46 research outputs found
Re: 'Critical factors in the recovery of pathogenic microorganisms in blood' by Wilson et al
No full textFosfomycin Susceptibility Testing Using Commercial Agar Dilution Test
No full textThe reference standard for fosfomycin antimicrobial susceptibility testing (AST) is agar dilution, but it is laborious and is not routinely used in diagnostic microbiology. In this study, we evaluated the performance of a ready-to-use commercially available agar dilution kit for fosfomycin AST (Liofilchem Diagnostics). We compared this kit with the reference standard agar dilution, performed according to the Clinical & Laboratory Standards Institute (CLSI) in 229 clinical isolates. The isolates were selected to represent both Gram-positive and Gram-negative microorganisms, with various MIC values. It consisted of 43 enterococci (E. faecalis n = 16, E. faecium n = 27), 13 methicillin-resistant S. aureus (MRSA), 118 Enterobacterales (Escherichia coli n = 94, Klebsiella pneumoniae n = 20, and Enterobacter cloacae complex n = 4), 55 Pseudomonas aeruginosa, and three ATCC isolates. Using CLSI breakpoints for enterococci for oral treatment of urinary tract infections, European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints for intravenous dosing for Enterobacterales and Staphylococci, and epidemiological cutoff value for P. aeruginosa, the essential agreement was 87.5%, and 99.6% after discrepancy resolution. There was no very major error, and 1.9% major error before, and 0.9% major error after resolution of discrepancies. The commercial test showed 100% reproducibility. In conclusion, in comparison to the reference standard, the ready-to-use commercially available agar dilution kit for fosfomycin AST showed excellent performance
Thirteen years of antibiotic susceptibility surveillance of Pseudomonas aeruginosa from intensive care units and urology services in the Netherlands
No full textThe purpose of this study was the evaluation of trends in the antimicrobial resistance of Pseudomonas aeruginosa from intensive care unit (ICU) patients and urology patients in the Netherlands. From 1998 to 2010, 1,927 consecutive P. aeruginosa isolates from ICU (n = 1,393) and urology service patients (n = 534) of 14 university and referral hospitals all over the Netherlands were collected and their susceptibility to relevant antibiotics was determined according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Over time, a significant upward trend in the resistance of P. aeruginosa strains collected from ICUs to piperacillin (1.2 % to 10.6 %, p = 0.0175), piperacillin-tazobactam (1.2 % to 12.1 %, p = 0.0008), ceftazidime (1.2 % to 7.8 %, p = 0.0064), cefepime (4.8 % to 6.4 %, p = 0.0166), imipenem (6 % to 19.1 %, p < 0.0001), meropenem (8.3 % to 17 %, p = 0.0022) and ciprofloxacin (13.1 % to 31.2 %, p = 0.0024) was observed, as was the prevalence of multi-resistance (1.2 % to 8.5 %, p = 0.0002). For P. aeruginosa isolates from the urology services, the resistance to imipenem increased (4.1 % to 7.8 %, p = 0.0006) and to ciprofloxacin it decreased (22.4 % to 18.8 %, p = 0.025). Like in other countries, in the Netherlands, an increase in multi-resistant Gram-negatives is observed, suggesting the presence and dissemination of several mechanisms of resistance. Our findings emphasise the importance of local surveillance for the setting up of local antibiotic guidelines and to support optimal empiric therapy. With the observed increase in multi-resistance, the direct testing of alternative antibiotics like polymyxins and fosfomycin is essential. Our data also illustrate the importance of adequate outbreak control measures
Antimicrobial Effect Of Visible Blue Light Used In A Minimally Invasive Intramedullary Fracture Stabilization System
No full textThe accuracy of four commercial broth microdilution tests in the determination of the minimum inhibitory concentration of colistin
No full textColistin is considered as one of the last-resort antibiotics and reliable antimicrobial susceptibility testing is therefore crucial. The reference standard for AST according to EUCAST and CLSI is broth microdilution (BMD). However, BMD is labor intensive to perform. Commercial antimicrobial susceptibility tests derived from BMD method are available. We investigated the performance of four different commercial tests: Sensititre™, SensiTest™ Colistin, Micronaut MIC Strip Colistin and UMIC Colistin using 70 clinical isolates (half of them was deemed by VITEK2 as resistant), including isolates from cystic fibrosis patients and mcr-1 bearing isolates. We used two reference standards: BMD and composite MIC as determined by all four tests. Sensititre™ had essential agreement (EA, defined as minimum inhibitory concentration within ± 1 dilution) of 87% and 89% compared to BMD and composite reference standard, respectively. For SensiTest™, the EA’s were 93% and 90%. For UMIC, 87% and 90%, and for Micronaut, 83% and 84%. All four tests demonstrated categorical agreement (CA) above 90%. CA for SensiTest™ and Micronaut was both 96%, UMIC 94%, and Sensititre™ 93%. All tests were reproducible as tested in two quality control isolates. In conclusion, in clinical isolates from a large referral center, the four commercial tests for determination of colistin minimum inhibitory concentrations showed acceptable performance
Pseudomonas aeruginosa antimicrobial susceptibility profiles, resistance mechanisms and international clonal lineages: update from ESGARS-ESCMID/ISARPAE Group.
No full textScope: Pseudomonas aeruginosa, a ubiquitous opportunistic pathogen considered one of the paradigms of antimicrobial resistance, is among the main causes of hospital-acquired and chronic infections associated with significant morbidity and mortality. This growing threat results from the extraordinary capacity of P. aeruginosa to develop antimicrobial resistance through chromosomal mutations, the increasing prevalence of transferable resistance determinants (such as the carbapenemases and the extended spectrum β-lactamases), and the global expansion of epidemic lineages. The general objective of this initiative is to provide a comprehensive update of P. aeruginosa resistance mechanisms, especially for the extensively drug-resistant (XDR)/difficult to treat resistance (DTR) international high-risk epidemic lineages, and how the recently approved β-lactams and β-lactam/β-lactamase inhibitor combinations may affect resistance mechanisms and the definition of susceptibility profiles. Methods: To address this challenge, the European Study Group for Antimicrobial Resistance Surveillance (ESGARS) from the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) launched the "Improving Surveillance of Antibiotic-Resistant Pseudomonas aeruginosa in Europe" (ISARPAE) initiative in 2022, supported by the Joint programming initiative on antimicrobial resistance (JPIAMR) network call and included a panel of over 40 researchers from 18 European Countries. Thus, an ESGARS-ISARPAE position paper was designed and the final version agreed after four rounds of revision and discussion by all panel members. Questions addressed in the position paper: To provide an update on (i) the emerging resistance mechanisms to classical and novel antipseudomonal agents, with a particular focus on β-lactams, (ii) the susceptibility profiles associated with the most relevant β-lactam resistance mechanisms, (iii) the impact of the novel agents and resistance mechanisms on the definitions of resistance profiles and (iv) the globally expanding XDR/DTR high-risk lineages and their association with transferable resistance mechanisms. Implication: The evidence presented herein can be used for coordinated epidemiological surveillance and decision-making at the European and global level
Evaluating the Clinical Relevance of Routine Sonication for Periprosthetic Hip or Knee Joint Infection Diagnosis
No full textPeriprosthetic joint infection (PJI) is a serious complication after joint arthroplasty. PJI screening and conventional cultures may be inconclusive. Sonication fluid culturing stands out as a valuable adjunct technique for PJI diagnosis. This study aims to determine the clinical relevance of routine sonication for all (a)septic revisions. All patients who underwent (partial) hip or knee revision arthroplasty between 2012 and 2021 were retrospectively reviewed. We formed three groups based on the European Bone and Joint Society PJI criteria: infection confirmed, likely, and unlikely. We analyzed clinical, laboratory, and radiological screening. Sensitivity and specificity were calculated for synovial fluid (preoperative), tissue, and sonication fluid cultures. We determined the clinical relevance of sonication as the percentage of patients for whom sonication confirmed PJI; 429 patients who underwent (partial) revision of hip or knee arthroplasty were included. Sensitivity and specificity were 69% and 99% for synovial fluid cultures, 76% and 92% for tissue cultures, and 80% and 89% for sonication fluid cultures, respectively. Sonication fluid cultures improved tissue culture sensitivity and specificity to 83% and 99%, respectively. In 11% of PJIs, sonication fluid cultures were decisive for diagnosis. This is applicable to acute and chronic infections. Sonication fluid cultures enhanced the sensitivity and specificity of PJI diagnostics. In 11% of PJI cases, causative pathogens were confirmed by sonication fluid culture results. Sonication fluid culture should be performed in all revision arthroplasties.</p
Risk for re-revision and type of antibiotic-loaded bone cement in hip or knee arthroplasty revisions: report of the Dutch Arthroplasty Register
No full textBackground and purpose: High-dose dual antibiotic-loaded bone cement (ALBC) may reduce the risk of revision after total hip and knee replacements. The aim of our study therefore was to determine the risk of re-revision following first time aseptic hip or knee revision using single versus dual ALBC.
Patients and methods: Patients from the Dutch Arthroplasty Register treated from 2007 to 2018 with first time cemented aseptic hip (n = 2,529) or knee revisions (n = 7,124) were incorporated into 2 datasets. The primary endpoint of this observational cohort study was subsequent all-cause re-revision. Multivariable Cox proportional hazard and competing risk was analyzed for both groups.
Results: There was no difference in re-revision rate (any reason) with single versus dual ALBC (hazard ratio 1.06, 95% confidence interval [CI] 0.83–1.35 for hip and 0.93, CI 0.80–1.07 for knee revisions). The 10-year crude cumulative re-revision rate also showed no differences for single versus dual ALBC use. The crude cumulative 7-year THA re-revision and 9-year TKA re-revision rates did not show any difference in implant survival for common cement types used.
Conclusion: We could not confirm the potential benefit of using dual ALBC compared with single ALBC for aseptic hip and knee revisions
Efficacy of single and multiple oral doses of fosfomycin against Pseudomonas aeruginosa urinary tract infections in a dynamic in vitro bladder infection model
No full textWe used a dynamic bladder infection in vitro model with synthetic human urine (SHU) to examine fosfomycin exposures to effectively kill, or prevent emergence of resistance, among Pseudomonas aeruginosa isolates. Methods: Dynamic urinary fosfomycin concentrations after 3 g oral fosfomycin were simulated, comparing single and multiple (daily for 7 days) doses. Pharmacodynamic response of 16 P. aeruginosa (MIC range 1 to >1024 mg/L) were examined. Baseline disc diffusion susceptibility, broth microdilution MIC and detection of heteroresistance were assessed. Pathogen kill and emergence of resistance over 72 h following a single dose, and over 216 h following daily dosing for 7 days, were investigated. The fAUC 0-24 /MIC associated with stasis and 1, 2 and 3log 10 kill were determined. Results: Pre-exposure high-level resistant (HLR) subpopulations were detected in 11/16 isolates after drug-free incubation in the bladder infection model. Five of 16 isolates had >2log 10 kill after single dose, reducing to 2/16 after seven doses. Post-exposure HLR amplification occurred in 8/16 isolates following a single dose and in 11/16 isolates after seven doses. Baseline MIC ≥8mg/L with an HLR subpopulation predicted post-exposure emergence of resistance following the multiple doses. A PK/PD target of fAUC 0-24 /MIC >5000 was associated with 3log 10 kill at 72 h and 7 day-stasis. Conclusions: Simulated treatment of P. aeruginosa urinary tract infections with oral fosfomycin was ineffective, despite exposure to high urinary concentrations and repeated daily doses for 7 days. Emergence of resistance was observed in the majority of isolates and worsened following prolonged therapy. Detection of a baseline resistant subpopulation predicted treatment failure. © 2020 The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved
