccines against bacterial infectious diseases on AMR.

A decade of antimicrobial resistance research in social science fields: a scientometric review

Background

Though social sciences are expectedly instrumental in combating antimicrobial resistance (AMR), their research on AMR has been historically lacking.

Objectives

This study aims to understand the current academic literature on AMR within the social science field by investigating international contributions, emerging topics, influential articles, and prominent outlets, to identify research gaps and future directions.

Methods

Bibliometric data of 787 peer-reviewed journal articles published in the period of 2010 to 2019 were extracted from the Social Science Citation Index in the Web of Science database. Bibliographic networks of the extracted articles were examined.

Results

Social science research on AMR has grown rapidly in the past 5 years. While western developed countries contributed the most to the field in the past decade, research within developing regions such as Asia and Africa have increased in the last 2 years. Social sciences have been contributing to AMR research in several different domains from surveillance and risk assessment of AMR, to promotions of appropriate use of antimicrobials in primary care and clinical settings. Though the idea of one health has been incorporated into research on AMR within the medical and microbial science fields, it has not been well recognized by social sciences.

Conclusion

Social science research on AMR is a new, while rapidly developing, research area that requires continued and intense global efforts from an interdisciplinary and one health approach. Research on social issues surrounding AMR transmissions between human, animal, and environments should be emphasized in the future.

The challenges of estimating the human global burden of disease of antimicrobial resistant bacteria

Estimating the contribution of antimicrobial resistance (AMR) to global mortality and healthcare costs enables evaluation of interventions, informs policy decisions on resource allocation, and drives research priorities. However assembling the high quality, patient-level data required for global estimates is challenging. Capacity for accurate microbiology culture and antimicrobial susceptibility testing is woefully neglected in low and middle-income countries, and further surveillance and research on community antimicrobial usage, bias in blood culture sampling, and the contribution of co-morbidities such as diabetes is essential. International collaboration between governments, policy makers, academics, microbiologists, front-line clinicians, veterinarians, the food and agriculture industry and the public is critical to understand and tackle AMR.

Evaluating the appropriateness of carbapenem and piperacillin-tazobactam prescribing in a tertiary care hospital in Saudi Arabia

Background

Antimicrobial resistance (AMR) is presently considered an emergent major global public health concern and excessive and/or inappropriate use of broad-spectrum antimicrobials contribute to the development of AMR.

Objective

To evaluate the appropriateness of carbapenems and piperacillin-tazobactam use in a tertiary care hospital.

Methods

A retrospective, observational, cross-sectional, drug-utilization study was conducted. The study included all adult hospitalized patients who had received at least one dose of the antimicrobials during their admission for the period between 1 January 2016 and 31 December 2017. The appropriateness of antimicrobial therapy was evaluated according to the Infectious Diseases Society of America (IDSA) guidelines with the consideration of the institutional antibiogram.

Results

Overall, 2731 patients received 5005 courses with one of the antimicrobials, for a total of 5045.9 defined daily doses (DDD) of imipenem-cilastatin, 6492.3 of meropenem and 15,595 of piperacillin-tazobactam (4.93, 6.34 and 15.24 DDD/100 bed days, respectively). The mean age of the patients who received either antimicrobial was 55.5 ± 20.3 years, with a 14-day average length of hospital stay. About half (52%) of the prescriptions were written for patients treated in the medical ward. Pneumonia (26.6%) and sepsis (24.9%) were the most common indication for the initiation of antimicrobial therapy. Of the assessed prescriptions, only 2787 (56.5%) were prescribed appropriately, with 2142 (43.5%) deemed inappropriate. The three most common reasons for inappropriate prescription were: the spectrum of activity was too broad (44.6%), followed by antimicrobial use without culture request (32.4%), and failure of suitable antimicrobial de-escalation (19.9%).

Conclusions

The study indicates that the overall rate of inappropriateness was high, emphasizing the need to develop initiatives to effectively improve broad-spectrum antimicrobial prescribing.

Estimating the Value of New Antimicrobials in the Context of Antimicrobial Resistance: Development and Application of a Dynamic Disease Transmission Model

OBJECTIVES

Antimicrobial resistance (AMR) represents a significant threat to patient and population health. The study aim was to develop and validate a model of AMR that defines and quantifies the value of new antibiotics.

METHODS

A dynamic disease transmission and cost-effectiveness model of AMR consisting of three components (disease transmission, treatment pathway and optimisation) was developed to evaluate the health economic value of new antibiotics. The model is based on the relationship between AMR, antimicrobial availability and consumption. Model analysis explored the impact of different antibiotic treatment strategies on the development of AMR, patient and population estimates of health benefit, across three common treatment indications and pathogens in the UK.

RESULTS

Population-level resistance to existing antimicrobials was estimated to increase from 10.3 to 16.1% over 10 years based on current antibiotic availability and consumption. In comparison, the diversified use of a new antibiotic was associated with significant reduction in AMR (12.8% vs. 16.1%) and quality-adjusted life year (QALY) gains at a patient (7.7-10.3, dependent on antimicrobial efficacy) and population level (3657-8197, dependent on antimicrobial efficacy and the prevalence of AMR). Validation across several real-world data sources showed that the model output does not tend to systematically under- or over-estimate observed data.

CONCLUSIONS

The development of new antibiotics and the appropriate use of existing antibiotics are key to addressing the threat of AMR. This study presents a validated model that quantifies the value of new antibiotics through clinical and economic outcomes of relevance, and accounts for disease transmission of infection and development of AMR. In this context, the model may be a useful tool that could contribute to the decision-making process alongside other potential models and expert advice.

Trends in antimicrobial resistance over 10 years among key bacterial pathogens from Canadian hospitals: results of the CANWARD study 2007-16

OBJECTIVES

We sought to analyse 10 years of longitudinal surveillance data (2007-16) from the CANWARD study and describe emerging trends in antimicrobial resistance for key bacterial pathogens across Canada.

METHODS

Longitudinal data from CANWARD study sites that contributed isolates every year from 2007 to 2016 were analysed to identify trends in antimicrobial resistance over time using univariate tests of trend and multivariate regression models to account for the effects of patient demographics.

RESULTS

Statistically significant increases occurred in the proportion of Escherichia coli isolates resistant to extended-spectrum cephalosporins, amoxicillin/clavulanate, trimethoprim/sulfamethoxazole and ciprofloxacin. Similarly, the proportion of Klebsiella pneumoniae isolates resistant to extended-spectrum cephalosporins, amoxicillin/clavulanate, trimethoprim/sulfamethoxazole, ciprofloxacin and carbapenems increased during the study. The proportion of Enterobacter cloacae isolates resistant to ceftazidime and trimethoprim/sulfamethoxazole increased. The proportion of both ESBL-positive E. coli and K. pneumoniae (including bloodstream isolates) increased significantly between 2007 and 2016. A reduction in the proportion of Pseudomonas aeruginosa that were ciprofloxacin, cefepime, colistin, amikacin and gentamicin resistant and an increase in the proportion of P. aeruginosa isolates non-susceptible to meropenem were observed. The proportion of isolates of Staphylococcus aureus non-susceptible to clarithromycin, clindamycin and trimethoprim/sulfamethoxazole decreased over time while an increase in the proportion of isolates of Streptococcus pneumoniae non-susceptible to clarithromycin, clindamycin and doxycycline was observed.

CONCLUSIONS

Increases in Enterobacteriaceae resistance to multiple classes of antimicrobials, increases in ESBL-positive E. coli and K. pneumoniae, and the small but significant increase in carbapenem-resistant K. pneumoniae were the most remarkable changes in antimicrobial resistance observed from 2007 to 2016 in Canada.

Risk Factors of Multidrug-Resistant Bacteria in Lower Respiratory Tract Infections: A Systematic Review and Meta-Analysis

Background

Multidrug-resistant (MDR) bacteria are the main cause of lower respiratory tract infections (LRTIs) with high mortality. The purpose of this study is to identify the risk factors associated with MDR by performing a systematic review and meta-analysis.

Methods

PubMed, EMBASE (via Ovid), and Cochrane Library were systematically searched for studies on the risk factors for MDR bacteria in LRTIs as of November 30, 2019. Literature screening, data abstraction, and quality assessment of the eligible studies were performed independently by two researchers.

Results

A total of 3,607 articles were retrieved, of which 21 articles representing 20 cohort studies published in English were included after title/abstract and full-text screening. Among the 21 articles involving 7,650 patients and 1,360 MDR organisms, ten reported the risk factors for MDR Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB), ten for MDR GNB, and one for MDR GPB. The meta-analysis results suggested that prior antibiotic treatment, inappropriate antibiotic therapy, chronic lung disease, chronic liver disease and cerebral disease, prior MDR and PA infection/colonization, recent hospitalization, longer hospitalization stay, endotracheal tracheostomy and mechanical ventilation, tube feeding, nursing home residence, and higher disease severity score were independent risk factors for MDR bacteria.

Conclusions

This review identified fourteen clinical factors that might increase the risk of MDR bacteria in patients with LRTIs. Clinicians could take into account these factors when selecting antibiotics for patients and determine whether coverage for MDR bacteria is required. More well-designed studies are needed to confirm the various risk factors for MDR bacteria in the future.

A broad-spectrum beta-lactam-sparing stewardship program in a middle-income country public hospital: antibiotic use and expenditure outcomes and antimicrobial susceptibility profiles

Background

Antimicrobial stewardship programs are an efficient way to reduce inappropriate use of antimicrobials and costs; however, supporting data are scarce in middle-income countries. The aim of this study was to evaluate antibiotic use, bacterial susceptibility profiles, and the economic impact following implementation of a broad-spectrum beta-lactam-sparing antimicrobial stewardship program.

Methods

An interrupted time-series analysis was performed to evaluate antibiotic use and expenditure over a 24-month period (12 months before the antimicrobial stewardship program and in the 12 months after implementation of the antimicrobial stewardship program). Antibiotics were classified into one of two groups: beta-lactam antibiotics and beta-lactam-sparing antibiotics. We also compared the antimicrobial susceptibility profiles of key pathogens in each period.

Results

Beta-lactam antibiotics use decreased by 43.04 days of therapy/1000 patient-days (p = 0.04) immediately following antimicrobial stewardship program implementation, whereas beta-lacta-sparing antibiotics use increased during the intervention period (slope change 6.17 days of therapy/1000 patient-days, p < 0.001). Expenditure decreased by $2089.99 (p < 0.001) immediately after intervention and was maintained at this level over the intervention period ($−38.45; p = 0.24). We also observed that a greater proportion of pathogens were susceptible to cephalosporins and aminoglycosides after the antimicrobial stewardship program.

Conclusions

The antimicrobial stewardship program significantly reduced the use of broad-spectrum beta-lactam-antibiotics associated with a decrease in expenditure and maintenance of the susceptibility profile in Gram-negative bacteria.

Five-year surveillance and correlation of antibiotic consumption and resistance of Gram-negative bacteria at an intensive care unit in Serbia

A surveillance study was performed in an intensive care unit in the largest tertiary health care center in Vojvodina, Serbia from 2014 to 2018. Antibiotic prescription data were collated in the WHO anatomical therapeutic chemical (ATC)/defined daily dose (DDD) format, while antibiotic resistance was expressed as incidence density adjusted for total inpatient-days. Individual trends were determined by linear regression, while possible associations between antibiotic prescription and resistance were evaluated using cross-correlation analysis. An overall decrease in antibiotic utilization was observed. The prescription rates of piperacillin-tazobactam increased significantly, while consumption of 3rd and 4th generation cephalosporins and fluoroquinolones decreased. There were rising incidence densities of doripenem resistant Acinetobacter spp., piperacillin-tazobactam resistant Pseudomonas aeruginosa and carbapenem and colistin resistant Klebsiella pneumoniae. These results can serve as a basis for the development of antimicrobial stewardship strategies in the current setting.

Changes of resistance rates in Pseudomonas aeruginosa strains are unrelated to antimicrobial consumption in ICU populations with invasive device-related infection

OBJECTIVE

To evaluate the relationship between antipseudomonal antibiotic consumption and each individual drug resistance rate in Pseudomonas aeruginosa strains causing ICU acquired invasive device-related infections (IDRI).

DESIGN

A post hoc analysis was made of the data collected prospectively from the ENVIN-HELICS registry.

SETTING

Intensive Care Units participating in the ENVIN-UCI registry between the years 2007 and 2016 (3-month registry each year).

PATIENTS

Patients admitted for over 24h.

MAIN VARIABLES

Annual linear and nonlinear trends of resistance rates of P. aeruginosa strains identified in IDRI and days of treatment of each antipseudomonal antibiotic family per 1000 occupied ICU bed days (DOT) were calculated.

RESULTS

A total of 15,095 episodes of IDRI were diagnosed in 11,652 patients (6.2% out of a total of 187,100). Pseudomonas aeruginosa was identified in 2095 (13.6%) of 15,432 pathogens causing IDRI. Resistance increased significantly over the study period for piperacillin-tazobactam (P<0.001), imipenem (P=0.016), meropenem (P=0.004), ceftazidime (P=0.005) and cefepime (P=0.015), while variations in resistance rates for amikacin, ciprofloxacin, levofloxacin and colistin proved nonsignificant. A significant DOT decrease was observed for aminoglycosides (P<0.001), cephalosporins (P<0.001), quinolones (P<0.001) and carbapenems (P<0.001).

CONCLUSIONS

No significant association was observed between consumption of each antipseudomonal antibiotic family and the respective resistance rates for P. aeruginosa strains identified in IDRI.

Variation in a novel antipseudomonal antimicrobial consumption metric across hospital inpatient units at a Veterans Affairs hospital: A retrospective cohort study

A novel antimicrobial consumption metric designed to identify the proportion of carbapenem consumption (PoCC) among broad-spectrum antipseudomonal antimicrobials has been shown to vary significantly by US Census Bureau region. This retrospective surveillance study identified significant total PoCC variability (27%; P = .001) across 8 inpatient units from January 2017 through June 2018. This metric may be useful in identifying and comparing inpatient units that may be overusing antipseudomonal carbapenems.

Antimicrobial resistance surveillance and prediction of Gram-negative bacteria based on antimicrobial consumption in a hospital setting: A 15-year retrospective study

Antimicrobial resistance, a major threat to human health, is mainly driven by the overuse of antimicrobials. The purpose of this study was to further investigate the relationship between antimicrobial use and resistance with a 15-year record in Southwest hospital, one of the largest hospitals in Southwest China and a university affiliated hospital, thus to further predict the antimicrobial resistance in an autoregressive integrated moving average (ARIMA) manner. Kirby-Bauer tests were carried out to figure out the drug sensitivity of Gram-negative bacterial. Antimicrobials (β-lactamase inhibitor complex, aminoglycosides, quinolones, third and fourth-generation cephalosporins, carbapenems, cephamycins, oxacephems, and sulfonamides) consumption were calculated according to World Health Organization (WHO) anatomical therapeutic chemical classification index and expressed as annual defined daily dose (DDD) or DDD per 1000 out patients. Resistance rates of levofloxacin-resistant Escherichia coli, ceftazidime-resistant Klebsiella pneumoniae, amikacin-resistant Bacterium levans, imipenem-resistant Pseudomonas aeruginosa is positively correlated with the usage of aminoglycosides and quinolones; resistance rates of imipenem-resistant Acinetobacter baumanii is positively correlated with the usage of carbapenemes (P-value between the drug resistance of levofloxacin-resistant E. coli, ceftazidime-resistant K. pneumoniae and the usage of aminoglycosides is under .05, the other P-value are under .01); resistance rates of the drug resistance of levofloxacin-resistant E. coli is positively correlated with the usage of oxacephems (P < .01); resistance rates of imipenem-resistant P. aeruginosa is positively correlated with the usage of oxacephems and sulfonamides (P < .01).The present study presents one of the largest and longest retrospective analyses in China between antimicrobial consumption and antimicrobial resistance. Change of the usage of several antibacterial drugs has great influence on the drug resistance of Gram-negative bacterial. Of particular, ARIMA forecasting revealed that carbapenem related bacterial resistance should be closely watched.

Restrictive measure for the commercialization of antimicrobials in Brazil: results achieved

OBJECTIVE

To assess whether the incidence of hospital infection by a resistant microorganism decreased after the implementation of the restrictive measure of the National Health Surveillance Agency for the commercialization of antimicrobials.

METHODS

A historical cohort study of medical records of adult patients admitted to a general and public hospital from May 2010 to July 2011. A cohort was formed with patients admitted in the period before the restrictive measure for the commercialization of antimicrobials (Phase I) and a second cohort was formed with patients admitted after the implementation of the restrictive measure (Phase II).

RESULTS

The instantaneous risk of hospital infection by a resistant microorganism was estimated at seven by 1,000 people-time (95%CI 0.006-0.008) in Phase I, and four by 1,000 people-time (95%CI 0.003-0.005) in Phase II of the study. The differences between the survival curves in the different phases of the study and stratified by age group were also significant (p < 0.05).

CONCLUSIONS

The results suggest that the implementation of the restrictive measure of the commercialization of antimicrobials by the National Health Surveillance Agency reduced the incidence of hospital infection by a resistant microorganism.

Carbapenem-resistant Pseudomonas aeruginosa and carbapenem use in Japan: an ecological study

Objective

This study focused on carbapenem resistance in Pseudomonas aeruginosa and examined potential ecological correlations with carbapenem use in Japan.

Methods

The proportion of carbapenem-resistant P. aeruginosa isolates from 2015 and 2016 by prefecture was obtained from the Japan Nosocomial Infections Surveillance system. Data on carbapenem use was obtained from the National Database of Health Insurance Claims. The correlation between the proportion of carbapenem-resistant isolates and carbapenem consumption was assessed in a cross-sectional manner. The study also collected information on other variables including the numbers of physicians, nurses and medical facilities per 100 000 individuals by prefecture.

Results

Both the proportion of carbapenem-resistant P. aeruginosa isolates and levels of carbapenem use were higher in western Japan. Using a multivariate model, only carbapenem use remained significantly associated with the proportion of carbapenem-resistant isolates.

Conclusions

Carbapenem use and the proportion of carbapenem-resistant P. aeruginosa isolates were positively correlated. By longitudinal data collection, this approach offers an avenue to establish causal links as the frequency of carbapenem-resistant P. aeruginosa isolates starts to change in the future.

Risk factors and the resistance mechanisms involved in Pseudomonas aeruginosa mutation in critically ill patients

Background

The objective of this study was to determine the main risk factors of Pseudomonas aeruginosa mutation as well as the mechanisms of acquired resistance.

Methods

We conducted a 2-year prospective study in patients who were carriers of a Pseudomonas aeruginosa strain and who had been admitted to a medical/surgical ICU.

Results

Of the 153 patients who were included, 34 had a mutation in their strain. In a multivariate analysis, a duration of ventilation > 24 days was a risk factor for mutation (risk ratio 4.29; CI 95% 1.94-9.49) while initial resistance was a protective factor (RR 0.36; CI 95% 0.18-0.71). In a univariate analysis, exposure of P. aeruginosa to ceftazidime was associated with an over-production of AmpC cephalosporinase and exposure to meropenem was associated with impermeability. A segmentation method based on the duration of ventilation (> 24 days), initial resistance, and exposure of strains to ceftazidime made it possible to predict at 83% the occurrence of mutation.

Conclusion

The duration of ventilation and the presence of resistance as soon as P. aeruginosa is identified are predictive factors of mutation in ICU patients.

Clinical outcomes of carbapenem de-escalation regardless of microbiological results: A propensity score analysis

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of de-escalation in patients under treatment with carbapenems and its impact on clinical outcomes.

METHODS

A prospective observational study was conducted for 1year. Patients administered active carbapenems for at least 24h were included. Primary outcomes were in-hospital mortality, mortality at 30 days after carbapenem prescription, and infection-related readmission within 30 days. De-escalation was defined as the substitution of carbapenem with narrower spectrum antimicrobial agents or its discontinuation during the first 96h of treatment.

RESULTS

The study included 1161 patients, and de-escalation was performed in 667 (57.5%) of these. In the de-escalation group, 54.9% of cultures were positive. After propensity score matching, 30-day mortality was lower (17.4% vs. 25.7%, p=0.036), carbapenem treatment was 4 days shorter (4 vs. 8 days, p<0.001), total antibiotic therapy duration was 2 days longer (12 vs. 10 days, p=0.003), and length of hospital stay was 5 days shorter (8 vs. 13 days, p=0.008) in the de-escalated versus non-de-escalated patients. In-hospital mortality and 30-day readmission rates did not differ significantly between these groups.

CONCLUSION

Carbapenem de-escalation is a safe strategy that does not compromise the clinical status of patients.

Correlation between antimicrobial consumption and the prevalence of carbapenem-resistant Escherichia coli and carbapenem-resistant Klebsiella pneumoniae at a university hospital in Thailand

WHAT IS KNOWN AND OBJECTIVE

Carbapenem-resistant Enterobacteriaceae (CRE) are virulent gram-negative bacilli and cause urgent healthcare problems worldwide. One of the main factors leading to the emergence of CRE is antimicrobial consumption. The objective of this study was to assess how closely the rate of antimicrobial consumption and the prevalences of carbapenem-resistant Escherichia coli (CR-EC) and carbapenem-resistant Klebsiella pneumoniae (CR-KP) are correlated.

METHODS

A retrospective study was performed at a university hospital in Thailand from January 2013 to September 2016. The prevalence of E coli and K pneumoniae was represented as percentages per species per quarter. The antimicrobial consumption rate per quarter was expressed as the defined daily dose (DDD)/1000 patient-days. Evaluation of the relationships between the rate of antimicrobial consumption and the prevalences of CR-EC and CR-KP was conducted via Pearson's or Spearman's correlation analyses.

RESULTS AND DISCUSSION

During the study period, the prevalence of CR-EC and CR-KP was less than 6%; however, significantly increasing prevalences were reported for both CR-EC (r = 0.55, P = 0.03) and CR-KP (r = 0.87, P < 0.01). There was a significant increasing trend in the consumption of meropenem (r = 0.65, P = 0.01), levofloxacin (r = 0.63, P = 0.01), ceftriaxone (r = 0.55, P = 0.03), ertapenem (r = 0.52, P = 0.05) and the carbapenem group (r = 0.64, P = 0.01). A significant correlation was observed between CR-KP prevalence and total carbapenem consumption (r = 0.55, P = 0.04). Moreover, levofloxacin consumption had a significant positive relationship with the prevalence of CR-KP (r = 0.65, P = 0.01). No positive correlation was found with the prevalence of CR-EC.

WHAT IS NEW AND CONCLUSION

The rate of consumption of levofloxacin and carbapenems was the important key factor correlated with the rate of emergence of CR-KP. This is the first report demonstrating the correlation between levofloxacin consumption and CR-KP prevalence.

In Vitro Activity of Ceftolozane/Tazobactam vs Nonfermenting, Gram-Negative Cystic Fibrosis Isolates

Ceftolozane/tazobactam (C/T) was tested and compared against 93 nonfermenting, Gram-negative clinical isolates from cystic fibrosis specimens. Based on current breakpoints for intra-abdominal and urinary tract infections (which may not be appropriate for pulmonary infections), C/T was found to be the most active agent against P. aeruginosa (95.7% susceptible), followed by piperacillin/tazobactam (89.4% susceptible). For other Gram-negative pathogens included, C/T had varying activity.

Impact of carbapenem restriction on the antimicrobial susceptibility pattern of Pseudomonas aeruginosa isolates in the ICU

Background

Rates of carbapenem-resistant Pseudomonas aeruginosa are increasing. Aggressive prevention strategies, including instituting antimicrobial stewardship programmes, are essential for combating antimicrobial resistance.

Objectives

We conducted this study to compare the antimicrobial susceptibility pattern of P. aeruginosa before and after carbapenem restriction.

Methods

We conducted a two-phase retrospective study in an adult ICU. The first phase was from May until July 2016 (before carbapenem restriction), whereas the second phase was from September until November 2016 (while implementing carbapenem restriction). The antimicrobial susceptibility pattern of P. aeruginosa was reviewed in August and December 2016. The measure of carbapenem-resistant P. aeruginosa was the proportion of resistant isolates (percentage resistant). The measure of antibacterial consumption in the study phases was DDDs/1000 patient days.

Results

The overall carbapenem consumption decreased significantly in the second phase, from 28.44 to 11.67 DDDs/1000 patient days (P = 0.012). The resistance of P. aeruginosa to imipenem and meropenem decreased significantly from 76.0% to 38.5% (P = 0.019) and from 74.1% to 30.0% (P = 0.012), respectively. Susceptibility of P. aeruginosa to other antibacterials was not affected by carbapenem restriction.

Conclusions

These data suggest that restricting carbapenems, even for a short duration, may be an effective strategy for managing the problem of carbapenem resistance in P. aeruginosa.

Measuring and mapping the global burden of antimicrobial resistance

The increasing number and global distribution of pathogens resistant to antimicrobial drugs is potentially one of the greatest threats to global health, leading to health crises arising from infections that were once easy to treat. Infections resistant to antimicrobial treatment frequently result in longer hospital stays, higher medical costs, and increased mortality. Despite the long-standing recognition of antimicrobial resistance (AMR) across many settings, there is surprisingly poor information about its geographical distribution over time and trends in its population prevalence and incidence. This makes reliable assessments of the health burden attributable to AMR difficult, weakening the evidence base to drive forward research and policy agendas to combat AMR. The inclusion of mortality and morbidity data related to drug-resistant infections into the annual Global Burden of Disease Study should help fill this policy void.

Sparing carbapenem usage

Background

Carbapenem resistance in Gram-negative bacteria is increasing in many countries and use of carbapenems and antibiotics to which resistance is linked should be reduced to slow its emergence. There are no directly equivalent antibiotics and the alternatives are less well supported by clinical trials. The few new agents are expensive.

Objectives

To provide guidance on strategies to reduce carbapenem usage.

Methods

A literature review was performed as described in the BSAC/HIS/BIA/IPS Joint Working Party on Multiresistant Gram-negative Infection Report.

Results

Older agents remain active against some of the pathogens, although expectations of broad-spectrum cover for empirical treatment have risen. Education, expert advice on treatment and antimicrobial stewardship can produce significant reductions in use.

Conclusions

More agents may need to be introduced onto the antibiotic formulary of the hospital, despite the poor quality of scientific studies in some cases.

Antimicrobial resistance (AMR) nanomachines-mechanisms for fluoroquinolone and glycopeptide recognition, efflux and/or deactivation

In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics-the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins. Expression of efflux systems is regulated by GntR-like (S. aureus NorG), MarR-like (MgrA, MepR) regulators or a two-component signal transduction system (TCS) (S. aureus ArlSR). Resistance to the glycopeptide antibiotic teicoplanin occurs via efflux regulated by the TcaR regulator in S. aureus. Resistance to vancomycin occurs through modification of the D-Ala-D-Ala target in the cell wall peptidoglycan and removal of high affinity precursors, or by target protection via cell wall thickening. Of the six Van resistance types (VanA-E, VanG), the VanA resistance type is considered in this review, including its regulation by the VanSR TCS. We describe the recent application of biophysical approaches such as the hydrodynamic technique of analytical ultracentrifugation and circular dichroism spectroscopy to identify the possible molecular effector of the VanS receptor that activates expression of the Van resistance genes; both approaches demonstrated that vancomycin interacts with VanS, suggesting that vancomycin itself (or vancomycin with an accessory factor) may be an effector of vancomycin resistance. With 16 and 19 proteins or protein complexes involved in fluoroquinolone and glycopeptide resistances, respectively, and the complexities of bacterial sensing mechanisms that trigger and regulate a wide variety of possible resistance mechanisms, we propose that these antimicrobial resistance mechanisms might be considered complex 'nanomachines' that drive survival of bacterial cells in antibiotic environments.

Previous Antibiotic Exposure and Antimicrobial Resistance Patterns of Acinetobacter spp. and Pseudomonas aeruginosa Isolated from Patients with Nosocomial Infections

BACKGROUND

The alarming spread of antibiotic-resistant bacteria causing healthcare-associated infections has been extensively reported in recent medical literature.

AIMS

To compare trends in antimicrobial consumption and development of resistance among isolates of Acinetobacter spp. and Pseudomonas aeruginosa that cause hospital infections.

STUDY DESIGN

Cross-sectional study.

METHODS

A study was conducted in a tertiary healthcare institution in central Serbia, during the 7-year period between January 2009 and December 2015. The incidence rate of infections caused by Acinetobacter or Pseudomonas, as well as their resistance density to commonly used antibiotics, were calculated. Utilization of antibiotics was expressed as the number of defined daily doses per 1000 patient-days.

RESULTS

A statistically significant increase in resistance density in 2015 compared to the first year of observation was noted for Acinetobacter, but not for Pseudomonas, to third-generation cephalosporins (p=0.008), aminoglycosides (p=0.005), carbapenems (p=0.003), piperacillin/tazobactam (p=0.025), ampicillin/sulbactam (p=0.009) and tigecycline (p=0.048).

CONCLUSION

Our study showed that there is an association between the resistance density of Acinetobacter spp. and utilization of carbapenems, tigecycline and aminoglycosides. A multifaceted intervention is needed to decrease the incidence rate of Acinetobacter and Pseudomonas hospital infections, as well as their resistance density to available antibiotics.

Evaluation of Microorganisms Causing Ventilator-Associated Pneumonia in a Pediatric Intensive Care Unit

OBJECTIVE

The aim of this study was to identify microorganisms causing ventilator-associated pneumonia (VAP) and also study the antibiotic resistance/susceptibility.

MATERIALS AND METHODS

We retrospectively assessed microorganisms isolated from patients diagnosed with VAP in a pediatric intensive care unit between January 1, 2014, and June 30, 2016.

RESULTS

We included 44 patients diagnosed with VAP. The prevalence thereof was 8.6 patients per 1,000 ventilator days. Mechanical ventilation was required for 56.5% of patients. Thirty-three patients (75%) died. An underlying chronic disease was detected in 75% of patients (n=33). Fifty microorganisms were isolated from 44 patients. Single microorganisms were isolated from 86.4% (n=38) and two from 13.6% (n=6) of patients. Of all the isolated bacteria, 96% (n=48) were gram-negative; the most common was Pseudomonas aeruginosa (32%), followed by Klebsiella pneumoniae (24%) and Acinetobacter baumannii (22%). The isolates were most susceptible to colistin (92.6%), followed by piperacillin-tazobactam (71.4%), amikacin (65.2%), and gentamicin (52.2%). No enterobacterium or Acinetobacter strain was resistant to colistin; however, 13% of P. aeruginosa isolates were resistant.

CONCLUSION

In VAP, it is essential to catalog antibiotic resistance patterns of bacteria present in the unit to ensure that empirical antibiotic therapy is effective.

Antibiotics: practice and opinions of Cambodian commercial farmers, animal feed retailers and veterinarians

BACKGROUND

Cambodia has reported multidrug resistant bacteria in poultry, similar to other countries in the region. We visited commercial food animal farms to explore opinions and antibiotic practices on the farms.

METHODS

We used individual in-depth qualitative interviews with 16 commercial farmers, four feed retailers and nine veterinarians from food animal industry and government offices from the southwestern region of Phnom Penh. Transcribed interviews were thematically analysed.

RESULTS

Widespread antibiotic use occurred on all farms and was driven by four facilitators: belief that antibiotics were necessary for animal raising, limited knowledge, unrestricted antibiotic access, and weak monitoring and control systems. "If we treat ducks for two days and they aren't cured we change to human drugs. We cocktail 10 tablets of this, 10 tablets of that and 20 tablets of this one. Altogether 200 tablets are mixed in 100 or 200 L of water for the ducks to drink. No one taught me, just my experiences." Antibiotics were believed to be necessary for disease prevention. "On the first day when we bring in the chicks, we let them drink Enro [enrofloxacin] and vitamins to make them resist to the weather. We place them in the house and there are some bacteria in the environment. When they are newly arrived, we have to give them feed. So we're afraid they get diarrhea when they eat feed, we have to use Enro." All farmers used pre-mixed feed that veterinarians and feed retailers acknowledged contained antibiotics but not all listed the antibiotics. Farmers viewed pre-mixed feed as a necessary 'feed supplement' for growth promotion. "….The fatten supplement is mixed in feed. Pigs aren't growing well unless I use the supplement." Farmers and veterinarians were concerned that 'antibiotic residuals' in animal meat could harm human health. But they did not link this with antibiotic resistance.

CONCLUSIONS

Antibiotic use in food animals was widespread and uncontrolled. Farmers focused on the benefits of food animal production rather than concerns about the consequences of antibiotic use. Therefore, education for prudent use of antibiotics in food animals and regulations are urgently needed in food animal farming in Cambodia.