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Microbiology Spectrum Jun 2023Understanding the pathogenesis of bacterial infections is critical for combatting them. For some infections, animal models are inadequate and functional genomic studies...
Understanding the pathogenesis of bacterial infections is critical for combatting them. For some infections, animal models are inadequate and functional genomic studies are not possible. One example is bacterial meningitis, a life-threatening infection with high mortality and morbidity. Here, we used the newly developed, physiologically relevant, organ-on-a-chip platform integrating the endothelium with neurons, closely mimicking conditions. Using high-magnification microscopy, permeability measurements, electrophysiological recordings, and immunofluorescence staining, we studied the dynamic by which the pathogens cross the blood-brain barrier and damage the neurons. Our work opens up possibilities for performing large-scale screens with bacterial mutant libraries for identifying the virulence genes involved in meningitis and determining the role of these genes, including various capsule types, in the infection process. These data are essential for understanding and therapy of bacterial meningitis. Moreover, our system offers possibilities for the study of additional infections-bacterial, fungal, and viral. The interactions of newborn meningitis (NBM) with the neurovascular unit are very complex and are hard to study. This work presents a new platform to study NBM in a system that enables monitoring of multicellular interactions and identifies processes that were not observed before.
Topics: Animals; Meningitis, Bacterial; Blood-Brain Barrier; Neurons; Lab-On-A-Chip Devices
PubMed: 37222614
DOI: 10.1128/spectrum.01233-23 -
Cureus Apr 2021Drug-induced aseptic meningitis is a rare entity. Diagnosis of drug-induced aseptic meningitis can be challenging due to the difficulty in distinguishing clinical...
Drug-induced aseptic meningitis is a rare entity. Diagnosis of drug-induced aseptic meningitis can be challenging due to the difficulty in distinguishing clinical presentation from bacterial or viral meningitis. We present a case of a 52-year-old Caucasian female patient who presented to the emergency room on two different occasions with severe headache, neck pain, and confusion. Initial cerebrospinal fluid (CSF) analysis showed lymphocytic pleocytosis, and empirical intravenous acyclovir was initiated. Bacterial and viral CSF analysis and cultures were negative. The patient completely recovered. Several days later, the patient returned to the emergency room with similar symptoms. Second CSF analysis revealed neutrophilic pleocytosis, and empirical intravenous antibiotic and antiviral therapy were started. Bacterial, fungal, and viral CSF analysis and cultures were negative. Imaging studies of the brain were unremarkable on both occasions. The patient reported taking trimethoprim-sulfamethoxazole (TMP-SMX) for right foot infection before and after the initial presentation. The patient's symptoms resolved without neurological sequelae after discontinuation of TMP-SMX. This case report highlights the importance of taking a detailed history to diagnose drug-induced aseptic meningitis.
PubMed: 33996314
DOI: 10.7759/cureus.14454 -
Medicine Jul 2022Viral infection is the most common cause of aseptic meningitis. The purpose of this study was to identify the viruses responsible for aseptic meningitis to better...
BACKGROUND
Viral infection is the most common cause of aseptic meningitis. The purpose of this study was to identify the viruses responsible for aseptic meningitis to better understand the clinical presentations of this disease.
METHOD
Between March 2009 and February 2010, we collected 297 cerebrospinal fluid specimens from children with aseptic meningitis admitted to a pediatric hospital in Yunnan (China). Viruses were detected by using "in house" real-time quantitative polymerase chain reaction or reverse-transcription real-time quantitative polymerase chain reaction from these samples. Phylogenetic analyses were conducted using the Molecular Evolutionary Genetic Analysis version 7.0 software, with the neighbor-joining method.
RESULTS
Viral infection was diagnosed in 35 of the 297 children (11.8%). The causative viruses were identified to be enteroviruses in 25 cases (71.4%), varicella-zoster virus in 5 cases (14.3%), herpes simplex virus 1 in 2 cases (5.7%), and herpes simplex virus 2, Epstein-Barr virus, and human herpesvirus 6 in 1 case each (2.9% each). Of the enteroviruses, coxsackievirus B5 was the most frequently detected serotype (10/25 cases; 40.0%) and all coxsackievirus B5 strains belonged to C group.
CONCLUSIONS
In the study, a causative virus was only found in the minority of cases, of them, enteroviruses were the most frequently detected viruses in patients with viral meningitis, followed by varicella-zoster virus and herpes simplex virus. Our findings underscore the need for enhanced surveillance and etiological study of aseptic meningitis.
Topics: Child; China; Enterovirus; Enterovirus Infections; Epstein-Barr Virus Infections; Herpesvirus 2, Human; Herpesvirus 3, Human; Herpesvirus 4, Human; Humans; Meningitis, Aseptic; Meningitis, Viral; Phylogeny; Viruses
PubMed: 35777023
DOI: 10.1097/MD.0000000000029772 -
Frontiers in Immunology 2024The host immune response determines the differential outcome of acute or chronic viral infections. The comprehensive comparison of lymphoid tissue immune cells at the...
INTRODUCTION
The host immune response determines the differential outcome of acute or chronic viral infections. The comprehensive comparison of lymphoid tissue immune cells at the single-cell level between acute and chronic viral infections is largely insufficient.
METHODS
To explore the landscape of immune responses to acute and chronic viral infections, single-cell RNA sequencing(scRNA-seq), scTCR-seq and scBCR-seq were utilized to evaluate the longitudinal dynamics and heterogeneity of lymph node CD45 immune cells in mouse models of acute (LCMV Armstrong) and chronic (LCMV clone 13) viral infections.
RESULTS
In contrast with acute viral infection, chronic viral infection distinctly induced more robust NK cells and plasma cells at the early stage (Day 4 post-infection) and acute stage (Day 8 post-infection), respectively. Moreover, chronic viral infection exerted decreased but aberrantly activated plasmacytoid dendritic cells (pDCs) at the acute phase. Simultaneously, there were significantly increased IgA plasma cells (MALT B cells) but differential usage of B-cell receptors in chronic infection. In terms of T-cell responses, Gzma-high effector-like CD8 T cells were significantly induced at the early stage in chronic infection, which showed temporally reversed gene expression throughout viral infection and the differential usage of the most dominant TCR clonotype. Chronic infection also induced more robust CD4 T cell responses, including follicular helper T cells (Tfh) and regulatory T cells (Treg). In addition, chronic infection compromised the TCR diversity in both CD8 and CD4 T cells.
DISCUSSION
In conclusion, gene expression and TCR/BCR immune repertoire profiling at the single-cell level in this study provide new insights into the dynamic and differential immune responses to acute and chronic viral infections.
Topics: Mice; Animals; CD8-Positive T-Lymphocytes; Lymphocytic Choriomeningitis; Lymphocytic choriomeningitis virus; Persistent Infection; Receptors, Antigen, T-Cell; Lymph Nodes; Sequence Analysis, RNA
PubMed: 38352870
DOI: 10.3389/fimmu.2024.1341985 -
Microbiology Spectrum Jun 2023Central nervous system (CNS) infections such as meningitis and encephalitis are life-threatening conditions that demand hospital care and prompt identification of the...
Central nervous system (CNS) infections such as meningitis and encephalitis are life-threatening conditions that demand hospital care and prompt identification of the causative agent. Since 2015, there has been only one CE-IVD-marked rapid multiplexed diagnostic assay in cassette format for bacterial and viral detection from cerebrospinal fluid (CSF): the BioFire FilmArray meningitis/encephalitis (ME) panel. In the beginning of 2022, Qiagen introduced the QIAstat-Dx meningitis/encephalitis panel. It is a CE-IVD-marked multiplex PCR cassette test intended for the identification of suspected infectious meningitis, encephalitis, or meningoencephalitis caused by bacterial, viral, or fungal pathogens. In this study, we evaluated patient and quality control samples using the QIAstat-Dx meningitis/encephalitis panel and compared the results to those of the BioFire FilmArray meningitis/encephalitis panel and reference methods (current routine analysis methods in our laboratory, PCR, or cultivation). The combined positive percent agreement between the two panel assays was 100%, and the negative percent agreement was 94%. We further compared specifically herpes simplex virus 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV) dilution series using six commercial herpesvirus assays, including the two cassette tests. The results suggested that real-time PCR methods (with separate extraction) were the most sensitive methods. When comparing the cassette tests, the BioFire FilmArray meningitis/encephalitis panel produced more positive results than the QIAstat-Dx meningitis/encephalitis panel in the herpesvirus analyses. The diagnosis of infectious meningitis and encephalitis relies mostly on specific PCR and culturing methods, but commercial syndromic panel assays are bringing a change in diagnostics. With multiplexed analysis, the identification of the pathogen is potentially faster, and less sample material is needed. The novel QIAstat-Dx meningitis/encephalitis panel assay is intended for the rapid identification of pathogens from cerebrospinal fluid for suspected central nervous system (CNS) infection, which is a life-threatening condition and difficult to diagnose. We studied the performance of this panel assay using patient samples and dilution series of selected viruses. The evaluation data for this novel meningitis/encephalitis panel assay are useful for other clinical laboratories and organizations using or considering using this test.
Topics: Humans; Multiplex Polymerase Chain Reaction; Meningitis; Encephalitis; Viruses; Bacteria
PubMed: 37042772
DOI: 10.1128/spectrum.05144-22 -
Current Protocols in Immunology Sep 2020In this invited article, we explain technical aspects of the lymphocytic choriomeningitis virus (LCMV) system, providing an update of a prior contribution by Matthias...
In this invited article, we explain technical aspects of the lymphocytic choriomeningitis virus (LCMV) system, providing an update of a prior contribution by Matthias von Herrath and J. Lindsay Whitton. We provide an explanation of the LCMV infection models, highlighting the importance of selecting an appropriate route and viral strain. We also describe how to quantify virus-specific immune responses, followed by an explanation of useful transgenic systems. Specifically, our article will focus on the following protocols. © 2020 Wiley Periodicals LLC. Basic Protocol 1: LCMV infection routes in mice Support Protocol 1: Preparation of LCMV stocks ASSAYS TO MEASURE LCMV TITERS Support Protocol 2: Plaque assay Support Protocol 3: Immunofluorescence focus assay (IFA) to measure LCMV titer MEASUREMENT OF T CELL AND B CELL RESPONSES TO LCMV INFECTION Basic Protocol 2: Triple tetramer staining for detection of LCMV-specific CD8 T cells Basic Protocol 3: Intracellular cytokine staining (ICS) for detection of LCMV-specific T cells Basic Protocol 4: Enumeration of direct ex vivo LCMV-specific antibody-secreting cells (ASC) Basic Protocol 5: Limiting dilution assay (LDA) for detection of LCMV-specific memory B cells Basic Protocol 6: ELISA for quantification of LCMV-specific IgG antibody Support Protocol 4: Preparation of splenic lymphocytes Support Protocol 5: Making BHK21-LCMV lysate Basic Protocol 7: Challenge models TRANSGENIC MODELS Basic Protocol 8: Transfer of P14 cells to interrogate the role of IFN-I on CD8 T cell responses Basic Protocol 9: Comparing the expansion of naïve versus memory CD4 T cells following chronic viral challenge.
Topics: Adaptive Immunity; Animals; Antibodies, Viral; Antibody Specificity; B-Lymphocytes; Cell Culture Techniques; Cell Line; Cytokines; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Host-Pathogen Interactions; Immunologic Memory; Lymphocyte Depletion; Lymphocytic Choriomeningitis; Lymphocytic choriomeningitis virus; Mice; T-Cell Antigen Receptor Specificity; T-Lymphocytes; Viral Load; Viral Plaque Assay
PubMed: 32940427
DOI: 10.1002/cpim.99 -
BMJ Case Reports Aug 2020Bacterial co-infection in the ongoing pandemic of COVID-19 is associated with poor outcomes but remains little understood. A 22-year-old woman presented with a 3-week...
Bacterial co-infection in the ongoing pandemic of COVID-19 is associated with poor outcomes but remains little understood. A 22-year-old woman presented with a 3-week history of fever, headache, neck stiffness, rigours and confusion. She was noted to have a purpuric rash over her hands and feet. Cerebrospinal fluid bacterial PCR was positive for A concurrent nasopharyngeal RT-PCR was positive for SARS-CoV-2, the causative virus of COVID-19. She was treated with antibiotics for bacterial meningitis and made a complete recovery. Bacterial infection from nasopharyngeal organisms has followed previous pandemic viral upper respiratory illnesses and the risk of bacterial co-infection in COVID-19 remains unclear. Research characterising COVID-19 should specify the frequency, species and outcome of bacterial co-infection. Management of bacterial co-infection in COVID-19 presents major challenges for antimicrobial stewardship and clinical management. Judicious use of local antibiotic guidelines and early liaison with infection specialists is key.
Topics: Anti-Bacterial Agents; Betacoronavirus; COVID-19; Ceftriaxone; Coinfection; Coronavirus Infections; Female; Humans; Meningitis, Meningococcal; Pandemics; Pneumonia, Viral; Risk Factors; SARS-CoV-2; Young Adult
PubMed: 32843469
DOI: 10.1136/bcr-2020-237366 -
Cureus Apr 2022Purpose In this study, we aimed to describe the clinical characteristics, laboratory findings, aetiologies, and role of PCR in the decision on the management plan and...
Purpose In this study, we aimed to describe the clinical characteristics, laboratory findings, aetiologies, and role of PCR in the decision on the management plan and duration of hospital stay in Jordanian children diagnosed with aseptic meningitis. Methods This retrospective observational cohort study included children diagnosed with meningitis who were admitted to the paediatric ward at Jordan University Hospital (JUH) during the period from January 2016 to August 2020. Patients were identified through the ICD9 discharge code of meningitis. Patients diagnosed with aseptic meningitis (defined as a patient with signs and symptoms of meningitis with a cerebrospinal fluid (CSF) white cell count of >5 cells/mm, and a negative CSF Gram stain) were included, while patients who had low CSF glucose (<50% of serum) positive cerebrospinal fluid Gram stain and/or culture for bacterial meningitis were excluded. Files were reviewed to collect data on the clinical picture, viruses identified by the CSF viral polymerase chain reaction (PCR) panel, duration of medication, and hospital stay in patients with identified virus versus those with negative viral PCR. Results One hundred and thirty-one patients were included: 87 males (66.4%) and 44 females (33.5%). Fever was the most common presenting symptom, followed by headache, vomiting, and excessive sleep in 48.0%, 42.7%, and 35.8% of the patients, respectively. Prior oral antibiotic use was reported in 48/125 (38.4%) patients. White blood cell count (WBC) ranged from 4.800 to 22.000. cells/mL, 45 patients (34.3%) had counts above 15.000 cells/mL. C-reactive protein level was high in 61/103 (59.2%) patients. CSF WBC count was <100 in 62 (47.3%) patients while neutrophils predominance of >70% was present in 27 (20.6%) patients. Viral panel PCR was done for 100/131 (76.3%) patients and was positive in 66/100 (66%) patients; with enterovirus being the most common identified viruses (60/100; 60%). The average duration of hospital stay was 5.9 and 5.5 days for those with negative and positive PCR respectively. Ten (7.6%) patients had seizures upon presentation. None of the patients had any neurological sequel related to his meningitis. Conclusion Enteroviruses are the most common identified cause of paediatric aseptic meningitis in Jordan. Although PCR revealed an identified virus in around half of the patients, nevertheless, there was no adjustment in the management plan regarding duration of empirical antibiotic use and hospital stay. Increasing knowledge and awareness among clinicians on viral meningitis' lab characteristics might have great impact on duration of hospital stay and thus would be reflected on the patient and the healthcare system as well.
PubMed: 35611041
DOI: 10.7759/cureus.24383 -
Human Vaccines & Immunotherapeutics Dec 2024Measles, mumps, and rubella (MMR) are highly infectious viral diseases affecting young children and have high secondary attack rates. Present MMR vaccines show... (Review)
Review
Measles, mumps, and rubella (MMR) are highly infectious viral diseases affecting young children and have high secondary attack rates. Present MMR vaccines show consistent seroconversion rates for anti-measles and anti-rubella antibodies with variable responses for anti-mumps antibodies. Most common strains for MMR vaccines, currently available in India, are the Edmonston-Zagreb measles strain, Leningrad Zagreb (L-Z) mumps strain, and the RA 27/3 rubella strain. L-Z strain of mumps virus has been found to be associated with aseptic meningitis by different studies from different parts of the world including India. Recently, a novel freeze-dried MMR vaccine developed by Zydus Lifesciences (Zyvac MMR) contains Edmonston Zagreb measles strain, Hoshino mumps strain, and RA 27/3 rubella strain. The Hoshino strain is WHO approved and was found to induce interferon gamma production. This review article aims to provide a comprehensive appraisal of the data available on the safety and immunogenicity of the novel MMR vaccine.
Topics: Child; Humans; Infant; Child, Preschool; Mumps; Rubella Vaccine; Measles-Mumps-Rubella Vaccine; Measles; Rubella; Mumps virus; Antibodies, Viral; Measles Vaccine
PubMed: 38236022
DOI: 10.1080/21645515.2024.2302685 -
Journal of Virology May 2022Echovirus 30 (E30), a member of species B enterovirus, is associated with outbreaks of aseptic meningitis and has become a global health emergency. However, the...
Echovirus 30 (E30), a member of species B enterovirus, is associated with outbreaks of aseptic meningitis and has become a global health emergency. However, the pathogenesis of E30 remains poorly understood due to the lack of appropriate animal models. In this study, we established a mouse infection model to explore the pathogenicity of E30. The 2-day-old mice infected with E30 strain WZ16 showed lethargy and paralysis, and some died. Obvious pathological changes were observed in the skeletal muscle, brain tissue, and other tissues, with the highest viral load in the skeletal muscles. Transcriptome analysis of brain and skeletal muscle tissues from infected mice showed that significant differentially expressed genes were enriched in complement response and neuropathy-related pathways. Using immunofluorescence assay, we found that the viral double-stranded RNA (dsRNA) was detected in the mouse brain region and could infect human glioma (U251) cells. These results indicated that E30 affects the nervous system, and they provide a theoretical basis for understanding its pathogenesis. Echovirus 30 (E30) infection causes a wide spectrum of diseases with mild symptoms, such as hand, foot, and mouth disease (HFMD), acute flaccid paralysis, and aseptic meningitis and other diseases, especially one of the most common pathogens causing aseptic meningitis outbreaks. We established a novel mouse model of E30 infection by inoculating neonatal mice with clinical isolates of E30 and observed the pathological changes induced by E30. Using the E30 infection model, we found complement responses and neuropathy-related genes in the mice tissues at the transcriptome level. Moreover, we found that the viral dsRNA localized in the mouse brain and could replicate in human glioma cell line U251 rather than in the neuroblastoma cell line, SK-N-SH.
Topics: Animals; Cell Line, Tumor; Disease Models, Animal; Echovirus Infections; Enterovirus B, Human; Glioma; Humans; Meningitis, Aseptic; Mice; Mice, Knockout; Phylogeny; RNA, Viral; Sequence Analysis, DNA
PubMed: 35420443
DOI: 10.1128/jvi.00129-22