scholarly journals Next-Generation Sequencing for Pathogen Identification in Infected Foot Ulcers

2021 ◽  
Vol 6 (3) ◽  
pp. 247301142110269
Author(s):  
Yoonjung Choi ◽  
Eimi Oda ◽  
Olivia Waldman ◽  
Thomas Sajda ◽  
Christopher Beck ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Molecular Diagnostic ◽  
Diagnostic Study ◽  
Foot And Ankle ◽  
Next Generation ◽  
Accurate Identification ◽  
Conventional Culture ◽  
Corynebacterium Striatum ◽  
Standard Culture ◽  
Generation Sequencing

Background: Accurate identification of primary pathogens in foot infections remains challenging due to the diverse microbiome. Conventional culture may show false-positive or false-negative growth, leading to ineffective postoperative antibiotic treatment. Next-generation sequencing (NGS) has been explored as an alternative to standard culture in orthopedic infections. NGS is highly sensitive and can detect an entire bacterial genome along with genes conferring antibiotic resistance in a given sample. We investigated the potential use of NGS for accurate identification and quantification of microbes in infected diabetic foot ulcer (DFU). We hypothesize that NGS will aid identification of dominant pathogen and provide a more complete profile of microorganisms in infected DFUs compared to the standard culture method. Methods: Data were prospectively collected from 30 infected DFU patients who underwent operative treatment by a fellowship-trained orthopedic foot and ankle surgeon from October 2018 to September 2019. The average age of the patient was 60.4 years. Operative procedures performed were irrigation and debridement (12), toe or ray amputation (13), calcanectomies (4), and below-the-knee amputation (1). Infected bone specimens were obtained intraoperatively and processed for standard culture and NGS. Concordance between the standard culture and NGS was assessed. Results: In 29 of 30 patients, pathogens were identified by both NGS and culture, with a concordance rate of 70%. In standard culture, Staphylococcus aureus (58.6%) was the most common pathogen, followed by coagulase-negative Staphylococcus (24.1%), Corynebacterium striatum (17.2%), and Enterococcus faecalis (17.2%). In NGS, Finegoldia magna (44.8%) was the most common microorganism followed by S. aureus (41.4%), and Anaerococcus vaginalis (24.1%). On average, NGS revealed 5.1 (range, 1-11) pathogens in a given sample, whereas culture revealed 2.6 (range, 1-6) pathogens. Conclusion: NGS is an emerging molecular diagnostic method of microbial identification in orthopedic infection. It frequently provides different profiles of microorganisms along with antibiotic-resistant gene information compared to conventional culture in polymicrobial foot infection. Clinical use of NGS for management of foot and ankle infections warrants further investigation. Level of Evidence: Level II, diagnostic study.

scholarly journals Data analysis workflow for the detection of canine vector-borne pathogens using 16 S rRNA Next-Generation Sequencing

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Elton J. R. Vasconcelos ◽  
Chayan Roy ◽  
Joseph A. Geiger ◽  
Kristina M. Oney ◽  
Melody Koo ◽  
...  
Keyword(s):  
Veterinary Medicine ◽  
Next Generation Sequencing ◽  
Complete Analysis ◽  
Molecular Diagnostic ◽  
Rrna Gene ◽  
Spotted Fever Group ◽  
Next Generation ◽  
Vector Borne ◽  
16 S Rrna ◽  
Generation Sequencing

Abstract Background Vector-borne diseases (VBDs) impact both human and veterinary medicine and pose special public health challenges. The main bacterial vector-borne pathogens (VBPs) of importance in veterinary medicine include Anaplasma spp., Bartonella spp., Ehrlichia spp., and Spotted Fever Group Rickettsia. Taxon-targeted PCR assays are the current gold standard for VBP diagnostics but limitations on the detection of genetically diverse organisms support a novel approach for broader detection of VBPs. We present a methodology for genetic characterization of VBPs using Next-Generation Sequencing (NGS) and computational approaches. A major advantage of NGS is the ability to detect multiple organisms present in the same clinical sample in an unsupervised (i.e. non-targeted) and semi-quantitative way. The Standard Operating Procedure (SOP) presented here combines industry-standard microbiome analysis tools with our ad-hoc bioinformatic scripts to form a complete analysis pipeline accessible to veterinary scientists and freely available for download and use at https://github.com/eltonjrv/microbiome.westernu/tree/SOP. Results We tested and validated our SOP by mimicking single, double, and triple infections in genomic canine DNA using serial dilutions of plasmids containing the entire 16 S rRNA gene sequence of (A) phagocytophilum, (B) v. berkhoffii, and E. canis. NGS with broad-range 16 S rRNA primers followed by our bioinformatics SOP was capable of detecting these pathogens in biological replicates of different dilutions. These results illustrate the ability of NGS to detect and genetically characterize multi-infections with different amounts of pathogens in a single sample. Conclusions Bloodborne microbiomics & metagenomics approaches may help expand the molecular diagnostic toolbox in veterinary and human medicine. In this paper, we present both in vitro and in silico detailed protocols that can be combined into a single workflow that may provide a significant improvement in VBP diagnostics and also facilitate future applications of microbiome research in veterinary medicine.

scholarly journals Next-Generation Sequencing for Pathogen Identification in Infected Foot Ulcers

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0002
Author(s):  
Yoonjung Choi ◽  
Irvin Oh
Keyword(s):  
Next Generation Sequencing ◽  
False Positive ◽  
Bacterial Genome ◽  
Rrna Gene ◽  
Next Generation ◽  
Antibiotic Resistant ◽  
Streptococcus Species ◽  
Resistant Genes ◽  
Standard Culture ◽  
Generation Sequencing

Category: Other Introduction/Purpose: Foot infections are often polymicrobial with diverse microbiomes. Accurate identification of the main pathogen in diabetic foot ulcer (DFU) remain challenging due to contamination or negative cultures often leading to ineffective post-surgical antibiotic treatment. Application of molecular diagnostics, such as next generation sequencing (NGS) has been explored as an alternative to standard culture in orthopaedic infections. NGS is highly sensitive and detects an entire bacterial genome along with pharmacologic resistant genes in a given sample. We sought to investigate the potential use of NGS for accurate diagnosis and quantification of various species in infected DFU. We hypothesize that NGS will provide a more accurate means of diagnosing and profiling microorganisms in infected DFU compared to the standard culture method. Methods: We investigated 30 infected DFU patients who underwent surgical treatment by a single academic orthopaedic surgeon from October 2018 to September 2019. The average age of the patient was 60.4 (range 33-82) years-old. Surgical procedures performed were irrigation and debridement (12), toe or ray amputation (13), calcanectomies (4), and below-knee amputation (1). Infected bone specimens were obtained intraoperatively and processed for standard culture and NGS. Quantitative PCR was performed to determine the bacterial burden present in the sample. DNA was amplified by PCR from a highly conserved region of the rRNA gene in the bacteria (16S rRNA). Once a high level of DNA was generated and determined, it was compared against NIH GenBank database. Concordance between the standard culture and NGS was assessed. Results: In 28 of 29 patients, pathogens were identified by both NGS and culture, with complete consistency of organisms in 13 cases (concordance rate: 43.3%). NGS provided relative quantitative measures and the presence of antibiotic resistant genes for each pathogen. In NGS, Anaerococcus species (79.3%) was the most common organism, followed by Streptococcus species (44.8%), Prevotella species (44.8%), Finegoldia magna (44.8%). In culture, S. aureus (58.6%) was the most common, followed by Streptococcus species (34.5%), coagulase-negative Staphylococci (24.1%), Corynebacterium species (20.7%). On average, NGS revealed 5.1 (1-11) number of pathogens, whereas standard culture revealed 2.6 (1-6) pathogens in a given sample. NGS identified 2 cases with false positive standard culture and detected antibiotic resistant organisms in 15 specimens. Conclusion: NGS is an emerging method of microbial identification in orthopedic infection. It is particularly helpful in profiling diverse microbes in polymicrobial infected DFU. It can identify major pathogens and may correct false positive or false negative culture. NGS may allow a faster invitation of postoperative targeted antibiotic therapy. [Table: see text]

scholarly journals Clinical Application of Next-Generation Sequencing of Plasma Cell-Free DNA for Genotyping Untreated Advanced Non-Small Cell Lung Cancer

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2707
Author(s):  
Maria Gabriela O. Fernandes ◽  
Natália Cruz-Martins ◽  
Conceição Souto Moura ◽  
Susana Guimarães ◽  
Joana Pereira Reis ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Next Generation Sequencing ◽  
Clinical Outcomes ◽  
Test Performance ◽  
Molecular Diagnostic ◽  
Test Accuracy ◽  
Newly Diagnosed ◽  
Next Generation ◽  
Clinical Value ◽  
Generation Sequencing

Background: Analysis of circulating tumor DNA (ctDNA) has remarkable potential as a non-invasive lung cancer molecular diagnostic method. This prospective study addressed the clinical value of a targeted-gene amplicon-based plasma next-generation sequencing (NGS) assay to detect actionable mutations in ctDNA in patients with newly diagnosed advanced lung adenocarcinoma. Methods: ctDNA test performance and concordance with tissue NGS were determined, and the correlation between ctDNA findings, clinical features, and clinical outcomes was evaluated in 115 patients with paired plasma and tissue samples. Results: Targeted-gene NGS-based ctDNA and NGS-based tissue analysis detected 54 and 63 genomic alterations, respectively; 11 patients presented co-mutations, totalizing 66 hotspot mutations detected, 51 on both tissue and plasma, 12 exclusively on tissue, and 3 exclusively on plasma. NGS-based ctDNA revealed a diagnostic performance with 81.0% sensitivity, 95.3% specificity, 94.4% PPV, 83.6% NPV, test accuracy of 88.2%, and Cohen’s Kappa 0.764. PFS and OS assessed by both assays did not significantly differ. Detection of ctDNA alterations was statistically associated with metastatic disease (p = 0.013), extra-thoracic metastasis (p = 0.004) and the number of organs involved (p = 0.010). Conclusions: This study highlights the potential use of ctDNA for mutation detection in newly diagnosed NSCLC patients due to its high accuracy and correlation with clinical outcomes.

scholarly journals Identification of Genetic Hereditary Predisposition to Hematologic Malignancies By Clinical Next-Generation Sequencing

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3854-3854 ◽  
Author(s):  
Amy E Knight Johnson ◽  
Lucia Guidugli ◽  
Kelly Arndt ◽  
Gorka Alkorta-Aranburu ◽  
Viswateja Nelakuditi ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Sanger Sequencing ◽  
Family Members ◽  
Hematologic Malignancies ◽  
Dyskeratosis Congenita ◽  
Molecular Diagnostic ◽  
Next Generation ◽  
Hereditary Predisposition ◽  
Ngs Data ◽  
Generation Sequencing

Abstract Introduction: Myelodysplastic syndrome (MDS) and acute leukemia (AL) are a clinically diverse and genetically heterogeneous group of hematologic malignancies. Familial forms of MDS/AL have been increasingly recognized in recent years, and can occur as a primary event or secondary to genetic syndromes, such as inherited bone marrow failure syndromes (IBMFS). It is critical to confirm a genetic diagnosis in patients with hereditary predisposition to hematologic malignancies in order to provide prognostic information and cancer risk assessment, and to aid in identification of at-risk or affected family members. In addition, a molecular diagnosis can help tailor medical management including informing the selection of family members for allogeneic stem cell transplantation donors. Until recently, clinical testing options for this diverse group of hematologic malignancy predisposition genes were limited to the evaluation of single genes by Sanger sequencing, which is a time consuming and expensive process. To improve the diagnosis of hereditary predisposition to hematologic malignancies, our CLIA-licensed laboratory has recently developed Next-Generation Sequencing (NGS) panel-based testing for these genes. Methods: Thirty six patients with personal and/or family history of aplastic anemia, MDS or AL were referred for clinical diagnostic testing. DNA from the referred patients was obtained from cultured skin fibroblasts or peripheral blood and was utilized for preparing libraries with the SureSelectXT Enrichment System. Libraries were sequenced on an Illumina MiSeq instrument and the NGS data was analyzed with a custom bioinformatic pipeline, targeting a panel of 76 genes associated with IBMFS and/or familial MDS/AL. Results: Pathogenic and highly likely pathogenic variants were identified in 7 out of 36 patients analyzed, providing a positive molecular diagnostic rate of 20%. Overall, 6 out of the 7 pathogenic changes identified were novel. In 2 unrelated patients with MDS, heterozygous pathogenic sequence changes were identified in the GATA2 gene. Heterozygous pathogenic changes in the following autosomal dominant genes were each identified in a single patient: RPS26 (Diamond-Blackfan anemia 10), RUNX1 (familial platelet disorder with propensity to myeloid malignancy), TERT (dyskeratosis congenita 4) and TINF2 (dyskeratosis congenita 3). In addition, one novel heterozygous sequence change (c.826+5_826+9del, p.?) in the Fanconi anemia associated gene FANCA was identified. . The RNA analysis demonstrated this variant causes skipping of exon 9 and results in a premature stop codon in exon 10. Further review of the NGS data provided evidence of an additional large heterozygous multi-exon deletion in FANCA in the same patient. This large deletion was confirmed using array-CGH (comparative genomic hybridization). Conclusions: This study demonstrates the effectiveness of using NGS technology to identify patients with a hereditary predisposition to hematologic malignancies. As many of the genes associated with hereditary predisposition to hematologic malignancies have similar or overlapping clinical presentations, analysis of a diverse panel of genes is an efficient and cost-effective approach to molecular diagnostics for these disorders. Unlike Sanger sequencing, NGS technology also has the potential to identify large exonic deletions and duplications. In addition, RNA splicing assay has proven to be helpful in clarifying the pathogenicity of variants suspected to affect splicing. This approach will also allow for identification of a molecular defect in patients who may have atypical presentation of disease. Disclosures No relevant conflicts of interest to declare.

scholarly journals Tumor BRCA Test for Patients with Epithelial Ovarian Cancer: The Role of Molecular Pathology in the Era of PARP Inhibitor Therapy

Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1641 ◽  
Author(s):  
Caterina Fumagalli ◽  
Federica Tomao ◽  
Ilaria Betella ◽  
Alessandra Rappa ◽  
Mariarosaria Calvello ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Next Generation Sequencing ◽  
Epithelial Ovarian Cancer ◽  
Success Rate ◽  
Parp Inhibitor ◽  
Turnaround Time ◽  
Molecular Diagnostic ◽  
Next Generation ◽  
Clinical Implementation ◽  
Generation Sequencing

The PARP inhibitor olaparib has been approved in the maintenance setting of platinum-sensitive epithelial ovarian cancer patients with germline or somatic BRCA1/2 mutation. Therefore, the availability of a tumor BRCA test has become a clinical need. We report the results of the clinical implementation of a tumor BRCA test within the frame of an institutional workflow for the management of patients with nonmucinous and nonborderline epithelial ovarian cancer. In total, 223 patients with epithelial ovarian cancer were prospectively analyzed. BRCA1/2 status was evaluated on formalin-fixed, paraffin-embedded tumor specimens using next-generation sequencing technology. The tumor BRCA test had a success rate of 99.1% (221 of 223 successfully analyzed cases) and a median turnaround time of 17 calendar days. Among the 221 cases, BRCA1 or BRCA2 pathogenic/likely pathogenic mutations were found in 62 (28.1%) cases and variants of uncertain significance in 25 (11.3%) cases. The concordance rate between tumor BRCA test results and germline BRCA1/2 status was 87%, with five cases harboring pathogenic/likely pathogenic somatic-only mutations. The next-generation, sequencing-based tumor BRCA test showed a high success rate and a turnaround time compatible with clinical purposes. The tumor BRCA test could be implemented in a molecular diagnostic setting and it may guide the clinical management of patients with epithelial ovarian cancer.

scholarly journals Next-Generation Sequencing Identifies Gene Mutations That Are Predictive of Malignancy in Residual Needle Rinses Collected From Fine-Needle Aspirations of Thyroid Nodules

2017 ◽  
Vol 142 (2) ◽  
pp. 178-183 ◽  
Author(s):  
Maren Y. Fuller ◽  
Dina Mody ◽  
April Hull ◽  
Kristi Pepper ◽  
Heather Hendrickson ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Thyroid Nodules ◽  
Gene Mutations ◽  
Braf V600e ◽  
Molecular Diagnostic ◽  
Thyroid Malignancy ◽  
Next Generation ◽  
Fine Needle ◽  
Thyroid Fna ◽  
Generation Sequencing

Context.— Thyroid nodules have a prevalence of approximately 70% in adults. Fine-needle aspiration (FNA) is a minimally invasive, cost-effective, standard method to collect tissue from thyroid nodules for cytologic examination. However, approximately 15% of thyroid FNA specimens cannot be unambiguously diagnosed as benign or malignant. Objective.— To investigate whether clinically actionable data can be obtained using next-generation sequencing of residual needle rinse material. Design.— A total of 24 residual needle rinse specimens with malignant (n = 6), indeterminate (n = 9), or benign (n = 9) thyroid FNA diagnoses were analyzed in our clinical molecular diagnostics laboratory using next-generation sequencing assays designed to detect gene mutations and translocations that commonly occur in thyroid cancer. Results were correlated with surgical diagnoses and clinical outcomes. Results.— Interpretable data were generated from 23 of 24 residual needle rinse specimens. Consistent with its well-known role in thyroid malignancy, BRAF V600E mutations were detected in 4 malignant cases. An NRAS mutation was detected in 1 benign case. No mutations were detected from specimens with indeterminate diagnoses. Conclusions.— Our data demonstrate that residual thyroid FNA needle rinses are an adequate source of material for molecular diagnostic testing. Importantly, detection of a mutation implicated in thyroid malignancy was predictive of the final surgical diagnosis and clinical outcome. Our strategy to triage thyroid nodules with indeterminate cytology with molecular testing eliminates the need to perform additional FNA passes into dedicated media or to schedule additional invasive procedures. Further investigation with a larger sample size to confirm the clinical utility of our proposed strategy is underway.

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