Antimicrobial use and antimicrobial resistance: a population perspective

Comparison of the Respiratory Resistomes and Microbiota in Children Receiving Short versus Standard Course Treatment for Community-Acquired Pneumonia

Pediatric community-acquired pneumonia (CAP) is often treated with 10 days of antibiotics. Shorter treatment strategies may be effective and lead to less resistance. The impact of duration of treatment on the respiratory microbiome is unknown. Data are from children (n = 171), ages 6 to 71 months, enrolled in the SCOUT-CAP trial (NCT02891915). Children with CAP were randomized to a short (5 days) versus standard (10 days) beta-lactam treatment strategy. Throat swabs were collected at enrollment and the end of the study and used for shotgun metagenomic sequencing. The number of beta-lactam and multidrug efflux resistance genes per prokaryotic cell (RGPC) was significantly lower in children receiving the short compared to standard treatment strategy at the end of the study (Wilcoxon rank sum test, P < 0.05 for each). Wilcoxon effect sizes were small for beta-lactam (r: 0.15; 95% confidence interval [CI], 0.01 to 0.29) and medium for multidrug efflux RGPC (r: 0.23; 95% CI, 0.09 to 0.37). Analyses comparing the resistome at the beginning and end of the trial indicated that in contrast to the standard strategy group, the resistome significantly differed in children receiving the short course strategy. Relative abundances of commensals such as Neisseria subflava were higher in children receiving the standard strategy, and Prevotella species and Veillonella parvula were higher in children receiving the short course strategy. We conclude that children receiving 5 days of beta-lactam therapy for CAP had a significantly lower abundance of antibiotic resistance determinants than those receiving standard 10-day treatment. These data provide an additional rationale for reductions in antibiotic use when feasible. IMPORTANCE Antibiotic resistance is a major threat to public health. Treatment strategies involving shorter antibiotic courses have been proposed as a strategy to lower the potential for antibiotic resistance. We examined relationships between the duration of antibiotic treatment and its impact on resistance genes and bacteria in the respiratory microbiome using data from a randomized controlled trial of beta-lactam therapy for pediatric pneumonia. The randomized design provides reliable evidence of the effectiveness of interventions and minimizes the potential for confounding. Children receiving 5 days of therapy for pneumonia had a lower prevalence of two different types of resistance genes than did those receiving the 10-day treatment. Our data also suggest that children receiving longer durations of therapy have a greater abundance of antibiotic resistance genes for a longer period of time than do children receiving shorter durations of therapy. These data provide an additional rationale for reductions in antibiotic use.

Acquisition of carbapenem-resistant gram-negative bacilli among intensive care unit (ICU) patients with no previous use of carbapenems: Indirect population impact of antimicrobial use

Objective:

To measure the impact of exposure to patients using carbapenem on the acquisition of carbapenem-resistant gram-negative bacilli (CR-GNB) among patients not using carbapenems.

Design:

An ecological study and a cohort study.

Setting:

Two medical surgical intensive care units (ICUs) in inner Brazil.

Participants:

Patients admitted to 2 ICUs from 2013 through 2018 to whom carbapenem was not prescribed.

Methods:

In the ecologic study, the monthly use of carbapenems (days of therapy [DOT] per 1,000 patient days) was tested for linear correlation with the 2-month moving average of incidence CR-GNB among patients to whom carbapenem was not prescribed. In the cohort study, those patients were addressed individually for risk factors (demographics, invasive interventions, use of antimicrobials) for acquisition of CR-GNB, including time at risk and the “carbapenem pressure,” described as the aggregate DOT among other ICU patients during time at risk. The analysis was performed in univariate and multivariable Poisson regression models.

Results:

The linear regression model revealed an association of total carbapenem use and incidence of CR-GNB (coefficient, 0.04; 95% confidence interval [CI], 0.02–0.06; P = .001). In the cohort model, the adjusted rate ratio (RR) for carbapenem DOT was 1.009 (95% CI, 1.001–1.018; P = .03). Other significant risk factors were mechanical ventilation and the previous use of ceftazidime (with or without avibactam).

Conclusions:

Every additional DOT of total carbapenem use increased the risk of CR-GNB acquisition by patients not using carbapenems by nearly 1%. We found evidence for a population (“herd effect”-like) impact of antimicrobial use in the ICUs.

From Pathophysiological Hypotheses to Case-Control Study Design: Resistance from Antibiotic Exposure in Community-Onset Infections

Antimicrobial resistance is a global public health concern, at least partly due to the misuse of antibiotics. The increasing prevalence of antibiotic-resistant infections in the community has shifted at-risk populations into the general population. Numerous case-control studies attempt to better understand the link between antibiotic use and antibiotic-resistant community-onset infections. We review the designs of such studies, focusing on community-onset bloodstream and urinary tract infections. We highlight their methodological heterogeneity in the key points related to the antibiotic exposure, the population and design. We show the impact of this heterogeneity on study results, through the example of extended-spectrum β-lactamases producing Enterobacteriaceae. Finally, we emphasize the need for the greater standardization of such studies and discuss how the definition of a pathophysiological hypothesis specific to the bacteria-resistance pair studied is an important prerequisite to clarify the design of future studies.

Impact of restriction of over-the-counter sales of antimicrobials on antimicrobial resistance in Escherichia coli from community-onset urinary tract infections in inner São Paulo State, Brazil

Background

Antimicrobial resistance in community-associated infections is an increasing worldwide concern. In low-to-middle income countries, over-the-counter (OTC) sales of antimicrobials without medical prescription have been blamed for increasing consumption and resistance. We studied the impact of restriction of OTC sales of antimicrobials in Brazil (instituted in October 2010) on resistance trends of Escherichia coli from community-onset urinary tract infections.

Methods

We analyzed monthly resistance trend of Escherichia coli from community-onset urinary tract infections from 2005 through 2018. The data were submitted to interrupted time series analysis in both linear and Poisson regression models.

Results

We found impact on cefazolin (p<0.001) and amikacin (p<0.001) resistance as immediate impact of the intervention, and no beneficial impact on resistance to ciprofloxacin, ceftriaxone or sulfamethoxazole-trimethoprim.

Conclusion

At the present study, we found that OTC sales restriction did not generally impact on antimicrobial resistance.

Effect of Delays in Concordant Antibiotic Treatment on Mortality in Patients With Hospital-Acquired Acinetobacter Species Bacteremia: Emulating a Target Randomized Trial With a 13-Year Retrospective Cohort

Delays in treating bacteremias with antibiotics to which the causative organism is susceptible are expected to adversely affect patient outcomes. Quantifying the impact of such delays to concordant treatment is important for decision-making about interventions to reduce the delays and for quantifying the burden of disease due to antimicrobial resistance. There are, however, potentially important biases to be addressed, including immortal time bias. We aimed to estimate the impact of delays in appropriate antibiotic treatment of patients with Acinetobacter species hospital-acquired bacteremia in Thailand on 30-day mortality by emulating a target trial using retrospective cohort data from Sunpasitthiprasong Hospital in 2003–2015. For each day, we defined treatment as concordant if the isolated organism was susceptible to at least 1 antibiotic given. Among 1,203 patients with Acinetobacter species hospital-acquired bacteremia, 682 had 1 or more days of delays to concordant treatment. Surprisingly, crude 30-day mortality was lower in patients with delays of ≥3 days compared with those who had 1–2 days of delays. Accounting for confounders and immortal time bias resolved this paradox. Emulating a target trial, we found that these delays were associated with an absolute increase in expected 30-day mortality of 6.6% (95% confidence interval: 0.2, 13.0), from 33.8% to 40.4%.

Rapid Changes in Nasopharyngeal Antibiotic Resistance Gene Profiles After Short Courses of Antibiotics in a Pilot Study of Ambulatory Young Children

We quantified antibiotic resistance genes before and after short antibiotic courses in nasopharyngeal specimens from ambulatory children. Carriage of certain bacteria and resistance genes was common before antibiotics. After antibiotics, we observed substantial reductions in pneumococcal and Staphylococcus aureus carriage and rapid expansion in the abundance of certain resistance genes.

Microbiome-pathogen interactions drive epidemiological dynamics of antibiotic resistance: A modeling study applied to nosocomial pathogen control

The human microbiome can protect against colonization with pathogenic antibiotic-resistant bacteria (ARB), but its impacts on the spread of antibiotic resistance are poorly understood. We propose a mathematical modeling framework for ARB epidemiology formalizing within-host ARB-microbiome competition, and impacts of antibiotic consumption on microbiome function. Applied to the healthcare setting, we demonstrate a trade-off whereby antibiotics simultaneously clear bacterial pathogens and increase host susceptibility to their colonization, and compare this framework with a traditional strain-based approach. At the population level, microbiome interactions drive ARB incidence, but not resistance rates, reflecting distinct epidemiological relevance of different forces of competition. Simulating a range of public health interventions (contact precautions, antibiotic stewardship, microbiome recovery therapy) and pathogens (Clostridioides difficile, methicillin-resistant Staphylococcus aureus, multidrug-resistant Enterobacteriaceae) highlights how species-specific within-host ecological interactions drive intervention efficacy. We find limited impact of contact precautions for Enterobacteriaceae prevention, and a promising role for microbiome-targeted interventions to limit ARB spread.

The Population-Level Effect of Screening for Mycoplasma genitalium on Antimicrobial Resistance: A Quasi-Experimental Study

BACKGROUND

No studies have evaluated the utility and risks of screening for Mycoplasma genitalium in men who have sex with men taking preexposure prophylaxis (PrEP). We made use of a quasi-experimental design to evaluate the effect of screening for M. genitalium in a demonstration PrEP cohort with 3-monthly follow-up.

METHODS

We compared the proportion of PrEP participants with M. genitalium clearance, the duration of persistence, proportion with incident symptoms, the incidence of fluoroquinolone and macrolide resistance, and the proportion of noncleared infections with resistance-associated mutations between 2 groups: those in whom the first episode of M. genitalium was treated and those in whom it was not treated.

RESULTS

M. genitalium was detected in 70 of 179 individuals. The first episode of infection was treated in 46 individuals. Treatment was not significantly associated with the incidence of symptomatic infections or the acquisition of genotypic resistance. Treatment was associated with a higher probability of clearance of infection but at the expense of increasing the proportion of remaining infections that were resistant. In the nontreated group, the infections that did not clear were less likely to be fluoroquinolone resistant (1/6 [16.7%]) than those that did clear (4/4 [100%]; P = 0.048). In contrast, in the treated group, there was no significant difference in the proportion of fluoroquinolone resistance between the infections that persisted and cleared.

CONCLUSIONS

If screening and treatment increase the ratio of resistant to susceptible M. genitalium in a population, then this could play a role in the spread of antimicrobial resistance.

Effect of Oral Azithromycin vs Placebo on COVID-19 Symptoms in Outpatients With SARS-CoV-2 Infection: A Randomized Clinical Trial

IMPORTANCE

Azithromycin has been hypothesized to have activity against SARS-CoV-2.

OBJECTIVE

To determine whether oral azithromycin in outpatients with SARS-CoV-2 infection leads to absence of self-reported COVID-19 symptoms at day 14.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial of azithromycin vs matching placebo conducted from May 2020 through March 2021. Outpatients from the US were enrolled remotely via internet-based surveys and followed up for 21 days. Eligible participants had a positive SARS-CoV-2 diagnostic test result (nucleic acid amplification or antigen) within 7 days prior to enrollment, were aged 18 years or older, and were not hospitalized at the time of enrollment. Among 604 individuals screened, 297 were ineligible, 44 refused participation, and 263 were enrolled. Participants, investigators, and study staff were masked to treatment randomization.

INTERVENTIONS

Participants were randomized in a 2:1 fashion to a single oral 1.2-g dose of azithromycin (n = 171) or matching placebo (n = 92).

MAIN OUTCOMES AND MEASURES

The primary outcome was absence of self-reported COVID-19 symptoms at day 14. There were 23 secondary clinical end points, including all-cause hospitalization at day 21.

RESULTS

Among 263 participants who were randomized (median age, 43 years; 174 [66%] women; 57% non-Hispanic White and 29% Latinx/Hispanic), 76% completed the trial. The trial was terminated by the data and safety monitoring committee for futility after the interim analysis. At day 14, there was no significant difference in proportion of participants who were symptom free (azithromycin: 50%; placebo: 50%; prevalence difference, 0%; 95% CI, -14% to 15%; P > .99). Of 23 prespecified secondary clinical end points, 18 showed no significant difference. By day 21, 5 participants in the azithromycin group had been hospitalized compared with 0 in the placebo group (prevalence difference, 4%; 95% CI, -1% to 9%; P = .16).

CONCLUSIONS AND RELEVANCE

Among outpatients with SARS-CoV-2 infection, treatment with a single dose of azithromycin compared with placebo did not result in greater likelihood of being symptom free at day 14. These findings do not support the routine use of azithromycin for outpatient SARS-CoV-2 infection.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04332107.

Assessment of Knowledge, Attitude, and Practice of Antibiotic Use among the Population of Boyolali, Indonesia: A Cross-Sectional Study

Misuse and overuse of antibiotics are potential causes of the increasing prevalence of antibiotic resistance (ABR). Having information about the knowledge, attitude, and practices concerning antibiotics use by the public might help control ABR growth. Therefore, this cross-sectional study aimed to investigate the levels and associated factors of knowledge, attitude, and practice (KAP) of antibiotics use among the public. A questionnaire was designed and validated, which consisted of a total of 51 questions with four sections: demographics (6), knowledge (20), attitude (12), and practice (13) to measure KAP. Univariate analysis (using Mann-Whitney U and Kruskal-Wallis analysis) was applied to assess the differences in the mean scores of KAP. Linear regression analysis was performed to identify factors associated with KAP. Finally, using Spearman analysis we have examined the correlation between responses to the KAP. The sample size of this study was 575, with a 99.96% response rate. Regarding knowledge, 73.12% of respondents stated that antibiotics could be used to treat viral infections, and 63.35% of respondents answered that antibiotics could reduce fever. Concerning attitude, 50% of respondents had considered stopping taking antibiotics as soon as symptoms had disappeared. In analyzing practice, we found 40% of respondents obtained antibiotics from a pharmacy without a prescription from a physician, a nurse, or a midwife. Statistical analysis revealed that KAP about antibiotic use was significantly associated with gender, area of residence, level of education, and monthly income (p < 0.05). Our findings concluded that men, respondents with low income, those with low-level education, and those living in rural areas are more prone to excessive use of antibiotics without knowing the adverse effects of improper use and how it can contribute to high ABR. So it is urgently necessary to strengthen policies on antibiotics use, including drug provision, distribution, and sales. In addition, people with low KAP should be a priority consideration in education outreach initiatives.

Prevalence and risk factors for antimicrobial resistance among newborns with gram-negative sepsis

INTRODUCTION

Newborn sepsis accounts for more than a third of neonatal deaths globally and one in five neonatal deaths in Ethiopia. The first-line treatment recommended by WHO is the combination of gentamicin with ampicillin or benzylpenicillin. Gram-negative bacteria (GNB) are increasingly resistant to previously effective antibiotics.

OBJECTIVES

Our goal was to estimate the prevalence of antibiotic-resistant gram-negative bacteremia and identify risk factors for antibiotic resistance, among newborns with GNB sepsis.

METHODS

At a tertiary hospital in Ethiopia, we enrolled a cohort pregnant women and their newborns, between March and December 2017. Newborns who were followed up until 60 days of life for clinical signs of sepsis. Among the newborns with clinical signs of sepsis, blood samples were cultured; bacterial species were identified and tested for antibiotic susceptibility. We described the prevalence of antibiotic resistance, identified newborn, maternal, and environmental factors associated with multidrug resistance (MDR), and combined resistance to ampicillin and gentamicin (AmpGen), using multivariable regression.

RESULTS

Of the 119 newborns with gram-negative bacteremia, 80 (67%) were born preterm and 82 (70%) had early-onset sepsis. The most prevalent gram-negative species were Klebsiella pneumoniae 94 (79%) followed by Escherichia coli 10 (8%). Ampicillin resistance was found in 113 cases (95%), cefotaxime 104 (87%), gentamicin 101 (85%), AmpGen 101 (85%), piperacillin-tazobactam 47 (39%), amikacin 10 (8.4%), and Imipenem 1 (0.8%). Prevalence of MDR was 88% (n = 105). Low birthweight and late-onset sepsis (LOS) were associated with higher risks of AmpGen-resistant infections. All-cause mortality was higher among newborns treated with ineffective antibiotics.

CONCLUSION

There was significant resistance to current first-line antibiotics and cephalosporins. Additional data are needed from primary care and community settings. Amikacin and piperacillin-tazobactam had lower rates of resistance; however, context-specific assessments of their potential adverse effects, their local availability, and cost-effectiveness would be necessary before selecting a new first-line regimen to help guide clinical decision-making.

Change-points in antibiotic consumption in the community, European Union/European Economic Area, 1997-2017

OBJECTIVES

Surveillance of antibiotic consumption in the community is of utmost importance to inform and evaluate control strategies. Data on two decades of antibiotic consumption in the community were collected from 30 EU/European Economic Area (EEA) countries. This article reviews temporal trends and the presence of abrupt changes in subgroups of relevance in antimicrobial stewardship.

METHODS

For the period 1997-2017, data on yearly antibiotic consumption in the community, aggregated at the level of the active substance, were collected using the WHO ATC classification and expressed in DDD (ATC/DDD index 2019) per 1000 inhabitants per day. We applied a range of non-linear mixed models to assess the presence of changes in the consumption of antibacterials for systemic use (ATC group J01) and eight antibiotic subgroups.

RESULTS

For the majority of the studied groups, a country-specific change-point model provided the best fit. Depending on the antibiotic group/subgroup and on the country, change-points were spread out between 2000 and 2013.

CONCLUSIONS

Due to the heterogeneity in antibiotic consumption in the community across EU/EEA countries, a country-specific change-point model provided the better fit. Given the limitations of this model, our recommendation for the included countries is to carefully interpret the country-specific results presented in this article and to use the tutorial included in this series to conduct their own change-point analysis when evaluating the impact of changes in regulations, public awareness campaigns, and other national interventions to improve antibiotic consumption in the community.

Herbicide resistance management strategies: how do they compare with those for insecticides, fungicides and antibiotics?

Herbicides are the largest category of pesticides used in global agriculture, which is reflected in the rate of increase in the number of unique cases of herbicide-resistant weed biotypes since the late 1950s. Recommended herbicide resistance management strategies and tactics have evolved over the past 50 years through cumulative research and experience and have been regularly reviewed. Nevertheless, new perspectives may be gained by viewing current recommended strategies through the lens of insecticide, fungicide, and antibiotic resistance management. What commonalities exist and what is the basis for disparate strategies? Although pesticide and antibiotic mixtures (or combinations) are generally more effective than rotations (or alternations) in mitigating or managing resistance, the latter strategy is often employed because of greater ease of implementation and other reasons. We conclude that there are more common than different strategies for mitigating or managing pesticide and antibiotic resistance. Overall, a reduction in selection pressure for resistance evolution through diverse multi-tactic management programmes, and disruption or mitigation of the dispersal or transmission of problematic genotypes are needed to sustain the longevity of current and future mode-of-action products for crop and human health protection. © 2021 Society of Chemical Industry. © 2021 Society of Chemical Industry.

Hospital-wide surveillance-based antimicrobial treatments: A Monte-Carlo look-ahead method

BACKGROUND AND OBJECTIVES

We present a heuristic solution method to the problem of choosing hospital-wide antimicrobial treatments that minimize the cumulative infected patient-days in the long run in a health care facility.

METHODS

Our solution method is a rollout algorithm. We rely on the stochastic version of a compartmental model to describe the spread of an infecting organism in the health care facility and the emergence and spread of resistance to two drugs. We assume that the parameters of the model are known. Treatments are chosen at the beginning of each period based on the count of patients with each health status, and on stochastic simulations of the future emergence and spread of antimicrobial resistance. The same treatment is then administered to all patients, including uninfected patients, during the period and cannot be adjusted until the next period.

RESULTS

In our simulations, our algorithm allows to reduce the average cumulative infected patient-days over two years by 47.0% compared to the best standard therapy, and by 32.2% compared to a similar heuristic algorithm not using surveillance data (significantly at the 95% threshold).

CONCLUSION

Our heuristic solution method is simple yet flexible. We explain how it can be used either to perform online optimization, or to produce data for quantitative analysis. Its performance is illustrated using a relatively simple infectious disease transmission model, but it is compatible with more advanced epidemiological models.

Indication for antibiotic prescription among children attending primary healthcare services in rural Burkina Faso

We evaluated diagnoses leading to antibiotic use for children <5 years in 48 government-run primary health facilities in Nouna District, Burkina Faso. Among 61,355 visits, 30,975 received an antibiotic (58% pneumonia). Diagnoses not requiring an antibiotic, including malaria, non-bloody diarrhea, and cough without pneumonia, contributed a minority of antibiotic prescriptions.

Impact of the COVID-19 Pandemic on the Prescribing Patterns of First-Line Antibiotics in English Primary Care: A Longitudinal Analysis of National Prescribing Dataset

The COVID-19 pandemic has impacted on public access to health services. This study aimed to investigate the impact of COVID-19 pandemic on commonly prescribed first-line antibiotics in English primary care. A secondary analysis of publicly available government data pertaining to primary care prescribing was conducted. A list of twenty first-line antibiotics used to treat common infections was developed following the National Institute of Clinical Excellence (NICE) guidelines. All primary care prescription and cost data pertaining to commonly prescribed first-line antibiotics in England between March and September of 2018-2020 were extracted and adjusted for inflation. Analysis suggests prescribing of antibiotics significantly reduced by 15.99% (p = 0.018) and 13.5% (p = 0.002) between March and September 2020 compared with same time period for 2018 and 2019, respectively. The most noticeable decrease in 2020 was noticed for prescribing for meningitis (-62.3%; p = 0.002) followed by respiratory tract infections (-39.13%; p = 0.035), in terms of indications. These results are suggestive of reduced transmission of infections in the community due to national lockdowns, social distancing and hygiene practices. In addition, the impact of reduced face-to-face consultations in general practices needs to be investigated as a potential reason for reduced prescribing. The pandemic also offers an opportunity to rationalize antibiotics use in the community.

Choosing New Therapies for Gonorrhoea: We Need to Consider the Impact on the Pan-Neisseria Genome. A Viewpoint

The development of new gonorrhoea treatment guidelines typically considers the resistance-inducing effect of the treatment only on Neisseria gonorrhoeae. Antimicrobial resistance in N. gonorrhoeae has, however, frequently first emerged in commensal Neisseria species and then been passed on to N. gonorrhoeae via transformation. This creates the rationale for considering the effect of gonococcal therapies on resistance in commensal Neisseria. We illustrate the benefits of this pan-Neisseria strategy by evaluating three contemporary treatment options for N. gonorrhoeae-ceftriaxone plus azithromycin, monotherapy with ceftriaxone and zoliflodacin.

Cracking the Challenge of Antimicrobial Drug Resistance with CRISPR/Cas9, Nanotechnology and Other Strategies in ESKAPE Pathogens

Antimicrobial resistance is mushrooming as a silent pandemic. It is considered among the most common priority areas identified by both national and international agencies. The global development of multidrug-resistant strains now threatens public health care improvement by introducing antibiotics against infectious agents. These strains are the product of both continuous evolution and unchecked antimicrobial usage (AMU). The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are the leading cause of nosocomial infections throughout the world. Most of them are now multidrug-resistant, which pose significant challenges in clinical practice. Understanding these bacteria’s resistance mechanisms is crucial for developing novel antimicrobial agents or other alternative tools to fight against these pathogens. A mechanistic understanding of resistance in these pathogens would also help predict underlying or even unknown mechanisms of resistance of other emerging multidrug-resistant pathogens. Research and development to find better antibacterial drugs and research on tools like CRISPER-Cas9, vaccines, and nanoparticles for treatment of infections that can be further explored in the clinical practice health sector have recognized these alternatives as essential and highly effective tools to mitigate antimicrobial resistance. This review summarizes the known antimicrobial resistance mechanisms of ESKAPE pathogens and strategies for overcoming this resistance with an extensive overview of efforts made in this research area.

Appropriateness of Antibiotic Prescribing in United States Children's Hospitals: A National Point Prevalence Survey

BACKGROUND

Studies estimate that 30%-50% of antibiotics prescribed for hospitalized patients are inappropriate, but pediatric data are limited. Characterization of inappropriate prescribing practices for children is needed to guide pediatric antimicrobial stewardship.

METHODS

Cross-sectional analysis of antibiotic prescribing at 32 children's hospitals in the United States. Subjects included hospitalized children with ≥ 1 antibiotic order at 8:00 am on 1 day per calendar quarter, over 6 quarters (quarter 3 2016-quarter 4 2017). Antimicrobial stewardship program (ASP) physicians and/or pharmacists used a standardized survey to collect data on antibiotic orders and evaluate appropriateness. The primary outcome was the percentage of antibiotics prescribed for infectious use that were classified as suboptimal, defined as inappropriate or needing modification.

RESULTS

Of 34 927 children hospitalized on survey days, 12 213 (35.0%) had ≥ 1 active antibiotic order. Among 11 784 patients receiving antibiotics for infectious use, 25.9% were prescribed ≥ 1 suboptimal antibiotic. Of the 17 110 antibiotic orders prescribed for infectious use, 21.0% were considered suboptimal. Most common reasons for inappropriate use were bug-drug mismatch (27.7%), surgical prophylaxis > 24 hours (17.7%), overly broad empiric therapy (11.2%), and unnecessary treatment (11.0%). The majority of recommended modifications were to stop (44.7%) or narrow (19.7%) the drug. ASPs would not have routinely reviewed 46.1% of suboptimal orders.

CONCLUSIONS

Across 32 children's hospitals, approximately 1 in 3 hospitalized children are receiving 1 or more antibiotics at any given time. One-quarter of these children are receiving suboptimal therapy, and nearly half of suboptimal use is not captured by current ASP practices.

Does Intense Sexually Transmitted Infection Screening Cause or Prevent Antimicrobial Resistance in Sexually Transmitted Infections? It Depends on One's Underlying Epistemology. A Viewpoint

Certain authors argue that intensive sexually transmitted infection (STI) screening is a crucial way to reduce STI prevalence and prevent the emergence and spread of antimicrobial resistance (AMR) in STIs. Others argue the opposite: intense screening in high STI prevalence populations has little effect on prevalence and is likely to select for AMR. In this viewpoint, I argue that these radical differences in outlook stem, in part, from different conceptual frameworks of the determinants of STI prevalence and AMR. In the absence of strong evidence from randomized controlled trials, our brains interpret the weaker evidence from other sources in different ways, depending on our underlying epistemologies. To illustrate the argument, I contrast a predominantly biomedical individualist conceptual framework with a more ecological conceptual framework. I argue that if one's conceptual framework is based in biomedical individualism, then one is more likely to think that screening reduces STI prevalence and less likely to appreciate the connection between screening, antimicrobial exposure, and AMR than perspectives grounded in ecological frameworks.

Effect of a Sepsis Screening Algorithm on Care of Children with False-Positive Sepsis Alerts

OBJECTIVES

To determine if implementation of an automated sepsis screening algorithm with low positive predictive value led to inappropriate resource utilization in emergency department (ED) patients as evidenced by an increased proportion of children with false-positive sepsis screens receiving intravenous (IV) antibiotics.

STUDY DESIGN

Retrospective cohort study comparing children <18 years of age presenting to an ED who triggered a false-positive sepsis alert during 2 different 5-month time periods: a silent alert period when alerts were generated but not visible to clinicians and an active alert period when alerts were visible. Primary outcome was the proportion of patients who received IV antibiotics. Secondary outcomes included proportion receiving IV fluid boluses, proportion admitted to the hospital, and ED length of stay (LOS).

RESULTS

Of 1457 patients, 1277 triggered a false-positive sepsis alert in the silent and active alert periods, respectively. In multivariable models, there were no changes in the proportion administered IV antibiotics (27.0% vs 27.6%, aOR 1.1 [0.9,1.3]) or IV fluid boluses (29.7% vs 29.1%, aOR 1.0 [0.8,1.2]). Differences in ED LOS and proportion admitted to the hospital were not significant when controlling for similar changes seen across all ED encounters.

CONCLUSIONS

An automated sepsis screening algorithm did not lead to changes in the proportion receiving IV antibiotics or IV fluid boluses, department LOS, or the proportion admitted to the hospital for patients with false-positive sepsis alerts.

ICU Patients' Antibiotic Exposure and Triazole-Resistance in Invasive Candidiasis: Parallel Analysis of Aggregated and Individual Data

Background: The relationship between antibiotic use and the incidence of triazole-resistant phenotypes of invasive candidiasis (IC) in critically ill patients is unclear. Different methodologies on determining this relationship may yield different results.

Methods: A retrospective multicenter observational analysis was conducted to investigate exposure to antibiotics and the incidence of non-duplicate clinical isolates of Candida spp. resistant to fluconazole, voriconazole, or both during November 2013 to April 2018, using two different methodologies: group-level (time-series analysis) and individual-patient-level (regression analysis and propensity-score adjusting).

Results: Of 393 identified Candida spp. from 388 critically ill patients, there were three phenotypes of IC identified: fluconazole-resistance (FR, 63, 16.0%); voriconazole-resistance (VR, 46, 11.7%); and cross-resistance between fluconazole and voriconazole (CR, 32, 8.1%). Exposure to several antibacterial agents with activity against the anaerobic gastrointestinal flora, especially third-generation cefalosporins (mainly cefoperazone/sulbactam and ceftriaxone), but not triazoles, have an immediate effect (time lag = 0) on subsequent ICU-acquired triazole-resistant IC in the group-level (p < 0.05). When the same patient database was analyzed at the individual-patient-level, we found that exposure to many antifungal agents was significantly associated with triazole-resistance (fluconazole [adjusted odds ratio (aOR) = 2.73] or caspofungin [aOR = 11.32] on FR, voriconazole [aOR = 2.87] on CR). Compared to the mono-triazole-resistant phenotype, CR IC has worse clinical outcomes (14-days mortality) and a higher level of resistance.

Conclusion: Group-level and individual-patient-level analyses of antibiotic-use-versus-resistance relations yielded distinct but valuable results. Antibacterials with antianaerobic activity and antifungals might have “indirect” and “direct” effect on triazole-resistant IC, respectively.

The Governance and Implementation of the National Action Plan on Antimicrobial Resistance in Tanzania: A Qualitative Study

Tanzania launched its first National Action Plan (NAP) on antimicrobial resistance (AMR) in 2017 to reduce the burden of AMR in the country and contribute to the global response. We aimed to analyze the implementation of the NAP on AMR in Tanzania using the governance framework. In-depth interviews were conducted with human and animal health practitioners and national-level policy actors. We adapted Chua's AMR governance framework to analyze the development and implementation of the NAP in Tanzania. Implementation of the NAP has realized several achievements, including: (i) the establishment of a functioning Multi-Sectoral Coordinating Committee for coordinating the implementation of AMR activities; (ii) existence of governance structure; (iii) establishment of human and animal surveillance sites; (iv) creation of AMR awareness in the community and (v) availability of guidelines at the health facility level to ensure AMR stewardship. However, some dimensions of the governance areas, including reporting and feedback mechanisms, accountability, transparency and sustainability of AMR plans, are not effectively implemented. Addressing these challenges should involve strengthening the collaboration of the different sectors involved at different NAP implementation levels by careful planning and coordination, and provision of adequate resources to ensure sustainability.

Distance to primary care facilities and healthcare utilization for preschool children in rural northwestern Burkina Faso: results from a surveillance cohort

Background

Delays in care-seeking for childhood illness may lead to more severe outcomes. We evaluated whether community distance from a primary healthcare facility was associated with decreased healthcare utilization in a rural district of northwestern Burkina Faso.

Methods

We conducted passive surveillance of all government-run primary healthcare facilities in Nouna District, Burkina Faso from March 1 through May 31, 2020. All healthcare visits for children under 5 years of age were recorded on a standardized form for sick children. We recorded the age, sex, and community of residence of the child as well as any diagnoses and treatments administered. We calculated healthcare utilization per 100 child-months by linking the aggregate number of visits at the community level to the community’s population of children under 5 months per a census that was conducted from August 2019 through February 2020. We calculated the distance between each community and its corresponding healthcare facility and assessed the relationship between distance and the rate of healthcare utilization.

Results

In 226 study communities, 12,676 primary healthcare visits were recorded over the three-month period. The median distance between the community and primary healthcare facility was 5.0 km (IQR 2.6 to 6.9 km), and median number of healthcare visits per 100 child-months at the community level was 6.7 (IQR 3.7 to 12.3). The rate of primary healthcare visits declined with increasing distance from clinic (Spearman’s rho − 0.42, 95% CI − 0.54 to − 0.31, P < 0.0001). This relationship was similar for cause-specific clinic visits (including pneumonia, malaria, and diarrhea) and for antibiotic prescriptions.

Conclusions

We documented a distance decay effect between community distance from a primary healthcare facility and the rate of healthcare visits for children under 5. Decreasing distance-related barriers, for example by increasing the number of facilities or targeting outreach to more distant communities, may improve healthcare utilization for young children in similar settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06226-5.

Rates of increase of antibiotic resistance and ambient temperature in Europe: a cross-national analysis of 28 countries between 2000 and 2016

Background

The rapid increase of bacterial antibiotic resistance could soon render our most effective method to address infections obsolete. Factors influencing pathogen resistance prevalence in human populations remain poorly described, though temperature is known to contribute to mechanisms of spread.

Aim

To quantify the role of temperature, spatially and temporally, as a mechanistic modulator of transmission of antibiotic resistant microbes.

Methods

An ecologic analysis was performed on country-level antibiotic resistance prevalence in three common bacterial pathogens across 28 European countries, collectively representing over 4 million tested isolates. Associations of minimum temperature and other predictors with change in antibiotic resistance rates over 17 years (2000–2016) were evaluated with multivariable models. The effects of predictors on the antibiotic resistance rate change across geographies were quantified.

Results

During 2000–2016, for Escherichia coli and Klebsiella pneumoniae, European countries with 10°C warmer ambient minimum temperatures compared to others, experienced more rapid resistance increases across all antibiotic classes. Increases ranged between 0.33%/year (95% CI: 0.2 to 0.5) and 1.2%/year (95% CI: 0.4 to 1.9), even after accounting for recognised resistance drivers including antibiotic consumption and population density. For Staphylococcus aureus a decreasing relationship of −0.4%/year (95% CI:  −0.7 to 0.0) was found for meticillin resistance, reflecting widespread declines in meticillin-resistant S. aureus across Europe over the study period.

Conclusion

We found evidence of a long-term effect of ambient minimum temperature on antibiotic resistance rate increases in Europe. Ambient temperature might considerably influence antibiotic resistance growth rates, and explain geographic differences observed in cross-sectional studies. Rising temperatures globally may hasten resistance spread, complicating mitigation efforts.

Is There a Resistance Threshold for Macrolide Consumption? Positive Evidence from an Ecological Analysis of Resistance Data from Streptococcus pneumoniae, Treponema pallidum, and Mycoplasma genitalium

If we were to keep macrolide consumption below a certain threshold, would this reduce the probability of macrolide resistance emerging? No study that we are aware of has addressed this question. We, therefore, assessed at a country level if there was a macrolide consumption threshold for the selection of a prevalence of macrolide resistance of over 5% in Streptococcus pneumoniae, Treponema pallidum, and Mycoplasma genitalium. In this ecological-level analysis, we found evidence for a macrolide consumption threshold of 1.3 defined daily doses per 1,000 inhabitants per day (DID) for M. genitalium, 1.8 DID for T. pallidum, and 2.3 DID for S. pneumoniae. Our results provide further motivation for macrolide stewardship campaigns that strive to reduce macrolide consumption to levels below at least 2 DID.

The Role of Uniform Meropenem Usage in Acinetobacter baumannii Clone Replacement

The dominant carbapenem resistant Acinetobacter baumannii harboring bla_OXA-23-like carbapenemase was replaced by bla_OXA-40-like carriers in a Hungarian tertiary-care center with high meropenem but relatively low imipenem use. We hypothesized that alterations in antibiotic consumption may have contributed to this switch. Our workgroup previous study examined the relation between resistance spiral and the antibiotic consumption, and the results suggest that the antibiotic usage provoked the increasing resistance in case of A. baumannii. We aimed at measuring the activity of imipenem and meropenem to compare the selection pressure exerted by the different carbapenems in time-kill assays. Strain replacement was confirmed by whole genome sequencing, core-genome multilocus sequence typing (cgMLST), and resistome analysis. Based on results of the time-kill assays, we found a significant difference between two different sequence-types (STs) in case of meropenem, but not in case of imipenem susceptibility. The newly emerged ST636 and ST492 had increased resistance level against meropenem compared to the previously dominant ST2 and ST49. On the other hand, the imipenem and colistin resistance profiles were similar. These results suggest, that the uniform meropenem usage may have contributed to A. baumannii strain replacement in our setting.

One Health drivers of antibacterial resistance: Quantifying the relative impacts of human, animal and environmental use and transmission

Objectives

Antibacterial resistance (ABR) is a major global health security threat, with a disproportionate burden on lower-and middle-income countries (LMICs). It is not understood how 'One Health', where human health is co-dependent on animal health and the environment, might impact the burden of ABR in LMICs. Thailand's 2017 "National Strategic Plan on Antimicrobial Resistance" (NSP-AMR) aims to reduce AMR morbidity by 50% through 20% reductions in human and 30% in animal antibacterial use (ABU). There is a need to understand the implications of such a plan within a One Health perspective.

Methods

A model of ABU, gut colonisation with extended-spectrum beta-lactamase (ESBL)-producing bacteria and transmission was calibrated using estimates of the prevalence of ESBL-producing bacteria in Thailand. This model was used to project the reduction in human ABR over 20 years (2020-2040) for each One Health driver, including individual transmission rates between humans, animals and the environment, and to estimate the long-term impact of the NSP-AMR intervention.

Results

The model predicts that human ABU was the most important factor in reducing the colonisation of humans with resistant bacteria (maximum 65.7-99.7% reduction). The NSP-AMR is projected to reduce human colonisation by 6.0-18.8%, with more ambitious targets (30% reductions in human ABU) increasing this to 8.5-24.9%.

Conclusions

Our model provides a simple framework to explain the mechanisms underpinning ABR, suggesting that future interventions targeting the simultaneous reduction of transmission and ABU would help to control ABR more effectively in Thailand.

Amoxicillin Utilization Pattern at Governmental Hospitals in Eastern Ethiopia

INTRODUCTION

Penicillin is among the highly used antibiotics in most parts of the world, with amoxicillin being the most frequently utilized drug in the category. However, amoxicillin use has been found to deviate from standard treatment guidelines (STGs).

OBJECTIVE

This study aimed to evaluate amoxicillin utilization patterns based on Ethiopian STGs criteria at four governmental hospitals in Harar town: Hiwot Fana Specialized University Hospital, Jugel Hospital, South East Command III Hospital, and Federal Harar Police Hospital in Eastern Ethiopia in 2016.

METHODS

A hospital-based retrospective cross-sectional study was employed using medication records of patients who received amoxicillin in 2016 at four governmental hospitals from May 15 to June 30, 2018. A total of 502 medication records were proportionally allocated based on the ratio of consumption data of each hospital. Simple random sampling was employed to collect the required sample from the sampling frame. The collected data were entered into SPSS version 21 and analyzed using descriptive analysis.

RESULTS

Amoxicillin was used in all age groups, including pregnant and lactating women. The majority (96.2%) of patients were from the outpatient departments. Complete blood count was the most laboratory investigation carried out in 24.9% whereas microbiological culture was not recorded at all. Top three indications include nonspecific upper respiratory tract infections (15.1%), pneumonia (13.5%) and dental problems (10.6%). Non-steroidal anti-inflammatory drugs (56.2%) were frequently co-administered agents. An appropriate utilization was made considering indication, dose, frequency and therapy duration in 23.9% as per the Ethiopian STG. The wrong indication (65.4%) was the prime reason for inappropriateness, followed by dose (14.6%) and duration of therapy (12.2%).

CONCLUSION

Amoxicillin utilization was appropriate in less than a quarter of patients. The wrong indication was the main reason for inappropriateness, predisposing to resistance development. Further studies identifying factors related to misuse and sensitivity tests should be the next steps.

Population-Level Antimicrobial Consumption Is Associated With Decreased Antimicrobial Susceptibility in Neisseria gonorrhoeae in 24 European Countries: An Ecological Analysis

OBJECTIVES

There are substantial variations between different populations in the susceptibility of Neisseria gonorrhoeae to antimicrobials, and the reasons for this are largely unexplored. We aimed to assess whether the population-level consumption of antimicrobials is a contributory factor.

METHODS

Using antimicrobial susceptibility data from 24 countries in the European Gonococcal Antimicrobial Surveillance Programme and antimicrobial consumption data from the IQVIA MIDAS database, we built mixed-effects linear/logistic regression models with country-level cephalosporin, fluoroquinolone, and macrolide consumption (standard doses/1000 population/year) as the explanatory variables (from 2009 to 2015) and 1-year-lagged ceftriaxone, cefixime, azithromycin, and ciprofloxacin geometric mean minimum inhibitory concentrations (MICs) as the outcome variables (from 2010 to 2016).

RESULTS

Positive correlations were found between the consumption of cephalosporins and the geometric mean MICs of ceftriaxone and cefixime (P < .05 for both comparisons). Fluoroquinolone consumption was positively associated with the prevalence of resistance to ciprofloxacin (P < .05).

CONCLUSIONS

Differences in the population-level consumption of particular antimicrobials may contribute to variations in the level of antimicrobial resistance in N. gonorrhoeae in different settings. Further interventions to reduce misuse and overuse of antimicrobials in high-consumption populations and core groups are required.

Building trans-bicyclo[4.4.0]decanes/decenes in complex multifunctional frameworks: the case for antibiotic development

Covering: 2000 to 2020. trans-Bicyclo[4.4.0]decane/decene (such as trans-decalin and trans-octalin)-containing natural products display a wide range of structural diversity and frequently exhibit potent and selective antibacterial activities. With one of the major factors in combatting antibiotic resistance being the discovery of novel scaffolds, the efficient construction of these natural products is an attractive pursuit in the development of novel antibiotics. This highlight aims to provide a critical analysis on how the presence of dense architectural and stereochemical complexity necessitated special strategies in the synthetic pursuits of these natural trans-bicyclo[4.4.0]decane/decene antibiotics.

Optimal dynamic empirical therapy in a health care facility: A Monte-Carlo look-ahead method

BACKGROUND AND OBJECTIVES

Empirical antimicrobial prescription strategies have been proposed to counteract the selection of resistant pathogenic strains. The respective merits of such strategies have been debated. Rather than comparing a finite number of policies, we take an optimization approach and propose a solution to the problem of finding an empirical therapy policy in a health care facility that minimizes the cumulative infected patient-days over a given time horizon.

METHODS

We assume that the parameters of the model are known and that when the policy is implemented, all patients receive the same treatment at a given time. We model the emergence and spread of antimicrobial resistance at the population level with the stochastic version of a compartmental model. The model features two drugs and the possibility of double resistance. Our solution method is a rollout algorithm.

RESULTS

In our example, the optimal policy computed with this method allows to reduce the average cumulative infected patient-days over two years by 22% compared to the best standard therapy. Considering regularity constraints, we could derive a policy with a fixed period and a performance close to that of the optimal policy. The average cumulative infected patient-days over two years obtained with the optimal policy is 6% lower (significantly at the 95% threshold) than that obtained with the fixed period policy.

CONCLUSION

Our results illustrate the performance of a highly flexible solution method that will contribute to the development of implementable empirical therapy policies.

Community Pharmacists' Views of the Enforced Antibiotics Dispensing Law and Its Impact on Oral Antibiotics Sales in Saudi Arabia

Objective(s)

The aim of this study was to explore community pharmacists’ views toward the antibiotics dispensing law that was enforced in May 2018 and bans the sale of antibiotics without a prescription in community pharmacy settings in Saudi Arabia. Moreover, the potential impact of the law enforcement on the sales of oral antibiotics in Saudi Arabia was also explored.

Methods

A questionnaire-based cross-sectional study was conducted between September 2019 and March 2020 in Riyadh, Saudi Arabia. A multistage sampling technique was used to recruit community pharmacists from different districts. Pharmacists who consented to participate and reported practicing prior to the law enforcement were interviewed about their views of the law using a 14-item newly developed questionnaire. The annual sales of oral antibiotics for the years of 2017, 2018, and 2019 were retrieved from the Saudi Food and Drug Authority (SFDA) database.

Results

Two hundred and eighty six pharmacists consented to participate and met the inclusion criteria. After the law enforcement, approximately 51% of the participants reported that the percentage of patients seeking antibiotics without a prescription is less than 25%. Moreover, the majority (87.41%) reported a drop in the sales of antibiotics. Additionally, about 90% of the participants believed that the rate of inappropriate use of antibiotics will decrease as a result of the law enforcement. About 41% of the participants reported that the law has negatively impacted their pharmacies’ profits. The sales of oral antibiotics have seen a 16.6% drop in the year of 2019 as compared to 2017.

Conclusion

The antibiotics dispensing law is favorably perceived among community pharmacists in Saudi Arabia despite some concerns about its impact on their sales. Exploring different business models that delink the profits from the volume of antibiotics sales is necessary for this vital industry to thrive.

Can breastfeeding protect against antimicrobial resistance?

BACKGROUND

The proportion of infections among young children that are antimicrobial-resistant is increasing across the globe. Newborns may be colonized with enteric antimicrobial-resistant pathogens early in life, which is a risk factor for infection-related morbidity and mortality. Breastfeeding is actively promoted worldwide for its beneficial impacts on newborn health and gut health. However, the role of breastfeeding and human milk components in mitigating young children's carriage of antimicrobial-resistant pathogens and antibiotic resistance genes has not been comprehensively explored.

MAIN BODY

Here, we review how the act of breastfeeding, early breastfeeding, and/or human milk components, such as the milk microbiota, secretory IgA, human milk oligosaccharides, antimicrobial peptides, and microRNA -bearing extracellular vesicles, could play a role in preventing the establishment of antimicrobial-resistant pathogens in young children's developing gut microbiomes. We describe findings from recent human studies that support this concept.

CONCLUSION

Given the projected rise in global morbidity and mortality that will stem from antimicrobial-resistant infections, identifying behavioral or nutritional interventions that could decrease children's susceptibility to colonization with antimicrobial-resistant pathogens may be one strategy for protecting their health. We suggest that breastfeeding and human milk supplements deserve greater attention as potential preventive measures in the global effort to combat antimicrobial resistance, particularly in low- and middle-income settings.

The role of "spillover" in antibiotic resistance

Antibiotic use is a key driver of antibiotic resistance. Understanding the quantitative association between antibiotic use and resulting resistance is important for predicting future rates of antibiotic resistance and for designing antibiotic stewardship policy. However, the use-resistance association is complicated by "spillover," in which one population's level of antibiotic use affects another population's level of resistance via the transmission of bacteria between those populations. Spillover is known to have effects at the level of families and hospitals, but it is unclear if spillover is relevant at larger scales. We used mathematical modeling and analysis of observational data to address this question. First, we used dynamical models of antibiotic resistance to predict the effects of spillover. Whereas populations completely isolated from one another do not experience any spillover, we found that if even 1% of interactions are between populations, then spillover may have large consequences: The effect of a change in antibiotic use in one population on antibiotic resistance in that population could be reduced by as much as 50%. Then, we quantified spillover in observational antibiotic use and resistance data from US states and European countries for three pathogen-antibiotic combinations, finding that increased interactions between populations were associated with smaller differences in antibiotic resistance between those populations. Thus, spillover may have an important impact at the level of states and countries, which has ramifications for predicting the future of antibiotic resistance, designing antibiotic resistance stewardship policy, and interpreting stewardship interventions.

Healthcare Challenges and Future Solutions in Dental Practice: Assessing Oral Antibiotic Resistances by Contemporary Point-Of-Care Approaches

Antibiotic resistance poses a global threat, which is being acknowledged at several levels, including research, clinical implementation, regulation, as well as by the World Health Organization. In the field of oral health, however, the issue of antibiotic resistances, as well as of accurate diagnosis, is underrepresented. Oral diseases in general were ranked third in terms of expenditures among the EU-28 member states in 2015. Yet, the diagnosis and patient management of oral infections, in particular, still depend primarily on empiric means. On the contrary, on the global scale, the field of medical infections has more readily adopted the integration of molecular-based systems in the diagnostic, patient management, and antibiotic stewardship workflows. In this perspective review, we emphasize the clinical significance of supporting in the future antibiotic resistance screening in dental practice with novel integrated and point-of-care operating tools that can greatly support the rapid, accurate, and efficient administration of oral antibiotics.

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

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

Interventions for prudent antibiotic use in primary healthcare: an econometric analysis

Background

Rational antibiotic prescribing is crucial to combat antibiotic resistance. Optimal strategies to improve antibiotic use are not known. Strama, the Swedish strategic program against antibiotic resistance, has been successful in reducing antibiotic prescription rates. This study investigates whether two specific interventions directed toward healthcare centers, an informational visit and a self-evaluation meeting, played a role in observed reduction in rates of antibiotic prescriptions in primary healthcare.

Methods

The study was a retrospective, observational, empirical analysis exploiting the variation in the timing of the interventions and considering past prescriptions through use of estimations from dynamic panel data models. Primary healthcare data from 2011 to 2014 were examined. Data were from public and private primary healthcare centers in western Sweden. The key variables were prescription of antibiotics and indicator variables for the two interventions.

Results

The first intervention, an educational information intervention, decreased the number of prescriptions among public healthcare centers, but this effect was only temporary. We found no proof that the second intervention, a self-evaluation meeting at the healthcare center, had an impact on the reduction of prescriptions.

Conclusions

Single educational interventions aimed at influencing rates of antibiotic prescriptions have limited impact. A multifaceted approach is needed in efforts to reduce the use of antibiotics in primary health care.

Strong Environment-Genotype Interactions Determine the Fitness Costs of Antibiotic Resistance In Vitro and in an Insect Model of Infection

The acquisition of antibiotic resistance commonly imposes fitness costs, a reduction in the fitness of bacteria in the absence of drugs. These costs have been quantified primarily using in vitro experiments and a small number of in vivo studies in mice, and it is commonly assumed that these diverse methods are consistent. Here, we used an insect model of infection to compare the fitness costs of antibiotic resistance in vivo to those in vitro Experiments explored diverse mechanisms of resistance in a Gram-positive pathogen, Bacillus thuringiensis, and a Gram-negative intestinal symbiont, Enterobacter cloacae Rifampin resistance in B. thuringiensis showed fitness costs that were typically elevated in vivo, although these were modulated by genotype-environment interactions. In contrast, resistance to cefotaxime via derepression of AmpC β-lactamase in E. cloacae resulted in no detectable costs in vivo or in vitro, while spontaneous resistance to nalidixic acid, and carriage of the IncP plasmid RP4, imposed costs that increased in vivo Overall, fitness costs in vitro were a poor predictor of fitness costs in vivo because of strong genotype-environment interactions throughout this study. Insect infections provide a cheap and accessible means of assessing the fitness consequences of resistance mutations, data that are important for understanding the evolution and spread of resistance. This study emphasizes that the fitness costs imposed by particular mutations or different modes of resistance are extremely variable and that only a subset of these mutations is likely to be prevalent outside the laboratory.

Pharmacists' practices for non-prescribed antibiotic dispensing in Mozambique

Background

Antibiotics are the most frequently used medicines worldwide with most of the countries defining these as prescription-only medicines. Though, dispensing non-prescribed antibiotics represent one of the chief causal factors to the irrational use of antibiotics that paves the way to the development of antimicrobial resistance.

Objective

We aimed at describing the practices and the enablers for non-prescribed antibiotic dispensing in Maputo city, Mozambique.

Methods

A qualitative study was conducted, between October 2018 and March 2019, in nine private pharmacies randomly selected across Maputo city. Eighteen pharmacists were contacted and seventeen enrolled through snowball sampling. In-depth interviews were conducted, audiotaped, and transcribed verbatim. Transcripts were coded and analysed though thematic analysis with guidelines from Braun and Clark. The Consolidated Criteria for Reporting Qualitative Studies (COREQ) checklist by (Tong, 2007) was performed.

Results

Out of seventeen, fifteen pharmacists admitted non-prescribed dispensing of antibiotics. Common antibiotic dispensing practices included; dispensing without prescription, without asking for a brief clinical history of patients, without clear explanation of the appropriate way of administering, without advising on the side effects. Reasons for non-prescribed antibiotic dispensing are linked to patients' behaviour of demanding for non-prescribed antibiotics, to the patients expectations and beliefs on the healing power of antibiotics, to the physicians' prescribing practices. Other reasons included the pressure for profits from the pharmacy owners, the fragile law enforcement, and absence of accountability mechanisms.

Conclusions

The practices of non-prescribed antibiotic dispensing characterize the 'daily life' of the pharmacists. On the one hand, the patient's demand for antibiotics without valid prescriptions, and pharmacist's wish to assist based on their role in the pharmacy, the pressure for profits and on the understanding of the larger forces driving the practices of self-medication with antibiotics - rock. On the other hand, pharmacists are aware of the legal status of antibiotics and the public health consequences of their inappropriate dispensing practices and their professional and ethical responsibility for upholding the law - hard place. Highlighting the role of pharmacists and their skills as health promotion professionals is needed to optimizing antibiotic dispensing and better conservancy in Mozambique.

Informed and uninformed empirical therapy policies

We argue that a proper distinction must be made between informed and uninformed decision making when setting empirical therapy policies, as this allows one to estimate the value of gathering more information about the pathogens and their transmission and thus to set research priorities. We rely on the stochastic version of a compartmental model to describe the spread of an infecting organism in a health care facility and the emergence and spread of resistance to two drugs. We focus on information and uncertainty regarding the parameters of this model. We consider a family of adaptive empirical therapy policies. In the uninformed setting, the best adaptive policy allowsone to reduce the average cumulative infected patient days over 2 years by 39.3% (95% confidence interval (CI), 30.3-48.1%) compared to the combination therapy. Choosing empirical therapy policies while knowing the exact parameter values allows one to further decrease the cumulative infected patient days by 3.9% (95% CI, 2.1-5.8%) on average. In our setting, the benefit of perfect information might be offset by increased drug consumption.

Hand hygiene improvement or antibiotic restriction to control the household transmission of extended-spectrum β-lactamase-producing Escherichia coli: a mathematical modelling study

Background

The best strategy to control ESBL-producing Escherichia coli (ESBL-EC) spread in the community is lacking.

Methods

We developed an individual-based transmission model to evaluate the impact of hand hygiene (HH) improvement and reduction in antibiotic use on the within-household transmission of ESBL-EC. We used data from the literature and incorporated key elements of ESBL-EC transmission such as the frequency and nature of contacts among household members, antibiotic use in the community and hand hygiene behaviour. We introduced in a household a single ESBL-EC colonised person and simulated the transmission dynamics of ESBL-EC over a one-year time horizon.

Results

The probability of ESBL-EC transmission depended on the household composition and the profile of the initial carrier. In the two-person household, the probability of ESBL-EC transmission was 5.3% (95% CI 5.0–5.6) or 6.6% (6.3–6.9) when the index person was a woman or a man, respectively. In a four-person household, the probability of transmission varied from 61.4% (60.9–62.0) to 68.8% (68.3–69.3) and was the highest when the index patient was the baby. Improving HH by 50% reduced the probability of transmission by 33–62%. Antibiotic restriction by 50% reduced the transmission by 2–6%.

Conclusions

The transmission of ESBL-EC is frequent in households and especially those with a baby. Antibiotic reduction had little impact on ESBL-EC. Improvement of hygiene in the community could help prevent transmission of ESBL-EC.

Resident Physician Prescribing Variability Demonstrates Need for Antimicrobial Stewardship in Continuity Clinic: A Pilot Study

BACKGROUND

Inappropriate antimicrobial use is common in the outpatient setting but often goes unaddressed by stewardship education. Residents might benefit from directed stewardship education.

OBJECTIVE

We conducted a needs assessment of resident knowledge, attitudes, and behaviors regarding antibiotic use and stewardship in outpatient continuity clinics.

METHODS

Internal medicine (IM) residents with continuity clinic at Minneapolis Veterans Affairs Health Care System were eligible. Antimicrobial prescriptions and number of visits were extracted from the Computerized Patient Record System (July 1, 2017-March 31, 2018). Antimicrobial rate (prescriptions per 1000 visits) was calculated for each resident. Results from a resident survey that included demographics, attitudes, and case-based multiple-choice knowledge questions were linked by unique identifier to antimicrobial rate.

RESULTS

Prescription and visit data were available for 37 residents. Mean monthly antimicrobial rate was 51 prescriptions per 1000 visits (range 8-239). Surveys were completed by 19 residents (51%). Respondents were 32% female, 32% interns, and 11% international medical graduates. An online resource was most commonly used for prescribing guidance, whereas lectures and small group sessions for residents were rated as the most helpful educational modalities. Many respondents reported being unprepared to perform basic tasks related to antimicrobial stewardship. Median percentage correct was 57% of case-based knowledge questions (interquartile range 50%-71%).

CONCLUSIONS

Antimicrobial rates among IM residents at a VA outpatient continuity clinic are low and vary by provider. Residents agree with key antimicrobial stewardship concepts but lack preparation in tasks related to antimicrobial stewardship. Knowledge regarding antimicrobial prescribing was low.

Why is preventing antibiotic resistance so hard? Analysis of failed resistance management

We describe the case of a patient with pancreatitis followed by intra-abdominal infection in which source control was not achieved. Antimicrobial therapy led to the emergence of resistance in multiple organisms through multiple population dynamics processes. While the initial insult was not due to infection, subsequent infections with resistant organisms contributed to a poor outcome for the patient. Though resistance evolution was a known risk, it was difficult to predict the next organism that would arise in the setting of antibiotic pressure and its resistance profile. This case illustrates the clinical challenge of antibiotic resistance that current approaches cannot readily prevent.

LAY SUMMARY

Why is antibiotic resistance management so complex? Distinct evolutionary processes unfold when antibiotic treatment is initiated that lead, separately and together, to the undesired outcome of antibiotic resistance. This clinical case exemplifies some of those processes and highlights the dire need for evolutionary risk assessments to be incorporated into clinical decision making.

Pneumococcal Carriage and Antibiotic Resistance in Children Younger than 5 Years in Nouna District, Burkina Faso

Increasing antibiotic consumption has been shown to lead to increased antibiotic resistance selection. We evaluated the prevalence of antibiotic resistance in Streptococcus pneumoniae to commonly used antibiotic classes as well as correlations between resistance and antibiotic consumption at the individual and community levels in children aged 0-59 months in Nouna district, Burkina Faso. A population-based sample of 300 children aged 0-59 months was randomly selected from the most recent census in 18 communities in the Nouna Health and Demographic Surveillance Site. Caregivers were interviewed about children's recent antibiotic use, and a nasopharyngeal swab was collected from each child. Nasopharyngeal swabs were processed using standard microbiological methods to determine pneumococcal carriage and resistance. Community-level antibiotic consumption was determined by record review from primary healthcare facilities, which routinely collect prescription data for children aged 0-59 months. Streptococcus pneumoniae was isolated from 101 (35.7%) nasopharyngeal samples. Among positive isolates, co-trimoxazole (75.6%) and tetracycline (69.3%) resistance was the most common, followed by oxacillin (26.7%) and azithromycin (9.9%). Recent antibiotic use was associated with decreased pneumococcal carriage (odds ratio 0.56, 95% CI: 0.33-0.93) at the individual level. There was no statistically significant relationship between antibiotic use and antibiotic resistance at the individual or community levels, although CIs were generally wide. The prevalence of antibiotic resistance to commonly used antibiotics was high in the study area. Expanding antimicrobial resistance surveillance in areas with little population-based data will be important for informing policy related to antibiotic use.

Urban informal settlements as hotspots of antimicrobial resistance and the need to curb environmental transmission

Antimicrobial resistance (AMR) is a growing public health challenge that is expected to disproportionately burden lower- and middle-income countries (LMICs) in the coming decades. Although the contributions of human and veterinary antibiotic misuse to this crisis are well-recognized, environmental transmission (via water, soil or food contaminated with human and animal faeces) has been given less attention as a global driver of AMR, especially in urban informal settlements in LMICs-commonly known as 'shanty towns' or 'slums'. These settlements may be unique hotspots for environmental AMR transmission given: (1) the high density of humans, livestock and vermin living in close proximity; (2) frequent antibiotic misuse; and (3) insufficient drinking water, drainage and sanitation infrastructure. Here, we highlight the need for strategies to disrupt environmental AMR transmission in urban informal settlements. We propose that water and waste infrastructure improvements tailored to these settings should be evaluated for their effectiveness in limiting environmental AMR dissemination, lowering the community-level burden of antimicrobial-resistant infections and preventing antibiotic misuse. We also suggest that additional research is directed towards developing economic and legal incentives for evaluating and implementing water and waste infrastructure in these settings. Given that almost 90% of urban population growth will occur in regions predicted to be most burdened by the AMR crisis, there is an urgent need to build effective, evidence-based policies that could influence massive investments in the built urban environment in LMICs over the next few decades.

Quantifying antibiotic impact on within-patient dynamics of extended-spectrum beta-lactamase resistance

Antibiotic-induced perturbation of the human gut flora is expected to play an important role in mediating the relationship between antibiotic use and the population prevalence of antibiotic resistance in bacteria, but little is known about how antibiotics affect within-host resistance dynamics. Here we develop a data-driven model of the within-host dynamics of extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae. We use blaCTX-M (the most widespread ESBL gene family) and 16S rRNA (a proxy for bacterial load) abundance data from 833 rectal swabs from 133 ESBL-positive patients followed up in a prospective cohort study in three European hospitals. We find that cefuroxime and ceftriaxone are associated with increased blaCTX-M abundance during treatment (21% and 10% daily increase, respectively), while treatment with meropenem, piperacillin-tazobactam, and oral ciprofloxacin is associated with decreased blaCTX-M (8% daily decrease for all). The model predicts that typical antibiotic exposures can have substantial long-term effects on blaCTX-M carriage duration.

Using Genetic Distance from Archived Samples for the Prediction of Antibiotic Resistance in Escherichia coli

The rising rates of antibiotic resistance increasingly compromise empirical treatment. Knowing the antibiotic susceptibility of a pathogen's close genetic relative(s) may improve empirical antibiotic selection. Using genomic and phenotypic data for Escherichia coli isolates from three separate clinically derived databases, we evaluated multiple genomic methods and statistical models for predicting antibiotic susceptibility, focusing on potentially rapidly available information, such as lineage or genetic distance from archived isolates. We applied these methods to derive and validate the prediction of antibiotic susceptibility to common antibiotics. We evaluated 968 separate episodes of suspected and confirmed infection with Escherichia coli from three geographically and temporally separated databases in Ontario, Canada, from 2010 to 2018. Across all approaches, model performance (area under the curve [AUC]) ranges for predicting antibiotic susceptibility were the greatest for ciprofloxacin (AUC, 0.76 to 0.97) and the lowest for trimethoprim-sulfamethoxazole (AUC, 0.51 to 0.80). When a model predicted that an isolate was susceptible, the resulting (posttest) probabilities of susceptibility were sufficient to warrant empirical therapy for most antibiotics (mean, 92%). An approach combining multiple models could permit the use of narrower-spectrum oral agents in 2 out of every 3 patients while maintaining high treatment adequacy (∼90%). Methods based on genetic relatedness to archived samples of E. coli could be used to predict antibiotic resistance and improve antibiotic selection.

Listeria monocytogenes Wall Teichoic Acid Glycosylation Promotes Surface Anchoring of Virulence Factors, Resistance to Antimicrobial Peptides, and Decreased Susceptibility to Antibiotics

The cell wall of Listeria monocytogenes (Lm), a major intracellular foodborne bacterial pathogen, comprises a thick peptidoglycan layer that serves as a scaffold for glycopolymers such as wall teichoic acids (WTAs). WTAs contain non-essential sugar substituents whose absence prevents bacteriophage binding and impacts antigenicity, sensitivity to antimicrobials, and virulence. Here, we demonstrated, for the first time, the triple function of Lm WTA glycosylations in the following: (1) supporting the correct anchoring of major Lm virulence factors at the bacterial surface, namely Ami and InlB; (2) promoting Lm resistance to antimicrobial peptides (AMPs); and (3) decreasing Lm sensitivity to some antibiotics. We showed that while the decoration of WTAs by rhamnose in Lm serovar 1/2a and by galactose in serovar 4b are important for the surface anchoring of Ami and InlB, N-acetylglucosamine in serovar 1/2a and glucose in serovar 4b are dispensable for the surface association of InlB or InlB/Ami. We found that the absence of a single glycosylation only had a slight impact on the sensibility of Lm to AMPs and antibiotics, however the concomitant deficiency of both glycosylations (rhamnose and N-acetylglucosamine in serovar 1/2a, and galactose and glucose in serovar 4b) significantly impaired the Lm capacity to overcome the action of antimicrobials. We propose WTA glycosylation as a broad mechanism used by Lm, not only to properly anchor surface virulence factors, but also to resist AMPs and antibiotics. WTA glycosyltransferases thus emerge as promising drug targets to attenuate the virulence of bacterial pathogens, while increasing their susceptibility to host immune defenses and potentiating the action of antibiotics.