Journal of Clinical Microbiology最新文献

{"title":"Evaluation of the cobas MTB and MTB-RIF/INH assay in clinical samples for the detection of <i>Mycobacterium tuberculosis</i> in respiratory specimens.","authors":"Ulrich Eigner, Jasmin Köffer, Ulrike Betz, Janina Koglin, Elvira Richter","doi":"10.1128/jcm.01959-24","DOIUrl":"10.1128/jcm.01959-24","url":null,"abstract":"<p><p>The aim of this study was to evaluate the performance of the automated cobas MTB-Real-Time PCR assay for the rapid direct detection of <i>Mycobacterium tuberculosis</i> complex (MTBC) in clinical specimens and the ability of the cobas MTB-RIF/INH assay to correctly detect drug resistance to rifampin (RIF) and isoniazid (INH). The PCR assays were set up on the automated Cobas 6800 system, and the results were compared to liquid culture using BACTEC mycobacteria growth indicator tubes 960 TB system as the gold standard and line probe assays or sequencing results. A total of 500 N-acetyl-L-cysteine/sodium hydroxide (NALC-NaOH)-processed sputum samples were tested with the respective methods. The performance of MTBC detection in pulmonary specimens showed 91.8% sensitivity and 99.3% specificity in comparison to culture. The sensitivity for acid-fast bacteria (AFB) smear-positive specimens and for AFB smear-negative specimens was 100% and 85.1%, respectively. Due to the low prevalence of tuberculosis (TB) resistance in Germany, a collection of resistant TB strains with a wide variety of mutations was analyzed. The cobas MTB-RIF/INH assay detected 19 out of 21 INH-resistant and 22 out of 24 RIF-resistant TB strains. In conclusion, the cobas MTB and the cobas MTB-RIF/INH assays implemented on the automated cobas6800 instrument are reliable and versatile tools for the detection of MTB and RIF/INH resistance.</p><p><strong>Importance: </strong>Our manuscript addresses the WHO recommendation for the use of \"moderate-complexity automated NAATs for detection of TB and resistance to rifampicin and isoniazid\" as a part of the WHO End TB Strategy. Rapid detection of tuberculosis (TB) patients is essential to preventing TB transmission and finally reducing TB burden. In this study, we present data on the sensitivity and specificity of the novel cobas MTB assay for TB detection in a low-incidence country, demonstrating highly promising results. Additionally, by analyzing TB strains with various mutations conferring resistance to INH and/or RMP, we assess the opportunities and limitations of the cobas MTB-RIF/INH assay in reliably detecting drug resistance in sputum specimens, thereby facilitating the early onset of appropriate treatment.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0195924"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077164/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Epidemiology of positive bacterial cultures and the coverage gaps in multiplex PCR diagnostics: a single-center retrospective study.","authors":"Vishwaratn Asthana, Rishi Chanderraj, J Scott VanEpps, Robert P Dickson","doi":"10.1128/jcm.01600-24","DOIUrl":"10.1128/jcm.01600-24","url":null,"abstract":"","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0160024"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077099/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hematology thin smears perform equally to parasitology thick and thin blood smears for the diagnosis of <i>Plasmodium</i> and <i>Babesia</i> infections in a low prevalence setting.","authors":"Janmesh Patel, Jill Schuett, Derrick J Chen","doi":"10.1128/jcm.01601-24","DOIUrl":"10.1128/jcm.01601-24","url":null,"abstract":"<p><p>Malaria and babesiosis are significant parasitic infections, requiring timely diagnosis to avoid severe complications. This study retrospectively compared hematology thin smears (HS) with parasitology thick and thin blood smears (PS), the gold standard for diagnosis, to evaluate HS's performance in detecting <i>Plasmodium</i> and <i>Babesia</i> infections. Of 529 cases with paired HS and PS testing, HS demonstrated 93.3% sensitivity and 99.8% specificity, with 97.7% positive and 99.4% negative predictive values. When only considering new diagnoses, HS and PS were 100% concordant. No significant difference was found in percent parasitemia between HS and PS, highlighting HS as a reliable diagnostic tool in settings where PS or other diagnostic modalities may not be readily available.IMPORTANCEThis study demonstrates that hematology thin smears-often available in laboratories that may not have other means of diagnosing blood parasite infections such as parasitology thick and thin smears, rapid diagnostics tests, or polymerase chain reaction-are an accurate and reliable way to diagnose <i>Plasmodium</i> and <i>Babesia</i> infections in a low prevalence setting.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0160124"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077176/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Population structure of <i>Helicobacter pylori</i> and antibiotic resistance-associated variants in a high-risk area of gastric cancer.","authors":"Qiu-Yu Jin, Roberto C Torres, Chao Yang, Li-Hua He, Zong-Chao Liu, Wen-Qing Li, Wei-Dong Liu, Lan-Fu Zhang, Daniel Falush, Yang Zhang, Kai-Feng Pan","doi":"10.1128/jcm.00033-25","DOIUrl":"10.1128/jcm.00033-25","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The increasing antibiotic resistance of &lt;i&gt;Helicobacter pylori&lt;/i&gt; has had a serious impact on gastric cancer prevention. Our study aimed to profile the genomic characteristics and explore variants associated with resistance in &lt;i&gt;H. pylori&lt;/i&gt; strains from a high-risk area of gastric cancer in China. We isolated 153 strains from a community-based cohort and assessed their susceptibility to six antibiotics by MIC Test Strip and genomic characteristics by whole-genome sequencing. Phylogenetic analysis identified the strains as an independent cluster within &lt;i&gt;H. pylori&lt;/i&gt; East Asian population (hpEastAsia). &lt;i&gt;HefA&lt;/i&gt;, an efflux pump gene, showed the highest differentiation in the Linqu strains compared with the other Chinese strains. Bacterial genome-wide association study (GWAS) identified 86 resistance variants covering 44 genes. Novel resistance variants were found in &lt;i&gt;lon&lt;/i&gt; and &lt;i&gt;babA&lt;/i&gt; for metronidazole, &lt;i&gt;HP1168&lt;/i&gt; for clarithromycin, &lt;i&gt;hcpC&lt;/i&gt; for levofloxacin, and &lt;i&gt;sabA&lt;/i&gt; for rifamycin. Two newly identified &lt;i&gt;hefA&lt;/i&gt; mutations (R229K and A283V) showed significant associations with metronidazole (&lt;i&gt;P&lt;/i&gt; = 0.012) and tetracycline (&lt;i&gt;P&lt;/i&gt; = 0.044) resistance, respectively. &lt;i&gt;HefA&lt;/i&gt; mutations and GWAS variants were integrated with the significant literature-reported mutations to optimize the prediction models for metronidazole, levofloxacin, clarithromycin, and tetracycline resistance with area under the receiver operating characteristic curves of 0.82-0.93. Double-antibiotic resistance models were established for clinical applicability. Furthermore, &lt;i&gt;hefA&lt;/i&gt; expression may play a potential mediating role in the associations between mutations and resistance. This study identified genetic independence in the representative &lt;i&gt;H. pylori&lt;/i&gt; strains from a high-risk area of gastric cancer. Optimized resistance prediction panels, including novel &lt;i&gt;hefA&lt;/i&gt; mutations and GWAS variants, may provide preliminary guidance for localized precise treatment and helpful experiences for the similar high-risk populations.IMPORTANCE&lt;i&gt;Helicobacter pylori&lt;/i&gt; is a remarkable pathogen due to its virulence in gastric cancer and high genetic plasticity. Linqu County in China, a high-risk area of gastric cancer, faces serious antibiotic resistance issues and necessitates genomic profiling of local &lt;i&gt;H. pylori&lt;/i&gt; strains. Phylogenetic analysis revealed the Linqu strains as a relatively independent cluster within the hpEastAsia population. Novel antibiotic resistance-associated &lt;i&gt;hefA&lt;/i&gt; mutations and variants from our bacterial genome-wide association study in the Linqu strains were optimized to improve the prediction performances for single antibiotic and double-drug combination resistance compared with traditional literature-reported mutations. This study identified relative genetic independence and high differentiation in the representative &lt;i&gt;H. pylori&lt;/i&gt; strains from a population with high risk of gastric cancer and hig","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":"63 5","pages":"e0003325"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077087/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144010805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating antimicrobial stewardship strategies in candidemia: a novel desirability of outcome ranking (DOOR) analysis comparing blood culture versus T2Candida diagnostic approaches.","authors":"Kaylee E Caniff, Mohammed Al Musawa, Chloe Judd, Macy Shupp, Michael P Veve, George Alangaden, Kimberly C Claeys, Marco R Scipione, Thomas J Walsh, Michael J Rybak","doi":"10.1128/jcm.00043-25","DOIUrl":"10.1128/jcm.00043-25","url":null,"abstract":"<p><p>The T2Candida Panel (T2 Biosystems, Lexington, MA) is a rapid diagnostic test that detects <i>Candida</i> from whole blood within 3-5 hours. We developed and applied a desirability of outcome ranking (DOOR) analysis to investigate if an antimicrobial stewardship program (ASP) strategy centered on T2Candida diagnosis is associated with improved outcomes compared to an ASP strategy that relies on conventional blood culture diagnosis in critically ill patients with candidemia. This is a retrospective, observational cohort of patients with candidemia identified ≤72 h of intensive care unit admission at two medical centers in Detroit, MI (one T2Candida site and one blood culture site) from 2016 to 2023. Management strategies for candidemia were compared using an original DOOR analysis with inverse probability of treatment weighting (IPTW) to account for confounding. Two hundred patients were included, 100 from each site. Baseline illness severity, race, and <i>Candida</i> species varied between groups; however, source control procedures, echocardiogram, and ophthalmologic exam occurred at similar frequencies. T2Candida/ASP was associated with faster median (interquartile range [IQR]) detection of candidemia (7.0 [5.0-10.75] h vs 45.5 h [34.25-68.75], <i>P</i> < 0.001) and timelier median (IQR) initiation of directed antifungal therapy (6.0 [0-11.0] h vs 49.0 [34.0-77.0] h, <i>P</i> < 0.001). T2Candida/ASP patients had a 58.0% probability of achieving an overall better outcome compared to those managed with blood culture/ASP (95% confidence interval: 50.4-65.2%) in IPTW-adjusted DOOR analysis. An ASP strategy incorporating T2Candida was associated with an overall better patient outcome compared to patients managed via conventional blood culture diagnosis.IMPORTANCE<i>Candida</i> species are a significant cause of bloodstream infections in critically ill patients. Conventional diagnostic methods, such as blood cultures, have poor sensitivity and delayed results. The T2Candida Panel is a diagnostic tool that rapidly detects <i>Candida</i> directly from the blood in 3-5 h, enabling faster initiation of antifungal therapy. Antimicrobial stewardship programs (ASPs) optimize the management of bloodstream infections and may benefit from incorporating T2Candida to improve patient outcomes. This study examined whether an ASP intervention based on T2Candida diagnosis, compared to one relying on traditional blood culture methods, could improve outcomes in candidemia using a desirability of outcome ranking (DOOR) analysis. The DOOR method provides a comprehensive evaluation by integrating multiple outcomes into a single end point, which is ideal given the complexity of patients with candidemia. The T2Candida/ASP intervention resulted in an overall better patient outcome, considering infectious complications, treatment failure, and all-cause mortality.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":"63 5","pages":"e0004325"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077142/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144020053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction for Lamberink et al., \"Multicenter validation of a galactomannan chemiluminescence immunoassay for the diagnosis of pulmonary aspergillosis on serum of patients with hematological disease\".","authors":"Hanne Lamberink, Sammy Huygens, Robina Aerts, Katrien Lagrou, Karin van Dijk, Diana Langerak, Ine Moors, Jerina Boelens, Marijke Reynders, Johan Maertens, Alexander Schauwvlieghe, Mireille van Westreenen, Ga-Lai M Chong, Paul E Verweij, Jochem B Buil, Bart J A Rijnders","doi":"10.1128/jcm.00394-25","DOIUrl":"10.1128/jcm.00394-25","url":null,"abstract":"","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0039425"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077167/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of media brand on cefiderocol disk diffusion results.","authors":"M G DeMarco, A M Field, L E Donohue, H L Cox, T S Kidd, K E Barry, A J Mathers","doi":"10.1128/jcm.01648-24","DOIUrl":"10.1128/jcm.01648-24","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Cefiderocol is a siderophore cephalosporin that utilizes iron transport systems to cross cell membranes. This unique strategy complicates antimicrobial susceptibility testing (AST) due to variable iron content in media. While guidance for using iron-depleted media exists for broth microdilution (BMD), disk diffusion (DD) with commercial media is a common AST method in the clinical laboratory. We investigated cefiderocol DD result variability using multiple Mueller-Hinton agar (MHA) brands. DD results using Remel (Thermo Fisher Scientific, San Diego, CA), Hardy (Hardy Diagnostics, Springboro, OH), and BBL (Becton Dickinson, East Rutherford, NJ) MHA were compared to those of BMD using iron-depleted cation-adjusted Mueller-Hinton broth. BMD reproducibility, BMD trailing endpoints, and DD intra- and inter-brand variability in zones of inhibition were investigated. Forty-seven multidrug-resistant clinical isolates and three Antibiotic Resistance Bank isolates composed of &lt;i&gt;Pseudomonas aeruginosa&lt;/i&gt;, carbapenemase (CP-) and non-carbapenemase-producing (non-CP-) carbapenem-resistant Enterobacterales (CRE), &lt;i&gt;Acinetobacter baumannii&lt;/i&gt; complex, &lt;i&gt;Stenotrophomonas maltophilia&lt;/i&gt;, and &lt;i&gt;Burkholderia cepacia&lt;/i&gt; complex were tested. Categorical agreement (CA) ≥ 90% was only demonstrated using CLSI breakpoints with BBL agar. Intra- and inter-brand variability in DD were highest for &lt;i&gt;P. aeruginosa&lt;/i&gt; and CRE, with 25% (5/20) and 16.7% (3/18) exhibiting discrepant AST interpretations, respectively. Isolates not susceptible to cefiderocol via BMD were commonly associated with AST interpretation errors and lower CA. Using commercial MHA for DD resulted in frequent AST interpretation discrepancies, particularly for isolates that were not susceptible to cefiderocol by BMD. Methods and quality control may need to be revisited to ensure the reliability of DD for cefiderocol AST.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Importance: &lt;/strong&gt;The novel mechanism of action of cefiderocol overcomes a variety of resistance mechanisms associated with gram-negative bacteria and positions the agent as an attractive option for treating infections involving multidrug-resistant pathogens. The availability of accurate, timely antimicrobial susceptibility testing methods for cefiderocol in clinical microbiology laboratories is critical as cefiderocol-resistant isolates have been described and may contribute to treatment failure. Iron-depleted broth microdilution testing may not be feasible for use in many clinical laboratories. While disk diffusion is an appealing, practical method to implement, our data demonstrate reproducibility issues across agar brands, most notably for organisms that do not test susceptible to cefiderocol when using broth microdilution. Discrepancy errors and misclassifications of resistant isolates as susceptible, and susceptible isolates as resistant, may mislead clinicians and compromise the treatment efficacy. More work is needed to standardize practical yet repro","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0164824"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077100/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photo Quiz: Unexpected pathogens in the Gram staining of a blood culture smear.","authors":"Jan Esse, Julius Sommer, Johannes Träger, Richard Strauß, Julia Fürst, Giuseppe Valenza, Christian Bogdan, Jürgen Held","doi":"10.1128/jcm.01925-24","DOIUrl":"10.1128/jcm.01925-24","url":null,"abstract":"","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":"63 5","pages":"e0192524"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077183/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144002729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of disk diffusion, gradient test, and VITEK 2 for carbapenem susceptibility testing in OXA-48-like carbapenemase-producing <i>Enterobacterales</i>: a comparative study.","authors":"Cansu Cimen, Philipp Siemer, Janko Sattler, Andreas Voss, Matthijs S Berends, Axel Hamprecht","doi":"10.1128/jcm.01893-24","DOIUrl":"10.1128/jcm.01893-24","url":null,"abstract":"<p><p>This study aimed to compare the performance of disk diffusion, gradient test (ETEST), and VITEK 2 (AST-N223, AST-N428, AST-N432 cards) antibiotic susceptibility testing methods with the reference broth microdilution (BMD) for carbapenem susceptibility in OXA-48-like carbapenemase-producing <i>Enterobacterales</i> (CPE). A total of 107 CPE and 142 controls (<i>Enterobacterales</i> that do not produce any type of carbapenemases), all molecularly characterized by whole-genome sequencing, were tested for carbapenem susceptibility using BMD and derivative methods. Essential agreement (EA), categorical agreement (CA), major error, very major error, and bias were evaluated. In the OXA-48-like group, resistance frequencies by BMD for ertapenem, imipenem, and meropenem were 86.9%, 12.1%, and 10.3%, respectively. For OXA-48-like CPE, ETEST showed the highest EA among all methods for meropenem (100/107, 93.5%) and ertapenem (99/107, 92.5%), while EA for VITEK 2 cards were <90%. In contrast, for imipenem, VITEK 2 AST-N428 performed best with an EA of 95/105 (90.5%). CA was higher for ertapenem across all methods (93.5%-98.1%) compared to imipenem (59.8%-81.4%) and meropenem (78.8%-95.3%). The highest CA was achieved with ETEST for ertapenem and meropenem, and with VITEK 2 AST-N223 for imipenem. Significant variability was observed across different tests in resistance frequencies, MICs, EA, and CA for the OXA-48-like group. Ertapenem was the most useful carbapenem for detecting resistance in OXA-48-like CPE across all methods. Laboratories should be aware that susceptibility testing of imipenem leads to more erroneous results compared to the other carbapenems when using derivative methods. Additionally, most derivative methods tend to overcall carbapenem resistance in OXA-48-like CPE.IMPORTANCEOXA-48-like is the most frequent carbapenemase in western Europe, and both its rapid spread and its challenging-to-detect nature are a particular concern for adequate treatment and infection control purposes. Accurate determination of carbapenem minimal inhibitory concentrations (MICs) is of utmost importance, both for the selection of the best therapy and as a marker for carbapenemase detection. However, the performance of derivative susceptibility testing methods is unclear for OXA-48-like isolates. Our study reports on the varying performance of carbapenem susceptibility testing by disk diffusion, gradient test (ETEST), and VITEK 2 in OXA-48-like-producing <i>Enterobacterales</i>. The results of the present study can help to inform about the limitations of current susceptibility testing methods and serve to improve MIC determination in these challenging isolates.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":"63 5","pages":"e0189324"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077119/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144010151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of disc diffusion and four commercially available MIC tests to determine mecillinam susceptibility on carbapenemase-producing Enterobacterales.","authors":"Sacha Milleville, Lamia Rouabah, Sandrine Bernabeu, Anne Santerre Henriksen, Hippolyte De Swardt, Inès Rezzoug, Laurent Dortet, Cécile Emeraud","doi":"10.1128/jcm.01473-24","DOIUrl":"10.1128/jcm.01473-24","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Urinary tract infections (UTIs) are predominantly caused by Enterobacterales, and escalating resistance poses significant challenges due to carbapenemase production, which can compromise the efficacy of last-resort antibiotics. Pivmecillinam, as the prodrug of mecillinam, may serve as a treatment option for UTIs caused by carbapenemase-producing Enterobacterales (CPE). However, accurate methods are required to accurately assess susceptibility to this antibiotic. This study aimed to evaluate the &lt;i&gt;in vitro&lt;/i&gt; susceptibility of mecillinam on a collection of 161 well-characterized CPE isolates collected from July to November 2023 in France and assess the performances of disc diffusion, Liofilchem MTS gradient strip, bioMérieux E-test, Sensititre broth microdilution, and VITEK 2 compared to agar dilution (reference method) in this specific population of CPE. None of the commercially available tests met the International Organization for Standardization standards with this entire collection. Using Clinical and Laboratory Standards Institute (CLSI) or European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines on the complete collection of CPE, disc diffusion possessed the best categorical agreement [77.0 (124/161) or 84.5% (131/161), respectively]. Sensititre broth microdilution and VITEK 2 overestimated MICs (by 1.8 and one doubling-dilution, respectively) but had low very major error (VME) rates (0% (0/53) for Sensititre and 4.2% (6/53) for VITEK 2 with CLSI and 0% (0/53) for Sensititre and 11.3% (6/53) for VITEK 2 with EUCAST). Notably, when focusing solely on &lt;i&gt;E. coli&lt;/i&gt; isolates (&lt;i&gt;n&lt;/i&gt; = 45), performance improved considerably. Both disc diffusion and VITEK 2 demonstrated high categorical agreements [95.6 (43/45) and 93.3% (42/45), respectively] with no VME observed for either method using CLSI breakpoints. In conclusion, while agar dilution remains the reference method for mecillinam MIC determination, disc diffusion and VITEK2 are accurate alternatives to determine mecillinam susceptibility in CPE isolates, especially for &lt;i&gt;Escherichia coli&lt;/i&gt;.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Importance: &lt;/strong&gt;The rising prevalence of carbapenemase-producing Enterobacterales (CPE) poses significant challenges to effective antibiotic therapy, particularly for urinary tract infections. Pivmecillinam, the prodrug of mecillinam, offers a promising treatment option due to its activity against certain carbapenemase-producing strains. However, selecting accurate susceptibility testing methods is crucial for ensuring appropriate clinical use. This study rigorously evaluates the performances of various susceptibility testing methods against a challenging collection of CPE isolates, identifying the strengths and limitations of each. By providing critical insights into their reliability, particularly for routine clinical settings, this research supports improved diagnostic accuracy and optimal use of mecillinam in combating multidrug-resistant infection","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":"63 5","pages":"e0147324"},"PeriodicalIF":6.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077098/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144027347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}