Journal of Clinical Microbiology最新文献

{"title":"Deciphering <i>Bordetella pertussis</i> epidemiology through culture-independent multiplex amplicon and metagenomic sequencing.","authors":"Laurence Don Wai Luu, Raisa Rafique, Michael Payne, Sophie Octavia, Jennifer Robson, Vitali Sintchenko, Ruiting Lan","doi":"10.1128/jcm.01178-24","DOIUrl":"https://doi.org/10.1128/jcm.01178-24","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Whooping cough (pertussis) has re-emerged despite high vaccine coverage in Australia and many other countries worldwide, partly attributable to genetic adaptation of the causative organism, &lt;i&gt;Bordetella pertussis,&lt;/i&gt; to vaccines. Therefore, genomic surveillance has become essential to monitor circulating strains for these genetic changes. However, increasing uptake of PCR for the diagnosis of pertussis has affected the availability of cultured isolates for typing. In this study, we evaluated the use of targeted multiplex PCR (mPCR) amplicon sequencing and shotgun metagenomic sequencing for culture-independent typing of &lt;i&gt;B. pertussis&lt;/i&gt; directly from respiratory swabs. We developed a nine-target mPCR amplicon assay that could accurately type major lineages [&lt;i&gt;ptxP3/&lt;/i&gt;non-&lt;i&gt;ptxpP3&lt;/i&gt;, &lt;i&gt;fim3A/B&lt;/i&gt;, &lt;i&gt;fhaB3/&lt;/i&gt;non-&lt;i&gt;fhaB3,&lt;/i&gt; and epidemic lineages (ELs) 1-5] circulating in Australia. Validation using DNA from isolates and 178 residual specimens collected in 2010-2012 (&lt;i&gt;n&lt;/i&gt; = 87) and 2019 (&lt;i&gt;n&lt;/i&gt; = 91) showed that mPCR amplicon sequencing was highly sensitive with a limit of detection of 4.6 copies [IS&lt;i&gt;481&lt;/i&gt; cycle threshold (Ct) 27.3]. Shotgun metagenomic sequencing was successful in genotyping &lt;i&gt;B. pertussis&lt;/i&gt; in 84% of clinical specimens with PCR Ct &lt; 24 and was concordant with mPCR typing results. The results revealed an expansion of EL4 strains from 2010 to 2012 to 2019 in Australia and identified unrecognized co-circulating cases of &lt;i&gt;Bordetella holmesii&lt;/i&gt;. This study provides valuable insight into the circulating lineages in Australia prior to the COVID-19 pandemic during which border closure and other interventions reduced pertussis cases to an all-time low, and paves the way for the genomic surveillance of &lt;i&gt;B. pertussis&lt;/i&gt; in the era of culture-independent PCR-based diagnosis.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Importance: &lt;/strong&gt;In this paper, we evaluated the use of targeted multiplex PCR (mPCR) amplicon sequencing and shotgun metagenomic sequencing for culture-independent typing of &lt;i&gt;Bordetella pertussis&lt;/i&gt; directly in respiratory swabs. We first developed a novel targeted mPCR amplicon sequencing assay that can type major circulating lineages and validated its accuracy and sensitivity on 178 DNA extracts from clinical swabs. We also demonstrate the feasibility of using deep metagenomic sequencing for determining strain lineage and markers of virulence, vaccine adaptation, macrolide resistance, and co-infections. Our culture-independent typing methods applied to clinical specimens revealed the expansion of a major global epidemic lineage in Australia (termed EL4) just prior to the COVID-19 pandemic. It also detected cases of previously hidden co-infections from another &lt;i&gt;Bordetella&lt;/i&gt; species called &lt;i&gt;Bordetella holmesii&lt;/i&gt;. These findings offer valuable insight into the circulating pertussis lineages in Australia prior to the COVID-19 pandemic during which border closure and other interventions reduced pertussi","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0117824"},"PeriodicalIF":6.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142567522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An update on novel taxa and revised taxonomic status of bacteria isolated from domestic companion and agricultural animals described in 2023.","authors":"Sara D Lawhon, Claire R Burbick, Trinity Krueger, Elena Ruiz-Reyes, Erik Munson","doi":"10.1128/jcm.01041-24","DOIUrl":"https://doi.org/10.1128/jcm.01041-24","url":null,"abstract":"<p><p>With the proliferation of abundant bacterial genomic data comes the recognition of new organisms as well as a better understanding of the relatedness of known bacteria. Recognizing the associated taxonomic changes enhances communication and understanding about the significance of novel organisms and deeper understanding of known pathogens. This review addresses the addition of multiple gastrointestinal bacteria that form the normal microbiota in a variety of animals including honeybees as well as novel bacteria from domestic animals including an alpha-hemolytic <i>Streptococcus</i> species from guinea pigs, two <i>Moraxella</i> spp. from cows and goats, a new <i>Capnocytophaga</i> species from cats, a thermophilic <i>Campylobacter</i> species from pigs, and the new <i>Exercitatus</i> genus in Family <i>Pasteurellaceae</i>. Several revisions to the nomenclature also appeared in 2023 including the change of <i>Clostridium spiroforme,</i> which causes anorexia and diarrhea in domestic rabbits, to <i>Thomasclavelia spiroformis</i> comb. nov. and <i>Mannheimia ovis</i> to <i>Mannheimia pernigra</i>.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0104124"},"PeriodicalIF":6.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142567499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of the LifeScale automated rapid phenotypic antimicrobial susceptibility testing on Gram-negative rods directly from positive blood cultures.","authors":"James W Snyder, Nadia Chaudhry, Wesley Hoffmann","doi":"10.1128/jcm.00922-24","DOIUrl":"10.1128/jcm.00922-24","url":null,"abstract":"<p><p>Rapid antimicrobial susceptibility testing (rAST) performed directly from blood cultures is essential to influencing the selection of appropriate antibiotics, preferably targeted therapy, for the treatment of bloodstream infections. Affinity Biosensors has developed the LifeScale, a phenotypic rAST system based on microfluidic sensors with a mechanical resonator that measures the mass of individual microbes. The combination of replication, biomass, and population profiling of individual microbes is analyzed to produce rAST results. The performance of the LifeScale was evaluated and compared to our current standard of care (SOC) antimicrobial susceptibility testing (AST) system under clinical conditions. The results indicated that the LifeScale is easy to use and provides rapid, reliable, and accurate AST results in less than 5 h directly from from positive blood cultures containing Gram-negative organisms listed in the current database. For all organism-antibiotic combinations involving polymicrobial cultures, LifeScale showed a resistant result when either mixed isolate was resistant. If these results prove to be robust on further testing, this may justify the reporting of rapid LifeScale results without the need for additional confirmatory testing.</p><p><strong>Importance: </strong>This is the first clinical-based study of a unique technology using microfluidic sensors to generate rapid antimicrobial susceptibility test results directly from blood cultures containing Gram-negative rods. The issue of polymicrobial cultures was also addressed in this study, which, to our knowledge, has not been addressed in publications of other rapid phenotypic AST systems. Overall, LifeScale results compared favorably with the SOC in terms of overall agreement, especially categorical agreement.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0092224"},"PeriodicalIF":6.1,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142545765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel multiplex and glycoprotein-based immunochromatographic serologic IgM test for the rapid diagnosis of <i>Escherichia coli</i> O157 and O145 causing bloody diarrhea and hemolytic uremic syndrome.","authors":"Stella M Landivar, Luciano J Melli, Cynthia Maiztegui, Carla Schesi, Ariela Baschkier, Valeria Francisetti, Isabel Chinen, Elizabeth Miliwebsky, Marta Rivas, Diego J Comerci, Juan E Ugalde, Andrés E Ciocchini","doi":"10.1128/jcm.01003-24","DOIUrl":"10.1128/jcm.01003-24","url":null,"abstract":"<p><p>Shiga toxin-producing <i>Escherichia coli</i> (STEC) are the main etiological agents of hemolytic uremic syndrome (HUS). Good clinical management of STEC infections and HUS depends on early, rapid, and accurate diagnosis. Here, we have developed and evaluated the first multiplex and glycoprotein-based immunochromatographic test for the detection of IgM antibodies against the O-polysaccharide of the lipopolysaccharide of <i>E. coli</i> O157 and O145 in human serum samples. A retrospective study was carried out resulting in a diagnostic sensitivity of the <i>E. coli</i> O157/O145 LFIA (lateral flow immunoassay) of 97.1% and 98.9% for O157 and O145, respectively, and 97.9% for both serogroups. The diagnostic specificity was 98.7% for O157 and O145, and the overall specificity 97.4%. In samples obtained before 3 days after the onset of diarrhea, the detection percentage was 83%, increasing to 100% from 3 days onward. Finally, the association of bloody diarrhea (BD) or HUS cases to an STEC infection increased from 22.8% to 77.2% when stool culture and <i>stx</i>/Stx detection were combined with serology by LFIA. Our results demonstrate that the <i>E. coli</i> O157/O145 LFIA is a highly accurate and serospecific test for the early and rapid diagnosis of <i>E. coli</i> O157 and O145 infections in BD or HUS cases. This test allows the detection of specific IgM antibodies very early in the course of the infection, making it an ideal diagnostic tool to be implemented in pediatric emergencies and, thus, avoid delays in the application of the correct supportive or specific treatment and prevent complications associated with HUS.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0100324"},"PeriodicalIF":6.1,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142545764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photo Quiz: Eccentric target sign in renal transplant recipient.","authors":"Mahdi Ouafi, Caroline Couvreur, Arnaud Salmon-Rousseau, Anne-Sophie Deleplancque, Sarah Stabler, Claude-Alain Maurage, Camille Cordier","doi":"10.1128/jcm.00298-24","DOIUrl":"10.1128/jcm.00298-24","url":null,"abstract":"","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":"62 10","pages":"e0029824"},"PeriodicalIF":6.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11481496/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142545766","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":"An immunoassay based on bioluminescent sensors for rapid detection of African swine fever virus antibodies.","authors":"Zhonghui Zhang, Jinming Wang, Qingli Niu, Guiquan Guan, Hong Yin, Jifei Yang","doi":"10.1128/jcm.00463-24","DOIUrl":"10.1128/jcm.00463-24","url":null,"abstract":"<p><p>Serological assays for antibody detection have contributed significantly to the diagnosis and control of infectious diseases. African swine fever is the most devastating infectious disease of domestic pigs and wild boars, severely threatening the global pig industry in recent years. Here, we developed a rapid, simple, and sensitive immunoassay based on the split-luciferase system to detect IgG antibodies against African swine fever virus (ASFV). In this assay, the p30 protein of ASFV was genetically coupled to the LgBiT and SmBiT subunits of nanoluciferase, which were used as fusion probes for specific antibodies. Target engagement of the probes results in the reconstitution of a functional nanoluciferase, which further catalyzes bioluminescent reactions. Different orientations of the LgBiT and SmBiT-p30 fusion sensors were designed and investigated, and N-LgBiT/p30 and N-SmBiT/p30 were identified as a promising sensor pair for reforming active nanoluciferase in the presence of specific antibodies. After optimization, this split-luciferase complementation assay showed high sensitivity and specificity for the detection of ASFV antibodies. The analytical sensitivity of the assay was 16 times greater than that of the blocking enzyme-linked immunosorbent assay (ELISA) by the detection of serial dilutions of serum, and no cross-reaction was observed with other swine pathogens. As demonstrated in clinical samples, its performance is highly consistent with that of a commercial ELISA kit, with a concordance rate of 98.19%. This assay is simple and easy to perform, providing a more flexible and efficient approach for the measurement of ASFV antibodies in clinical applications.</p><p><strong>Importance: </strong>The study is about a homogeneous split-luciferase assay for antibody detection. Split nanoluciferase biosensors for the detection of ASFV antibodies were designed. This sensor platform enables the sensitive and specific detection of antibodies. The split-luciferase assay is simple, rapid, and easy to use.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0046324"},"PeriodicalIF":6.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11481549/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132879","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":"Diagnostic performance of an automated robot for MALDI target preparation in microbial identification.","authors":"Arthur B Pranada, Michal Cicatka, Clara Heß, Jan Karasek","doi":"10.1128/jcm.00434-24","DOIUrl":"10.1128/jcm.00434-24","url":null,"abstract":"<p><p>The MBT Pathfinder is an automated colony-picking robot designed for efficient sample preparation in matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. This article presents results from three key experiments evaluating the instrument's performance in conjunction with MALDI Biotyper instrument. The method comparison experiment assessed its clinical performance, demonstrating comparable results with gram-positive, gram-negative, and anaerobic bacteria (scores larger than 2.00) and superior performance over simple direct yeast transfer (score: 1.80) when compared to samples prepared manually. The repeatability experiment confirmed consistent performance over multiple days and labs (average log score: 2.12, std. deviation: 0.59). The challenge panel experiment showcased its consistent and accurate performance across various samples and settings, yielding average scores between 1.76 and 2.19. These findings underline the MBT Pathfinder as a reliable and efficient tool for MALDI-TOF mass spectrometry sample preparation in clinical and research applications.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0043424"},"PeriodicalIF":6.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11481498/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142288393","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":"Evaluation of the STANDARD M10 MDR-TB and MTB/NTM assays for the detection of <i>Mycobacterium tuberculosis</i>, rifampicin and isoniazid resistance, and nontuberculous mycobacteria in a low-incidence setting.","authors":"Bruno Luukinen, Janne Aittoniemi, Terhi Miikkulainen-Lahti, Silja Mentula, Anu Pätäri-Sampo","doi":"10.1128/jcm.00402-24","DOIUrl":"10.1128/jcm.00402-24","url":null,"abstract":"<p><p>Rapid detection is crucial for tuberculosis (TB) control. GeneXpert (Cepheid) is a widely used PCR system, known for its simplicity, random access, and point-of-care compatibility. SD BIOSENSOR recently introduced a similar system, STANDARD M10, including a <i>Mycobacterium tuberculosis</i> (MTB) and rifampicin (RIF) and isoniazid resistance (herein, MDR-TB) assay and an MTB/nontuberculous mycobacteria (NTM) assay. We evaluated these assays for the potential to replace the established Xpert MTB/RIF Ultra assay in a low-TB incidence setting. We analyzed 160 clinical respiratory samples (45 MTB-positive and 35 NTM-positive) and further 24 drug-resistant MTB, 30 mycobacterial species (2 MTB, 28 NTM), and 37 non-mycobacterial isolates. Compared with culture, clinical sensitivities and specificities for MTB detection were 88.9% (95% confidence interval [CI] = 76.1-95.6%) and 97.4% (CI = 92.3-99.4%) with Xpert Ultra, 88.9% (95% CI = 76.1-95.6%) and 98.3% (CI = 93.5-99.9%) with M10 MDR-TB, and 84.4% (CI = 70.9-94.4%) and 98.3% (CI = 93.5-99.9%) with M10 MTB/NTM, respectively. For NTM detection, M10 MTB/NTM showed sensitivity and specificity of 65.7% (CI = 49.1-79.2%) and 96.8% (CI = 91.8-99.0%). Compared with phenotypic drug susceptibility testing (DST), sensitivity and specificity for detecting RIF resistance were 100% (CI = 77.3-100%) and 95.6% (CI = 84.4-99.6%) with Xpert Ultra, and 100% (CI = 74.9-100%) and 95.5% (CI = 84.0-99.6%) with M10 MDR-TB. M10 MDR-TB showed 92.3% sensitivity (CI = 74.7-99.0%) and 100% specificity (CI = 87.3-100%) for detecting isoniazid resistance. All discrepancies in DST by PCR were concordant with whole-genome sequencing. While M10 MDR-TB demonstrated great potential as an alternative to Xpert Ultra, M10 MTB/NTM had limitations in NTM screening. Additionally, the M10 sputum pretreatment did not inactivate MTB efficiently, which should be considered in process risk assessment.</p><p><strong>Importance: </strong>The molecular diagnostic STANDARD M10 system is highly analogous to the widely established GeneXpert system, which significantly increases the relevance of this evaluation study in the field of rapid detection of <i>M. tuberculosis</i>. To our knowledge, this is the first clinical evaluation describing the performance of the STANDARD M10 MDR-TB and MTB/NTM assays, including an extensive analytical specificity panel (inclusivity and exclusivity) for the detection of <i>M. tuberculosis</i>, drug resistance, and nontuberculous mycobacteria.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0040224"},"PeriodicalIF":6.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11481502/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142288396","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":"Nanopore-based targeted sequencing test for direct tuberculosis identification, genotyping, and detection of drug resistance mutations: a side-by-side comparison of targeted next-generation sequencing technologies.","authors":"Andrea Maurizio Cabibbe, Kiarash Moghaddasi, Virginia Batignani, Godstime Stephen Kojo Morgan, Federico Di Marco, Daniela Maria Cirillo","doi":"10.1128/jcm.00815-24","DOIUrl":"10.1128/jcm.00815-24","url":null,"abstract":"<p><p>We investigated the performance of the targeted next-generation sequencing (tNGS)-based Oxford Nanopore Diagnostics AmPORE TB assay, recently approved by the World Health Organization (WHO) as tuberculosis (TB) diagnostic test for the detection of drug resistance on respiratory specimens. A total of 104 DNA samples from Xpert MTB/RIF-positive TB sputum specimens were tested using the AmPORE TB kit, with the GenoScreen Deeplex Myc-TB as a comparative tNGS assay. For AmPORE TB, DNA samples were divided into five sequencing runs on the MinION device. Data analysis was performed using proprietary software. The WHO catalog of mutations was used for drug resistance interpretation. The assay achieved a high validity rate of 98% (102/104 DNA samples), homogeneous mean reads coverage across TB-positive specimens, and 100% positive and negative agreements for detecting mutations associated with resistance to rifampicin, pyrazinamide, fluoroquinolones, ethambutol, and capreomycin compared with Deeplex Myc-TB. The main discrepancies for the remaining drugs were attributable to the different assay panel designs. The AmPORE TB turnaround time was approximately 5-6 hours from extracted DNA to tNGS reporting for batches of 22 DNA samples. The AmPORE TB assay drastically reduced the time to tNGS reporting from days to hours and showed good performance for drug-resistant TB profiling compared with Deeplex Myc-TB.</p><p><strong>Importance: </strong>Targeted next-generation sequencing (tNGS) of <i>Mycobacterium tuberculosis</i> provides comprehensive resistance predictions matched to new multidrug-resistant/rifampicin-resistant tuberculosis regimens and received World Health Organization approval for clinical use in respiratory samples in 2024. The advanced version of the Oxford Nanopore Diagnostics AmPORE TB tNGS kit was evaluated in this study for the first time and demonstrated good performance, flexibility, and faster turnaround time compared with the existing solutions.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0081524"},"PeriodicalIF":6.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11481573/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142140186","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":"Evaluation of a point-of-care multiplex immunochromatographic assay for the diagnosis of typhoid: results from a retrospective diagnostic accuracy study.","authors":"Rumina Hasan, Zahida Azizullah, Hina Shams, Sabine Dittrich, Jason R Andrews, Richelle C Charles, Javan Esfandiari, Dhammika Gunasekera, Kevin K A Tetteh, Jyotshna Sapkota","doi":"10.1128/jcm.00428-24","DOIUrl":"10.1128/jcm.00428-24","url":null,"abstract":"<p><p>There is a clear medical need for an accurate diagnostic test for typhoid that can be performed at point of care. Two antigens (lipopolysaccharide [LPS] and hemolysin E [HlyE]) have recently been identified that can distinguish typhoid from other bacterial infections. Here, we present the results of a diagnostic accuracy study of the Dual Path Platform (DPP) Typhoid assay (Chembio) that detects IgA to both LPS and HlyE using blood culture as the reference standard. This was a retrospective, observational, laboratory study conducted at the Aga Khan University research laboratory, Pakistan, to evaluate the sensitivity and specificity of the DPP Typhoid assay, using archived frozen serum samples collected during a previous typhoid diagnostic accuracy study (NCT04801602). The sensitivity, specificity, and accuracy (area under the receptor operating characteristics curve [AUC]) were then assessed using the manufacturer's and Youden's optimal thresholds. In total, 385 samples were included in the analysis. Using the manufacturer's thresholds, the sensitivity, specificity, and AUC were 97.8% (95% confidence interval [CI] 94.6-99.2), 65.3% (95% CI 58.5-71.6), and 81.5% (95% CI 75.5-85.3), respectively. At Youden's optimal threshold, the overall sensitivity of the DPP Typhoid assay was 89.7% and the specificity was 82.2%. In latent class modeling compared with other nine rapid diagnostic tests evaluated from the same cohort sample, the DPP Typhoid assay demonstrated the highest balanced accuracy (89.2%). The DPP Typhoid assay demonstrated a high diagnostic accuracy for typhoid fever. However, further adjustment to new thresholds is recommended to enhance its performance capabilities.</p><p><strong>Importance: </strong>Currently available diagnostic tests for typhoid have several limitations, including low sensitivity and specificity. Dual Path Platform Typhoid assay is a multiplex rapid test that detects IgA antibodies to lipopolysaccharide and hemolysin E antigen. It is considered to have high sensitivity and specificity, and its results were found to be highly correlated with ELISA results. However, very few studies have been conducted to evaluate this test and limited information about the accuracy of this test is present. Hence, this study evaluated the new typhoid test.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":" ","pages":"e0042824"},"PeriodicalIF":6.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11481547/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142288394","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}