Antimicrobial Resistance of Escherichia coli Urinary Isolates in the Veterans Affairs Health Care System

Real-world utilization of ceftazidime/avibactam among inpatients in the national Veterans Affairs Healthcare System

PURPOSE

Multidrug-resistant (MDR) infections are challenging to treat due to underlying patient conditions, pathogen characteristics, and high antibiotic resistance rates. As newer antibiotic therapies come to market, limited data exist about their real-world utilization.

METHODS

This was a national retrospective cohort study of ceftazidime/avibactam (approved in 2015) utilization among inpatients from the Veterans Affairs (VA) Healthcare System, from 2015 through 2021. Joinpoint regression was used to estimate time trends in utilization.

RESULTS

Ceftazidime/avibactam use increased by 52.3% each year (days of therapy per 1,000 bed days; 95% confidence interval, 12.4%-106.4%). We identified 1,048 unique predominantly male (98.3%) and white (66.2%; Black, 27.7%) patients treated with ceftazidime/avibactam, with a mean (SD) age of 71.5 (11.9) years. The most commonly isolated organisms were Pseudomonas aeruginosa (36.3%; carbapenem resistant, 80.6%; MDR, 65.0%) and Klebsiella species (34.1%; carbapenem resistant, 78.4%; extended-spectrum cephalosporin resistant, 90.7%). Common comorbid conditions included hypertension (74.8%), nervous system disorders (60.2%), diabetes mellitus (48.7%), and cancer (45.1%). Median time to ceftazidime/avibactam initiation from admission was 6 days, with a median of 3 changes in therapy before ceftazidime/avibactam initiation and a subsequent median length of inpatient stay of 14 days (median of 8 days of ceftazidime/avibactam therapy). Treatment heterogeneity was high, both before ceftazidime/avibactam initiation (89.6%) and during ceftazidime/avibactam treatment (85.6%), and common concomitant antibiotics included vancomycin (41.4%), meropenem (24.1%), cefepime (15.2%), and piperacillin/tazobactam (15.2%). The inpatient mortality rate was 23.6%, and 20.8% of patients had a subsequent admission with ceftazidime/avibactam treatment.

CONCLUSION

Utilization of ceftazidime/avibactam increased from 2015 to 2021 in the national VA Healthcare System. Ceftazidime/avibactam was utilized in complex, difficult-to-treat patients, with substantial treatment heterogeneity and variation in the causative organism and culture sites.

Identification of novel inhibitors against Escherichia coli utilizing HisC as a target from histidine biosynthesis pathway

Escherichia coli is a gram-negative bacterial pathogen that poses a significant challenge both clinically and epidemiologically. Large numbers of multi-drug resistant E. coli have emerged in the last decade, because of the selection pressure generated by the inadequate use of antibiotics. Although research to combat antibiotic resistance has been going on extensively but still lags in the rate of development of newer antibiotics. Therefore, newer approaches are required to speed up the rate of discovery of antibiotics. Computational methods for screening of inhibitors have made a significant contribution to the discovery of novel antimicrobials. The present study utilized histidinol-phospho aminotransferase (HisC) as a target. HisC is an enzyme that plays a crucial role in the biosynthesis of histidine and its absence in mammals makes it an attractive drug target. A ZINC library of 5000 natural compounds was screened against HisC (PDB ID: 1FG7) using PyRx and the first 500 hits were selected for secondary screening after sorting the result on the basis of binding score. Fifteen compounds passed the secondary filter ADME and out of these five passed toxicity filters; the best among five hits was selected on the basis of its binding score and inhibition constants. Further, molecular dynamics simulations and free binding were computed of selected five compounds and two natural compounds ZINC402598829 and ZINC31157928 complexed with HisC were found as highly stable. Overall, our results indicated that these natural sources could be used as potential HisC inhibitors.Communicated by Ramaswamy H. Sarma.

Decreasing Antibiotic Resistance Trends Nationally in Gram-Negative Bacteria Across United States Veterans Affairs Medical Centers, 2011-2020

INTRODUCTION

Gram-negative resistance is a well-acknowledged public health threat. Surveillance data can be used to monitor resistance trends and identify strategies to mitigate their threat. The objective of this study was to assess antibiotic resistance trends in Gram-negative bacteria.

METHODS

The first cultures of Pseudomonas aeruginosa, Citrobacter, Escherichia coli, Enterobacter, Klebsiella, Morganella morganii, Proteus mirabilis, and Serratia marcescens per hospitalized patient per month collected from 125 Veterans Affairs Medical Centers (VAMCs) between 2011 to 2020 were included. Time trends of resistance phenotypes (carbapenem, fluoroquinolone, extended-spectrum cephalosporin, multi-drug, and difficult-to-treat) were analyzed with Joinpoint regression to estimate average annual percent changes (AAPC) with 95% confidence intervals and p values. A 2020 antibiogram of reported antibiotic percent susceptibilities was also created to evaluate resistance rates at the beginning of the COVID-19 pandemic.

RESULTS

Among 40 antimicrobial resistance phenotype trends assessed in 494,593 Gram-negative isolates, there were no noted increases; significant decreases were observed in 87.5% (n = 35), including in all P. aeruginosa, Citrobacter, Klebsiella, M. morganii, and S. marcescens phenotypes (p < 0.05). The largest decreases were seen in carbapenem-resistant phenotypes of P. mirabilis, Klebsiella, and M. morganii (AAPCs: - 22.9%, - 20.7%, and - 20.6%, respectively). In 2020, percent susceptibility was over 80% for all organisms tested against aminoglycosides, cefepime, ertapenem, meropenem, ceftazidime-avibactam, ceftolozane-tazobactam, and meropenem-vaborbactam.

CONCLUSION

We observed significant decreases in antibiotic resistance for P. aeruginosa and Enterobacterales over the past decade. According to the 2020 antibiogram, in vitro antimicrobial activity was observed for most treatment options. These results may be related to the robust infection control and antimicrobial stewardship programs instituted nationally among VAMCs.

Prescribing for different antibiotic classes across age groups in the Kaiser Permanente Northern California population in association with influenza incidence, 2010-2018

There is limited information on the volume of antibiotic prescribing that is influenza-associated, resulting from influenza infections and their complications (such as streptococcal pharyngitis). We estimated that for the Kaiser Permanente Northern California population during 2010-2018, 3.4% (2.8%-4%) of all macrolide prescriptions (fills), 2.7% (2.3%-3.2%) of all aminopenicillin prescriptions, 3.1% (2.4%-3.9%) of all 3rd generation cephalosporins prescriptions, 2.2% (1.8%-2.6%) of all protected aminopenicillin prescriptions and 1.3% (1%-1.6%) of all quinolone prescriptions were influenza-associated. The corresponding proportions were higher for select age groups, e.g. 4.3% of macrolide prescribing in ages over 50 years, 5.1% (3.3%-6.8%) of aminopenicillin prescribing in ages 5-17 years and 3.3% (1.9%-4.6%) in ages <5 years was influenza-associated. The relative contribution of influenza to antibiotic prescribing for respiratory diagnoses without a bacterial indication in ages over 5 years was higher than the corresponding relative contribution to prescribing for all diagnoses. Our results suggest a modest benefit of increasing influenza vaccination coverage for reducing prescribing for the five studied antibiotic classes, particularly for macrolides in ages over 50 years and aminopenicillins in ages <18 years, and the potential benefit of other measures to reduce unnecessary antibiotic prescribing for respiratory diagnoses with no bacterial indication, both of which may contribute to the mitigation of antimicrobial resistance.

Development of a Prediction Model for Antibiotic-Resistant Urinary Tract Infections Using Integrated Electronic Health Records from Multiple Clinics in North-Central Florida

INTRODUCTION

Urinary tract infections (UTIs) are common infections for which initial antibiotic treatment decisions are empirically based, often without antibiotic susceptibility testing to evaluate resistance, increasing the risk of inappropriate therapy. We hypothesized that models based on electronic health records (EHR) could assist in the identification of patients at higher risk for antibiotic-resistant UTIs and help guide the selection of antimicrobials in hospital and clinic settings.

METHODS

EHR from multiple centers in North-Central Florida, including patient demographics, previous diagnoses, prescriptions, and antibiotic susceptibility tests, were obtained for 9990 patients diagnosed with a UTI during 2011-2019. Decision trees, boosted logistic regression (BLR), and random forest models were developed to predict resistance to common antibiotics used for UTI management [sulfamethoxazole-trimethoprim (SXT), nitrofurantoin (NIT), ciprofloxacin (CIP)] and multidrug resistance (MDR).

RESULTS

There were 6307 (63.1%) individuals with a UTI caused by a resistant microorganism. Overall, the population was majority female, white, non-Hispanic, and older aged (mean = 60.7 years). The BLR models yielded the highest discriminative ability, as measured by the out-of-bag area under the receiver-operating curve (AUROC), for the resistance outcomes [AUROC = 0.58 (SXT), 0.62 (NIT), 0.64 (CIP), and 0.66 (MDR)]. Variables in the best performing model were sex, history of UTIs, catheterization, renal disease, dementia, hemiplegia/paraplegia, and hypertension.

CONCLUSIONS

The discriminative ability of the prediction models was moderate. Nonetheless, these models based solely on EHR demonstrate utility for the identification of patients at higher risk for resistant infections. These models, in turn, may help guide clinical decision-making on the ordering of urine cultures and decisions regarding empiric therapy for these patients.

Antimicrobial Stewardship in the Pediatric Primary Care Setting

Antibiotics are the most commonly prescribed medications in the pediatric outpatient setting, yet 30% to 50% of these prescriptions are deemed to be unnecessary. Outpatient antimicrobial stewardship is the concerted effort to monitor and improve antibiotic use in the community setting. The best methods of conducting antimicrobial stewardship in the outpatient setting are currently unknown, and an individualized approach is likely needed. In this review, we discuss the importance of, resources for, and research supporting outpatient antimicrobial stewardship and review ways an individual pediatric provider can further steward efforts. [Pediatr Ann. 2022;51(5):e196-e201.].

Evaluating outcomes associated with revised fluoroquinolone breakpoints for Enterobacterales urinary tract infections: A retrospective cohort study

PURPOSE

In 2019, minimum inhibitory concentration (MIC) breakpoints of ciprofloxacin and levofloxacin for Enterobacterales were lowered. This study sought to determine whether there is a correlation between MIC and outcomes in those receiving fluoroquinolones (FQs) for urinary tract infections (UTIs) caused by Enterobacterales pathogens.

METHODS

This was a retrospective study of adult patients treated with ciprofloxacin or levofloxacin for a UTI caused by an Enterobacterales pathogen. Patients were placed into low MIC (ciprofloxacin: ≤ 0.25 mcg/mL; levofloxacin ≤ 0.5 mcg/mL), intermediate MIC (ciprofloxacin: 0.5-2 mcg/mL; levofloxacin: 1-4 mcg/mL), or high MIC groups (ciprofloxacin: > 2 mcg/mL; levofloxacin: > 4 mcg/mL). The primary outcome was UTI recurrence, defined as hospital admission, emergency department or clinic visit due to UTI, or antibiotic prescription within 28 days of FQ initiation.

RESULTS

A total of 1022 patients were included: 887, 75, and 60 with a low, intermediate, and high MIC, respectively. UTI recurrence within 28 days occurred most frequently in the high MIC group (20.5% vs. 25.3% vs. 60%; P < 0.01). Risk factors for UTI recurrence identified by multivariable analysis were those with a high MIC (high vs. low MIC: OR 5.20, 95% CI 2.99-9.05, P < 0.01; high vs. intermediate MIC: OR 4.72, 95%CI 2.22-10.03, P < 0.01), a complicated UTI (OR 1.85, 95% CI 1.35-2.54; P < 0.01), a history of recurrent UTIs (OR 1.84, 95% CI 1.29-2.62; P < 0.01), or a respiratory disorder (OR 1.58, 95% CI 1.04-2.42; P = 0.03).

CONCLUSION

This study supports separate, less stringent FQ MIC breakpoint interpretive criteria for UTIs caused by Enterobacterales pathogens.

Poor clinical outcomes associated with suboptimal antibiotic treatment among older long-term care facility residents with urinary tract infection: a retrospective cohort study

BACKGROUND

Antibiotic use is associated with several antibiotic-related harms in vulnerable, older long-term care (LTC) residents. Suboptimal antibiotic use may also be associated with harms but has not yet been investigated. The aim of this work was to compare rates of poor clinical outcomes among LTC residents with UTI receiving suboptimal versus optimal antibiotic treatment.

METHODS

We conducted a retrospective cohort study among residents with an incident urinary tract infection (UTI) treated in Veterans Affairs LTC units (2013-2018). Potentially suboptimal antibiotic treatment was defined as use of a suboptimal initial antibiotic drug choice, dose frequency, and/or excessive treatment duration. The primary outcome was time to a composite measure of poor clinical outcome, defined as UTI recurrence, acute care hospitalization/emergency department visit, adverse drug event, Clostridioides difficile infection (CDI), or death within 30 days of antibiotic discontinuation. Shared frailty Cox proportional hazard regression models were used to compare the time-to-event between suboptimal and optimal treatment.

RESULTS

Among 19,701 LTC residents with an incident UTI, 64.6% received potentially suboptimal antibiotic treatment and 35.4% experienced a poor clinical outcome. In adjusted analyses, potentially suboptimal antibiotic treatment was associated with a small increased hazard of poor clinical outcome (aHR 1.06, 95% CI 1.01-1.11) as compared with optimal treatment, driven by an increased hazard of CDI (aHR 1.94, 95% CI 1.54-2.44).

CONCLUSION

In this national cohort study, suboptimal antibiotic treatment was associated with a 6% increased risk of the composite measure of poor clinical outcomes, in particular, a 94% increased risk of CDI. Beyond the decision to use antibiotics, clinicians should also consider the potential harms of suboptimal treatment choices with regards to drug type, dose frequency, and duration used.

Discovery of VNRX-7145 (VNRX-5236 Etzadroxil): An Orally Bioavailable β-Lactamase Inhibitor for Enterobacterales Expressing Ambler Class A, C, and D Enzymes

A major antimicrobial resistance mechanism in Gram-negative bacteria is the production of β-lactamase enzymes. The increasing emergence of β-lactamase-producing multi-drug-resistant “superbugs” has resulted in increases in costly hospital Emergency Department (ED) visits and hospitalizations due to the requirement for parenteral antibiotic therapy for infections caused by these difficult-to-treat bacteria. To address the lack of outpatient treatment, we initiated an iterative program combining medicinal chemistry, biochemical testing, microbiological profiling, and evaluation of oral pharmacokinetics. Lead optimization focusing on multiple smaller, more lipophilic active compounds, followed by an exploration of oral bioavailability of a variety of their respective prodrugs, provided 36 (VNRX-7145/VNRX-5236 etzadroxil), the prodrug of the boronic acid-containing β-lactamase inhibitor 5 (VNRX-5236). In vitro and in vivo studies demonstrated that 5 restored the activity of the oral cephalosporin antibiotic ceftibuten against Enterobacterales expressing Ambler class A extended-spectrum β-lactamases, class A carbapenemases, class C cephalosporinases, and class D oxacillinases.

Sociodemographic Inequalities in Urinary Tract Infection in 2 Large California Health Systems

Background

Urinary tract infection (UTI) accounts for a substantial portion of outpatient visits and antibiotic prescriptions in the United States. Few studies have considered sociodemographic factors including low socioeconomic status (SES)—which may increase residential crowding, inappropriate antibiotic prescribing, or comorbidities—as UTI or multidrug-resistant (MDR) UTI risk factors.

Methods

We used 2015–2017 electronic health record data from 2 California health care systems to assess whether 3 sociodemographic factors—use of Medicaid, use of an interpreter, and census tract–level deprivation—were associated with overall UTI or MDR UTI. UTIs resistant to ≥3 antibiotic classes were considered MDR.

Results

Analyses included 601 352 UTI cases, 1 303 455 controls, and 424 977 urinary Escherichia coli isolates from Kaiser Permanente Southern California (KPSC) and Sutter Health in Northern California. The MDR prevalence was 10.4% at KPSC and 12.8% at Sutter Health. All 3 sociodemographic factors (ie, use of Medicaid, using an interpreter, and community deprivation) were associated increased risk of MDR UTI. For example, using an interpreter was associated with a 36% (relative risk [RR], 1.36; 95% CI, 1.31 to 1.40) and 28% (RR, 1.28; 95% CI, 1.22 to 1.34) increased risk of MDR UTI at KPSC and Sutter Health, respectively, adjusted for SES and other potential confounding variables. The 3 sociodemographic factors were only weakly associated with UTI overall.

Conclusions

We found low SES and use of an interpreter to be novel risk factors for MDR UTI in the United States.

Association of Fluoroquinolones With the Risk of Aortic Aneurysm or Aortic Dissection

IMPORTANCE

Previous observational studies have suggested that fluoroquinolones are associated with aortic aneurysm or dissection, but these studies may be subject to confounding by indication or surveillance bias.

OBJECTIVE

To assess the association of fluoroquinolones with risk of aortic aneurysm or aortic dissection (AA/AD) while accounting for potential confounding by fluoroquinolone indication and bias owing to differential surveillance.

DESIGN, SETTING, AND PARTICIPANTS

In an observational cohort study using a US commercial claims database, 2 pairwise 1:1 propensity score-matched cohorts were identified: patients aged 50 years or older with a diagnosis of pneumonia 3 days or less before initiating treatment with a fluoroquinolone or azithromycin and patients aged 50 years or older with a urinary tract infection (UTI) diagnosis 3 days or less before initiating a fluoroquinolone or combined trimethoprim and sulfamethoxazole. Hazard ratios (HRs) and 95% CIs were estimated controlling for 85 baseline confounders. In a secondary analysis, patients receiving fluoroquinolones were compared with those receiving amoxicillin, both with and without considering baseline aortic imaging, to address differences in detection of AA/AD before antibiotic use. Data on patients within the database from January 1, 2003, through September 30, 2015, were analyzed. Data analysis was conducted from July 23, 2019, to July 6, 2020.

MAIN OUTCOMES AND MEASURES

Hospitalization for AA/AD occurring within 60 days following treatment initiation.

RESULTS

After propensity score matching, patient characteristics were well balanced, with 279 554 patients (mean [SD] age, 63.66 [10.93] years; 149 976 women [53.6%]) in the pneumonia cohort and 948 364 patients (mean [SD] age, 62.06 [10.33] years; 823 667 women [86.9%]) in the UTI cohort. Initiators of fluoroquinolones (n = 139 772 pairs in the pneumonia cohort and n = 474 182 pairs in the UTI cohort) had an increased rate of AA/AD compared with initiators of azithromycin (HR, 2.57; 95% CI, 1.36-4.86; incidence, 0.03% for fluoroquinolones vs 0.01% for azithromycin) but no increased rate compared with initiators of combined trimethoprim and sulfamethoxazole (HR, 0.99; 95% CI, 0.62-1.57; incidence, <0.01% in both UTI groups). Secondary analysis using amoxicillin as a comparator (n = 3 976 162 pairs) produced results consistent with those from earlier studies (HR, 1.54; 95% CI, 1.33-1.79; incidence, <0.01% in both groups). Requiring baseline imaging in this cohort (n = 542 649 pairs) to address surveillance bias attenuated the increased rate (HR, 1.13; 95% CI, 0.96-1.33; incidence, 0.06% for fluoroquinolones vs 0.05% for amoxicillin).

CONCLUSIONS AND RELEVANCE

The findings of this nationwide cohort study of adults with pneumonia or UTI suggest an increased relative rate of AA/AD associated with fluoroquinolones within the pneumonia cohort but not within the UTI cohort. In both cohorts, the absolute rate of AA/AD appeared to be low (<0.1%). The increased relative rate observed in the pneumonia cohort may be due to residual confounding or surveillance bias.

Antimicrobial pharmacokinetics and preclinical in vitro models to support optimized treatment approaches for uncomplicated lower urinary tract infections

INTRODUCTION

Urinary tract infections (UTIs) are extremely common. Millions of people, particularly healthy women, are affected worldwide every year. One-in-two women will have a recurrence within 12-months of an initial UTI. Inadequate treatment risks worsening infection leading to acute pyelonephritis, bacteremia and sepsis. In an era of increasing antimicrobial resistance, it is critical to provide optimized antimicrobial treatment.

AREAS COVERED

Literature was searched using PubMed and Google Scholar (up to 06/2020), examining the etiology, diagnosis and oral antimicrobial therapy for uncomplicated UTIs, with emphasis on urinary antimicrobial pharmacokinetics (PK) and the application of dynamic in vitro models for the pharmacodynamic (PD) profiling of pathogen response.

EXPERT OPINION

The majority of antimicrobial agents included in international guidelines were developed decades ago without well-described dose-response relationships. Microbiology laboratories still apply standard diagnostic methodology that has essentially remained unchanged for decades. Furthermore, it is uncertain how relevant standard in vitro susceptibility is for predicting antimicrobial efficacy in urine. In order to optimize UTI treatments, clinicians must exploit the urine-specific PK of antimicrobial agents. Dynamic in vitro models are valuable tools to examine the PK/PD and urodynamic variables associated with UTIs, while informing uropathogen susceptibility reporting, optimized dosing schedules, clinical trials and treatment guidelines.

Oral β-Lactam Antibiotics vs Fluoroquinolones or Trimethoprim-Sulfamethoxazole for Definitive Treatment of Enterobacterales Bacteremia From a Urine Source

Importance

Oral β-lactam antibiotics are traditionally not recommended to treat Enterobacterales bacteremia because of concerns over subtherapeutic serum concentrations, but there is a lack of outcomes data, specifically after initial treatment with parenteral antibiotics. Given the limited data and increasing limitations of fluoroquinolones or trimethoprim-sulfamethoxazole (TMP-SMX), oral β-lactam antibiotics may be a valuable additional treatment option.

Objective

To compare definitive therapy with oral β-lactam antibiotics vs fluoroquinolones or TMP-SMX for Enterobacterales bacteremia from a suspected urine source.

Design, Setting, and Participants

A retrospective cohort study was conducted from January 1, 2007, to September 30, 2015, at 114 Veterans Affairs hospitals among 4089 adults with Escherichia coli, Klebsiella spp, or Proteus spp bacteremia and matching urine culture results. Additional inclusion criteria were receipt of active parenteral antibiotic(s) followed by conversion to an oral antibiotic. Exclusion criteria were previous Enterobacterales bacteremia, urologic abscess, or chronic prostatitis. Data were analyzed from April 15, 2019, to July 26, 2020.

Exposures

Conversion of therapy to an oral β-lactam antibiotic vs fluoroquinolones or TMP-SMX after 1 to 5 days of parenteral antibiotics.

Main Outcomes and Measures

The main outcome was a composite of either 30-day all-cause mortality or 30-day recurrent bacteremia. Propensity-based overlap weights were used to adjust for differences between groups. Log binomial regression models were used to estimate adjusted relative risks (aRRs) and adjusted risk differences (aRDs).

Results

Of the 4089 eligible patients (3731 men [91.2%]; median age, 71 years [interquartile range, 63-81 years]), 955 received an oral β-lactam antibiotic, and 3134 received fluoroquinolones or TMP-SMX. The primary outcome occurred for 42 patients (4.4%) who received β-lactam antibiotics and 94 patients (3.0%) who received fluoroquinolones or TMP-SMX (aRD, 0.99% [95% CI, -0.42% to 2.40%]; aRR, 1.31 [95% CI, 0.87-1.95]). Mortality rates were 3.0% (n = 29) for patients receiving β-lactam antibiotics vs 2.6% (n = 82) for those receiving fluoroquinolones or TMP-SMX (aRD, 0.06% [95% CI, -1.13% to 1.26%]; aRR, 1.02 [95% CI, 0.67-1.56]). Recurrent bacteremia rates were 1.5% (n = 14) among those receiving β-lactam antibiotics vs 0.4% (n = 12) among those receiving fluoroquinolones or TMP-SMX (aRD, 1.03% [95% CI, 0.24%-1.82%]; aRR, 3.43 [95% CI, 0.42-27.90]).

Conclusions and Relevance

In this cohort study of adults with E coli, Klebsiella spp, or Proteus spp bacteremia from a suspected urine source, the relative risk of recurrent bacteremia was not significantly higher with β-lactam antibiotics compared with fluoroquinolones or TMP-SMX, and the absolute risk and risk difference were small (ie, <3%). No significant difference in mortality was observed. Oral β-lactam antibiotics may be a reasonable step-down treatment option, primarily when alternative options are limited by resistance or adverse effects. Further study is needed because statistical power was limited owing to a low number of recurrent bacteremia events.

Enzyme-Activated Nitric Oxide-Releasing Composite Material for Antibacterial Activity Against Escherichia coli

Bacterial infections occurring on medical devices are incredibly difficult to treat, highlighting the urgency for progress in developing antibiotics and antibacterial materials. This work describes the preparation of an antibacterial prodrug polymer composite material for use as an antibacterial coating for medical devices to prevent infections. Polyvinyl chloride and polyurethane films are prepared containing a bacterial nitroreductase enzyme-activated diazeniumdiolate that releases nitric oxide (NO), a known potent antimicrobial agent. Characterization of the surface of the composite materials by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDS) reveals that the surface of the materials is composed of high amounts of nitrogen due to incorporation of the NO donor compound, up to 13.2% nitrogen on the surface of the 2.5% w/v diazeniumdiolate composite. NO release from the composite films is observed only after metabolism by a bacterial nitroreductase enzyme isolated from E. coli, demonstrating the prodrug nature of the polymer composite materials. Antibacterial efficacy experiments resulted in up to a 66% reduction in E. coli after exposure to the diazeniumdiolate-composite materials. This work details the first illustration of an antibacterial enzyme-activated NO-releasing polymer, a material with potential application as a medical device coating to prevent device-associated infections and improve patient outcomes.

Management of Urinary Tract Infections in Direct to Consumer Telemedicine

BACKGROUND

Urinary tract infections (UTI) are a common reason for seeking care via direct to consumer (DTC) telemedicine, yet patterns of care, including antibiotic prescribing, have not been reported.

OBJECTIVE

To describe management of UTI in a large nationwide DTC telemedicine platform.

DESIGN

Cross-sectional observational study.

PARTICIPANTS

Patients seeking care for or diagnosed with UTI via DTC telemedicine between July 2016 and July 2018.

MAIN MEASURES

Patient measures included age, sex, geographic region, satisfaction with care, and patient-reported call reason. High-risk patients were defined as males, patients over 65 years, or those diagnosed with pyelonephritis. Physician measures included specialty and geographic region. Antibiotic prescription was assessed overall and by antibiotic type. Variation in antibiotic prescriptions was assessed by patient and physician factors, including geographic region of both parties.

KEY RESULTS

Of the 20,600 patients diagnosed with a UTI during the study period, 96% were female. Most (84%) stated their call reason was a UTI. Overall, 94% of UTI patients received an antibiotic; 56% got nitrofurantoin, 29% got trimethoprim-sulfamethoxazole, and 10% got a quinolone. Receipt of an antibiotic was associated with higher satisfaction with care (p < 0.001). While nitrofurantoin was the most common antibiotic for all physician regions, antibiotic type varied by physician region. Of the 6% of the study population defined as high risk, 69% received an antibiotic: 72% of males, 91% of women over 65, and 21% of patients diagnosed with pyelonephritis.

CONCLUSIONS

Management of UTI via DTC telemedicine appears to be appropriate for average-risk patients, and most are able to self-diagnose. Most patients received guideline-concordant care, but over half of high-risk patients received antibiotics. DTC telemedicine offers convenient, low-cost care that is generally appropriate. Efforts should be made to ensure high-risk patients get proper follow-up.

The relation between prescribing of different antibiotics and rates of mortality with sepsis in US adults

BACKGROUND

Antibiotic use contributes to the rates of sepsis and the associated mortality, particularly through lack of clearance of resistant infections following antibiotic treatment. At the same time, there is limited information on the effects of prescribing of some antibiotics vs. others on subsequent sepsis and sepsis-related mortality.

METHODS

We used a multivariable mixed-effects model to relate state-specific rates of outpatient prescribing overall for oral fluoroquinolones, penicillins, macrolides, and cephalosporins between 2014 and 2015 to state-specific rates of mortality with sepsis (ICD-10 codes A40-41 present as either underlying or contributing causes of death on a death certificate) in different age groups of US adults between 2014 and 2015, adjusting for additional covariates and random effects associated with the ten US Health and Human Services (HHS) regions.

RESULTS

Increase in the rate of prescribing of oral penicillins by 1 annual dose per 1000 state residents was associated with increases in annual rates of mortality with sepsis of 0.95 (95% CI (0.02,1.88)) per 100,000 persons aged 75-84y, and of 2.97 (0.72,5.22) per 100,000 persons aged 85 + y. Additionally, the percent of individuals aged 50-64y lacking health insurance, as well as the percent of individuals aged 65-84y who are African-American were associated with rates of mortality with sepsis in the corresponding age groups.

CONCLUSIONS

Our results suggest that prescribing of penicillins is associated with rates of mortality with sepsis in older US adults. Those results, as well as the related epidemiological data suggest that replacement of certain antibiotics, particularly penicillins in the treatment of different syndromes should be considered with the aim of reducing the rates of severe outcomes, including mortality related to bacterial infections.

The burden of antimicrobial resistance among urinary tract isolates of Escherichia coli in the United States in 2017

Urinary tract infections (UTIs) caused by Escherichia coli have been historically managed with oral antibiotics including the cephalosporins, fluoroquinolones and trimethoprim-sulfamethoxazole. The use of these agents is being compromised by the increase in extended spectrum β-lactamase (ESBL)-producing organisms, mostly caused by the emergence and clonal expansion of E. coli multilocus sequence typing (ST) 131. In addition, ESBL isolates show co-resistance to many of oral agents. Management of UTIs caused by ESBL and fluoroquinolone-resistant organisms is becoming increasingly challenging to treat outside of the hospital setting with clinicians having to resort to intravenous agents. The aim of this study was to assess the prevalence of ESBL phenotypes and genotypes among UTI isolates of E. coli collected in the US during 2017 as well as the impact of co-resistance to oral agents such as the fluoroquinolones and trimethoprim-sulfamethoxazole. The national prevalence of ESBL phenotypes of E. coli was 15.7% and was geographically distributed across all nine Census regions. Levofloxacin and trimethoprim-sulfamethoxazole-resistance rates were ≥ 24% among all isolates and this co-resistance phenotype was considerably higher among isolates showing an ESBL phenotype (≥ 59.2%) and carrying bla_CTX-M-15 (≥ 69.5%). The agents with the highest potency against UTI isolates of E. coli, including ESBL isolates showing cross-resistance across oral agents, were the intravenous carbapenems. The results of this study indicate that new oral options with the spectrum and potency similar to the intravenous carbapenems would address a significant unmet need for the treatment of UTIs in an era of emergence and clonal expansion of ESBL isolates resistant to several classes of antimicrobial agents, including oral options.

Antibiotic Resistance Among Uropathogenic Escherichia coli

Urinary tract infections (UTIs) belong to the most common community-acquired and nosocomial infections. A main etiological factor of UTIs is uropathogenic Escherichia coli (UPEC). This review describes the current state of knowledge on the resistance of UPEC to antibiotics recommended for the treatment of UTIs based on the available literature data. Nitrofurantoin and fosfomycin are recommended as first-line therapy in the treatment of uncomplicated cystitis, and the resistance to these antimicrobial agents remains low between UPEC. Recently, in many countries, the increasing resistance is observed to trimethoprim-sulfamethoxazole, which is widely used as the first-line antimicrobial in the treatment of uncomplicated UTIs. In European countries, the resistance of UPEC to this antimicrobial agent ranges from 14.6% to 60%. The widespread use of fluoroquinolones (FQs), especially ciprofloxacin, in the outpatients is the cause of a continuous increase in resistance to these drugs. The resistance of UPEC to FQs is significantly higher in developing countries (55.5–85.5%) than in developed countries (5.1–32.0%). Amoxicillin-clavulanic acid is recommended as first line-therapy for pyelonephritis or complicated UTI. Resistance rates of UPEC to amoxicillin-clavulanic acid are regionally variable. In European countries the level of resistance to this antimicrobial ranges from 5.3% (Germany) to 37.6% (France). Increasing rates of UPEC resistance to antimicrobials indicate that careful monitoring of their use for UTI treatment is necessary.

MarR family proteins are important regulators of clinically relevant antibiotic resistance

There has been a rapid spread of multidrug-resistant (MDR) bacteria across the world. MDR efflux transporters are an important mechanism of antibiotic resistance in many pathogens among both Gram positive and Gram negative bacteria. These pumps can recognize a variety of chemically and structurally different compounds, including innate and clinically administered antibiotics. Intriguingly, these efflux pumps are often regulated by transcription factors that themselves bind a diverse set of substrates thereby allowing them to regulate the expression of their cognate MDR efflux pumps. One significant family of such transcription factors is the Multiple antibiotic resistance Repressor (MarR) family. Members of this family are well conserved across different bacterial species and in some cases are known to regulate vital bacterial functions. This review focusses on the role of MarR family transcriptional factors in antibiotic resistance within a select group of clinically relevant pathogens.

Prediction of trimethoprim/sulfamethoxazole resistance in community-onset urinary tract infections

OBJECTIVES

This study aimed to predict trimethoprim/sulfamethoxazole (SXT) resistance in patients with community-onset urinary tract infection (UTI) due to Enterobacteriaceae based on patient-specific risk factors.

METHODS

This was a retrospective case-control study in Prisma Health facilities in central South Carolina, USA, including three community hospitals, affiliated emergency departments and ambulatory clinics, including adult patients with community-onset UTI due to Enterobacteriaceae (1 April 2015 to 29 February 2016). Multivariate logistic regression was used to examine risk factors for SXT resistance.

RESULTS

Among 351 unique patients with community-onset UTI, 71 (20.2%) had SXT-resistant Enterobacteriaceae urinary isolates. Overall, median age was 64 years and 252 (71.8%) were female. A multivariate model identified prior urinary infection/colonisation with SXT-resistant Enterobacteriaceae (OR=8.58, 95% CI 3.92-18.81; P<0.001) and SXT use within past 12 months (OR=2.58, 95% CI 1.13-5.89; P=0.02) as predictors of SXT resistance among urinary isolates. Most patients with UTI (285; 81.2%) had no risk factors for SXT resistance. SXT resistance rates increased from 13% in the absence of risk factors to 31% in patients with prior SXT use, 66% in those with prior urinary infection/colonisation with SXT-resistant Enterobacteriaceae and 73% in the presence of both risk factors.

CONCLUSION

SXT resistance in Enterobacteriaceae urinary isolates may be predicted based on prior urine culture results and SXT use within the previous year. Utilisation of a patient-specific antibiogram may allow empirical SXT use in patients with community-onset UTI in the absence of risk factors for resistance.

Treatment of urinary tract infections in the era of antimicrobial resistance and new antimicrobial agents

Urinary tract infections (UTIs) caused by antibiotic-resistant Gram-negative bacteria are a growing concern due to limited treatment options. Knowledge of the common uropathogens in addition to local susceptibility patterns is essential in determining appropriate empiric antibiotic therapy of UTIs. The recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam. High rates of resistance for trimethoprim-sulfamethoxazole and ciprofloxacin preclude their use as empiric treatment of UTIs in several communities, particularly if patients who were recently exposed to them or in patients who are at risk of infections with extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriales. Second-line options include oral cephalosporins such as cephalexin or cefixime, fluoroquinolones and β-lactams, such as amoxicillin-clavulanate. Current treatment options for UTIs due to AmpC- β -lactamase-producing Enterobacteriales include nitrofurantoin, fosfomycin, pivmecillinam, fluoroquinolones, cefepime, piperacillin-tazobactam and carbapenems. Treatment oral options for UTIs due to ESBLs-E coli include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin while pivmecillinam, fosfomycin, finafloxacin, and sitafloxacin are treatment oral options for ESBLs- Klebsiella pneumoniae. Parenteral treatment options for UTIs due to ESBLs-producing Enterobacteriales include piperacillin-tazobactam (for ESBL-E coli only), carbapenems including meropenem/vaborbactam, imipenem/cilastatin-relebactam, and sulopenem, ceftazidime-avibactam, ceftolozane-tazobactam, aminoglycosides including plazomicin, cefiderocol, fosfomycin, sitafloxacin, and finafloxacin. Ceftazidime-avibactam, meropenem/vaborbactam, imipenem/cilastatin-relebactam, colistin, fosfomycin, aztreonam and ceftazidime-avibactam, aztreonam and amoxicillin-clavulanate, aminoglycosides including plazomicin, cefiderocol, tigecycline are treatment options for UTIs caused by carbapenem-resistant Enterobacteriales (CRE). Treatment options for UTIs caused by multidrug resistant (MDR)-Pseudomonas spp. include fluoroquinolones, ceftazidime, cefepime, piperacillin-tazobactam, carbapenems including imipenem-cilastatin/relebactam, meropenem, and fosfomycin, ceftolozane-tazobactam, ceftazidime-avibactam, aminoglycosides including plazomicin, aztreonam and ceftazidime-avibactam, cefiderocol, and colistin. It is important to use the new antimicrobials wisely for treatment of UTIs caused by MDR-organisms to avoid resistance development.

Antibacterial and Antifungal Activity of Novel Synthesized Neodymium-Substituted Cobalt Ferrite Nanoparticles for Biomedical Application

Neodymium (Nd)-substituted cobalt ferrite nanoparticles (NPs), i.e., CoNdxFe2−xO4 (0.0 ≤ x ≤ 0.2) NPs, were synthesized by the sonochemical method. The compositional characterization was done by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). Antistaphylococcal activity was found to be enhanced, i.e., survival rate was 50%, 45%, 40%, and 30% with the increase in the ratio of Nd (0.0 ≤ x ≤ 0.2), whereas anticandidal activity was found efficient, i.e., 9%, 20%, 22%, and 40% survival rate at all the four ratios. The morphogenesis studies indicated that the synthesized metal–ligand, improves the antimicrobial capacity by binding them strongly to the microbial walls. To the best of our knowledge, this is the first report which demonstrates the series of CoNdxFe2−xO4 (0.0 ≤ x ≤ 0.2) NPs being active towards Staphylococcus aureus and Candida albicans and encourages its potential candidature for pharmaceutical and biomedical purposes.

Temocillin against Enterobacteriaceae isolates from community-acquired urinary tract infections: low rate of resistance and good accuracy of routine susceptibility testing methods

Background

Temocillin is an old 'revived' antibiotic that may play an important role in the treatment of febrile urinary tract infection (UTI). Data regarding its activity against current Enterobacteriaceae isolates as well as the performance of routine susceptibility testing methods are, however, scarce.

Objectives

To determine the MICs of temocillin for Enterobacteriaceae strains reflecting the current epidemiology and to analyse the accuracy of three commercial methods.

Methods

Enterobacteriaceae isolates causing community-acquired UTI were prospectively collected from September 2015 to January 2017 in two French centres. Temocillin MIC was determined by agar dilution (AD) as the reference method and then compared with: (i) susceptibility testing by disc diffusion; (ii) MIC determination by Etest; and (iii) MIC estimation by the Vitek 2 automated system.

Results

A total of 762 Enterobacteriaceae were analysed comprising 658 (86.4%) Escherichia coli and 37 (4.9%) ESBL-producing isolates. Susceptibility rate assessed by AD was 99.6% according to the 8 mg/L clinical breakpoint and was significantly lower against the ESBL-producing isolates than the non-ESBL-producing isolates (94.6% versus 99.9%, P < 0.01). The MIC50 and MIC90 for the total set were 3 and 6 mg/L, respectively. According to the 8 mg/L clinical breakpoint, the major error rate was <1% for disc diffusion and Etest, and significantly higher for Vitek 2 (4.3%, P < 0.01), but still low. No very major error was noticed.

Conclusions

Temocillin showed a high level of activity against Enterobacteriaceae from community-acquired UTI and good to excellent reliability of routine methods for susceptibility testing in such a setting.

Levels of outpatient prescribing for four major antibiotic classes and rates of septicemia hospitalization in adults in different US states - a statistical analysis

BACKGROUND

Rates of sepsis/septicemia hospitalization in the US have risen significantly during recent years. Antibiotic resistance and use may contribute to those rates through various mechanisms, including lack of clearance of resistant infections following antibiotic treatment, with some of those infections subsequently devolving into sepsis. At the same time, there is limited information on the effect of prescribing of certain antibiotics vs. others on the rates of septicemia and sepsis-related hospitalizations and mortality.

METHODS

We used multivariable linear regression to relate state-specific rates of outpatient prescribing overall for oral fluoroquinolones, penicillins, macrolides, and cephalosporins between 2011 and 2012 to state-specific rates of septicemia hospitalization (ICD-9 codes 038.xx present anywhere on a discharge diagnosis) in each of the following age groups of adults: (18-49y, 50-64y, 65-74y, 75-84y, 85 + y) reported to the Healthcare Cost and Utilization Project (HCUP) between 2011 and 2012, adjusting for additional covariates, and random effects associated with the ten US Health and Human Services (HHS) regions.

RESULTS

Increase in the rate of prescribing of oral penicillins by 1 annual dose per 1000 state residents was associated with increases in annual septicemia hospitalization rates of 0.19 (95% CI (0.02,0.37)) per 10,000 persons aged 50-64y, of 0.48(0.12,0.84) per 10,000 persons aged 65-74y, and of 0.81(0.17,1.40) per 10,000 persons aged 74-84y. Increase by 1 in the percent of African Americans among state residents in a given age group was associated with increases in annual septicemia hospitalization rates of 2.3(0.32,4.2) per 10,000 persons aged 75-84y, and of 5.3(1.1,9.5) per 10,000 persons aged over 85y. Average minimal daily temperature was positively associated with septicemia hospitalization rates in persons aged 18-49y, 50-64y, 75-84y and over 85y.

CONCLUSIONS

Our results suggest positive associations between the rates of prescribing for penicillins and the rates of hospitalization with septicemia in US adults aged 50-84y. Further studies are needed to better understand the potential effect of antibiotic replacement in the treatment of various syndromes, including the potential impact of the recent US FDA guidelines on restriction of fluoroquinolone use, as well as the potential effect of changes in the practices for prescribing of penicillins on the rates of sepsis-related hospitalization and mortality.

Antimicrobial resistance in nephrology

The prevalence of antimicrobial resistance among many common bacterial pathogens is increasing. The emergence and global dissemination of these antibiotic-resistant bacteria (ARB) is fuelled by antibiotic selection pressure, inter-organism transmission of resistance determinants, suboptimal infection prevention practices and increasing ease and frequency of international travel, among other factors. Patients with chronic kidney disease, particularly those with end-stage renal disease who require dialysis and/or kidney transplantation, have some of the highest rates of colonization and infection with ARB worldwide. These ARB include methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp. and several multidrug-resistant Gram-negative organisms. Antimicrobial resistance limits treatment options and increases the risk of infection-related morbidity and mortality. Several new antibiotic agents with activity against some of the most common ARB have been developed, but resistance to these agents is already emerging and highlights the dire need for new treatment options as well as consistent implementation and improvement of basic infection prevention practices. Clinicians involved in the care of patients with renal disease must be familiar with the local epidemiology of ARB, remain vigilant for the emergence of novel resistance patterns and adhere strictly to practices proven to prevent transmission of ARB and other pathogens.

Antimicrobial resistance prevalence, rates of hospitalization with septicemia and rates of mortality with sepsis in adults in different US states

OBJECTIVES

Rates of hospitalization with sepsis/septicemia and associated mortality in the US have risen significantly during the last two decades. Antibiotic resistance may contribute to the rates of sepsis-related outcomes through lack of clearance of bacterial infections following antibiotic treatment during different stages of infection. However, there is limited information about the relationship between prevalence of resistance to various antibiotics in different bacteria and rates of sepsis-related outcomes.

METHODS

For different age groups of adults (18-49y, 50-64y, 65-74y, 75-84y, 85+y) and combinations of antibiotics/bacteria, we evaluated associations between state-specific prevalence (percentage) of resistant samples for a given combination of antibiotics/bacteria among catheter-associated urinary tract infections (CAUTIs) in the CDC Antibiotic Resistance Patient Safety Atlas data between 2011-2014, and rates of hospitalization with septicemia (ICD-9 codes 038.xx present on the discharge diagnosis) reported to the Healthcare Cost and Utilization Project (HCUP), as well as rates of mortality with sepsis (ICD-10 codes A40-41.xx present on death certificate).

RESULTS

Among the different combinations of antibiotics/bacteria, prevalence of resistance to fluoroquinolones in Escherichia coli had the strongest association with septicemia hospitalization rates for individuals aged over 50y, and with sepsis mortality rates for individuals aged 18-84y. There were several positive correlations between prevalence of resistance for different combinations of antibiotics/bacteria and septicemia hospitalization/sepsis mortality rates in adults.

CONCLUSIONS

These findings, and those from work on the relationship between antibiotic use and sepsis rates, support the association between use of/resistance to certain antibiotics and rates of sepsis-related outcomes, indicating the potential utility of antibiotic replacement.

Geographic Mapping of Escherichia coli Susceptibility To Develop a Novel Clinical Decision Support Tool

Antimicrobial resistance (AMR) varies regionally. This study longitudinally maps Escherichia coli susceptibility leveraging Wisconsin antibiograms (n = 202) collected from 2009, 2013, and 2015 to inform the development of a novel clinical decision support tool. Spatial interpolation methods were tested with E. coli susceptibilities to create geographic AMR visualizations and to estimate susceptibility in areas without AMR data. These visualizations and an interactive mapping tool, the AMR Tracker, provide a proof of concept for empirical antibiotic treatment decisions.

A rapid and simple detection method for phenotypic antimicrobial resistance in Escherichia coli by loop-mediated isothermal amplification

PURPOSE

In infectious disease therapy, administration of adequate antimicrobial agents is essential for preventing the emergence and spread of resistant bacteria. However, conventional antimicrobial susceptibility testing (AST), based on bacterial growth, is time consuming; therefore, a rapid, simple assay is needed for the timely selection of appropriate antibiotics in clinical laboratories. Here, we established a simple, cost-effective, time-saving and highly sensitive AST assay based on loop-mediated isothermal amplification (LAMP).

METHODOLOGY

The targeted bacteria were cultivated for a short period with or without antibiotic before the LAMP reaction. The time to detect a positive reaction with LAMP was used to generate a threshold time (Tt) value, and subtraction of the Tt value for an antibiotic-free sample from the Tt value in an antibiotic-exposed sample generated the ΔTt value, which was used as a marker of antimicrobial susceptibility. The ΔTt value generated using the LAMP-based assay simply and quickly detected antimicrobial resistance in clinical Escherichia coli isolates.

RESULTS

Detection of susceptibility to levofloxacin using the ΔTt value perfectly matched with the results of the conventional assay. In addition, the sensitivity and specificity for the detection of ampicillin, trimethoprim-sulfamethoxazole and fosfomycin resistance were 100 %, 93.8 %, 100 % and 80.0 %, 93.3 %, 97.6 %, respectively.

CONCLUSION

These results showed that this LAMP-based AST has high sensitivity and specificity for detecting resistant strains and a significant time advantage compared with the conventional method.

Stopping the effective non-fluoroquinolone antibiotics at day 7 vs continuing until day 14 in adults with acute pyelonephritis requiring hospitalization: A randomized non-inferiority trial

Objective

To evaluate whether stopping the effective antibiotic treatment following clinical improvement at Day 7 (Truncated treatment) would be non-inferior to continued treatment until Day 14 (Continued treatment) in patients with acute pyelonephritis (APN) requiring hospitalization treated with non-fluoroquinolone (non-FQ) antibiotics.

Methods

Hospitalized adult men and non-pregnant women with culture-confirmed APN were eligible for participation after they had clinically improved following empirical or culture-guided treatment with intravenous non-FQ antibiotic(s). We excluded patients with severe sepsis, abscesses, prostatitis, recurrent or catheter-associated urinary tract infection, or urinary tract obstruction. We randomized eligible patients on Day 7 of effective treatment and assessed them at Weeks 1 and 6 after treatment completion. The primary outcome was retreatment for recurrent urinary tract infection. The prespecified non-inferiority margin was 15%.

Results

Between March 17, 2015 and August 22, 2016, we randomly allocated 54 patients—27 patients in each arm. Twenty-four (44%) patients were male, and 26 (48%) had diabetes mellitus. Escherichia coli was the most common urinary isolate (47 [87%] patients); 36 (78%) were resistant to ciprofloxacin. In all, 41 (76%) patients received amikacin-based treatment. At the end of 6 weeks, no patient in the truncated treatment arm required retreatment, whereas 1 patient in the continued treatment arm was retreated. Difference (90% CI) in retreatment was −3.7% (−15.01% to 6.15%). Upper bound of the difference (6.15%) was below the prespecified limit, establishing non-inferiority of truncated treatment. Asymptomatic bacteriuria at Week 6 was similar between the two arms (3/24 vs. 3/26; P = 1.0). Patients in the truncated treatment arm had significantly shorter hospital stay (8 [7–10] vs. 14 [14–15] days; P < 0.001) and less antibiotic consumption per patient (8.4 ± 2.8 vs. 17.4 ± 8.3 DDDs; P < 0.001).

Conclusion

Stopping the effective non-FQ antibiotics following clinical improvement at Day 7 is non-inferior to continued treatment until Day 14 in selected patients with APN requiring hospitalization.

Trial registration

Clinical Trials Registry-India; CTRI/2016/04/006810.

Top Questions in Uncomplicated, Non-Staphylococcus aureus Bacteremia

The Infectious Diseases Society of America infection-specific guidelines provide limited guidance on the management of focal infections complicated by secondary bacteremias. We address the following 3 commonly encountered questions and management considerations regarding uncomplicated bacteremia not due to Staphylococcus aureus: the role and choice of oral antibiotics focusing on oral beta-lactams, the shortest effective duration of therapy, and the role of repeat blood cultures.