Spatio-temporal brain invasion pattern of Streptococcus pneumoniae and dynamic changes in the cellular environment in bacteremia-derived meningitis.

Streptococcus pneumoniae (the pneumococcus) is the major cause of bacterial meningitis globally, and pneumococcal meningitis is associated with increased risk of long-term neurological sequelae. These include several sensorimotor functions that are controlled by specific brain regions which, during bacterial meningitis, are damaged by a neuroinflammatory response and the deleterious action of bacterial toxins in the brain. However, little is known about the invasion pattern of the pneumococcus into the brain. Using a bacteremia-derived meningitis mouse model, we combined 3D whole brain imaging with brain microdissection to show that all brain regions were equally affected during disease progression, with the presence of pneumococci closely associated to the microvasculature. In the hippocampus, the invasion provoked microglial activation, while the neurogenic niche showed increased proliferation and migration of neuroblasts. Our results indicate that, even before the outbreak of symptoms, the bacterial load throughout the brain is high and causes neuroinflammation and cell death, a pathological scenario which ultimately leads to a failing regeneration of new neurons.

Retrospective database analysis for clinical diagnoses commonly associated with pneumococcal diseases in the Malaysian healthcare system over a 3-year period (2013-2015).

BACKGROUND: Pneumococcal disease caused by Streptococcus pneumoniae is an important cause of morbidity and mortality across all ages, particularly in younger children and older adults. Here, we describe pneumococcal disease hospitalizations at Ministry of Health (MoH) facilities in Malaysia between 2013 and 2015. METHODS: This was a retrospective databases analysis. Tabular data from the Malaysian Health Data Warehouse (MyHDW) were used to identify microbiologically confirmed, pneumococcal disease hospitalizations and deaths during hospitalization, using hospital-assigned ICD-10 codes (i.e., classified as meningitis, pneumonia, or non-meningitis non-pneumonia). Case counts, mortality counts, and case fatality rates were reported by patient age group and by Malaysian geographic region. RESULTS: A total of 683 pneumococcal disease hospitalizations were identified from the analysis: 53 pneumococcal meningitis hospitalizations (5 deaths and 48 discharges), 413 pneumococcal pneumonia hospitalizations (24 deaths and 389 discharges), and 205 non-meningitis non-pneumonia pneumococcal disease hospitalizations (58 deaths and 147 discharges). Most hospitalizations occurred in children aged < 2 years. Crude mortality was highest among children aged < 2 years (for all three disease categories), among adults aged ≥ 65 years (for pneumococcal pneumonia), or among adults aged 65-85 years (for non-meningitis non-pneumonia pneumococcal disease). The case fatality rate, all ages included, was 5.8% for pneumococcal pneumonia, 9.1% for pneumococcal meningitis, and 28.3% for non-meningitis non-pneumonia pneumococcal disease. CONCLUSIONS: Our study is the first to document pneumococcal disease hospitalizations and deaths during hospitalization in Malaysia. Although this database analysis likely underestimated case counts, and the true disease burden could be even greater, the study demonstrates a substantial burden of pneumococcal disease. Public health measures, including vaccination, would significantly contribute to the prevention of hospitalizations and deaths associated with pneumococcal disease in Malaysia.

Seizures, focal neurological signs, and pneumococcal aetiology associate with impaired consciousness in childhood bacterial meningitis.

AIM: A low Glasgow Coma Scale Score (GCS) on admission is a known predictor of poor outcome from childhood bacterial meningitis. In turn, the factors associated with the admission GCS are less known. Our aim was to identify them, both for clinical alerts of reserved prognosis and to find potential targets for intervention. METHODS: This study is a secondary analysis of data collected prospectively in Angola and in Latin America between 1996 and 2007. Children with bacterial meningitis were examined on hospital admission and their GCS was assessed using the age-adjusted scale. Associations between on-admission GCS and host clinical factors were examined. RESULTS: A total of 1376 patients with confirmed bacterial meningitis were included in the analysis (609 from Latin America and 767 from Angola). The median GCS was 13 for all patients (12 in Angola and 13 in Latin America). In the multivariate analysis, in the areas combined, seizures, focal neurological signs, and pneumococcal aetiology associated with GCS <13, as did treatment delay in Latin America. CONCLUSION: Besides pneumococcal aetiology, we identified characteristics, easily registrable on admission, which are associated with a low GCS in childhood bacterial meningitis. Of these, expanding pneumococcal vaccinations and treatment delays could be modified.

[A multi-center epidemiological study on pneumococcal meningitis in children from 2019 to 2020]. / 2019­2020å¹´160ä¾‹å„¿ç«¥è‚ºç‚Žé“¾çƒèŒè„‘è†œç‚Žä¸´åºŠæµè¡Œç— å­¦å¤šä¸­å¿ƒç ”ç©¶.

OBJECTIVES: To investigate the clinical characteristics and prognosis of pneumococcal meningitis (PM), and drug sensitivity of Streptococcus pneumoniae (SP) isolates in Chinese children. METHODS: A retrospective analysis was conducted on clinical information, laboratory data, and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country. RESULTS: Among the 160 children with PM, there were 103 males and 57 females. The age ranged from 15 days to 15 years, with 109 cases (68.1%) aged 3 months to under 3 years. SP strains were isolated from 95 cases (59.4%) in cerebrospinal fluid cultures and from 57 cases (35.6%) in blood cultures. The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87) and 27% (21/78), respectively. Fifty-five cases (34.4%) had one or more risk factors for purulent meningitis, 113 cases (70.6%) had one or more extra-cranial infectious foci, and 18 cases (11.3%) had underlying diseases. The most common clinical symptoms were fever (147 cases, 91.9%), followed by lethargy (98 cases, 61.3%) and vomiting (61 cases, 38.1%). Sixty-nine cases (43.1%) experienced intracranial complications during hospitalization, with subdural effusion and/or empyema being the most common complication [43 cases (26.9%)], followed by hydrocephalus in 24 cases (15.0%), brain abscess in 23 cases (14.4%), and cerebral hemorrhage in 8 cases (5.0%). Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old, with rates of 91% (39/43) and 83% (20/24), respectively. SP strains exhibited complete sensitivity to vancomycin (100%, 75/75), linezolid (100%, 56/56), and meropenem (100%, 6/6). High sensitivity rates were also observed for levofloxacin (81%, 22/27), moxifloxacin (82%, 14/17), rifampicin (96%, 25/26), and chloramphenicol (91%, 21/23). However, low sensitivity rates were found for penicillin (16%, 11/68) and clindamycin (6%, 1/17), and SP strains were completely resistant to erythromycin (100%, 31/31). The rates of discharge with cure and improvement were 22.5% (36/160) and 66.2% (106/160), respectively, while 18 cases (11.3%) had adverse outcomes. CONCLUSIONS: Pediatric PM is more common in children aged 3 months to under 3 years. Intracranial complications are more frequently observed in children under 1 year old. Fever is the most common clinical manifestation of PM, and subdural effusion/emphysema and hydrocephalus are the most frequent complications. Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates. Adverse outcomes can be noted in more than 10% of PM cases. SP strains are high sensitivity to vancomycin, linezolid, meropenem, levofloxacin, moxifloxacin, rifampicin, and chloramphenicol.

Pericytes are protective in experimental pneumococcal meningitis through regulating leukocyte infiltration and blood-brain barrier function.

BACKGROUND: Brain pericytes participate in the regulation of cerebral blood flow and the maintenance of blood-brain barrier integrity. Because of their perivascular localization, their receptor repertoire, and their potential ability to respond to inflammatory and infectious stimuli by producing various cytokines and chemokines, these cells are also thought to play an active role in the immune response to brain infections. This assumption is mainly supported by in vitro studies, investigations in in vivo disease models are largely missing. Here, we analysed the role of brain pericytes in pneumococcal meningitis, in vitro and in vivo in two animal models of pneumococcal meningitis. METHODS: Primary murine and human pericytes were stimulated with increasing concentrations of different serotypes of Streptococcus pneumoniae in the presence or absence of Toll-like receptor inhibitors and their cell viability and cytokine production were monitored. To gain insight into the role of pericytes in brain infection in vivo, we performed studies in a zebrafish embryo model of pneumococcal meningitis in which pericytes were pharmacologically depleted. Furthermore, we analyzed the impact of genetically induced pericyte ablation on disease progression, intracranial complications, and brain inflammation in an adult mouse model of this disease. RESULTS: Both murine and human pericytes reacted to pneumococcal exposure with the release of selected cytokines. This cytokine release is pneumolysin-dependent, TLR-dependent in murine (but not human) pericytes and can be significantly increased by macrophage-derived IL-1b. Pharmacological depletion of pericytes in zebrafish embryos resulted in increased cerebral edema and mortality due to pneumococcal meningitis. Correspondingly, in an adult mouse meningitis model, a more pronounced blood-brain barrier disruption and leukocyte infiltration, resulting in an unfavorable disease course, was observed following genetic pericyte ablation. The degree of leukocyte infiltration positively correlated with an upregulation of chemokine expression in the brains of pericyte-depleted mice. CONCLUSIONS: Our findings show that pericytes play a protective role in pneumococcal meningitis by impeding leukocyte migration and preventing blood-brain barrier breaching. Thus, preserving the integrity of the pericyte population has the potential as a new therapeutic strategy in pneumococcal meningitis.

Neuronal death in pneumococcal meningitis is triggered by pneumolysin and RrgA interactions with ß-actin.

Neuronal damage is a major consequence of bacterial meningitis, but little is known about mechanisms of bacterial interaction with neurons leading to neuronal cell death. Streptococcus pneumoniae (pneumococcus) is a leading cause of bacterial meningitis and many survivors develop neurological sequelae after the acute infection has resolved, possibly due to neuronal damage. Here, we studied mechanisms for pneumococcal interactions with neurons. Using human primary neurons, pull-down experiments and mass spectrometry, we show that pneumococci interact with the cytoskeleton protein ß-actin through the pilus-1 adhesin RrgA and the cytotoxin pneumolysin (Ply), thereby promoting adhesion and invasion of neurons, and neuronal death. Using our bacteremia-derived meningitis mouse model, we observe that RrgA- and Ply-expressing pneumococci co-localize with neuronal ß-actin. Using purified proteins, we show that Ply, through its cholesterol-binding domain 4, interacts with the neuronal plasma membrane, thereby increasing the exposure on the outer surface of ß-actin filaments, leading to more ß-actin binding sites available for RrgA binding, and thus enhanced pneumococcal interactions with neurons. Pneumococcal infection promotes neuronal death possibly due to increased intracellular Ca2+ levels depending on presence of Ply, as well as on actin cytoskeleton disassembly. STED super-resolution microscopy showed disruption of ß-actin filaments in neurons infected with pneumococci expressing RrgA and Ply. Finally, neuronal death caused by pneumococcal infection could be inhibited using antibodies against ß-actin. The generated data potentially helps explaining mechanisms for why pneumococci frequently cause neurological sequelae.

The neurotoxic branch of the kynurenine pathway is highly activated in the central nervous system of patients with pneumococcal meningitis.

BACKGROUND: Acute bacterial meningitis (ABM) causes excessive activation of N-methyl-D-aspartate receptors (NMDAr), leading to cortical and hippocampal neuron death. As opposite, enteroviral meningitis is more frequently benign. The kynurenine (KYN) pathway is the major catabolic route of tryptophan (TRP) and some of its metabolites are agonists or antagonists of NMDAr. METHODS: In order to investigate the pathogen-specific patterns of KYN pathway modulation in the central nervous system of children with acute meningococcal (MM), pneumococcal (PM) or enteroviral (VM) meningitis, the cerebrospinal fluid (CSF) concentrations of TRP, KYN, kynurenic acid (KYNA) and quinolinic acid (QUINA) were evaluated by ultra-high performance liquid chromatography (uHPLC) coupled to mass spectrometry. In addition, CSF levels of IL-6, IL-10 and TNF-α were quantified by multi-analyte flow assay. The data was mined and integrated using statistical and machine learning methods. RESULTS: The three forms of meningitis investigated herein up-regulated the neurotoxic branch of the KYN pathway within the intrathecal space. However, this response, represented by the concentration of QUINA, was six and nine times higher in PM patients compared to MM or VM, respectively. CSF levels of IL-6, TNF-α, and IL-10 were increased in MM and PM patients when compared to controls. In VM, CSF IL-6 and IL-10, but not TNF-α were increased compared to controls, although not reaching the high levels found in bacterial meningitis. No correlation was found between the concentrations or the ratios of any pair of KYN metabolites and any cytokine or standard cytochemical parameter tested. CONCLUSIONS: CNS infection with meningococci, pneumococci, and enteroviruses intrathecally activate the KYN pathway, favoring its neurotoxic branch. However, in PM, higher CSF levels of QUINA, compared to MM and VM, may contribute to its poorer neurologic outcome.

Severe community-acquired Streptococcus pneumoniae bacterial meningitis: clinical and prognostic picture from the intensive care unit.

BACKGROUND: Severe community-acquired pneumococcal meningitis is a medical emergency. The aim of the present investigation was to evaluate the epidemiology, management and outcomes of this condition. METHODS: This was a retrospective, observational and multicenter cohort study. Sixteen Spanish intensive care units (ICUs) were included. Demographic, clinical and microbiological variables from patients with Streptococcus pneumoniae meningitis admitted to ICU were evaluated. Clinical response was evaluated at 72 h after antibiotic treatment initiation, and meningitis complications, length of stay and 30-day mortality were also recorded. RESULTS: In total, 255 patients were included. Cerebrospinal fluid (CSF) culture was positive in 89.7%; 25.7% were non-susceptible to penicillin, and 5.2% were non-susceptible to ceftriaxone or cefotaxime. The most frequent empiric antibiotic regimen was third-generation cephalosporin (47.5%) plus vancomycin (27.8%) or linezolid (12.9%). A steroid treatment regimen was administered to 88.6% of the patients. Clinical response was achieved in 65.8% of patients after 72 h of antibiotic treatment. Multivariate analysis identified two factors associated with early treatment failure: invasive mechanical ventilation (OR 10.74; 95% CI 3.04-37.95, p < 0.001) and septic shock (OR 1.18; 95% CI 1.03-1.36, p = 0.017). The 30-day mortality rate was 13.7%. Only three factors were independently associated with 30-day mortality: delay in start of antibiotic treatment (OR 18.69; 95% CI 2.13-163.97, p = 0.008), Sepsis-related Organ Failure Assessment (SOFA) score (OR 1.36; 95% CI 1.12-1.66, p = 0.002) and early treatment failure (OR 21.75 (3.40-139.18), p = 0.001). Neurological complications appeared in 124 patients (48.63%). CONCLUSIONS: Mortality rate in critically ill patients with pneumococcal meningitis is lower than previously reported. Delay in antibiotic treatment following admission is the only amendable factor associated with mortality.

Risk factors and pathogen characteristics associated with unfavorable outcomes among adults with pneumococcal meningitis in Japan, 2006 to 2016.

PURPOSE: In this study, we aimed to clarify the risk factors associated with unfavorable outcomes in adults with pneumococcal meningitis (PnM). METHODS: Surveillance was conducted between 2006 and 2016. Adults with PnM (n = 268) were followed up for outcomes within 28 days after admission using the Glasgow Outcome Scale (GOS). After classifying the patients into the unfavorable (GOS1-4) and favorable (GOS5) outcome groups, i) the underlying diseases, ii) biomarkers at admission, and iii) serotype, genotype, and antimicrobial susceptibility for all isolates were compared between both groups. RESULTS: Overall, 58.6% of patients with PnM survived,15.3% died, and 26.1% had sequelae. The number of living days in the GOS1 group was highly heterogeneous. Motor dysfunction, disturbance of consciousness, and hearing loss were the commonest sequelae. Of the underlying diseases identified in 68.9% of the PnM patients, liver and kidney diseases were significantly associated with unfavorable outcomes. Of the biomarkers, creatinine and blood urea nitrogen, followed by platelet and C-reactive protein had the most significant associations with unfavorable outcomes. There was a significant difference in the high protein concentrations in the cerebrospinal fluid between the groups. Serotypes 23F, 6C, 4, 23A, 22F, 10A, and 12F were associated with unfavorable outcomes. These serotypes were not penicillin-resistant isolates possessing three abnormal pbp genes (pbp1a, 2x, and 2b), except for 23F. The expected coverage rate of the pneumococcal conjugate vaccine (PCV) was 50.7% for PCV15 and 72.4% for PCV20. CONCLUSIONS: In the introduction of PCV for adults, the risk factors for underlying diseases should be prioritized over age, and serotypes with unfavorable outcomes should be considered.

Hearing outcomes in children with pneumococcal meningitis in the PCV13 era.

INTRODUCTION: Streptococcus pneumoniae, is associated with the highest incidence of post-meningitic SNHL. The exact impact of 13-valent pneumococcal conjugate vaccine (PCV) on pediatric SNHL from pneumococcal meningitis is unknown. We aimed to identify clinical factors associated with post-meningitic SNHL (pmSNHL) from pneumococcal meningitis and describe its rates based on three time periods: pre-PCV, PCV-7 and PCV13 eras. METHODS: A retrospective case-control study was performed for patients 18 years and younger diagnosed with pneumococcal meningitis from January 1, 2010 to December 31, 2020 at Children's Hospital Colorado. Demographic and clinical risk factors between those with or without SNHL were compared. Detailed hearing outcomes of those with resulting SNHL are described. RESULTS: 23 patients with CSF cultures or Meningitis/Encephalitis Panel positive for pneumococcal meningitis were identified. Twenty patients both survived the infection and had audiologic evaluation. Six patients had pmSNHL, with 50 % affected bilaterally. The rate of pmSNHL from S. pneumoniae in the PCV-13 era at our institution was similar to historical rates from the pre-PCV and PCV-7 eras. Similar proportions of patients with pmSNHL completed PCV vaccination (66.7 %) compared to those without (71.4 %). Non-PCV-13 serotypes were responsible 83 % of patients with pmSNHL versus 57 % of patients without pmSNHL. CONCLUSIONS: Despite high rates of PCV-13 uptake in our cohort, pmSNHL was still common, severe, and commonly associated with non-PCV-13 serotypes. Non-PCV-13 serotypes may be contributing to the persistently high rate of post-meningitic SNHL and the severity of SNHL. Newer pneumococcal conjugate vaccines with expanded serotypes may help mitigate the SNHL associated with pneumococcal meningitis.

Takotsubo cardiomyopathy in a 4-year-old female with pneumococcal meningitis.

A previously healthy 4-year-old female presented in cardiogenic shock with pneumococcal meningitis. Findings on echocardiogram raised suspicion for takotsubo cardiomyopathy. With supportive care, left ventricular systolic function normalised. Findings on cardiac imaging helped determine the aetiology and avoid further invasive studies or unnecessary treatment.

[Pneumococcal meningitis in children in Iceland - case report and summary].

An eleven month old girl was referred to the pediatric emergency department at Landspitali Hospital due to fever and lethargy. On examination she was acutely ill with fluctuating level of conciousness. She deteriorated quickly after arrival at the emergency department and was diagnosed with pneumococcal meningitis. In the past year several cases of bacterial meningitis have been diagnosed with Streptococcus pneumoniae as the most common pathogen. The disease causing serotypes have been serotypes that were not in the vaccine that was used in iceland and the Icelandic health authorities have decided to change the vaccination programme accordingly.

Pneumococcal Meningitis in Adults: A Prospective Nationwide Cohort Study Over a 20-year Period.

BACKGROUND: The epidemiology and treatment of pneumococcal meningitis has changed with the implementation of conjugate vaccines and the introduction of adjunctive dexamethasone therapy. METHODS: We analyzed episodes of community-acquired pneumococcal meningitis in adults (≥16 years) in the Netherlands, identified by the National Reference Laboratory for Bacterial Meningitis or treating physician between October 1, 1998, and April 1, 2002, and between January 1, 2006, and July 1, 2018. We studied incidence, pneumococcal serotypes, and clinical features. Predictors for unfavorable outcome (Glasgow Outcome Scale score 1-4) were identified in a multivariable logistic regression model. Two physicians independently categorized causes of death as neurological or systemic. RESULTS: There were 1816 episodes in 1783 patients. The incidence of 7- and 10-7-valent pneumococcal conjugate vaccine serotypes decreased (from 0.42 to 0.06, P = .001; from 0.12 to 0.03 episodes per 100 000 population per year, P = .014). Incidence of nonvaccine serotypes increased (from 0.45 to 0.68, P = .005). The use of adjunctive treatment with dexamethasone increased and was administered in 85% of patients in 2018. In-hospital death occurred in 363 episodes (20%) and unfavorable outcome in 772 episodes (43%). Delayed cerebral thrombosis occurred in 29 patients (2%), of whom 15 patients (52%) died. Adjunctive dexamethasone therapy was associated with favorable outcome (adjusted odds ratio 2.27, P < .001), individual pneumococcal serotypes were not. CONCLUSION: Implementation of conjugate vaccines and adjunctive dexamethasone therapy have changed the incidence and outcome of pneumococcal meningitis in adults over the last two decades. Despite recent advances pneumococcal meningitis remains associated with a residual high rate of mortality and morbidity.

Penicillin- and Cephalosporin-Resistant Pneumococcal Meningitis: Treatment in the Real World and in Guidelines.

To report on the therapy used for penicillin- and cephalosporin-resistant pneumococcal meningitis, we conducted an observational cohort study of patients admitted to our hospital with pneumococcal meningitis between 1977 and 2018. According to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations, we defined pneumococci as susceptible and resistant to penicillin with MIC values of ≤0.06 mg/L and > 0.06 mg/L, respectively; the corresponding values for cefotaxime (CTX) were ≤0.5 mg/L and >0.5 mg/L. We treated 363 episodes of pneumococcal meningitis during the study period. Of these, 24 had no viable strain, leaving 339 episodes with a known MIC for inclusion. Penicillin-susceptible strains accounted for 246 episodes (73%), penicillin-resistant strains for 93 (27%), CTX susceptible for 58, and CTX resistant for 35. Nine patients failed or relapsed and 69 died (20%), of whom 22% were among susceptible cases and 17% were among resistant cases. During the dexamethasone period, mortality was equal (12%) in both susceptible and resistant cases. High-dose CTX (300 mg/Kg/day) helped to treat failed or relapsed cases and protected against failure when used as empirical therapy (P = 0.02), even in CTX-resistant cases. High-dose CTX is a good empirical therapy option for pneumococcal meningitis in the presence of a high prevalence of penicillin and cephalosporin resistance, effectively treating pneumococcal strains with MICs up to 2 mg/L for either penicillin or CTX.

Role of astroglial Connexin 43 in pneumolysin cytotoxicity and during pneumococcal meningitis.

Streptococcus pneumoniae or pneumococcus (PN) is a major causative agent of bacterial meningitis with high mortality in young infants and elderly people worldwide. The mechanism underlying PN crossing of the blood brain barrier (BBB) and specifically, the role of non-endothelial cells of the neurovascular unit that control the BBB function, remains poorly understood. Here, we show that the astroglial connexin 43 (aCx43), a major gap junctional component expressed in astrocytes, plays a predominant role during PN meningitis. Following intravenous PN challenge, mice deficient for aCx43 developed milder symptoms and showed severely reduced bacterial counts in the brain. Immunofluorescence analysis of brain slices indicated that PN induces the aCx43-dependent destruction of the network of glial fibrillary acid protein (GFAP), an intermediate filament protein specifically expressed in astrocytes and up-regulated in response to brain injury. PN also induced nuclear shrinkage in astrocytes associated with the loss of BBB integrity, bacterial translocation across endothelial vessels and replication in the brain cortex. We found that aCx4-dependent astrocyte damages could be recapitulated using in vitro cultured cells upon challenge with wild-type PN but not with a ply mutant deficient for the pore-forming toxin pneumolysin (Ply). Consistently, we showed that purified Ply requires Cx43 to promote host cell plasma membrane permeabilization in a process involving the Cx43-dependent release of extracellular ATP and prolonged increase of cytosolic Ca2+ in host cells. These results point to a critical role for astrocytes during PN meningitis and suggest that the cytolytic activity of the major virulence factor Ply at concentrations relevant to bacterial infection requires co-opting of connexin plasma membrane channels.

DNase Treatment Prevents Cerebrospinal Fluid Block in Early Experimental Pneumococcal Meningitis.

OBJECTIVE: Streptococcus pneumoniae is the most common cause of bacterial meningitis, a disease that, despite treatment with antibiotics, still is associated with high mortality and morbidity worldwide. Diffuse brain swelling is a leading cause of morbidity in S pneumoniae meningitis. We hypothesized that neutrophil extracellular traps (NETs) disrupt cerebrospinal fluid (CSF) transport by the glymphatic system and contribute to edema formation in S pneumoniae meningitis. METHODS: We used DNase I treatment to disrupt NETs and then assessed glymphatic function by cisterna magna injections of CSF tracers in a rat model of S pneumoniae meningitis. RESULTS: Our analysis showed that CSF influx into the brain parenchyma, as well as CSF drainage to the cervical lymph nodes, was significantly reduced in the rat model of S pneumoniae meningitis. Degrading NETs by DNase treatment restored glymphatic transport and eliminated the increase in brain weight in the rats. In contrast, first-line antibiotic treatment had no such effect on restoring fluid dynamics. INTERPRETATION: This study suggests that CSF accumulation is responsible for cerebral edema formation and identifies the glymphatic system and NETs as possible new treatment targets in S pneumoniae meningitis. ANN NEUROL 2021;90:653-669.

Non-steroidal anti-inflammatory drugs ketorolac and etodolac can augment the treatment against pneumococcal meningitis by targeting penicillin-binding proteins.

BACKGROUND: Streptococcus pneumoniae is the principal etiological agent of acute bacterial meningitis (ABM) which has fatal outcome in children and elderly. Due to poor blood-brain barrier (BBB) permeation, conventional ß-lactam antibiotics fail to establish the requisite bactericidal concentration in central nervous system leading to resistance in meningeal infections. The present study intended to identify potential therapeutic alternatives against Streptococcal meningitis. METHODS: Virtual screening, pharmacokinetics/pharmacodynamics (PK/PD) and anti-bacterial evaluations were employed to screen potential drugs. Molecular docking and structural dynamics simulations were performed to analyze the binding affinity and interaction stability of the drugs against the conventional Penicillin binding protein (PBP) targets. Screened drugs were also checked for interactions with other possible Streptococcal targets and relevant host targets. RESULTS: Non-steroidal anti-inflammatory drugs (NSAIDs) ketorolac and etodolac exhibiting high BBB-permeation and anti-bacterial potency were identified. Ketorolac and etodolac possessed uniform binding affinities against PBP1A, PBP2X, PBP2B and PBP3 with low inhibition constants (<50 µM). Against PBP2B and PBP3, higher binding affinities were observed for ketorolac (-6.45 and -6Kcal/mol respectively) and etodolac (-6.36 and -6.55Kcal/mol respectively) than penicillin (-5.95 and -5.85Kcal/mol respectively) and cefotaxime (-5.08 and -5.07Kcal/mol respectively). The binding affinities were contributed by conventional H-bonds and non-canonical interactions with active site residues of PBPs. Structural dynamics simulations further indicated the overall stability of the drug-bound complexes through minimal overall average root-mean square fluctuations (RMSFs) (<1.0 Å). The average binding affinities of Ketorolac and Etodolac with PBPs were marginally higher than other Streptococcal targets and comparable to their conventional inflammatory targets. CONCLUSION: Pharmacological and structural profiles indicated that ketorolac and etodolac can potentially subdue the cause and effects of streptococcal meningitis and hence encourage experimental validations.

Relationship between serotypes, disease characteristics and 30-day mortality in adults with invasive pneumococcal disease.

PURPOSE: Invasive pneumococcal disease (IPD) is responsible for substantial mortality and morbidity worldwide. We aimed to identify host and bacterial factors associated with 30-day mortality in 18-year-old patients hospitalized with IPD in France from 2013 to 2015. METHODS: This study analyzed data collected from consecutives IPD cases included in two parallel multi-center cohort studies: COMBAT study (280 patients with pneumococcal community-acquired bacterial meningitis) and SIIP study (491 patients with non-meningitis IPD). Factors associated with 30-day mortality were identified using logistic regression. RESULTS: Among the 771 enrolled patients (median age 66 years, IQR [52.0-79.7]), 592/767 (77.2%) had at least one chronic disease. Patients with meningitis were younger (60.2 vs 70.9 years; p < 0.001) and had fewer chronic diseases than those with non-meningitis IPD (73.3% vs 79.4%; p = 0.05). Non-vaccine serotypes were more frequent in meningitis patients than in those with other IPD (36.1% vs 23.1%; p < 0.001). The overall 30-day mortality was 16.7% and patients with concurrent meningitis and extra-cerebral IPD had the highest 30-day mortality rate (26.5%). On multivariate analyses, older age, history of malignant solid tumor, meningeal IPD and serotypes previously identified with high mortality potential were independently associated with 30-day mortality. Of the serotypes with high mortality potential, 80% were included in licensed (PCV13 or PPV23) vaccines. CONCLUSION: We observed an effect of both host factors and pneumococcal serotypes on 30-day mortality in IPD. This highlights the need for a focused strategy to vaccinate at-risk patients. CLINICAL TRIAL: ClinicalTrial. Gov identification number: NCT01730690.

Pneumococcal meningitis and COVID-19: dangerous coexistence. A case report.

BACKGROUND: SARS-CoV-2 is the major cause of infections in humans since December 2019 and is top of the global health concern currently. Streptococcus pneumoniae is one of the leading pathogens of invasive bacterial diseases, including pneumonia, sepsis, and meningitis. Moreover, this bacteria is mostly responsible for secondary infections subsequent to post-viral respiratory disease. Co-infections with bacterial and viral pathogens are associated with severe course of the disease and are a major cause of mortality. In this report, we describe a rare case of COVID-19 patient with pneumococcal sepsis and meningitis of unsuccessful course. CASE PRESENTATION: A 89-year-old man, not vaccinated against SARS-CoV-2 infection, was diagnosed with COVID-19 pneumonia. Patient required oxygen therapy due to respiratory failure. The initial treatment of viral infection with tocilizumab and dexamethasone allowed for the stabilization of the patient's condition and improvement of laboratory parameters. On the 9th day of hospitalization the patient's condition deteriorated. Consciousness disorders and acute respiratory disorders requiring intubation and mechanical ventilation were observed. Brain computed tomography excluded intracranial bleeding. The Streptococcus pneumoniae sepsis with concomitant pneumoniae and meningitis was diagnosed based on microbiological culture of blood, bronchial wash, and cerebrospinal fluid examination. Despite targeted antibiotic therapy with ceftriaxone and multidisciplinary treatment, symptoms of multiple organ failure increased. On the 13th day of hospitalization, the patient died. CONCLUSIONS: Co-infections with bacterial pathogens appear to be not common among COVID-19 patients, but may cause a sudden deterioration of the general condition. Not only vascular neurological complications, but also meningitis should be always considered in patients with sudden disturbances of consciousness. Anti-inflammatory treatment with the combination of corticosteroids and tocilizumab (or tocilizumab alone) pose a severe risk for secondary lethal bacterial or fungal infections. Thus, treating a high-risk population (i.e. elderly and old patients) with these anti-inflammatory agents, require daily clinical assessment, regular monitoring of C-reactive protein and procalcitonin, as well as standard culture of blood, urine and sputum in order to detect concomitant infections, as rapidly as possible.

Clinical Features and Outcomes of Streptococcus pneumoniae Meningitis in Children: A Retrospective Analysis of 26 Cases in China.

BACKGROUND: Streptococcus pneumoniae is an important cause of pediatric meningitis. OBJECTIVE: The aim of this study was to analyze the clinical features and outcomes of children with pneumococcal meningitis at our hospital in China, so as to provide basis for improving the clinical treatment effect. METHODS: This retrospective analysis included patients aged <16 years treated for pneumococcal meningitis at the Department of Neurology, Children's Hospital of Shanxi (January 2014-February 2016). Clinical data were extracted from the medical records. Patients were followed up for 6 months after discharge. RESULTS: The analysis included 26 children aged 2 months to 13 years, with 17 (65.4%) aged <3 years. Presenting symptoms included fever (100%), lethargy (100%), impaired consciousness (88.5%), neck stiffness (69.2%), seizures (53.8%), and headache (50.0%). All patients had positive cerebrospinal fluid (CSF) cultures. The final treatment was vancomycin combined with a third-generation cephalosporin or other antibiotics in 25 patients. Eleven patients (42.3%) were recovered, 3 (11.5%) had neurological sequelae, and 12 (46.2%) died. Impaired consciousness (p = 0.035), cerebral hernia (p = 0.037), respiratory failure (p = 0.004), heart failure (p = 0.044), septic shock (p = 0.037), low CSF white blood cell count (p = 0.036), high CSF protein levels (p = 0.028), low white blood cell count (p = 0.036), and low blood neutrophil ratio (p = 0.016) are associated with a poor prognosis to pneumococcal meningitis. CONCLUSION: Pneumococcal meningitis is associated with a poor prognosis in many children. Poor prognosis might be related to early ineffective antibiotic therapy, a combination of systemic failure, neurological problems, and changed inflammatory response. It is important to rapid initiation of appropriate antibiotic therapy if meningitis is suspected.