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BACKGROUND: Thrombo-inflammation and neutrophil extracellular traps (NETs) are exacerbated in severe cases of COVID-19, potentially contributing to disease exacerbation. However, the mechanisms underpinning this dysregulation remain elusive. We hypothesised that lower DNase activity may be associated with higher NETosis and clinical worsening in patients with COVID-19. METHODS: Biological samples were obtained from hospitalized patients (15 severe, 37 critical at sampling) and 93 non-severe ambulatory cases. Our aims were to compare NET biomarkers, functional DNase levels, and explore mechanisms driving any imbalance concerning disease severity. RESULTS: Functional DNase levels were diminished in the most severe patients, paralleling an imbalance between NET markers and DNase activity. DNase1 antigen levels were higher in ambulatory cases but lower in severe patients. DNase1L3 antigen levels remained consistent across subgroups, not rising alongside NET markers. DNASE1 polymorphisms correlated with reduced DNase1 antigen levels. Moreover, a quantitative deficiency in plasmacytoid dendritic cells (pDCs), which primarily express DNase1L3, was observed in critical patients. Analysis of public single-cell RNAseq data revealed reduced DNase1L3 expression in pDCs from severe COVID-19 patient. CONCLUSION: Severe and critical COVID-19 cases exhibited an imbalance between NET and DNase functional activity and quantity. Early identification of NETosis imbalance could guide targeted therapies against thrombo-inflammation in COVID-19-related sepsis, such as DNase administration, to avert clinical deterioration. TRIAL REGISTRATION: COVERAGE trial (NCT04356495) and COLCOV19-BX study (NCT04332016).
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COVID-19 , Trampas Extracelulares , Enfermedades del Sistema Nervioso , Humanos , Trampas Extracelulares/metabolismo , Neutrófilos/metabolismo , Desoxirribonucleasas/metabolismo , Desoxirribonucleasa I/metabolismo , Inflamación/metabolismoRESUMEN
BACKGROUND: The clinical significance of newly available platforms for specific IgE measurement must be evaluated. However, data are lacking for NOVEOS (Hycor), especially for food allergens. OBJECTIVE: We compared the technical and clinical performance of two platforms (ImmunoCAP and NOVEOS) to measure specific IgE to 10 food allergens. METHODS: Sera from 289 clinically characterized patients were tested for IgE specific for six food allergen extracts (egg white, cow's milk, peanut, hazelnut, fish, and shrimp) and four molecular allergens (Gal d 1, Bos d 8, Ara h 2, and Cor a 14). Specific IgE measurements were carried out using ImmunoCAP and NOVEOS methods. Food allergy diagnoses were established according to international guidelines. RESULTS: A strong correlation (ρ > 0.9) was present between the two platforms whereas specific IgE concentrations measured with NOVEOS were consistently lower (mean, -15%) than with ImmunoCAP. NOVEOS and ImmunoCAP provided similar overall odds ratios and relative risks for food allergy diagnosis with both allergen extracts and molecular allergens. When all 10 allergens were considered, NOVEOS provided better receiver operating characteristic curves (P = .04). Finally, we found that the most discordant results were observed with hazelnut and peanut extracts and were related to cross-reactive carbohydrate determinants for these two with ImmunoCAP. CONCLUSIONS: Specific IgE determination by either ImmunoCAP or NOVEOS (odds ratios of allergy, 25.1 or 33.0, respectively) is highly informative regarding the risk of allergy in the selected population. The NOVEOS platform presents the advantage of being less affected by unwanted reactivity owing to carbohydrate determinant-specific IgE while requiring a 10-fold lower test sample volume.
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Alérgenos , Hipersensibilidad a los Alimentos , Inmunoglobulina E , Humanos , Hipersensibilidad a los Alimentos/diagnóstico , Hipersensibilidad a los Alimentos/inmunología , Inmunoglobulina E/sangre , Alérgenos/inmunología , Femenino , Masculino , Adulto , Adolescente , Niño , Preescolar , Persona de Mediana Edad , Adulto Joven , Lactante , Curva ROC , Sensibilidad y Especificidad , Inmunoensayo/métodos , AncianoRESUMEN
Rationale: Extracellular histones, released into the surrounding environment during extensive cell death, promote inflammation and cell death, and these deleterious roles have been well documented in sepsis. Clusterin (CLU) is a ubiquitous extracellular protein that chaperones misfolded proteins and promotes their removal. Objectives: We investigated whether CLU could protect against the deleterious properties of histones. Methods: We assessed CLU and histone expression in patients with sepsis and evaluated the protective role of CLU against histones in in vitro assays and in vivo models of experimental sepsis. Measurements and Main Results: We show that CLU binds to circulating histones and reduces their inflammatory, thrombotic, and cytotoxic properties. We observed that plasma CLU levels decreased in patients with sepsis and that the decrease was greater and more durable in nonsurvivors than in survivors. Accordingly, CLU deficiency was associated with increased mortality in mouse models of sepsis and endotoxemia. Finally, CLU supplementation improved mouse survival in a sepsis model. Conclusions: This study identifies CLU as a central endogenous histone-neutralizing molecule and suggests that, in pathologies with extensive cell death, CLU supplementation may improve disease tolerance and host survival.
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Antineoplásicos , Sepsis , Animales , Ratones , Histonas/metabolismo , Clusterina/metabolismo , Inflamación , Muerte Celular , Sepsis/tratamiento farmacológicoRESUMEN
Systemic lupus erythematosus (SLE) is a systemic and potentially fatal autoimmune disease. SLE pathophysiology is complex and involves the interplay between the innate and adaptive immune systems, with a particularly significant role for type I interferons. Recently, the participation of other actors such as platelets and IgE has been described in SLE. On the one hand, platelets activated by different stimuli (antiphospholipid antibodies, immune complexes ) participate in immune dysregulation through direct interactions with immune cells. On the other hand, autoreactive IgE can activate basophils, promoting a Th2 environment and subsequent antibody production by plasma cells. In synergy with IgG, IgE is also able to activate plasmacytoid DCs (pDCs) increasing interferon alpha production. Mirroring the IgG paradox, total nonautoreactive IgE is described as a potential regulator of IFNα production. This review summarizes recent and novel data on innate immunity in SLE pathophysiology with a focus on platelets and IgE, as they represent novel players in immune dysregulation and potential therapeutic targets.
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Plaquetas/inmunología , Plaquetas/metabolismo , Susceptibilidad a Enfermedades , Inmunidad Innata , Inmunoglobulina E/inmunología , Lupus Eritematoso Sistémico/etiología , Lupus Eritematoso Sistémico/metabolismo , Alarminas/metabolismo , Animales , Biomarcadores , Proteínas del Sistema Complemento/inmunología , Proteínas del Sistema Complemento/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Humanos , Lupus Eritematoso Sistémico/patología , Lupus Eritematoso Sistémico/terapia , Receptores de Reconocimiento de Patrones/metabolismo , Receptores Toll-Like/metabolismoRESUMEN
In a prospective, nationwide study in France of Escherichia coli responsible for pneumonia in patients receiving mechanical ventilation, we determined E. coli antimicrobial susceptibility, phylotype, O-type, and virulence factor gene content. We compared 260 isolates with those of 2 published collections containing commensal and bacteremia isolates. The preponderant phylogenetic group was B2 (59.6%), and the predominant sequence type complex (STc) was STc73. STc127 and STc141 were overrepresented and STc95 underrepresented in pneumonia isolates compared with bacteremia isolates. Pneumonia isolates carried higher proportions of virulence genes sfa/foc, papGIII, hlyC, cnf1, and iroN compared with bacteremia isolates. Virulence factor gene content and antimicrobial drug resistance were higher in pneumonia than in commensal isolates. Genomic and phylogenetic characteristics of E. coli pneumonia isolates from critically ill patients indicate that they belong to the extraintestinal pathogenic E. coli pathovar but have distinguishable lung-specific traits.
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Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/clasificación , Escherichia coli/genética , Filogenia , Neumonía Bacteriana/epidemiología , Neumonía Bacteriana/microbiología , Virulencia/genética , Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Infecciones por Escherichia coli/historia , Francia/epidemiología , Genes Bacterianos , Historia del Siglo XXI , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Neumonía Bacteriana/historia , Vigilancia en Salud Pública , Serogrupo , Factores de Virulencia/genéticaRESUMEN
BACKGROUND: In a previous study of subjects suspected of having ventilator-associated pneumonia, a rapid susceptibility testing approach by using ETEST (BioMérieux) strips directly applied to bronchoalveolar lavage samples provided valuable information at hour 24. The primary objective of this study was to assess a new direct specimen testing by using an even more-rapid E-test approach (at hour 10), which could promote an early de-escalation of the antimicrobial therapy. METHODS: Twenty-eight subjects with ventilator-associated pneumonia admitted to a medical ICU were prospectively included. In parallel with standard routine methods, E-test strips were directly applied onto agar plates seeded with bronchoalveolar lavage samples and were analyzed after 10 h of incubation. E-test results were used to identify potential drug choices by simulating clinical decision making if the microscopy results had been available at the point of care. These choices were analyzed for concordance with the narrowest adequate antimicrobial therapy according to the Minimum Inhibitory Concentrations (MICs) provided by the reference method (ie, the laboratory routine diagnostic). RESULTS: At hour 10, direct specimen testing was readable in 18 of 28 bronchoalveolar lavage samples (64%). Total agreement between the 10-h direct specimen testing approach and the laboratory routine diagnostic approach was 90%, with a sensitivity of 83% and a specificity of 95%, with 8% major errors and 3% very major errors. The concordance between the 2 tests was very good (kappa = 0.79). If the 10-h E-test results were taken into account, then an early de-escalation strategy would have been possible in 10 of 18 cases (55%) at hour 10. CONCLUSIONS: This rapid susceptibility testing approach provided early (10 h) and valuable information that could lead to an early adjustment of empirical antimicrobial treatment in a ventilator-associated pneumonia setting. (ClinicalTrials.gov registration NCT01266863.).
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Antibacterianos/farmacología , Líquido del Lavado Bronquioalveolar/microbiología , Neumonía Asociada al Ventilador/tratamiento farmacológico , Neumonía Asociada al Ventilador/microbiología , Anciano , Antibacterianos/uso terapéutico , Estudios de Cohortes , Diagnóstico Precoz , Femenino , Humanos , Unidades de Cuidados Intensivos , Masculino , Pruebas de Sensibilidad Microbiana/métodos , Persona de Mediana Edad , Neumonía Asociada al Ventilador/diagnóstico , Estudios Prospectivos , Sensibilidad y Especificidad , Factores de TiempoAsunto(s)
Endocarditis Bacteriana/microbiología , Filogenia , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Infecciones Estreptocócicas/microbiología , Streptococcus/clasificación , Streptococcus/genética , Adulto , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Proteínas Bacterianas/genética , Endocarditis Bacteriana/diagnóstico , Endocarditis Bacteriana/tratamiento farmacológico , Implantación de Prótesis de Válvulas Cardíacas , Humanos , Masculino , ARN Ribosómico 16S/genética , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/tratamiento farmacológico , Streptococcus/efectos de los fármacos , Streptococcus/aislamiento & purificación , Superóxido Dismutasa/genéticaAsunto(s)
Antibacterianos , Clorhexidina , Farmacorresistencia Bacteriana , Escherichia coli , Neumonía , Antibacterianos/farmacología , Clorhexidina/farmacología , Escherichia coli/efectos de los fármacos , Humanos , Unidades de Cuidados Intensivos , Pruebas de Sensibilidad Microbiana , Neumonía/tratamiento farmacológico , Neumonía/microbiologíaRESUMEN
Mycoplasma pneumoniae causes community-acquired respiratory tract infections, particularly in school-aged children and young adults. These infections occur both endemically and epidemically worldwide. M. pneumoniae lacks cell wall and is subsequently resistant to beta-lactams and to all antimicrobials targeting the cell wall. This mycoplasma is intrinsically susceptible to macrolides and related antibiotics, to tetracyclines and to fluoroquinolones. Macrolides and related antibiotics are the first-line treatment of M. pneumoniae respiratory tract infections mainly because of their low MIC against the bacteria, their low toxicity and the absence of contraindication in young children. The newer macrolides are now the preferred agents with a 7-to-14 day course of oral clarithromycin or a 5-day course of oral azithromycin for treatment of community-acquired pneumonia due to M. pneumoniae, according to the different guidelines worldwide. However, macrolide resistance has been spreading for 15 years worldwide, with prevalence now ranging between 0 and 15% in Europe and the USA, approximately 30% in Israel and up to 90-100% in Asia. This resistance is associated with point mutations in the peptidyl-transferase loop of the 23S rRNA and leads to high-level resistance to macrolides. Macrolide resistance-associated mutations can be detected using several molecular methods applicable directly from respiratory specimens. Because this resistance has clinical outcomes such as longer duration of fever, cough and hospital stay, alternative antibiotic treatment can be required, including tetracyclines such as doxycycline and minocycline or fluoroquinolones, primarily levofloxacin, during 7-14 days, even though fluoroquinolones and tetracyclines are contraindicated in all children and in children < 8 year-old, respectively. Acquired resistance to tetracyclines and fluoroquinolones has never been reported in M. pneumoniae clinical isolates but reduced susceptibility was reported in in vitro selected mutants. This article focuses on M. pneumoniae antibiotic susceptibility and on the development and the evolution of acquired resistance. Molecular detection of resistant mutants and therapeutic options in case of macrolide resistance will also be assessed.
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The gut microbiota is a complex ecosystem defined by the combination of microorganisms living in the gastrointestinal tract. Its equilibrium is intimately involved in several aspects of vital process for human physiology and nutrition. Its composition changes depending on both exogenous and endogenous factors. The disruption of the gut microbiota by antibiotics often leads to an opportunistic infection by Clostridium difficile. The unbalanced intestinal microbiota promotes spore germination, growth of vegetative forms and toxin production leading to C. difficile infection, which is characterized by diarrhea and possibly pseudomembranous colitis. This nosocomial infection is a good model to understand the role of the gut microbiota in preventing the development of pathogens.
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Clostridioides difficile/fisiología , Infecciones por Clostridium/patología , Microbioma Gastrointestinal , Modelos Biológicos , Animales , Antibacterianos/efectos adversos , Modelos Animales de Enfermedad , HumanosRESUMEN
AIM: To assess the lipoproteins that are involved in the interaction between Mycoplasma hominis and human dendritic cells. MATERIALS & METHODS: The surface lipoproteome of M. hominis PG21 was characterized by using Triton X-114 extraction and LC-MS/MS identification. The transcriptional changes in lipoprotein genes upon contact with human dendritic cells were determined by using reverse transcription quantitative PCR after identification of reference genes suitable for normalization. RESULTS: A large-scale overexpression of lipoprotein genes was observed with 21 upregulated transcripts. Seven genes of unknown function were M. hominis species specific and six genes were putatively associated with increased nutrient capture from the host cell and adhesion. CONCLUSION: M. hominis regulates lipoprotein gene expression and may use species-specific mechanisms during the host colonization process.
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Proteínas Bacterianas/genética , Células Dendríticas/microbiología , Lipoproteínas/genética , Mycoplasma hominis/genética , Proteoma , Secuencia de Aminoácidos , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Simulación por Computador , Expresión Génica , Genes Bacterianos , Interacciones Huésped-Patógeno/genética , Humanos , Lipoproteínas/aislamiento & purificación , Lipoproteínas/metabolismo , Mycoplasma hominis/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Espectrometría de Masas en TándemRESUMEN
We report 2 cases of pulmonary Bordetella hinzii infection in immunodeficient patients. One of these rare cases demonstrated the potential transmission of the bacteria from an avian reservoir through occupational exposure and its persistence in humans. We establish bacteriologic management of these infections and suggest therapeutic options if needed.
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Infecciones por Bordetella/microbiología , Infecciones del Sistema Respiratorio/microbiología , Adulto , Anciano , Animales , Infecciones por Bordetella/epidemiología , Infecciones por Bordetella/transmisión , Humanos , Huésped Inmunocomprometido , Enfermedades Pulmonares/microbiología , Masculino , Infecciones Oportunistas/microbiología , Infecciones Oportunistas/transmisión , Aves de Corral/microbiología , Infecciones del Sistema Respiratorio/epidemiologíaRESUMEN
OBJECTIVES: The objective of this study was to investigate whether the insertion sequence IS1294b (IS91 family) is able to mobilize the blaCMY-2 gene and its adjacent regions from one replicon to another. METHODS: Klebsiella pneumoniae Kp2735 was typed by MLST and its plasmid content was examined by S1-PFGE and PCR-based replicon typing. The genetic blaCMY-2 environment was analysed after cloning experiments and sequencing. Transposition assays were performed with an inactivation strategy based on the sacB gene, which confers sucrose-dependent lethality. RESULTS: Kp2735 (ST215) exhibited high-level resistance to ceftazidime owing to the presence of the cephalosporinase CMY-2. The blaCMY-2 gene was located on an IncI1 ST156 plasmid, p2735, of â¼95 kb. Analysis of the genetic environment revealed, upstream of blaCMY-2, the presence of ISEcp1 interrupted by IS1294b and, downstream of blaCMY-2, a region of 1395 bp belonging to the backbone of IncA/C replicons, suggesting a possible DNA transfer between the two plasmids. We showed that IS1294b is able to mobilize blaCMY-2 and its adjacent regions efficiently on the recipient plasmid with a mean frequency of 5.9%. This transfer was due to a one-ended transposition mechanism, implying the non-recognition of its terIS end. CONCLUSIONS: Our experimental data demonstrate for the first time, to our knowledge, the mobilization of a ß-lactamase gene mediated by a member of the IS91 family and highlight the important role of this mobile genetic element in the spread of antibiotic resistance genes.
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Elementos Transponibles de ADN , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Recombinación Genética , beta-Lactamasas/genética , Antibacterianos/farmacología , Ceftazidima/farmacología , Cefalosporinasa , ADN Bacteriano/química , ADN Bacteriano/genética , Humanos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/aislamiento & purificación , Datos de Secuencia Molecular , Plásmidos , Replicón , Análisis de Secuencia de ADN , Resistencia betalactámicaRESUMEN
The recently developed rapid immunochromatographic tests (ICT) have the potential to provide a quick and easy diagnosis of Campylobacter enteritis in comparison to culture. In a previous study we found them sensitive but lacking in specificity. The aim of the present study was to focus on the problem of specificity and determine the positive predictive value (PPV) of a positive result of the ImmunoCard Stat! Campy (Meridian Bioscience, Cincinnati, OH, USA). For this purpose, the stools positive by ICT were cultured according to 3 different protocols: Karmali agar, Preston enrichment broth subcultured on Karmali agar, and a filtration method on a blood agar without antibiotics, all incubated for 7 days at 37°C. Out of 609 stools from adults and children with community acquired enteritis, the reference methods detected 25 positive cases (4.1%) (culture: 19, specific PCR and ELISA both positive: 6) and the ICT: 31 including the 25 true positives. The PPV was 80.6%. We conclude that ICT is a good method to screen Campylobacter positive stools but because of its lack of specificity the positive stools must be tested by another method.