ABSTRACT
Influenza virus infection causes considerable morbidity and mortality, but current therapies have limited efficacy. We hypothesized that investigating the metabolic signaling during infection may help to design innovative antiviral approaches. Using bronchoalveolar lavages of infected mice, we here demonstrate that influenza virus induces a major reprogramming of lung metabolism. We focused on mitochondria-derived succinate that accumulated both in the respiratory fluids of virus-challenged mice and of patients with influenza pneumonia. Notably, succinate displays a potent antiviral activity in vitro as it inhibits the multiplication of influenza A/H1N1 and A/H3N2 strains and strongly decreases virus-triggered metabolic perturbations and inflammatory responses. Moreover, mice receiving succinate intranasally showed reduced viral loads in lungs and increased survival compared to control animals. The antiviral mechanism involves a succinate-dependent posttranslational modification, that is, succinylation, of the viral nucleoprotein at the highly conserved K87 residue. Succinylation of viral nucleoprotein altered its electrostatic interactions with viral RNA and further impaired the trafficking of viral ribonucleoprotein complexes. The finding that succinate efficiently disrupts the influenza replication cycle opens up new avenues for improved treatment of influenza pneumonia.
Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza, Human , Orthomyxoviridae Infections , Pneumonia , Animals , Antiviral Agents/pharmacology , Humans , Influenza A Virus, H3N2 Subtype/metabolism , Mice , Nucleocapsid Proteins , Nucleoproteins/metabolism , Succinic Acid/metabolism , Succinic Acid/pharmacology , Succinic Acid/therapeutic use , Virus ReplicationABSTRACT
OBJECTIVES: Patients at risk of adverse effects related to positive fluid balance could benefit from fluid intake optimization. Less attention is paid to nonresuscitation fluids. We aim to evaluate the heterogeneity of fluid intake at the initial phase of resuscitation. DESIGN: Prospective multicenter cohort study. SETTING: Thirty ICUs across France and one in Spain. PATIENTS: Patients requiring vasopressors and/or invasive mechanical ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All fluids administered by vascular or enteral lines were recorded over 24 hours following admission and were classified in four main groups according to their predefined indication: fluids having a well-documented homeostasis goal (resuscitation fluids, rehydration, blood products, and nutrition), drug carriers, maintenance fluids, and fluids for technical needs. Models of regression were constructed to determine fluid intake predicted by patient characteristics. Centers were classified according to tertiles of fluid intake. The cohort included 296 patients. The median total volume of fluids was 3546 mL (interquartile range, 2441-4955 mL), with fluids indisputably required for body fluid homeostasis representing 36% of this total. Saline, glucose-containing high chloride crystalloids, and balanced crystalloids represented 43%, 27%, and 16% of total volume, respectively. Whatever the class of fluids, center of inclusion was the strongest factor associated with volumes. Compared with the first tertile, the difference between the volume predicted by patient characteristics and the volume given was +1.2 ± 2.0 L in tertile 2 and +3.0 ± 2.8 L in tertile 3. CONCLUSIONS: Fluids indisputably required for body fluid homeostasis represent the minority of fluid intake during the 24 hours after ICU admission. Center effect is the strongest factor associated with the volume of fluids. Heterogeneity in practices suggests that optimal strategies for volume and goals of common fluids administration need to be developed.
Subject(s)
Critical Illness , Fluid Therapy , Humans , Prospective Studies , Critical Illness/therapy , Cohort Studies , Fluid Therapy/adverse effects , Crystalloid Solutions , ResuscitationABSTRACT
BACKGROUND: Herpes simplex encephalitis (HSE) is a disease with unfavorable vital and functional prognoses. There are no recent epidemiological data on HSE at a national level using real-life databases, especially in France. This study aimed to report the incidence, the clinical characteristics and outcomes of the patients with HSE. METHODS: We conducted a comprehensive retrospective cohort study on all patients hospitalized for HSE in France between 2015 and 2022 using national hospital discharge databases. Incidence, socio-demographic and clinical characteristics (including comorbidities, seizure, stays' features, intensive care supports) were described. The short- (first stay) and long-term (6-month) outcomes were reported, in terms of mortality and rehospitalizations. RESULTS: 1425 HSE patients were included (median age 67 [54-77] years old, M/F sex ratio 1.07), giving a mean yearly hospital incidence of 2.3 [2.1-2.5] per 1,000,000 inhabitants. 51.2% of the patients were admitted in ICU (n = 730), of whom 59.0% were mechanically ventilated. The overall mortality during the first stay was 14.3% (n = 204), up to 17.9% for ICU patients. Within 6 months, among the survivors, 10.1% had at least one rehospitalization related to HSE. At 6 months, 16.5% of all patients had died (n = 235), 20.8% for ICU patients. CONCLUSION: In France, the incidence of hospitalizations for HSE was 2.3 per 1,000,000 inhabitants with more than half of the patients admitted in ICU and a 6-month in-hospital mortality about 16.5%. This real-life update on the characteristics and severe outcomes of the disease raises awareness among care practitioners, of the serious nature of the disease, and thus can lead to higher vigilance.
Subject(s)
Encephalitis, Herpes Simplex , Patient Readmission , Humans , France/epidemiology , Male , Middle Aged , Female , Aged , Encephalitis, Herpes Simplex/epidemiology , Encephalitis, Herpes Simplex/mortality , Retrospective Studies , Patient Readmission/statistics & numerical data , Incidence , Hospitalization/statistics & numerical dataABSTRACT
BACKGROUND: Group A Streptococcus is responsible for severe and potentially lethal invasive conditions requiring intensive care unit (ICU) admission, such as streptococcal toxic shock-like syndrome (STSS). A rebound of invasive group A streptococcal (iGAS) infection after COVID-19-associated barrier measures has been observed in children. Several intensivists of French adult ICUs have reported similar bedside impressions without objective data. We aimed to compare the incidence of iGAS infection before and after the COVID-19 pandemic, describe iGAS patients' characteristics, and determine ICU mortality associated factors. METHODS: We performed a retrospective multicenter cohort study in 37 French ICUs, including all patients admitted for iGAS infections for two periods: two years before period (October 2018 to March 2019 and October 2019 to March 2020) and a one-year after period (October 2022 to March 2023) COVID-19 pandemic. iGAS infection was defined by Group A Streptococcus isolation from a normally sterile site. iGAS infections were identified using the International Classification of Diseases and confirmed with each center's microbiology laboratory databases. The incidence of iGAS infections was expressed in case rate. RESULTS: Two hundred and twenty-two patients were admitted to ICU for iGAS infections: 73 before and 149 after COVID-19 pandemic. Their case rate during the period before and after COVID-19 pandemic was 205 and 949/100,000 ICU admissions, respectively (p < 0.001), with more frequent STSS after the COVID-19 pandemic (61% vs. 45%, p = 0.015). iGAS patients (n = 222) had a median SOFA score of 8 (5-13), invasive mechanical ventilation and norepinephrine in 61% and 74% of patients. ICU mortality in iGAS patients was 19% (14% before and 22% after COVID-19 pandemic; p = 0.135). In multivariate analysis, invasive mechanical ventilation (OR = 6.08 (1.71-21.60), p = 0.005), STSS (OR = 5.75 (1.71-19.22), p = 0.005), acute kidney injury (OR = 4.85 (1.05-22.42), p = 0.043), immunosuppression (OR = 4.02 (1.03-15.59), p = 0.044), and diabetes (OR = 3.92 (1.42-10.79), p = 0.008) were significantly associated with ICU mortality. CONCLUSION: The incidence of iGAS infections requiring ICU admission increased by 4 to 5 after the COVID-19 pandemic. After the COVID-19 pandemic, the rate of STSS was higher, with no significant increase in ICU mortality rate.
Subject(s)
COVID-19 , Shock, Septic , Streptococcal Infections , Adult , Child , Humans , Retrospective Studies , Pandemics , Cohort Studies , Streptococcal Infections/epidemiology , COVID-19/epidemiology , Intensive Care Units , Streptococcus pyogenes , Shock, Septic/epidemiologyABSTRACT
BACKGROUND: Except in a few retrospective studies mainly including patients under chemotherapy, information regarding the impact of immunosuppressive therapy on the prognosis of patients admitted to the intensive care unit (ICU) for septic shock is scarce. Accordingly, the PACIFIC study aimed to asses if immunosuppressive therapy is associated with an increased mortality in patients admitted to the ICU for septic shock. METHODS: This was a retrospective epidemiological multicentre study. Eight high enroller centres in septic shock randomised controlled trials (RCTs) participated in the study. Patients in the "exposed" group were selected from the screen failure logs of seven recent RCTs and excluded because of immunosuppressive treatment. The "non-exposed" patients were those included in the placebo arm of the same RCTs. A multivariate logistic regression model was used to estimate the risk of death. RESULTS: Among the 433 patients enrolled, 103 were included in the "exposed" group and 330 in the "non-exposed" group. Reason for immunosuppressive therapy included organ transplantation (n = 45 [44%]) or systemic disease (n = 58 [56%]). ICU mortality rate was 24% in the "exposed" group and 25% in the "non-exposed" group (p = 0.9). Neither in univariate nor in multivariate analysis immunosuppressive therapy was associated with a higher ICU mortality (OR: 0.95; [95% CI 0.56-1.58]: p = 0.86 and 1.13 [95% CI 0.61-2.05]: p = 0.69, respectively) or 3-month mortality (OR: 1.13; [95% CI 0.69-1.82]: p = 0.62 and OR: 1.36 [95% CI 0.78-2.37]: p = 0.28, respectively). CONCLUSIONS: In this study, long-term immunosuppressive therapy excluding chemotherapy was not associated with significantly higher or lower ICU and 3-month mortality in patients admitted to the ICU for septic shock.
Subject(s)
Shock, Septic , Humans , Shock, Septic/drug therapy , Immunosuppressive Agents/therapeutic use , Long-Term Care , Immunosuppression Therapy , Intensive Care UnitsABSTRACT
Inflammation, oxidative stress, and protease/protease inhibitor imbalance with excessive production of proteases are factors associated with pathogenesis of the chronic obstructive pulmonary disease (COPD). In this study, we report that kallikrein-related peptidase 5 (KLK5) is a crucial protease involved in extracellular matrix (ECM) remodeling and bronchial epithelial repair after injury. First, we showed that KLK5 degrades the basal layer formed by culture of primary bronchial epithelial cells from COPD or non-COPD patients. Also, exogenous KLK5 acted differently on BEAS-2B cells already engaged in epithelial-to-mesenchymal transition (EMT) or on 16HBE 14o- cells harboring epithelial characteristics. Indeed, by inducing EMT, KLK5 reduced BEAS-2B cell adherence to the ECM. This effect, neutralized by tissue factor pathway inhibitor 2, a kunitz-type serine protease inhibitor, was due to a direct proteolytic activity of KLK5 on E-cadherin, ß-catenin, fibronectin, and α5ß1 integrin. Thus, KLK5 may strengthen EMT mechanisms and promote the migration of cells by activating the mitogen-activated protein kinase signaling pathway required for this function. In contrast, knockdown of endogenous KLK5 in 16HBE14o- cells, accelerated wound healing repair after injury, and exogenous KLK5 addition delayed the closure repair. These data suggest that among proteases, KLK5 could play a critical role in airway remodeling events associated with COPD during exposure of the pulmonary epithelium to inhaled irritants or smoking and the inflammation process.
Subject(s)
Airway Remodeling , Bronchi/pathology , Epithelial Cells/pathology , Epithelial-Mesenchymal Transition , Kallikreins/metabolism , Lung Neoplasms/pathology , Pulmonary Disease, Chronic Obstructive/pathology , Aged , Antigens, CD/genetics , Antigens, CD/metabolism , Bronchi/metabolism , Cadherins/genetics , Cadherins/metabolism , Case-Control Studies , Cells, Cultured , Epithelial Cells/metabolism , Female , Humans , Kallikreins/genetics , Lung Neoplasms/metabolism , Male , Middle Aged , Pulmonary Disease, Chronic Obstructive/metabolism , Signal TransductionABSTRACT
Excessive lung inflammation and airway epithelial damage are hallmarks of human inflammatory lung diseases, such as cystic fibrosis (CF). Enhancement of innate immunity provides protection against pathogens while reducing lung-damaging inflammation. However, the mechanisms underlying innate immunity-mediated protection in the lung remain mysterious, in part because of the lack of appropriate animal models for these human diseases. TLR5 (Toll-like receptor 5) stimulation by its specific ligand, the bacterial protein flagellin, has been proposed to enhance protection against several respiratory infectious diseases, although other cellular events, such as calcium signaling, may also control the intensity of the innate immune response. Here, we investigated the molecular events prompted by stimulation with flagellin and its role in regulating innate immunity in the lung of the pig, which is anatomically and genetically more similar to humans than rodent models. We found that flagellin treatment modulated NF-κB signaling and intracellular calcium homeostasis in airway epithelial cells. Flagellin pretreatment reduced the NF-κB nuclear translocation and the expression of proinflammatory cytokines to a second flagellin stimulus as well as to Pseudomonas aeruginosa infection. Moreover, in vivo administration of flagellin decreased the severity of P. aeruginosa-induced pneumonia. Then we confirmed these beneficial effects of flagellin in a pathological model of CF by using ex vivo precision-cut lung slices from a CF pigz model. These results provide evidence that flagellin treatment contributes to a better regulation of the inflammatory response in inflammatory lung diseases such as CF.
Subject(s)
Flagellin/pharmacology , Inflammation/drug therapy , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/pathogenicity , Animals , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Epithelial Cells/microbiology , Flagellin/immunology , Flagellin/metabolism , Immunity, Innate/drug effects , Lung/immunology , Lung/microbiology , Lung/pathology , Pseudomonas Infections/immunology , Pseudomonas aeruginosa/immunology , Signal Transduction/drug effects , SwineABSTRACT
We report a fatal case of measles inclusion-body encephalitis occurring in a woman from Romania with AIDS. After an extensive but unsuccessful diagnostic evaluation, a pan-pathogen shotgun metagenomic approach revealed a measles virus infection. We identified no mutations previously associated with neurovirulence.
Subject(s)
Acquired Immunodeficiency Syndrome , Measles , Subacute Sclerosing Panencephalitis , Adult , Brain/diagnostic imaging , Female , France , Humans , Measles/diagnosis , Measles virus/genetics , RomaniaABSTRACT
BACKGROUND: Intensive care unit (ICU) hospitalisations of elderly patients with acute respiratory infection have increased, yet the long-term effects of ICU admission among elderly individuals remain unknown. We examined differences over the 2 years after discharge in mortality, healthcare utilisation and frailty score between elderly survivors of ARI in the ICU and an elderly control population. METHODS: We used 2009-2017 data from 39 hospital discharge databases. Patients ≥ 80 years old discharged alive from ICU hospitalisation for acute respiratory infection were propensity score-matched with controls (cataract surgery) discharged from the hospital at the same time and adjusted for age, sex and comorbidities present before hospitalisation. We reported 2-year mortality and compared healthcare utilisation and frailty scores in the 2-year periods before and after ICU hospitalisation. RESULTS: One thousand two hundred and twenty elderly survivors of acute respiratory infection in the ICU were discharged, and 988 were successfully matched with controls. After discharge, patients had a 10.1-fold [95% CI, 6.1-17.3] higher risk of death at 6 months and 3.6-fold [95% CI, 2.9-4.6] higher risk of death at 2 years compared with controls. They also had a 2-fold increase in both healthcare utilisation and frailty score in the 2 years after hospital discharge, whereas healthcare utilisation and frailty scores among controls were stable before and after hospitalisation. CONCLUSIONS: We observed a substantially increased rate of death in the years following ICU hospitalisation for elderly patients along with elevated healthcare resource use and accelerated age-associated decline as assessed by frailty score. These findings provide data for better informed goals-of-care discussions and may help target post-ICU discharge services.
Subject(s)
Patient Admission/statistics & numerical data , Respiratory Tract Infections/mortality , Survivors/statistics & numerical data , Aged , Aged, 80 and over , Cohort Studies , Female , France/epidemiology , Hospitalization/statistics & numerical data , Humans , Intensive Care Units/organization & administration , Intensive Care Units/statistics & numerical data , Kaplan-Meier Estimate , Length of Stay/statistics & numerical data , Male , Patient Admission/trends , Propensity Score , Proportional Hazards Models , Qualitative Research , Respiratory Tract Infections/epidemiologyABSTRACT
BACKGROUND: Community-acquired pneumonia (CAP) requires urgent and specific antimicrobial therapy. However, the causal pathogen is typically unknown at the point when anti-infective therapeutics must be initiated. Physicians synthesize information from diverse data streams to make appropriate decisions. Artificial intelligence (AI) excels at finding complex relationships in large volumes of data. We aimed to evaluate the abilities of experienced physicians and AI to answer this question at patient admission: is it a viral or a bacterial pneumonia? METHODS: We included patients hospitalized for CAP and recorded all data available in the first 3-h period of care (clinical, biological and radiological information). For this proof-of-concept investigation, we decided to study only CAP caused by a singular and identified pathogen. We built a machine learning model prediction using all collected data. Finally, an independent validation set of samples was used to test the pathogen prediction performance of: (i) a panel of three experts and (ii) the AI algorithm. Both were blinded regarding the final microbial diagnosis. Positive likelihood ratio (LR) values > 10 and negative LR values < 0.1 were considered clinically relevant. RESULTS: We included 153 patients with CAP (70.6% men; 62 [51-73] years old; mean SAPSII, 37 [27-47]), 37% had viral pneumonia, 24% had bacterial pneumonia, 20% had a co-infection and 19% had no identified respiratory pathogen. We performed the analysis on 93 patients as co-pathogen and no-pathogen cases were excluded. The discriminant abilities of the AI approach were low to moderate (LR+ = 2.12 for viral and 6.29 for bacterial pneumonia), and the discriminant abilities of the experts were very low to low (LR+ = 3.81 for viral and 1.89 for bacterial pneumonia). CONCLUSION: Neither experts nor an AI algorithm can predict the microbial etiology of CAP within the first hours of hospitalization when there is an urgent need to define the anti-infective therapeutic strategy.
Subject(s)
Coinfection/diagnosis , Community-Acquired Infections/microbiology , Community-Acquired Infections/virology , Pneumonia, Bacterial/diagnosis , Pneumonia, Viral/diagnosis , Aged , Artificial Intelligence , Bacterial Load , Female , Hospitalization , Humans , Male , Middle Aged , Physicians , Pneumonia, Bacterial/microbiology , Pneumonia, Viral/microbiology , Proof of Concept Study , ROC Curve , Retrospective Studies , Time Factors , Viral LoadABSTRACT
Importance: Coronavirus disease 2019 (COVID-19) is associated with severe lung damage. Corticosteroids are a possible therapeutic option. Objective: To determine the effect of hydrocortisone on treatment failure on day 21 in critically ill patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and acute respiratory failure. Design, Setting, and Participants: Multicenter randomized double-blind sequential trial conducted in France, with interim analyses planned every 50 patients. Patients admitted to the intensive care unit (ICU) for COVID-19-related acute respiratory failure were enrolled from March 7 to June 1, 2020, with last follow-up on June 29, 2020. The study intended to enroll 290 patients but was stopped early following the recommendation of the data and safety monitoring board. Interventions: Patients were randomized to receive low-dose hydrocortisone (n = 76) or placebo (n = 73). Main Outcomes and Measures: The primary outcome, treatment failure on day 21, was defined as death or persistent dependency on mechanical ventilation or high-flow oxygen therapy. Prespecified secondary outcomes included the need for tracheal intubation (among patients not intubated at baseline); cumulative incidences (until day 21) of prone position sessions, extracorporeal membrane oxygenation, and inhaled nitric oxide; Pao2:Fio2 ratio measured daily from day 1 to day 7, then on days 14 and 21; and the proportion of patients with secondary infections during their ICU stay. Results: The study was stopped after 149 patients (mean age, 62.2 years; 30.2% women; 81.2% mechanically ventilated) were enrolled. One hundred forty-eight patients (99.3%) completed the study, and there were 69 treatment failure events, including 11 deaths in the hydrocortisone group and 20 deaths in the placebo group. The primary outcome, treatment failure on day 21, occurred in 32 of 76 patients (42.1%) in the hydrocortisone group compared with 37 of 73 (50.7%) in the placebo group (difference of proportions, -8.6% [95.48% CI, -24.9% to 7.7%]; P = .29). Of the 4 prespecified secondary outcomes, none showed a significant difference. No serious adverse events were related to the study treatment. Conclusions and Relevance: In this study of critically ill patients with COVID-19 and acute respiratory failure, low-dose hydrocortisone, compared with placebo, did not significantly reduce treatment failure (defined as death or persistent respiratory support) at day 21. However, the study was stopped early and likely was underpowered to find a statistically and clinically important difference in the primary outcome. Trial Registration: ClinicalTrials.gov Identifier: NCT02517489.
Subject(s)
Anti-Inflammatory Agents/therapeutic use , Coronavirus Infections/drug therapy , Hydrocortisone/therapeutic use , Pneumonia, Viral/drug therapy , Respiration, Artificial , Respiratory Insufficiency/therapy , Aged , Anti-Inflammatory Agents/administration & dosage , Betacoronavirus , COVID-19 , Coronavirus Infections/mortality , Coronavirus Infections/therapy , Critical Illness , Double-Blind Method , Early Termination of Clinical Trials , Female , Humans , Hydrocortisone/administration & dosage , Male , Middle Aged , Oxygen Inhalation Therapy , Pandemics , Pneumonia, Viral/mortality , Pneumonia, Viral/therapy , Respiration, Artificial/statistics & numerical data , Respiratory Insufficiency/drug therapy , Respiratory Insufficiency/etiology , SARS-CoV-2 , Treatment Failure , COVID-19 Drug TreatmentABSTRACT
Interleukin (IL)-22 plays a critical role in regulating the maintenance of the mucosal barrier. As airway epithelial regeneration is abnormal in cystic fibrosis (CF), we investigated IL-22 integrity in CF. We first demonstrated, using Il-22-/- mice, that IL-22 is important to prevent lung damage induced by the CF pathogen Pseudomonas aeruginosa. Next, IL-22 receptor was found normally expressed at the airway epithelial surfaces of CF patients. In wound-healing assays, IL-22-treated CF cultures had higher wound-closure rate than controls, suggesting that IL-22 signaling per se could be functional in a CF context. However, persistence of neutrophil-derived serine-proteases is a major feature of CF airways. Remarkably, IL-22 was found altered in this protease-rich inflammatory microenvironment; the serine protease-3 being the most prone to fully degrade IL-22. Consequently, we suspect an acquired deficiency of the IL-22 pathway in the lungs of CF patients due to IL-22 cleavage by the surrounding neutrophil serine-proteases.
Subject(s)
Interleukins/immunology , Lung/immunology , Pseudomonas Infections/immunology , Pseudomonas aeruginosa/immunology , Respiratory Mucosa/immunology , Adolescent , Adult , Aged , Animals , Child , Cystic Fibrosis , Female , Humans , Interleukins/genetics , Lung/microbiology , Lung/pathology , Male , Mice , Mice, Knockout , Middle Aged , Pseudomonas Infections/genetics , Pseudomonas Infections/pathology , Respiratory Mucosa/microbiology , Respiratory Mucosa/pathology , Interleukin-22ABSTRACT
BACKGROUND: Nebulization during mechanical ventilation is impeded by large extra-pulmonary drug deposition and long administration durations which currently limit implementation of inhaled antibiotic therapy. Direct intra-tracheal delivery using a sprayer represents an appealing alternative investigated in small animal models, but large animal data are lacking. METHODS: Amikacin was administered through intravenous infusion (20â¯mg/kg), nebulization (60â¯mg/kg) and direct intra-tracheal spray (30â¯mg/kg) to 10 intubated piglets, in a randomized cross-over design. Amikacin concentrations were measured in the serum and pulmonary parenchyma. Anatomic deposition was investigated using immuno-histochemistry. RESULTS: Spray delivery resulted in higher amikacin outputs than nebulization and infusion. Pulmonary inhaled delivery techniques yielded much higher lung concentrations and much lower serum concentrations than intravenous infusion. However, unlike nebulization and infusion, intra-tracheal spray delivery was associated with more than 100- and 1000-fold variability in lung concentrations between and within animals. Amikacin specific immuno-histochemistry showed consistent bronchial and alveolar drug deposition with all modalities. CONCLUSION: Nebulization remains the most reliable and simple technique to deliver inhaled amikacin uniformly to the lung during mechanical ventilation. Further development of tracheal sprays is required to take advantage of potential benefits related to high drug output and low extra-pulmonary deposition in large animals.
Subject(s)
Amikacin/administration & dosage , Anti-Bacterial Agents/administration & dosage , Drug Delivery Systems/methods , Lung/metabolism , Aerosols , Animals , Infusions, Intravenous , Inhalation , Intubation , Models, Anatomic , Models, Animal , Nebulizers and Vaporizers , Swine , TracheaABSTRACT
The endotracheal tube (ETT) is an essential interface between the patient and ventilator in mechanically ventilated patients. However, a microbial biofilm is formed gradually on this tube and is associated with the development of ventilator-associated pneumonia. The bacteria present in the biofilm are more resistant to antibiotics, and current medical practices do not make it possible to eliminate. Pseudomonas aeruginosa is one of the leading pathogens that cause biofilm infections and ventilator-associated pneumonia. Poly-l-lysine (pLK) is a cationic polypeptide possessing antibacterial properties and mucolytic activity by compacting DNA. Here, we explored the antibiofilm activity of pLK to treat P. aeruginosa biofilms on ETTs while taking into consideration the necessary constraints for clinical translation in our experimental designs. First, we showed that pLK eradicates a P. aeruginosa biofilm formed in vitro on 96-well microplates. We further demonstrated that pLK alters bacterial membrane integrity, as revealed by scanning electron microscopy, and eventually eradicates biofilm formed either by reference or clinical strains of P. aeruginosa biofilms generated in vitro on ETTs. Second, we collected the ETT from patients with P. aeruginosa ventilator-associated pneumonia. We observed that a single dose of pLK is able to immediately disrupt the biofilm structure and kills more than 90% of bacteria present in the biofilm. Additionally, we did not observe any lung tolerance issue when the pLK solution was instilled into the ETT of ventilated pigs, an animal model particularly relevant to mimic invasive mechanical ventilation in humans. In conclusion, pLK appears as an innovative antibiofilm molecule, which could be applied in the ETT of mechanically ventilated patients.
Subject(s)
Biofilms/drug effects , Intubation, Intratracheal/adverse effects , Polylysine/pharmacology , Pseudomonas aeruginosa/drug effects , Respiration, Artificial/adverse effects , Animals , Anti-Bacterial Agents/pharmacology , Equipment Contamination , Humans , Microscopy, Electron, Scanning/methods , Pneumonia, Ventilator-Associated/drug therapy , SwineABSTRACT
Hemagglutinin (HA) of influenza virus must be activated by proteolysis before the virus can become infectious. Previous studies indicated that HA cleavage is driven by membrane-bound or extracellular serine proteases in the respiratory tract. However, there is still uncertainty as to which proteases are critical for activating HAs of seasonal influenza A viruses (IAVs) in humans. This study focuses on human KLK1 and KLK5, 2 of the 15 serine proteases known as the kallikrein-related peptidases (KLKs). We find that their mRNA expression in primary human bronchial cells is stimulated by IAV infection. Both enzymes cleaved recombinant HA from several strains of the H1 and/or H3 virus subtype in vitro, but only KLK5 promoted the infectivity of A/Puerto Rico/8/34 (H1N1) and A/Scotland/20/74 (H3N2) virions in MDCK cells. We assessed the ability of treated viruses to initiate influenza in mice. The nasal instillation of only the KLK5-treated virus resulted in weight loss and lethal outcomes. The secretion of this protease in the human lower respiratory tract is enhanced during influenza. Moreover, we show that pretreatment of airway secretions with a KLK5-selective inhibitor significantly reduced the activation of influenza A/Scotland/20/74 virions, providing further evidence of its importance. Differently, increased KLK1 secretion appeared to be associated with the recruitment of inflammatory cells in human airways regardless of the origin of inflammation. Thus, our findings point to the involvement of KLK5 in the proteolytic activation and spread of seasonal influenza viruses in humans.IMPORTANCE Influenza A viruses (IAVs) cause acute infection of the respiratory tract that affects millions of people during seasonal outbreaks every year. Cleavage of the hemagglutinin precursor by host proteases is a critical step in the life cycle of these viruses. Consequently, host proteases that activate HA can be considered promising targets for the development of new antivirals. However, the specific proteases that activate seasonal influenza viruses, especially H3N2 viruses, in the human respiratory tract have remain undefined despite many years of work. Here we demonstrate that the secreted, extracellular protease KLK5 (kallikrein-related peptidase 5) is efficient in promoting the infectivity of H3N2 IAV in vitro and in vivo Furthermore, we found that its secretion was selectively enhanced in the human lower respiratory tract during a seasonal outbreak dominated by an H3N2 virus. Collectively, our data support the clinical relevance of this protease in human influenza pathogenesis.
Subject(s)
Hemagglutinin Glycoproteins, Influenza Virus/metabolism , Host-Pathogen Interactions , Influenza A Virus, H3N2 Subtype/growth & development , Kallikreins/metabolism , Animals , Body Weight , Cells, Cultured , Disease Models, Animal , Epithelial Cells/virology , Humans , Influenza A Virus, H1N1 Subtype/growth & development , Mice, Inbred C57BL , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/virology , Proteolysis , Survival AnalysisABSTRACT
BACKGROUND: Intra-osseous (IO) access is recommended in cases of pre-hospital emergency or resuscitation when intravascular (IV) route is difficult or impossible. Despite recent improvement in IO devices and increasing indications, it remains rarely used in practice. Various complications have been reported but are uncommon. CASE PRESENTATION: We report a case of massive acute tibial osteomyelitis in an adult male three months after an IO catheter insertion for emergency drug infusion. We review the literature on association between IO access and acute osteomyelitis in children and adults. CONCLUSIONS: Emergency-care givers and radiologists should be informed about this infrequent complication in order to make early diagnosis and initiate adequate antibiotic therapy.
Subject(s)
Catheter-Related Infections/etiology , Drug Overdose/therapy , Infusions, Intraosseous/adverse effects , Osteomyelitis/etiology , Resuscitation , Tibia/microbiology , Acute Disease , Adult , Catheter-Related Infections/microbiology , Catheter-Related Infections/pathology , Emergency Medical Services , Humans , Iatrogenic Disease , Male , Osteomyelitis/microbiology , Osteomyelitis/pathology , Resuscitation/adverse effects , Resuscitation/methods , Staphylococcal Infections/etiology , Staphylococcal Infections/pathology , Staphylococcus aureus/isolation & purification , Tibia/pathologyABSTRACT
We report acute tetraplegia caused by rat bite fever in a 59-year old man (snake keeper) and transmission of Streptobacillus moniliformis. We found an identical characteristic bacterial pattern in rat and human samples, which validated genotyping-based evidence for infection with the same strain, and identified diagnostic difficulties concerning infection with this microorganism.
Subject(s)
Quadriplegia/etiology , Rat-Bite Fever/complications , Streptobacillus/isolation & purification , Amoxicillin-Potassium Clavulanate Combination/therapeutic use , Animal Husbandry , Animals , Anti-Bacterial Agents/therapeutic use , Humans , Male , Middle Aged , Nucleic Acid Amplification Techniques , Rat-Bite Fever/drug therapy , Rats , SnakesABSTRACT
Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease of the airways caused mainly by cigarette smoke exposure. COPD progression is marked by exacerbations of the disease, often associated with infections. Recent data show the involvement in COPD pathophysiology of interleukin (IL)-17 and IL-22, two cytokines that are important in the control of lung inflammation and infection. During the initiation and progression of the disease, increased IL-17 secretion causes neutrophil recruitment, leading to chronic inflammation, airways obstruction and emphysema. In the established phase of COPD, a defective IL-22 response facilitates pathogen-associated infections and disease exacerbations. Altered production of these cytokines involves a complex network of immune cells and dysfunction of antigen-presenting cells. In this review, we describe current knowledge on the involvement of IL-17 and IL-22 in COPD pathophysiology at steady state and during exacerbations, and discuss implications for COPD management and future therapeutic approaches.