scholarly journals Metagenomic datasets of cerebrospinal fluid from a small cohort of MS/non-MS patients do not show DNA from the fungal genus Trichosporon

2018 ◽  
Author(s):  
Ralf Stephan
Keyword(s):  
Cerebrospinal Fluid ◽  
Nervous Tissue ◽  
True Positive ◽  
Small Cohort ◽  
Fungal Database ◽  
Trichosporon Species ◽  
Pcr Assays ◽  
Nested Pcr Assays ◽  
Genome Assemblies ◽  
Generation Sequencing

In [2] Alonso et al used nested PCR assays together with next-generation sequencing to find Trichosporon species in the nervous tissue of 10 patients with MS. We deemed it possible that the fungus would be present in cerebrospinal fluid (CSF) samples. Whole metagenomic shotgun (WMGS) sequencing allows detection of any organism in a sample. With Trichosporon any detection would be a true positive because these fungi are not known to be on the skin, or as typical lab contamination. We screened public WMGS datasets of CSF from a cohort of 43 Canadian patients (28 MS, 13 non-MS)[1], using Kraken2[7], the ultrafast kmer-based classifier, using a fungal database augmented with all cleaned available Trichosporon genome assemblies from the NCBI. Blasting the marked reads against an equally augmented blastn database revealed no alignments with an evalue <= 1e-50. In general Kraken2 marked not more than 5 consecutive kmers in any read, which is a clear negative.

scholarly journals 236. The Comparative Utility Of Metagenomic Next-Generation Sequencing and Universal PCR for Pathogen Detection on Cerebrospinal Fluid: A Retrospective Analysis From a Tertiary Care Center

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S134-S135
Author(s):  
Andrew D Kerkhoff ◽  
Michelle Matzko ◽  
Charles Chiu ◽  
Steve Miller ◽  
Jennifer M Babik
Keyword(s):  
Cerebrospinal Fluid ◽  
Next Generation Sequencing ◽  
Positive Result ◽  
Clinical Management ◽  
Clinical Utility ◽  
Pathogen Detection ◽  
Cns Infection ◽  
True Positive ◽  
Generation Sequencing ◽  
True Positive Result

Abstract Background Many neurologic syndromes are underpinned by infectious etiologies that are difficult to diagnose. Broad-range, universal PCR (uPCR), and metagenomic next-generation sequencing (mNGS) are emerging molecular techniques that may allow for enhanced pathogen detection in challenging cases. To date, their comparative clinical utility for pathogen detection in cerebrospinal fluid (CSF) has not been described. Methods We searched the electronic medical record at University of California, San Francisco for all patients who had mNGS and uPCR results available from the same CSF specimen. Using all available clinical information, patients’ clinical episodes were categorized into one of four categories: (1) confirmed central nervous system (CNS) infection, (2) likely CNS infection, (3) confirmed/likely noninfectious etiology, (4) unknown etiology. We also determined whether mNGS and/or uPCR results changed clinical management. Results We identified 75 patients with 78 paired mNGS and uPCR results on CSF. 14/78 (17.9%) had a confirmed CNS infection underpinning their clinical presentation, 11 (14.1%) had a likely CNS infection, 33 (42.3%) had a likely noninfectious cause, and 20 (25.6%) had etiologies that could not be determined. Of the 14 patients with confirmed CNS infection, n = 4 (28.6%) were diagnosed by mNGS and n = 1 (7.1%) by uPCR (Table 1). Most diagnoses missed by mNGS and uPCR were made by CSF serology or from sites other than CSF. Overall, mNGS detected a pathogen in n = 10/78 (12.8%) cases, compared with n = 4/78 (5.1%) using uPCR (Table 2). Among those with a positive mNGS result, n = 6/10 represented a true or likely true positive result, while the remaining were likely contaminants. Of those with a positive uPCR result, n = 1/4 represented a true positive result, while n = 3/4 were likely contaminants. Clinical management was changed by the mNGS or uPCR result in two cases (Table 2). Conclusion mNGS appears to have superior clinical utility to that of universal PCR for pathogen detection in CSF samples, in large part because of additional ability to detect DNA and RNA viruses. Further studies are required to determine the clinical contexts in which mNGS is likely to have maximal diagnostic yield and to better define the utility of uPCR for CNS infections. Disclosures All authors: No reported disclosures.

scholarly journals Bridging the Gap between Vertebrate Cytogenetics and Genomics with Single-Chromosome Sequencing (ChromSeq)

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 124
Author(s):  
Alessio Iannucci ◽  
Alexey I. Makunin ◽  
Artem P. Lisachov ◽  
Claudio Ciofi ◽  
Roscoe Stanyon ◽  
...  
Keyword(s):  
Genome Evolution ◽  
Karyotype Evolution ◽  
Genomic Data ◽  
Anolis Carolinensis ◽  
Vertebrate Genome ◽  
Single Chromosome ◽  
Sequencing Technologies ◽  
Novel Approaches ◽  
Genome Assemblies ◽  
Generation Sequencing

The study of vertebrate genome evolution is currently facing a revolution, brought about by next generation sequencing technologies that allow researchers to produce nearly complete and error-free genome assemblies. Novel approaches however do not always provide a direct link with information on vertebrate genome evolution gained from cytogenetic approaches. It is useful to preserve and link cytogenetic data with novel genomic discoveries. Sequencing of DNA from single isolated chromosomes (ChromSeq) is an elegant approach to determine the chromosome content and assign genome assemblies to chromosomes, thus bridging the gap between cytogenetics and genomics. The aim of this paper is to describe how ChromSeq can support the study of vertebrate genome evolution and how it can help link cytogenetic and genomic data. We show key examples of ChromSeq application in the refinement of vertebrate genome assemblies and in the study of vertebrate chromosome and karyotype evolution. We also provide a general overview of the approach and a concrete example of genome refinement using this method in the species Anolis carolinensis.

scholarly journals Development and Optimization of Metagenomic Next-Generation Sequencing Methods for Cerebrospinal Fluid Diagnostics

2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Patricia J. Simner ◽  
Heather B. Miller ◽  
Florian P. Breitwieser ◽  
Gabriel Pinilla Monsalve ◽  
Carlos A. Pardo ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Next Generation Sequencing ◽  
Sample Pretreatment ◽  
Standard Of Care ◽  
Nucleic Acid Amplification ◽  
Next Generation ◽  
Bead Beating ◽  
Dna And Rna ◽  
Positive Threshold ◽  
Generation Sequencing

ABSTRACT The purpose of this study was to develop and optimize different processing, extraction, amplification, and sequencing methods for metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) specimens. We applied mNGS to 10 CSF samples with known standard-of-care testing (SoC) results (8 positive and 2 negative). Each sample was subjected to nine different methods by varying the sample processing protocols (supernatant, pellet, neat CSF), sample pretreatment (with or without bead beating), and the requirement of nucleic acid amplification steps using DNA sequencing (DNASeq) (with or without whole-genome amplification [WGA]) and RNA sequencing (RNASeq) methods. Negative extraction controls (NECs) were used for each method variation (4/CSF sample). Host depletion (HD) was performed on a subset of samples. We correctly determined the pathogen in 7 of 8 positive samples by mNGS compared to SoC. The two negative samples were correctly interpreted as negative. The processing protocol applied to neat CSF specimens was found to be the most successful technique for all pathogen types. While bead beating introduced bias, we found it increased the detection yield of certain organism groups. WGA prior to DNASeq was beneficial for defining pathogens at the positive threshold, and a combined DNA and RNA approach yielded results with a higher confidence when detected by both methods. HD was required for detection of a low-level-positive enterovirus sample. We demonstrate that NECs are required for interpretation of these complex results and that it is important to understand the common contaminants introduced during mNGS. Optimizing mNGS requires the use of a combination of techniques to achieve the most sensitive, agnostic approach that nonetheless may be less sensitive than SoC tools.

scholarly journals Diagnosis of Enterococcus faecalis meningitis associated with long-term cerebrospinal fluid rhinorrhoea using metagenomics next-generation sequencing: a case report

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaobo Zhang ◽  
Chao Jiang ◽  
Chaojun Zhou
Keyword(s):  
Cerebrospinal Fluid ◽  
Next Generation Sequencing ◽  
Enterococcus Faecalis ◽  
Bone Defect ◽  
Next Generation ◽  
History Of ◽  
Diagnostic Approaches ◽  
Post Traumatic ◽  
Skull Bone Defect ◽  
Generation Sequencing

Abstract Background Enterococcus faecalis (E. faecalis) meningitis is a rare disease, and most of its occurrences are of post-operative origin. Its rapid diagnosis is critical for effective clinical management. Currently, the diagnosis is focused on cerebrospinal fluid (CSF) culture, but this is quite limited. By comparison, metagenomic next-generation sequencing (mNGS) can overcome the deficiencies of conventional diagnostic approaches. To our knowledge, mNGS analysis of the CSF in the diagnosis of E. faecalis meningitis has been not reported. Case presentation We report the case of E. faecalis meningitis in a 70-year-old female patient without a preceding history of head injury or surgery, but with an occult sphenoid sinus bone defect. Enterococcus faecalis meningitis was diagnosed using mNGS of CSF, and she recovered satisfactorily following treatment with appropriate antibiotics and surgical repair of the skull bone defect. Conclusions Non-post-traumatic or post-surgical E. faecalis meningitis can occur in the presence of occult defects in the cranium, and mNGS technology could be helpful in diagnosis in the absence of a positive CSF culture.

scholarly journals First report on clover proliferation phytoplasma related strain associated with Matthiola incana floral virescence in Uttar Pradesh, India

Plant Disease ◽  
2020 ◽  
Author(s):  
Priyam Panda ◽  
Jay Kumar Yadav ◽  
Sushil Kumar Singh ◽  
Amrita Nigam ◽  
Govind P Rao
Keyword(s):  
Uttar Pradesh ◽  
Rflp Analysis ◽  
Related Strain ◽  
New Host ◽  
First Report ◽  
Matthiola Incana ◽  
Ctab Method ◽  
Pcr Assays ◽  
Nested Pcr Assays ◽  
Virtual Rflp

Matthiola incana R. Br. (Fam: Brassicaceae) is an ornamental, commonly known as hoary stock has an extremely fragrant flowers, which blooms in dense clusters in a large variety of colors. During a survey of flower nurseries in March 2019 at Indian Institute of Sugarcane Research campus, Lucknow, floral virescence (MiV) symptoms (Fig. 1 A, B) were observed in M. incana pots with an incidence of over 40%. Leaf yellows symptoms were also observed on a weed Acalypha indica (AiLY) in Matthiola nursery (Fig. 1 C). Nested PCR assays were carried out to detect and identify the possible association of phytoplasmas with MiV and AiLY symptoms. Three each of symptomatic MiV and AiLY samples and two non-symptomatic samples were collected and processed for DNA extraction from the leaf midrib by CTAB method. Hishimonus phycitis (HP) (Hemiptera: Cicadellidae) leafhopper feeding on MiV symptomatic plants was also collected and DNA was extracted. The DNA of 8 symptomatic and 4 non-symptomatic plants and from the 10 leafhopper was used as a template for PCR assays. Phytoplasma specific 16Sr RNA gene specific primers (P1/P7 and 3Far/3Rev; Schneider et al. 1995; Manimekalai et al. 2010) and multilocus genes’ specific primer pairs for secA (SecAfor1/SecArev3;SecAfo5r/SecARev2; Bekele et al. 2011), secY (SecYF1(VI)/SecYR1(VI);SecYF2(VI)/SecYR1(VI); Lee et al. 2010) and rp genes (rpFIC/rp(I)R1A; rp(VI)F2/ rp(VI)R2; Martini et al. 2007) were employed as previously described. Amplified products of ~1.3kb, ~600bp, ~1.7kb and ~1.0kb of 16S rRNA, secA, secY and rp genes of phytoplasma were consistently amplified in all the MiV and AiLY samples and in the HP leafhopper. No amplifications were achieved in any of the asymptomatic plant samples. Amplified products of all the four genes of MiV, AiLY and HP isolates were purified, sequenced and submitted in GenBank. Sequence comparison and phylogeny analysis of the sequences of the four genes of MiV, AiLY and HP isolates revealed 99% - 100% sequence identity and clustering with clover proliferation phytoplasma related strains (16SrVI group)(Fig.2 A,B,C and D). The virtual RFLP analysis of 17 restriction endonucleases corresponding to the 16S rDNA sequence of MiV, AiLY and HP phytoplasma strains by pDraw program, assigned them into a novel phytoplasma subgroup strain under 16SrVI group, since its HpaII restriction profile was different to earlier classified 16SrVI subgroups but was very close to16SrVI-E subgroup (GenBank acc. no. AY270156) (Fig 3). Earlier, peanut witches’ broom (16SrII-A) phytoplasma was identified associated with M. incana from Italy (Davino et al. 2007). However, the association of clover proliferation phytoplasma (16SrVI) related strain associated with virescence symptom of M. incana is the first report in world. The weed (A. indica) and HP leafhopper were also reported as additional hosts of 16SrVI subgroup related new strain in India, which needs further investigation. The report of a new host and new subgroup of clover proliferation phytoplasma related strain in India is having an epidemiological significance and warrants attention.

scholarly journals Metagenomic Next-Generation Sequencing of Cerebrospinal Fluid for the Diagnosis of External Ventricular and Lumbar Drainage-Associated Ventriculitis and Meningitis

2020 ◽  
Vol 11 ◽  
Author(s):  
Lingye Qian ◽  
Yijun Shi ◽  
Fangqiang Li ◽  
Yufei Wang ◽  
Miao Ma ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Next Generation Sequencing ◽  
Staphylococcus Epidermidis ◽  
Coincidence Rate ◽  
Next Generation ◽  
Lumbar Drainage ◽  
Gram Positive Bacteria ◽  
Neurosurgical Patients ◽  
Generation Sequencing ◽  
Guided Therapy

Metagenomic next-generation sequencing (mNGS) has become a widely used technology that can accurately detect individual pathogens. This prospective study was performed between February 2019 and September 2019 in one of the largest clinical neurosurgery centers in China. The study aimed to evaluate the performance of mNGS on cerebrospinal fluid (CSF) from neurosurgical patients for the diagnosis of external ventricular and lumbar drainage (EVD/LD)-associated ventriculitis and meningitis (VM). We collected CSF specimens from neurosurgical patients with EVD/LD for more than 24 h to perform conventional microbiological studies and mNGS analyses in a pairwise manner. We also investigated the usefulness of mNGS of CSF for the diagnosis of EVD/LD-associated VM. In total, 102 patients were enrolled in this study and divided into three groups, including confirmed VM (cVM) (39), suspected VM (sVM) (49), and non-VM (nVM) (14) groups. Of all the patients, mNGS detected 21 Gram-positive bacteria, 20 Gram-negative bacteria, and five fungi. The three primary bacteria detected were Staphylococcus epidermidis (9), Acinetobacter baumannii (5), and Staphylococcus aureus (3). The mNGS-positive coincidence rate of confirmed EVD/LD-associated VM was 61.54% (24/39), and the negative coincidence rate of the nVM group was 100% (14/14). Of 15 VM pathogens not identified by mNGS in the cVM group, eight were negative with mNGS and seven were inconsistent with the conventional microbiological identification results. In addition, mNGS identified pathogens in 22 cases that were negative using conventional methods; of them, 10 patients received a favorable clinical treatment; thus, showing the benefit of mNGS-guided therapy.

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