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1.
Rev Med Virol ; 34(3): e2538, 2024 May.
Article in English | MEDLINE | ID: mdl-38658176

ABSTRACT

Serious adverse events following vaccination include medical complications that require hospitalisation. The live varicella vaccine that was approved by the Food and Drug Administration in the United States in 1995 has an excellent safety record. Since the vaccine is a live virus, adverse events are more common in immunocompromised children who are vaccinated inadvertently. This review includes only serious adverse events in children considered to be immunocompetent. The serious adverse event called varicella vaccine meningitis was first reported in a hospitalised immunocompetent child in 2008. When we carried out a literature search, we found 15 cases of immunocompetent children and adolescents with varicella vaccine meningitis; the median age was 11 years. Eight of the children had received two varicella vaccinations. Most of the children also had a concomitant herpes zoster rash, although three did not. The children lived in the United States, Greece, Germany, Switzerland, and Japan. During our literature search, we found five additional cases of serious neurological events in immunocompetent children; these included 4 cases of progressive herpes zoster and one case of acute retinitis. Pulses of enteral corticosteroids as well as a lack of herpes simplex virus antibody may be risk factors for reactivation in immunocompetent children. All 20 children with adverse events were treated with acyclovir and recovered; 19 were hospitalised and one child was managed as an outpatient. Even though the number of neurological adverse events remains exceedingly low following varicella vaccination, we recommend documentation of those caused by the vaccine virus.


Subject(s)
Chickenpox Vaccine , Meningitis, Viral , Adolescent , Child , Child, Preschool , Female , Humans , Male , Acyclovir/therapeutic use , Antiviral Agents/therapeutic use , Chickenpox/prevention & control , Chickenpox/virology , Chickenpox Vaccine/administration & dosage , Chickenpox Vaccine/adverse effects , Chickenpox Vaccine/immunology , Herpesvirus 3, Human/immunology , Meningitis, Viral/virology , Nervous System Diseases/virology , Nervous System Diseases/etiology , Vaccination/adverse effects , Virus Activation/drug effects
3.
JAMA Neurol ; 81(3): 240-247, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38285456

ABSTRACT

Importance: Antemortem infection is a risk factor for sudden infant death syndrome (SIDS)-the leading postneonatal cause of infant mortality in the developed world. Manifestations of infection and inflammation are not always apparent in clinical settings or by standard autopsy; thus, enhanced resolution approaches are needed. Objective: To ascertain whether a subset of SIDS cases is associated with neuroinflammation and occult infection. Design, Setting, and Participants: In this case-control study, postmortem fluids from SIDS cases and controls collected between July 2011 and November 2018 were screened for elevated inflammatory markers, specifically cerebrospinal fluid (CSF) neopterin and CSF and serum cytokines. CSF, liver, and brain tissue from SIDS cases with elevated CSF neopterin were subjected to metagenomic next-generation sequencing (mNGS) to probe for infectious pathogens. Brainstem tissue from a subset of these cases was analyzed by single-nucleus RNA sequencing (snRNAseq) to measure cell type-specific gene expression associated with neuroinflammation and infection. All tissue and fluid analyses were performed from April 2019 to January 2023 in a pathology research laboratory. Included was autopsy material from infants dying of SIDS and age-matched controls dying of known causes. Exposures: There were no interventions or exposures. Main Outcomes and Measures: CSF neopterin levels were measured by high-performance liquid chromatography. Cytokines were measured by multiplex fluorometric assay. mNGS was performed on liver, CSF, brain, and brainstem tissue. snRNAseq was performed on brainstem tissue. Results: A cohort of 71 SIDS cases (mean [SD] age, 55.2 [11.4] postconceptional weeks; 42 male [59.2%]) and 20 controls (mean [SD] age, 63.2 [16.9] postconceptional weeks; 11 male [55.0%]) had CSF and/or serum available. CSF neopterin was screened in 64 SIDS cases and 15 controls, with no exclusions. Tissues from 6 SIDS cases were further analyzed. For CSF neopterin measures, SIDS samples were from infants with mean (SD) age of 54.5 (11.3) postconceptional weeks (38 male [59.4%]) and control samples were from infants with mean (SD) age of 61.5 (17.4) postconceptional weeks (7 male [46.7%]). A total of 6 SIDS cases (9.3%) with high CSF neopterin were identified, suggestive of neuroinflammation. mNGS detected human parechovirus 3 (HPeV3) in tissue and CSF from 1 of these 6 cases. snRNAseq of HPeV3-positive brainstem tissue (medulla) revealed dramatic enrichment of transcripts for genes with predominately inflammatory functions compared with 3 age-matched SIDS cases with normal CSF neopterin levels. Conclusions and Relevance: Next-generation molecular tools in autopsy tissue provide novel insight into pathogens that go unrecognized by normal autopsy methodology, including in infants dying suddenly and unexpectedly.


Subject(s)
Encephalitis , Sudden Infant Death , Infant , Humans , Male , Middle Aged , Sudden Infant Death/genetics , Sudden Infant Death/pathology , Neuroinflammatory Diseases , Case-Control Studies , Multiomics , Neopterin , Brain Stem/pathology , Encephalitis/complications , Cytokines
4.
Open Forum Infect Dis ; 10(11): ofad515, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37965640

ABSTRACT

Background: Neurological opportunistic infections cause significant morbidity and mortality in people with human immunodeficiency virus (HIV) but are difficult to diagnose. Methods: One hundred forty people with HIV with acute neurological symptoms from Iquitos, Peru, were evaluated for cerebral toxoplasmosis with quantitative polymerase chain reaction (qPCR) of cerebrospinal fluid (CSF) and for cryptococcal meningitis with cryptococcal antigen test (CrAg) in serum or CSF. Differences between groups were assessed with standard statistical methods. A subset of samples was evaluated by metagenomic next-generation sequencing (mNGS) of CSF to compare standard diagnostics and identify additional diagnoses. Results: Twenty-seven participants were diagnosed with cerebral toxoplasmosis by qPCR and 13 with cryptococcal meningitis by CrAg. Compared to participants without cerebral toxoplasmosis, abnormal Glasgow Coma Scale score (P = .05), unilateral focal motor signs (P = .01), positive Babinski reflex (P = .01), and multiple lesions on head computed tomography (CT) (P = .002) were associated with cerebral toxoplasmosis. Photophobia (P = .03) and absence of lesions on head CT (P = .02) were associated with cryptococcal meningitis. mNGS of 42 samples identified 8 cases of cerebral toxoplasmosis, 7 cases of cryptococcal meningitis, 5 possible cases of tuberculous meningitis, and incidental detections of hepatitis B virus (n = 1) and pegivirus (n = 1). mNGS had a positive percentage agreement of 71% and a negative percentage agreement of 91% with qPCR for T gondii. mNGS had a sensitivity of 78% and specificity of 100% for Cryptococcus diagnosis. Conclusions: An infection was diagnosed by any method in only 34% of participants, demonstrating the challenges of diagnosing neurological opportunistic infections in this population and highlighting the need for broader, more sensitive diagnostic tests for central nervous system infections.

6.
PLoS Biol ; 21(9): e3002305, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37721949

ABSTRACT

Protein function can be modulated by phase transitions in their material properties, which can range from liquid- to solid-like; yet, the mechanisms that drive these transitions and whether they are important for physiology are still unknown. In the model plant Arabidopsis, we show that developmental robustness is reinforced by phase transitions of the plasma membrane-bound lipid-binding protein SEC14-like. Using imaging, genetics, and in vitro reconstitution experiments, we show that SEC14-like undergoes liquid-like phase separation in the root stem cells. Outside the stem cell niche, SEC14-like associates with the caspase-like protease separase and conserved microtubule motors at unique polar plasma membrane interfaces. In these interfaces, SEC14-like undergoes processing by separase, which promotes its liquid-to-solid transition. This transition is important for root development, as lines expressing an uncleavable SEC14-like variant or mutants of separase and associated microtubule motors show similar developmental phenotypes. Furthermore, the processed and solidified but not the liquid form of SEC14-like interacts with and regulates the polarity of the auxin efflux carrier PINFORMED2. This work demonstrates that robust development can involve liquid-to-solid transitions mediated by proteolysis at unique plasma membrane interfaces.

7.
Article in English | MEDLINE | ID: mdl-37339889

ABSTRACT

Mutations in the complement factor I (CFI) gene have previously been identified as causes of recurrent CNS inflammation. We present a case of a 26-year-old man with 18 episodes of recurrent meningitis, who had a variant in CFI(c.859G>A,p.Gly287Arg) not previously associated with neurologic manifestations. He achieved remission with canakinumab, a human monoclonal antibody targeted at interleukin-1 beta.


Subject(s)
Complement Factor I , Meningitis, Aseptic , Male , Humans , Adult , Meningitis, Aseptic/drug therapy , Meningitis, Aseptic/complications , Antibodies, Monoclonal , Inflammation/complications , Mutation
8.
Ann Neurol ; 93(3): 615-628, 2023 03.
Article in English | MEDLINE | ID: mdl-36443898

ABSTRACT

OBJECTIVE: Prospective studies of encephalitis are rare in regions where encephalitis is prevalent, such as low middle-income Southeast Asian countries. We compared the diagnostic yield of local and advanced tests in cases of pediatric encephalitis in Myanmar. METHODS: Children with suspected subacute or acute encephalitis at Yangon Children's Hospital, Yangon, Myanmar, were prospectively recruited from 2016-2018. Cohort 1 (n = 65) had locally available diagnostic testing, whereas cohort 2 (n = 38) had advanced tests for autoantibodies (ie, cell-based assays, tissue immunostaining, studies with cultured neurons) and infections (ie, BioFire FilmArray multiplex Meningitis/Encephalitis multiplex PCR panel, metagenomic sequencing, and pan-viral serologic testing [VirScan] of cerebrospinal fluid). RESULTS: A total of 20 cases (13 in cohort 1 and 7 in cohort 2) were found to have illnesses other than encephalitis. Of the 52 remaining cases in cohort 1, 43 (83%) had presumed infectious encephalitis, of which 2 cases (4%) had a confirmed infectious etiology. Nine cases (17%) had presumed autoimmune encephalitis. Of the 31 cases in cohort 2, 23 (74%) had presumed infectious encephalitis, of which one (3%) had confirmed infectious etiology using local tests only, whereas 8 (26%) had presumed autoimmune encephalitis. Advanced tests confirmed an additional 10 (32%) infections, 4 (13%) possible infections, and 5 (16%) cases of N-methyl-D-aspartate receptor antibody encephalitis. INTERPRETATION: Pediatric encephalitis is prevalent in Myanmar, and advanced technologies increase identification of treatable infectious and autoimmune causes. Developing affordable advanced tests to use globally represents a high clinical and research priority to improve the diagnosis and prognosis of encephalitis. ANN NEUROL 2023;93:615-628.


Subject(s)
Autoimmune Diseases of the Nervous System , Communicable Diseases , Encephalitis , Infectious Encephalitis , Meningitis , Child , Humans , Meningitis/cerebrospinal fluid , Meningitis/diagnosis , Prospective Studies , Myanmar , Encephalitis/cerebrospinal fluid
9.
Clin Infect Dis ; 76(6): 1080-1087, 2023 03 21.
Article in English | MEDLINE | ID: mdl-36303432

ABSTRACT

BACKGROUND: Cryptococcal meningitis is a common cause of AIDS-related mortality. Although symptom recurrence after initial treatment is common, the etiology is often difficult to decipher. We sought to summarize characteristics, etiologies, and outcomes among persons with second-episode symptomatic recurrence. METHODS: We prospectively enrolled Ugandans with cryptococcal meningitis and obtained patient characteristics, antiretroviral therapy (ART) and cryptococcosis histories, clinical outcomes, and cerebrospinal fluid (CSF) analysis results. We independently adjudicated cases of second-episode meningitis to categorize patients as (1) microbiological relapse, (2) paradoxical immune reconstitution inflammatory syndrome (IRIS), (3) persistent elevated intracranial pressure (ICP) only, or (4) persistent symptoms only, along with controls of primary cryptococcal meningitis. We compared groups with chi-square or Kruskal-Wallis tests as appropriate. RESULTS: 724 participants were included (n = 607 primary episode, 81 relapse, 28 paradoxical IRIS, 2 persistently elevated ICP, 6 persistent symptoms). Participants with culture-positive relapse had lower CD4 (25 cells/µL; IQR: 9-76) and lower CSF white blood cell (WBC; 4 cells/µL; IQR: 4-85) counts than paradoxical IRIS (CD4: 78 cells/µL; IQR: 47-142; WBC: 45 cells/µL; IQR: 8-128). Among those with CSF WBC <5 cells/µL, 86% (43/50) had relapse. Among those with CD4 counts <50 cells/µL, 91% (39/43) had relapse. Eighteen-week mortality (from current symptom onset) was 47% among first episodes of cryptococcal meningitis, 31% in culture-positive relapses, and 14% in paradoxical IRIS. CONCLUSIONS: Poor immune reconstitution was noted more often in relapse than IRIS as evidenced by lower CSF WBC and blood CD4 counts. These easily obtained laboratory values should prompt initiation of antifungal treatment while awaiting culture results. CLINICAL TRIALS REGISTRATION: NCT01802385.


Subject(s)
AIDS-Related Opportunistic Infections , HIV Infections , Meningitis, Cryptococcal , Humans , Meningitis, Cryptococcal/diagnosis , Meningitis, Cryptococcal/drug therapy , AIDS-Related Opportunistic Infections/drug therapy , HIV Infections/complications , HIV Infections/drug therapy , Antifungal Agents/therapeutic use , Recurrence
10.
Science ; 377(6607): 747-751, 2022 08 12.
Article in English | MEDLINE | ID: mdl-35951698

ABSTRACT

The shape of a plant's root system influences its ability to reach essential nutrients in the soil and to acquire water during drought. Progress in engineering plant roots to optimize water and nutrient acquisition has been limited by our capacity to design and build genetic programs that alter root growth in a predictable manner. We developed a collection of synthetic transcriptional regulators for plants that can be compiled to create genetic circuits. These circuits control gene expression by performing Boolean logic operations and can be used to predictably alter root structure. This work demonstrates the potential of synthetic genetic circuits to control gene expression across tissues and reprogram plant growth.


Subject(s)
Gene Expression Regulation, Plant , Gene Regulatory Networks , Genes, Synthetic , Plant Roots , Plant Roots/genetics , Plant Roots/growth & development , Soil , Water/metabolism
11.
Nat Plants ; 8(5): 549-560, 2022 05.
Article in English | MEDLINE | ID: mdl-35501452

ABSTRACT

The phytohormone abscisic acid (ABA) is a central regulator of acclimation to environmental stress; however, its contribution to differences in stress tolerance between species is unclear. To establish a comparative framework for understanding how stress hormone signalling pathways diverge across species, we studied the growth response of four Brassicaceae species to ABA treatment and generated transcriptomic and DNA affinity purification and sequencing datasets to construct a cross-species gene regulatory network (GRN) for ABA. Comparison of genes bound directly by ABA-responsive element binding factors suggests that cis-factors are most important for determining the target loci represented in the ABA GRN of a particular species. Using this GRN, we reveal how rewiring of growth hormone subnetworks contributes to stark differences in the response to ABA in the extremophyte Schrenkiella parvula. Our study provides a model for understanding how divergence in gene regulation can lead to species-specific physiological outcomes in response to hormonal cues.


Subject(s)
Arabidopsis , Brassicaceae , Abscisic Acid/metabolism , Arabidopsis/metabolism , Brassicaceae/genetics , Brassicaceae/metabolism , Gene Expression Regulation, Plant , Gene Regulatory Networks , Plant Growth Regulators/metabolism
12.
Viruses ; 13(11)2021 11 16.
Article in English | MEDLINE | ID: mdl-34835092

ABSTRACT

Varicella vaccine meningitis is an uncommon delayed adverse event of vaccination. Varicella vaccine meningitis has been diagnosed in 12 children, of whom 3 were immunocompromised. We now report two additional cases of vaccine meningitis in twice-immunized immunocompetent children and we perform further testing on a prior third case. We used three methods to diagnose or investigate cases of varicella vaccine meningitis, none of which have been used previously on this disease. These include metagenomic next-generation sequencing and cytokine multiplex profiling of cerebrospinal fluid and immunology exome analysis of white blood cells. In one new case, the diagnosis was confirmed by metagenomic next-generation sequencing of cerebrospinal fluid. Both varicella vaccine virus and human herpesvirus 7 DNA were detected. We performed cytokine multiplex profiling on the cerebrospinal fluid of two cases and found ten elevated biomarkers: interferon gamma, interleukins IL-1RA, IL-6, IL-8, IL-10, IL-17F, chemokines CXCL-9, CXCL-10, CCL-2, and G-CSF. In a second new case, we performed immunology exome sequencing on a panel of 356 genes, but no errors were found. After a review of all 14 cases, we concluded that (i) there is no common explanation for this adverse event, but (ii) ingestion of an oral corticosteroid burst 3-4 weeks before onset of vaccine meningitis may be a risk factor in some cases.


Subject(s)
Chickenpox Vaccine/adverse effects , Cytokines/cerebrospinal fluid , Herpes Zoster/immunology , Meningitis, Viral/etiology , Meningitis, Viral/immunology , Adolescent , Biomarkers/cerebrospinal fluid , Chickenpox Vaccine/immunology , Child , Female , High-Throughput Nucleotide Sequencing , Humans , Immunocompetence , Male , Metagenomics , Exome Sequencing
14.
Curr Biol ; 31(14): 3153-3161.e5, 2021 07 26.
Article in English | MEDLINE | ID: mdl-34043949

ABSTRACT

Plants display remarkable abilities to adjust growth and development to environmental conditions, such as the amount of available water. This developmental plasticity is apparent not only in root and shoot growth rates, but also in tissue patterning and cell morphology.1,2 We have previously shown that in response to limited water availability, Arabidopsis thaliana root displays changes in xylem morphology, mediated by the non-cell-autonomous action of abscisic acid, ABA.2 Here, we show, through analyses of ABA response reporters and tissue-specific suppression of ABA signaling, that xylem cells themselves act as primary signaling centers governing both xylem cell fate and xylem differentiation rate, revealing the cell-autonomous control of multiple aspects of xylem development by ABA. ABA rapidly activates the expression of genes encoding VASCULAR-RELATED NAC DOMAIN (VND) transcription factors. Molecular and genetic analyses revealed that the two ABA-mediated xylem developmental changes are regulated by distinct members of this transcription factor family, with VND2 and VND3 promoting differentiation rate of metaxylem cells, while VND7 promotes the conversion of metaxylem toward protoxylem morphology. This phenomenon shows how different aspects of developmental plasticity can be interlinked, yet genetically separable. Moreover, similarities in phenotypic and molecular responses to ABA in diverse species indicate evolutionary conservation of the ABA-xylem development regulatory network among eudicots. Hence, this study gives molecular insights into how environmental stress modifies plant vascular anatomy and has potential relevance for water use optimization and adaptation to drought conditions.


Subject(s)
Abscisic Acid/metabolism , Arabidopsis Proteins , Arabidopsis , Transcription Factors , Xylem , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Cell Differentiation , Gene Expression Regulation, Plant , Transcription Factors/genetics , Transcription Factors/metabolism , Water/metabolism , Xylem/growth & development
15.
Clin Infect Dis ; 73(9): e3428-e3434, 2021 11 02.
Article in English | MEDLINE | ID: mdl-33388751

ABSTRACT

BACKGROUND: Tuberculous meningitis (TBM) has a high fatality rate, with inadequate diagnostic tests being a major contributor. The rollout of Xpert MTB/Rif and Xpert MTB/RIF Ultra (Xpert Ultra) have improved time-to-diagnosis with sensitivities similar to culture, yet test availability and sensitivity are inadequate. The TB lipoarabinomannan lateral flow assay (AlereLAM) offers ease of use, but its low sensitivity in cerebrospinal fluid (CSF) limits clinical utility for TBM. The Fujifilm SILVAMP TB LAM (FujiLAM) assay has excellent sensitivity in urine, but performance on cerebrospinal fluid is uncertain. METHODS: We conducted a prospective cohort study at Kiruddu National Referral Hospital in Kampala, Uganda, enrolling patients suspected to have TBM. CSF was tested using AlereLAM, Xpert Ultra, culture, and FujiLAM. Results were compared with 2 reference standards: probable and definite TBM or definite TBM alone by the uniform TBM case definition. RESULTS: Of 101 patients enrolled (95/101 HIV-positive), 34 had definite TBM and 24 had probable TBM. FujiLAM sensitivity on CSF was 52% (30/58) for definite or probable TBM compared with 55% (32/58) for Xpert Ultra. AlereLAM had lower sensitivity than FujiLAM in the subgroup of patients tested with both assays (14% [4/28] vs 50% [14/28]; P < .01). FujiLAM specificity was 98% (42/43) for patients without probable or definite TBM. CONCLUSIONS: FujiLAM showed higher sensitivity than AlereLAM, with sensitivity potentially approaching that of Xpert Ultra. FujiLAM could improve time-to-treatment-initiation, especially in settings where the more technical Xpert Ultra system might not be feasible. Large confirmatory studies are needed.


Subject(s)
HIV Infections , Mycobacterium tuberculosis , Tuberculosis, Meningeal , Adult , Cerebrospinal Fluid , Diagnostic Tests, Routine , HIV , HIV Infections/complications , Humans , Lipopolysaccharides , Prospective Studies , Sensitivity and Specificity , Tuberculosis, Meningeal/diagnosis , Uganda
16.
PLoS One ; 15(10): e0238617, 2020.
Article in English | MEDLINE | ID: mdl-33027255

ABSTRACT

BACKGROUND: Neurosyphilis (NS) presents with a variety of clinical syndromes that can be attributed to other aetiologies due to difficulties in its diagnosis. We reviewed all cases of NS from the "Top End" of the Australian Northern Territory over a ten-year period to assess incidence, clinical and laboratory manifestations. METHODS: Patient data (2007-2016) were extracted from hospital records, centralised laboratory data and Northern Territory Centre for Disease Control records. Clinical records of patients with clinically suspected NS were reviewed. A diagnosis of NS was made based on the 2014 US CDC criteria. Results were also recategorized based on the 2018 US CDC criteria. RESULTS: The population of the "Top End" is 185,570, of whom 26.2% are Indigenous. A positive TPPA was recorded in 3126 individuals. A total of 75 (2.4%) of TPPA positive patients had a lumbar puncture (LP), of whom 25 (35%) were diagnosed with NS (9 definite, 16 probable). Dementia was the most common manifestation (58.3%), followed by epilepsy (16.7%), psychosis (12.5%), tabes dorsalis (12.5%) and meningovascular syphilis (8.3%). 63% of probable NS cases were not treated appropriately due to a negative CSF VDRL. Despite increased specificity of the 2018 US CDC criteria, 70% of patient in the probable NS group were not treated appropriately. The overall annual incidence [95%CI] of NS was 2.47[1.28-4.31] per 100 000py in the Indigenous population and 0.95[0.50-1.62] in the non-Indigenous population (rate ratio = 2.60 [1.19-5.70];p = 0.017). CONCLUSION: Neurosyphilis is frequently reported in the NT, particularly in Indigenous populations. Disturbingly, 60% of probable neurosyphilis patients based on the 2014 criteria, and 70% based on the 2018 criteria with were not treated appropriately. It is critical that clinicians should be aware of the diagnosis of NS and treat patients appropriately.


Subject(s)
Neurosyphilis/epidemiology , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Cohort Studies , Female , Humans , Incidence , Male , Middle Aged , Neurosyphilis/diagnosis , Neurosyphilis/drug therapy , Northern Territory/epidemiology , Penicillin G Benzathine/therapeutic use , Prevalence , Prospective Studies , Retrospective Studies
17.
Nat Rev Neurol ; 16(10): 547-556, 2020 10.
Article in English | MEDLINE | ID: mdl-32661342

ABSTRACT

Over the past two decades, the diagnosis rate for patients with encephalitis has remained poor despite advances in pathogen-specific testing such as PCR and antigen assays. Metagenomic next-generation sequencing (mNGS) of RNA and DNA extracted from cerebrospinal fluid and brain tissue now offers another strategy for diagnosing neurological infections. Given that mNGS simultaneously assays for a wide range of infectious agents in an unbiased manner, it can identify pathogens that were not part of a neurologist's initial differential diagnosis either because of the rarity of the infection, because the microorganism has not been previously associated with a clinical phenotype or because it is a newly discovered organism. This Review discusses the technical advantages and pitfalls of cerebrospinal fluid mNGS in the context of patients with neuroinflammatory syndromes, including encephalitis, meningitis and myelitis. We also speculate on how mNGS testing potentially fits into current diagnostic testing algorithms given data on mNGS test performance, cost and turnaround time. Finally, the Review highlights future directions for mNGS technology and other hypothesis-free testing methodologies that are in development.


Subject(s)
Central Nervous System Infections/diagnosis , Central Nervous System Infections/genetics , Imagination , Metagenomics/trends , Animals , Central Nervous System Infections/therapy , Computational Biology/methods , Computational Biology/trends , Data Interpretation, Statistical , Encephalitis/diagnosis , Encephalitis/genetics , Encephalitis/therapy , Humans , Metagenomics/methods
18.
Front Plant Sci ; 11: 570, 2020.
Article in English | MEDLINE | ID: mdl-32499804

ABSTRACT

Periods of drought, that threaten crop production, are expected to become more prominent in large parts of the world, making it necessary to explore all aspects of plant growth and development, to breed, modify and select crops adapted to such conditions. One such aspect is the xylem, where influencing the size and number of the water-transporting xylem vessels, may impact on hydraulic conductance and drought tolerance. Here, we focus on how plants adjust their root xylem as a response to reduced water availability. While xylem response has been observed in a wide array of species, most of our knowledge on the molecular mechanisms underlying xylem plasticity comes from studies on the model plant Arabidopsis thaliana. When grown under water limiting conditions, Arabidopsis rapidly adjusts its development to produce more xylem strands with altered identity in an abscisic acid (ABA) dependent manner. Other hormones such as auxin and cytokinin are essential for vascular patterning and differentiation. Their balance can be perturbed by stress, as evidenced by the effects of enhanced jasmonic acid signaling, which results in similar xylem developmental alterations as enhanced ABA signaling. Furthermore, brassinosteroids and other signaling molecules involved in drought tolerance can also impact xylem development. Hence, a multitude of signals affect root xylem properties and, potentially, influence survival under water limiting conditions. Here, we review the likely entangled signals that govern root vascular development, and discuss the importance of taking root anatomical traits into account when breeding crops for enhanced resilience toward changes in water availability.

19.
Am J Trop Med Hyg ; 103(1): 200-205, 2020 07.
Article in English | MEDLINE | ID: mdl-32342847

ABSTRACT

We aimed to identify the contribution of central nervous system (CNS) viral coinfection to illness in African children with retinopathy-negative or retinopathy-positive cerebral malaria (CM). We collected cerebrospinal fluid (CSF) from 272 children with retinopathy-negative or retinopathy-positive CM and selected CSF from 111 of these children (38 retinopathy positive, 71 retinopathy negative, 2 retinopathy unknown) for analysis by metagenomic next-generation sequencing. We found CSF viral coinfections in 7/38 (18.4%) retinopathy-positive children and in 18/71 (25.4%) retinopathy-negative children. Excluding HIV-1, human herpesviruses (HHV) represented 61% of viruses identified. Excluding HIV-1, CNS viral coinfection was equally likely in children who were retinopathy positive and retinopathy negative (P = 0.1431). Neither mortality nor neurological morbidity was associated with the presence of virus (odds ratio [OR] = 0.276, 95% CI: 0.056-1.363). Retinopathy-negative children with a higher temperature, lower white blood cell count, or being dehydrated were more likely to have viral coinfection. Level of consciousness at admission was not associated with CNS viral coinfection in retinopathy-negative children. Viral CNS coinfection is unlikely to contribute to coma in children with CM. The herpesviruses other than herpes simplex virus may represent incidental bystanders in CM, reactivating during acute malaria infection.


Subject(s)
Central Nervous System Viral Diseases/parasitology , Malaria, Cerebral/virology , Central Nervous System Viral Diseases/cerebrospinal fluid , Central Nervous System Viral Diseases/complications , Central Nervous System Viral Diseases/virology , Child , Coinfection/parasitology , Coinfection/virology , Female , Ghana , Herpesviridae Infections/complications , Herpesviridae Infections/parasitology , Herpesviridae Infections/virology , High-Throughput Nucleotide Sequencing , Humans , Malaria, Cerebral/cerebrospinal fluid , Malaria, Cerebral/complications , Malawi , Male , Retinal Diseases/parasitology , Retinal Diseases/virology , Uganda
20.
Article in English | MEDLINE | ID: mdl-32139440

ABSTRACT

OBJECTIVE: In 2016, Catalonia experienced a pediatric brainstem encephalitis outbreak caused by enterovirus A71 (EV-A71). Conventional testing identified EV in the periphery but rarely in CSF. Metagenomic next-generation sequencing (mNGS) and CSF pan-viral serology (VirScan) were deployed to enhance viral detection and characterization. METHODS: RNA was extracted from the CSF (n = 20), plasma (n = 9), stool (n = 15), and nasopharyngeal samples (n = 16) from 10 children with brainstem encephalitis and 10 children with meningitis or encephalitis. Pathogens were identified using mNGS. Available CSF from cases (n = 12) and pediatric other neurologic disease controls (n = 54) were analyzed with VirScan with a subset (n = 9 and n = 50) validated by ELISA. RESULTS: mNGS detected EV in all samples positive by quantitative reverse transcription polymerase chain reaction (qRT-PCR) (n = 25). In qRT-PCR-negative samples (n = 35), mNGS found virus in 23% (n = 8, 3 CSF samples). Overall, mNGS enhanced EV detection from 42% (25/60) to 57% (33/60) (p-value = 0.013). VirScan and ELISA increased detection to 92% (11/12) compared with 46% (4/12) for CSF mNGS and qRT-PCR (p-value = 0.023). Phylogenetic analysis confirmed the EV-A71 strain clustered with a neurovirulent German EV-A71. A single amino acid substitution (S241P) in the EVA71 VP1 protein was exclusive to the CNS in one subject. CONCLUSION: mNGS with VirScan significantly increased the CNS detection of EVs relative to qRT-PCR, and the latter generated an antigenic profile of the acute EV-A71 immune response. Genomic analysis confirmed the close relation of the outbreak EV-A71 and neuroinvasive German EV-A71. A S241P substitution in VP1 was found exclusively in the CSF.


Subject(s)
Brain Stem , Encephalitis, Viral/virology , Enterovirus A, Human/genetics , Enterovirus A, Human/isolation & purification , Enterovirus Infections/virology , Meningitis, Viral/virology , RNA, Viral/metabolism , Child, Preschool , Cohort Studies , Enzyme-Linked Immunosorbent Assay , Female , High-Throughput Nucleotide Sequencing , Humans , Infant , Male , Phylogeny , RNA, Viral/blood , RNA, Viral/cerebrospinal fluid , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, RNA
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