83,296 research outputs found

    Rapid antimicrobial susceptibility testing in patients with bacteraemia due to Enterobacterales: an implementation study

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    AIMS OF THE STUDY: The goal of this descriptive study was to assess the performance as well as the extent of the clinical impact of rapid automated antimicrobial susceptibility testing in patients with bacteraemia due to Enterobacterales. We also aimed to analyse how rapid automated antimicrobial susceptibility testing influences clinical decision-making. METHODS: This single-centre study conducted at the University Hospital of Zurich included data from all consecutive patients with Enterobacterales bacteraemia from November 2019 to October 2020. There was no control group. The primary outcome was the effect of rapid automated antimicrobial susceptibility testing on antibiotic therapy (no adjustment, escalation to a broader-spectrum antibiotic or de-escalation to a narrower-spectrum antibiotic). Rapid automated antimicrobial susceptibility testing results were further compared to susceptibility tests using European Committee on Antimicrobial Susceptibility Testing (EUCAST) standard methods and erroneous results were noted. Additionally, we investigated turnaround times for rapid automated antimicrobial susceptibility testing and routine diagnostic testing. RESULTS: We analysed 106 patients with 116 episodes of bacteraemia due to Enterobacterales, with Escherichia coli and Klebsiella pneumoniae being the most frequent isolates. Almost 8% of pathogens were multidrug resistant. Rapid automated antimicrobial susceptibility testing showed category agreement in 98.4% of all interpretable cases. A significant reduction of more than 20 h in turnaround times could be achieved with rapid automated antimicrobial susceptibility testing compared to the routine diagnostic workflow. In the majority of cases, rapid automated antimicrobial susceptibility testing had no effect, given that the empirical therapy was already correct or circumstances did not allow for de-escalation. In 38.8% of cases, antimicrobial therapy was adjusted, whereas eight cases were de-escalated based on rapid automated antimicrobial susceptibility testing alone. CONCLUSIONS: Rapid automated antimicrobial susceptibility testing may be a valuable and safe way to accelerate diagnosis. In particular, time to suitable therapy can be shortened in cases of incorrect therapy. However, physicians are reluctant to de-escalate antibiotic therapy based on rapid automated antimicrobial susceptibility testing alone, limiting its impact in everyday clinics. To further explore the potential of rapid automated antimicrobial susceptibility testing, a stringent/compulsory antibiotic stewardship programme would be a valuable next step

    Antimicrobial Susceptibility Patterns in Urinary Tract Infections in Dogs (2010-2013).

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    BackgroundUrinary tract infections (UTIs) are common in dogs. The responsible bacterial populations have evolved with increasing resistance to many antimicrobials.ObjectiveTo characterize the antimicrobial susceptibility patterns of canine urinary tract isolates over a 51-month period.AnimalsOne thousand six hundred and thirty-six bacterial isolates from 1,028 dogs.MethodsAerobic bacterial isolate growth and susceptibility data from urine cultures of dogs were identified, retrospectively. Medical records were reviewed to obtain signalment, comorbidities, and antimicrobial use in the previous 30 days. The UTIs were further categorized as uncomplicated, complicated, or pyelonephritis.ResultsCommon bacterial isolates identified were Escherichia coli (52.5%), Staphylococcus spp. (13.6%), and Enterococcus spp. (13.3%). In vitro susceptibility among all isolates varied for commonly prescribed antimicrobials (amoxicillin [59%], amoxicillin/clavulanic acid [76%], cephalexin [66%], enrofloxacin [74%] and trimethoprim-sulfamethoxazole [86%]). For all antimicrobials tested (except aminoglycosides), in vitro susceptibility was higher in uncomplicated versus complicated infections (P < .05). Uncomplicated infection isolate susceptibility rates remained ‚ȧ90% for PO administered antimicrobials. Administration of amoxicillin, doxycycline, and enrofloxacin, but not amoxicillin/clavulanic acid in the previous 30 days was associated with resistance to that antimicrobial. Multidrug resistant isolates of E. coli and Staphylococcus spp. were more common in dogs with complicated than uncomplicated UTIs (36% versus 21%, P < .0001).Conclusions and clinical importanceIn vitro susceptibility was highly variable and no PO administered antimicrobial had >90% efficacy among isolates tested. Multidrug resistance was frequent among isolates tested suggesting that routine culture and susceptibility testing is indicated. Previously prescribed antimicrobials may affect empirical choices made pending susceptibility testing

    Whole-Genome Sequencing and Concordance Between Antimicrobial Susceptibility Genotypes and Phenotypes of Bacterial Isolates Associated with Bovine Respiratory Disease.

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    Extended laboratory culture and antimicrobial susceptibility testing timelines hinder rapid species identification and susceptibility profiling of bacterial pathogens associated with bovine respiratory disease, the most prevalent cause of cattle mortality in the United States. Whole-genome sequencing offers a culture-independent alternative to current bacterial identification methods, but requires a library of bacterial reference genomes for comparison. To contribute new bacterial genome assemblies and evaluate genetic diversity and variation in antimicrobial resistance genotypes, whole-genome sequencing was performed on bovine respiratory disease-associated bacterial isolates (Histophilus somni, Mycoplasma bovis, Mannheimia haemolytica, and Pasteurella multocida) from dairy and beef cattle. One hundred genomically distinct assemblies were added to the NCBI database, doubling the available genomic sequences for these four species. Computer-based methods identified 11 predicted antimicrobial resistance genes in three species, with none being detected in M. bovis While computer-based analysis can identify antibiotic resistance genes within whole-genome sequences (genotype), it may not predict the actual antimicrobial resistance observed in a living organism (phenotype). Antimicrobial susceptibility testing on 64 H. somni, M. haemolytica, and P. multocida isolates had an overall concordance rate between genotype and phenotypic resistance to the associated class of antimicrobials of 72.7% (P < 0.001), showing substantial discordance. Concordance rates varied greatly among different antimicrobial, antibiotic resistance gene, and bacterial species combinations. This suggests that antimicrobial susceptibility phenotypes are needed to complement genomically predicted antibiotic resistance gene genotypes to better understand how the presence of antibiotic resistance genes within a given bacterial species could potentially impact optimal bovine respiratory disease treatment and morbidity/mortality outcomes

    Minimum inhibitory concentration-guided antimicrobial therapy ‚Äď the Achilles heel in the antimicrobial stewardship agenda

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    The global problem of resistance to antimicrobials has resulted in a co-ordinated drive to use antimicrobial agents more responsibly. At a clinical level this is promoted through antimicrobial stewardship which demands appropriate use through optimal drug selection. Many factors play a role in this process of selection, antimicrobial susceptibility and the pharmacodynamics of the drug being two key determinants. Yet the detail provided by current diagnostic antimicrobial susceptibility testing is suboptimal and does not allow for adequate dose optimisation. The minimum inhibitory concentration (MIC) which underlies all antimicrobial susceptibility testing is largely ignored in the decision-making process of optimal drug selection. Understanding and application of MIC-guided antimicrobial therapy is desperately needed if antimicrobial stewardship is to truly fulfil its mandate

    Penicillin Use in Meningococcal Disease Management: Active Bacterial Core Surveillance Sites, 2009.

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    In 2009, in the Active Bacterial Core surveillance sites, penicillin was not commonly used to treat meningococcal disease. This is likely because of inconsistent availability of antimicrobial susceptibility testing and ease of use of third-generation cephalosporins. Consideration of current practices may inform future meningococcal disease management guidelines

    Susceptibility testing and reporting of new antibiotics with a focus on tedizolid: an international working group report

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    Inappropriate use and overuse of antibiotics are among the most important factors in resistance development, and effective antibiotic stewardship measures are needed to optimize outcomes. Selection of appropriate antimicrobials relies on accurate and timely antimicrobial susceptibility testing. However, the availability of clinical breakpoints and in vitro susceptibility testing often lags behind regulatory approval by several years for new antimicrobials. A Working Group of clinical/medical microbiologists from Brazil, Canada, Mexico, Saudi Arabia, Russia and the UK recently examined issues surrounding antimicrobial susceptibility testing for novel antibiotics. While commercially available tests are being developed, potential surrogate antibiotics may be used as marker of susceptibility. Using tedizolid as an example of a new antibiotic, this special report makes recommendations to optimize routine susceptibility reporting

    Antimicrobial Resistance And Molecular Epidemiology Of Escherichia Coli Isolated From Urban And Rural River Systems

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    Antimicrobial resistance (AMR) is an emerging public health issue that threatens the efficacy of antibiotic treatment for bacterial infections and human health. Sources of antimicrobial resistance genes (ARGs) in the environment include wastewater treatment plants and animal feeding operations that discharge waste into waterways, such as rivers and streams. This retrospective descriptive study describes the presence of AMR, and specific ARGs in Escherichia coli isolates from two distinct watersheds, rural and urban, with the use of antimicrobial susceptibility testing, whole-genome sequencing (WGS) to detect ARGs, and multi-locus sequence typing. Antimicrobial susceptibility testing was performed for 143 E. coli isolates, 73 originating from a rural watershed and 70 originating from an urban watershed. E. coli isolates from the rural watershed had a significantly higher prevalence of phenotypic non-susceptibility and ARGs for tetracycline (21.9% vs. 2.9%, p \u3c 0.01) when compared to urban watershed isolates. Based on phenotypic-susceptibility testing, WGS data of 68 isolates were annotated for ARGs. These data were used for the prediction of antimicrobial susceptibility, demonstrating high accuracy for the prediction of non-susceptibility for tetracycline, trimethoprim-sulfamethoxazole, and cephalosporins. WGS multi-locus sequence typing (MLST) yielded 47 sequence types, dominated by ST58 (n=6), ST10 (n=5), and ST155 (n=4). Waterways are important reservoirs and disseminators of antimicrobial-resistant bacteria (ARB) and ARGs. The evaluation and monitoring of AMR and ARGs in aquatic environments will lead to improved health through better prevention and control of E. coli infections

    Recommendations of the Spanish Antibiogram Committee (COESANT) for selecting antimicrobial agents and concentrations for in vitro susceptibility studies using automated systems

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    Automated antimicrobial susceptibility testing devices are widely implemented in clinical microbiology laboratories in Spain, mainly using EUCAST (European Committee on Antimicrobial Susceptibility Testing) breakpoints. In 2007, a group of experts published recommendations for including antimicrobial agents and selecting concentrations in these systems. Under the patronage of the Spanish Antibiogram Committee (Comit√© Espa√Īol del Antibiograma, COESANT) and the Study Group on Mechanisms of Action and Resistance to Antimicrobial Agents (GEMARA) from the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), and aligned with the Spanish National Plan against Antimicrobial Resistance (PRAN), a group of experts have updated this document. The main modifications from the previous version comprise the inclusion of new antimicrobial agents, adaptation of the ranges of concentrations to cover the EUCAST breakpoints and epidemiological cut-off values (ECOFFs), and the inference of new resistance mechanisms. This proposal should be considered by different manufacturers and users when designing new panels or cards. In addition, recommendations for selective reporting are also included. With this approach, the implementation of EUCAST breakpoints will be easier, increasing the quality of antimicrobial susceptibility testing data and their microbiological interpretation. It will also benefit epidemiological surveillance studies as well as the clinical use of antimicrobials aligned with antimicrobial stewardship programs
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