A systematic review investigating the use of microbiology outcome measures in randomized controlled trials evaluating antimicrobial stewardship interventions published between 2011 and 2021

Introduction Antimicrobial stewardship interventions (ASIs) aim to reduce the emergence of antimicrobial resistance. We sought to systematically evaluate how microbiological outcomes have been handled and analysed in randomized controlled trials (RCTs) evaluating ASIs. Methods We searched PubMed and Embase from 2011–21. Studies were selected if they were RCTs evaluating ASIs. A narrative synthesis approach was taken, identifying whether the study reported any microbiological data (bacterial genus/species; bacterial colony counts; prevalence of bacterial, microbiologically defined infections; and antibiotic susceptibility, measured pre-randomization or post-randomization in one arm only) or outcomes (post-randomization data compared between arms). Studies with or without microbiological data/outcomes were summarized in terms of study characteristics, methods of reporting and analysis of these outcomes. Results We identified 117 studies, with 34 (29.1%) collecting microbiological data and 18 (15.4%) reporting microbiological outcomes. Most studies with microbiological outcomes were conducted in secondary care (12/18, 66.7%) and targeted adult populations (14/18, 77.8%), and the intervention involved biomarker-guided rapid diagnostic testing (7/18, 38.9%). The overall quality of reporting and analysing microbiological outcomes was low and inconsistent. The selected study population in analyses and methods of handling missing data were unclear. Conclusions This review demonstrates that the quality of handling and reporting microbiological outcomes in RCTs of ASIs was low. The lack of consistency and clarity made it difficult to compare the findings across studies, limiting policy- and clinical decision-making. Therefore, there is a clear need for the development of guidance for handling microbiological outcomes in RCTs and adopting appropriate methods to evaluate these data carefully

Global prevalence of antibiotic resistance in paediatric urinary tract infections caused by <i>Escherichia coli</i> and association with routine use of antibiotics in primary care:a systematic review and meta-analysis

Objectives To systematically review studies investigating the prevalence of antibiotic resistance in urinary tract infections caused by Escherichia coli in children and, when appropriate, to meta-analyse the relation between previous antibiotics prescribed in primary care and resistance. Design and data analysis Systematic review and meta-analysis. Pooled percentage prevalence of resistance to the most commonly used antibiotics in children in primary care, stratified by the OECD (Organisation for Economic Co-operation and Development) status of the study country. Random effects meta-analysis was used to quantify the association between previous exposure to antibiotics in primary care and resistance. Data sources Observational and experimental studies identified through Medline, Embase, Cochrane, and ISI Web of Knowledge databases, searched for articles published up to October 2015. Eligibility criteria for selecting studies Studies were eligible if they investigated and reported resistance in community acquired urinary tract infection in children and young people aged 0-17. Electronic searches with MeSH terms and text words identified 3115 papers. Two independent reviewers assessed study quality and performed data extraction. Results 58 observational studies investigated 77 783 E coli isolates in urine. In studies from OECD countries, the pooled prevalence of resistance was 53.4% (95% confidence interval 46.0% to 60.8%) for ampicillin, 23.6% (13.9% to 32.3%) for trimethoprim, 8.2% (7.9% to 9.6%) for co-amoxiclav, and 2.1% (0.8 to 4.4%) for ciprofloxacin; nitrofurantoin was the lowest at 1.3% (0.8% to 1.7%). Resistance in studies in countries outside the OECD was significantly higher: 79.8% (73.0% to 87.7%) for ampicillin, 60.3% (40.9% to 79.0%) for co-amoxiclav, 26.8% (11.1% to 43.0%) for ciprofloxacin, and 17.0% (9.8% to 24.2%) for nitrofurantoin. There was evidence that bacterial isolates from the urinary tract from individual children who had received previous prescriptions for antibiotics in primary care were more likely to be resistant to antibiotics, and this increased risk could persist for up to six months (odds ratio 13.23, 95% confidence interval 7.84 to 22.31). Conclusions Prevalence of resistance to commonly prescribed antibiotics in primary care in children with urinary tract infections caused by E coli is high, particularly in countries outside the OECD, where one possible explanation is the availability of antibiotics over the counter. This could render some antibiotics ineffective as first line treatments for urinary tract infection. Routine use of antibiotics in primary care contributes to antimicrobial resistance in children, which can persist for up to six months after treatment

Comparison of risk factors for, and prevalence of, antibiotic resistance in contaminating and pathogenic urinary Escherichia coli in children in primary care: prospective cohort study

Background All-cause antibiotic prescribing affects bowel flora antimicrobial susceptibility, and may increase risk of urinary autoinoculation with antibiotic-resistant microbes. However, little is known about relative prevalence of, or risk factors for, antimicrobial resistance among potentially pathogenic microbes thought to be contaminating and infecting urine. Methods Secondary analysis of 824 children under 5 years of age consulting in primary care for an acute illness and their Escherichia coli isolates cultured at ≥103 cfu/mL fromthe Diagnosis of Urinary Tract infection in Young children (DUTY) study. Multivariable logistic regression investigating risk factors for resistance to amoxicillin, co-amoxiclav, cefalexin, ciprofloxacin, trimethoprim, nitrofurantoin and cefpodoxime in microbes meeting the laboratory criteria for urinary tract infection: ‘pathogens’ (>105 cfu/mL, n=79) and ‘contaminants’ (103 to 105 cfu/mL, n=745). Results Forty-three percent of E. coli were resistant to at least one tested antibiotic, with resistance highest to amoxicillin (49.37% pathogenic versus 37.32% contaminant, P=0.04), trimethoprim (27.85% versus 16.52%, P=0.01) and co-amoxiclav (16.46% versus 21.48%, P=0.30). Multidrug resistance (to ≥3 antibiotic groups) was present in 17.07% of pathogens and 30.13% of contaminants (P=0.04). No isolates were resistant to nitrofurantoin. Recent (0–3months) exposure to antibiotics was associated with resistance in both pathogens (aOR: 1.10, 95% CI: 1.01–4.39) and contaminants (1.69, 1.09–2.67). Conclusions Prevalence of resistance (including multidrug) was high, but there was no consistent relationship between isolate pathogen/contamination status and resistance. Recent all-cause antibiotic prescribing increased the probability of antimicrobial resistance in both pathogenic and contaminating urinary E. coli in children in primary care.</p

Rapid detection of IMP, NDM, VIM, KPC and OXA-48-like carbapenemases from enterobacteriales and gram-negative non-fermenter bacteria by real-time PCR and melt-curve analysis

Carbapenemase-producing microorganisms are increasingly isolated and often associated with treatment failures and outbreaks. The need for reliable and timely detection and/or confirmation of carbapenemase production is paramount; therefore, a real-time PCR assay targeting IMP, NDM, VIM, KPC and OXA-48-like carbapenemases was designed and validated. All available allele variants of the above carbapenemases were downloaded from the Beta-Lactamase DataBase (http://bldb.eu/), aligned with Clustal Omega and primers designed using Primer-BLAST. Real-time PCR monoplexes were optimized for the QuantStudio 6-Flex (Applied Biosystems) using the PowerUp SYBR Green Master Mix (Life Technologies) and validated using a panel of 204 characterised strains carrying a wide range of beta-lactamases, sometimes in combination. Melt-curve analysis was used to confirm positive results. The in silico approach allowed primers to be designed in conserved regions of the KPC and NDM alignments, while three primer sets for IMP and two for VIM were necessary to ensure amplification of the different variants. One primer set was designed for OXA-48-like; however, it is unlikely to detect all variants. Expected results were obtained for all 204 tested strains, with 100% sensitivity and specificity. Melt-curve analysis showed consistent Tm results for KPC, NDM, and OXA-48-like; differences were instead noted for IMP and VIM as likely consequence of higher variability in the PCR target regions. Inhibition was not observed. The assay is rapid, easy to perform and implement. It enables unequivocal detection of IMP, NDM, VIM, KPC and OXA-48-like carbapenemases even when more than one type is present simultaneously

Evaluation of the Effectiveness of Common Hospital Hand Disinfectants Against Methicillin-Resistant Staphylococcus aureus, Glycopeptide-Intermediates, S aureus, and Heterogeneous Glycopeptide-Intermediate S. aureus

Background. The presence of methicillin‐resistant Staphylococcus aureus (MRSA) and glycopeptide‐intermediate S. aureus (GISA) in hospitals poses a significant challenge to hospital infection control teams. The use of disinfectants for both surface and hand cleaning is an essential part of the infection control measures. Objective. To evaluate the effectiveness of common hospital hand disinfectants against MRSA, GISA, and heterogeneous GISA (hGISA). Methods. For methicillin‐susceptible S. aureus (MSSA), MRSA, GISA, and hGISA, the levels of susceptibility to hand disinfectants and their active ingredients were determined. Suspension tests were performed on commercial handwashing products. Results. Minimum inhibitory concentrations (MICs) of 2‐propanol, chlorhexidine, and hexachlorophene were similar for all phenotypes. The MICs of cetrimide and triclosan were higher for the MRSA, GISA, and hGISA strains than for the MSSA strain. The MICs for the chlorhexidine‐containing agents Hibisol and Hibiscrub (AstraZeneca) and for the propanol‐containing agent Sterillium (Medline) were 1–2‐fold lower for the MSSA strains than for the MRSA, GISA, and hGISA strains. Suspension tests showed that the GISA and hGISA strains were less susceptible to the triclosan‐containing agent Aquasept (SSL) than were the MRSA and MSSA strains, with resistance increasing with glycopeptide resistance. Products containing Betadine (Purdue) were more effective against the GISA and hGISA strains than against the MRSA and MSSA strains, especially after the strain was exposed to the product for 30 seconds. Conclusions. Using the EN 1040 standard criteria for the performance of disinfectants, we determined that all agents, except 50% Aquasept for hGISA and 0.33% hexachlorophene for GISA, performed effectively. However, the GISA and hGISA strains were less susceptible to triclosan‐containing products, compared with the MRSA stains, but were more susceptible to products containing Betadine

Vancomycin Susceptibility within Methicillin-resistant Staphylococcus aureus Lineages

Methicillin-resistant Staphylococcus aureus (MRSA) with reduced vancomycin susceptibility (VISA, vancomycin-intermediate S. aureus) has been reported from many countries. Whether resistance is evolving regularly in different genetic backgrounds or in a single clone with a genetic predisposition, as early results suggest, is unclear. We have studied 101 MRSA with reduced vancomycin susceptibility from nine countries by multilocus sequence typing (MLST) and characterization of SCCmec (staphylococcal chromosomal cassette mec) and agr (accessory gene regulator). We found nine genotypes by MLST, with isolates within all five major hospital MRSA lineages. Most isolates (88/101) belonged to two of the earliest MRSA clones that have global prevalence. Our results show that reduced susceptibility to vancomycin has emerged in many successful epidemic lineages with no clear clonal disposition. Increasing antimicrobial resistance in genetically distinct pandemic clones may lead to MRSA infections that will become increasingly difficult to treat

Multicenter clinical evaluation of Etest meropenem-vaborbactam (bioMérieux) for susceptibility testing of Enterobacterales (Enterobacteriaceae) and Pseudomonas aeruginosa

Meropenem-vaborbactam (MEV) is a novel carbapenem-beta-lactamase inhibitor combination antibiotic approved by the U.S. Food and Drug Administration (FDA) for treatment of complicated urinary tract infections, including pyelonephritis, in adults. In this study, we evaluated the performance of Etest MEV (bioMérieux, Marcy l\u27Etoile, France) compared to that of broth microdilution for 62

Gold standard susceptibility testing of fosfomycin in Staphylococcus aureus and Enterobacterales using a new agar dilution panel

Abstract Objectives Many clinical laboratories have difficulty in routinely performing in vitro fosfomycin susceptibility testing using the agar dilution (AD) method, considered to be the gold standard method. The objective of our work was to evaluate a rapid commercial fosfomycin agar dilution panel against clinical Staphylococcus aureus and Enterobacterales strains, in two different centres located in Italy and in the UK. Methods A total of 99 Enterobacterales (mostly Escherichia coli and Klebsiella pneumoniae) and 80 S. aureus clinical isolates was used to evaluate the commercial device, a 12-well panel containing fosfomycin incorporated into CA-MH agar supplemented with 25 mg/L of glucose-6-phosphate (Liofilchem S.r.l., Roseto degli Abruzzi, Italy). Testing was performed in two centres (Italy and UK) and kit results were compared against the gold standard in-house AD MIC method. Results According to the EUCAST breakpoints, fosfomycin inhibited 61% of the S. aureus strains, and 76% of the Enterobacterales isolates tested by the AD reference method. There was a Categorical Agreement (CA) of 100% and an Essential Agreement (EA) of 91.25% for S. aureus; while the Enterobacterales strains showed a CA of 94% and an EA of 97%. No evaluation errors were observed among S. aureus, while 5% Major Error and 1% Very Major Error were observed for the Enterobacterales. Conclusions Our results confirmed the feasibility of determining fosfomycin susceptibility using a commercial AD panel as a routine substitution for the AD test. The few differences observed were only in strains with MICs around the breakpoint used

Phenylalanyl tRNA synthetase (PheRS) substrate mimics: design, synthesis, molecular dynamics and antimicrobial evaluation

Antimicrobial resistance is a very challenging medical issue and identifying novel antimicrobial targets is one of the means to overcome this challenge. Phenylalanyl tRNA synthetase (PheRS) is a promising antimicrobial target owing to its unique structure and the possibility of selectivity in the design of inhibitors. Sixteen novel benzimidazole based compounds (5a–b), (6a–e), (7a–d), (9a–e) and three N,N-dimethyl-7-deazapurine based compounds (16a–c) were designed to mimic the natural substrate of PheRS, phenylalanyl adenylate (Phe-AMP), that was examined through flexible alignment. The compounds were successfully synthesised chemically in two schemes using 4 to 6-steps synthetic pathways, and evaluated against a panel of five microorganisms with the best activity observed against Enterococcus faecalis. To further investigate the designed compounds, a homology model of E. faecalis PheRS was generated, and PheRS-ligand complexes obtained through computational docking. The PheRS–ligand complexes were subjected to molecular dynamics simulations and computational binding affinity studies. As a conclusion, and using data from the computational studies compound 9e, containing the (2-naphthyl)-L-alanine and benzimidazole moieties, was identified as optimal with respect to occupancy of the active site and binding interactions within the phenylalanine and adenosine binding pockets