Epidemiology, diagnosis, and antimicrobial treatment of acute bacterial meningitis

Heparin-Binding Protein in Cerebrospinal Fluid as a Biomarker for Bacterial Meningitis: A Study of Diagnostic Accuracy

OBJECTIVE

We aimed to evaluate the diagnostic accuracy of heparin-binding protein (HBP) in cerebrospinal fluid for the diagnosis of bacterial meningitis in patients with a suspected central nervous system infection.

METHODS

This prospective multicenter cohort study determined the diagnostic accuracy of HBP in cerebrospinal fluid (CSF) for bacterial meningitis among a cohort of consecutive patients with a suspected central nervous infection. The final clinical diagnosis was considered the reference standard. The results were validated in a separate cohort.

RESULTS

A total of 631 Dutch patients were evaluated for the current study, of which 73 (12%) had a final diagnosis of bacterial meningitis. For the differentiation of bacterial meningitis from all other disorders, diagnostic accuracy was high with an area under the curve (AUC) of 0.98 (95% confidence interval [CI] 0.96-1.00). With the proposed cutoff of 5.2 ng/ml, sensitivity was 97% with a specificity of 96%. In the population of patients with a CSF leukocyte count of 5-1,000/mm3, the AUC was 0.96 (95% CI 0.87-1.00), outperforming CSF leukocytes (AUC 0.88 [95% CI 0.79-0.97]). Combining HBP with CSF C-reactive protein (CRP) significantly increased accuracy in this population and reached a 100% sensitivity (AUC 1.00 [95% CI 0.99-1.00], cutoff 0.07, sensitivity 100%, specificity 96%). These results remained robust in an external validation cohort of 120 Danish patients (AUC 0.97 [95% CI 0.93-1.00]).

INTERPRETATION

HBP can correctly distinguish bacterial meningitis from other disorders. It can be of additional value to current diagnostics in cases where CSF leukocyte count is relatively low, particularly when combined with CSF CRP. ANN NEUROL 2025;97:1088-1095.

Lumbar Puncture and Brain Herniation in Acute Bacterial Meningitis: An Updated Narrative Review

The risk of lumbar puncture (LP) to precipitate brain herniation in acute bacterial meningitis (ABM) was reviewed in this journal in 2007. We report the case of an infant with ABM who had acute apnea requiring intubation and tonic posturing (mistaken for seizure), and then had brain herniation within four hours of an LP. The case prompted this updated narrative review, from 2007 to 2024, focused on the twelve points made in 2007. The review included 14 case reports of brain herniation shortly after LP in ABM, 23 observational studies or systematic reviews, 28 narrative reviews, and 9 guidelines, each with evidence, advice, or recommendations important for the decision to perform LP in ABM. We found evidence to support, and did not find convincing evidence to refute, the twelve points. We found five additional claims made that were meant to refute some of the original points; however, these were based upon data that did not support the claims made. Limitation of the evidence reviewed was the absence of randomized trials to prove whether those patients who herniated may have been destined to herniate regardless of whether they had an LP. Reasons why ABM may be a unique circumstance where normal CT scan cannot determine the risk of herniation after an LP were discussed. We argue that the preponderance of evidence supported the conclusion that, in a patient with strongly suspected ABM who is clinically considered at high risk for herniation, interventions to control ICP and antibiotics administration should be the priority, followed secondarily by an urgent CT scan and, even with a normal CT, not an LP. The case report emphasized that respiratory arrest or suspected tonic seizure can be due to early herniation, and indicate CT scan, and prolonged LP deferral (for 3-4 days) even with a normal CT.

Bacterial meningitis is a significant catalyst for neuroinflammation

Bacterial meningitis is a severe infection that can lead to neuroinflammation, posing risks to the central nervous system (CNS). This inflammation, if uncontrolled, can cause long-term neurological damage, cognitive decline, and neuron injury. Management strategies include telemedicine and remote monitoring, enabling continuous observation and timely adjustments in treatment. Early detection through biosensor technology is vital, offering healthcare providers insights for proactive intervention before critical issues arise. Nutritional support, particularly hydration, is also emphasized to strengthen immune response and potentially delay disease progression. The chapter highlights the transformative potential of Artificial Intelligence (AI) and machine learning in disease management, from prognostic assessments to creating personalized treatment plans. By integrating AI-driven insights with advanced monitoring and preventive approaches, healthcare providers can mitigate the impact of bacterial meningitis, enhancing patient outcomes and recovery potential.

Determinants of cerebrospinal fluid leakage in a large cohort of macroprolactinomas

INTRODUCTION

Macroprolactinomas are the most frequent subtype of pituitary adenomas. Their treatment has been improved since the onset of dopamin agonists (DA). Nevertheless, DA can cause a cerebospinal fluid (CSF) leakage by shrinking the tumor and lead to a bacterial meningitis. This complication might have lethal consequences.

METHODS

We conducted an observational, retrospective study in the Pituitary Unit in Pitié Salpêtrière Hospital. A total of 171 patients with macroprolactinomas (larger diameter greater than 10mm) were included in the study. We compared patients who presented cerebrospinal rhinorrhea and/or meningitis, so-called complicated patients (C group), to patients who presented no complications during their follow-up, so-called uncomplicated patients (UC group): no occurrence of rhinorrhea, meningitis.

RESULTS

Cerebrospinal fluid (CSF) leakage has been found in 5% of patients in our large cohort of macroprolactinoma. Determinants of CSF leakage seems to be : adenoma size with concomitant supra- and infrasellar extension, very high prolactin level (>1000µg/l), cabergoline treatment.

CONCLUSION

Cerebrospinal rhinorrhea is a rare complication of macroprolactinomas, but potentially lethal because of meningitis risk. Anti-pneumococcal and anti-haemophilus vaccination appears to be appropriate in these patients at the time of introduction of DA, to prevent meningitis.

Meningitis caused by Streptococcus pyogenes triggered by malignant otitis externa: A case report

A previously healthy 58-year-old male initially presented to a healthcare facility with otorrhea in his left ear, accompanied by a scab in both the auricle and ear canal, with a lesion protruding from the left cavity and oozing discharge (day 0). The following day, the patient was transferred to our facility with fever and altered consciousness. Imaging studies, including computed tomography and magnetic resonance imaging, revealed a soft tissue mass in the left maxillary, ethmoid and sphenoid sinuses, and diffuse pus within the subdural space over the bilateral frontoparietal regions. Cerebrospinal fluid (CSF) analysis showed elevated opening pressure, increased white blood cell count, predominance of polymorphonuclear leukocytes, elevated protein levels, and reduced glucose levels compared to the serum. Streptococcus pyogenes was identified in ear discharge, CSF, and blood cultures using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The presence of a papilloma in the left nasal cavity suggested that malignant otitis externa (MOE) served as the entry point for infection, leading to meningitis. The patient was treated with a combination of ceftriaxone and vancomycin, followed by ceftriaxone and cefotaxime, surgical resection of the tumor, and local debridement for infection control. To date, this is the first reported case of S. pyogenes-induced meningitis secondary to MOE. Although rare, the detection of S. pyogenes in otitis externa emphasizes the necessity of comprehensive evaluation of ear pathology to enable effectively source control as well as manage related infections and complications.

Bloodstream infections: mechanisms of pathogenesis and opportunities for intervention

Bloodstream infections (BSIs) are common in hospitals, often life-threatening and increasing in prevalence. Microorganisms in the blood are usually rapidly cleared by the immune system and filtering organs but, in some cases, they can cause an acute infection and trigger sepsis, a systemic response to infection that leads to circulatory collapse, multiorgan dysfunction and death. Most BSIs are caused by bacteria, although fungi also contribute to a substantial portion of cases. Escherichia coli, Staphylococcus aureus, coagulase-negative Staphylococcus, Klebsiella pneumoniae and Candida albicans are leading causes of BSIs, although their prevalence depends on patient demographics and geographical region. Each species is equipped with unique factors that aid in the colonization of initial sites and dissemination and survival in the blood, and these factors represent potential opportunities for interventions. As many pathogens become increasingly resistant to antimicrobials, new approaches to diagnose and treat BSIs at all stages of infection are urgently needed. In this Review, we explore the prevalence of major BSI pathogens, prominent mechanisms of BSI pathogenesis, opportunities for prevention and diagnosis, and treatment options.

The added value of metagenomic next-generation sequencing in central nervous system infections: a systematic review of case reports

BACKGROUND

The diversity of pathogens causing central nervous system (CNS) infections presents a diagnostic challenge. Patient demographics and geographical location affect the likelihood of certain pathogens causing infection. Current diagnostic methods rely on labour-intensive cultivation or targeted detection. Metagenomic next-generation sequencing (mNGS) is a promising tool for detecting pathogens in CNS infections, offering an unbiased approach. To enhance our understanding of patient demographics and the range of pathogens identified through mNGS, we conducted a systematic review of case reports.

METHODS

The PubMed database was searched in March 2024. Case reports on CNS infections and mNGS published from January 2014 through February 2024 were included based on predefined criteria.

RESULTS

The search yielded 649 articles, of which 76 were included, encompassing 104 patients. Most patients were male (75%), the median age was 31,5 years [0-75] and 28% were immunocompromised. The most common diagnosis was encephalitis (36%), followed by meningitis (23%) and meningoencephalitis (22%). 53 unique pathogens were identified, comprising 27 different viruses, 19 bacteria, 5 parasites, and 2 fungi. Syndromic encephalitis/meningitis panels would only have detected four of the viruses and five of the bacteria. Additionally, 14 of the bacterial species are considered slow-growing or fastidious and could be challenging to detect by culture.

CONCLUSION

The application of mNGS in diagnosing CNS infections reveals the diversity of pathogens responsible for these severe infections, thereby improving diagnostics and facilitating targeted treatment. While case reports may be subjected to bias, they provide valuable insights into the use of mNGS in this clinical context.

Validation of glucose and lactate in cerebrospinal fluid (CSF) on a Radiometer blood gas analyzer ABL90 Flex plus

PURPOSE

Rapid determination of cerebrospinal fluid (CSF) glucose and lactate is required by emergency rooms and intensive care units. Long turnaround time (TAT) on test results negatively impacts timely diagnosis and treatment of neurological infections like meningitis.

METHODS

The CSF glucose and lactate assays were evaluated on a blood gas analyzer, Radiometer ABL90 Flex Plus. Linearity, limit of quantitation (LOQ), and precision were determined using fresh and spiked patient CSF samples. Fifty-four fresh and 49 frozen CSF samples were used to compare the method againstAbbottArchitectC16000. An inter-laboratory comparison was done across eight hospital sites having ABL90 Flex Plus. The stability of both tests was tested for 48 h at ambient and refrigerated temperatures. Results were compared between centrifuged and uncentrifuged fresh CSF samples to determine if particulate in uncentrifuged samples impacted analysis.

RESULTS

Glucose and lactate assays were linear over a broad analytical range of 1-45 mmol/L and 0-37 mmol/L, respectively, and demonstrated a good correlation with the routine chemistry laboratory method. LOQ was determined as 0.4 mmol/L for CSF glucose with a coefficient of variation (CV) of 14.7 % and 0.2 mmol/L with 0 % CV for CSF lactate respectively. Repeatability and reproducibility show small imprecision for both these assays. Glucose and lactate were stable for over 48 h at room or refrigeration temperatures. Sample particulates had no impact on the measurement. The inter-laboratory comparison was within total allowable error for glucose and lactate.

CONCLUSIONS

Acceptable performance characteristics, small sample volume, and rapid TAT make ABL90 Flex Plus an acceptable alternative analyzer for CSF glucose and lactate.

Protonated carbon nitride for rapid photocatalytic sterilization via synergistic oxidative damage and physical destruction

Photocatalytic disinfection is an eco-friendly strategy for countering bacterial pollution in aquatic environments. Numerous strategies have been devised to facilitate the generation of reactive oxygen species (ROS) within photocatalysts, ultimately leading to the eradication of bacteria. However, the significance of the physical morphology of photocatalysts in the context of sterilization is frequently obscured, and the progress in the development of physical-chemical synergistic sterilization photocatalysts has been relatively limited. Herein, graphitic carbon nitride (g-C3N4) is chemically protonated to expose more sharp edges. PL fluorescence and EIS results indicate that the protonation can accelerate photogenerated carrier separation and enhance ROS production. Meanwhile, the sharp edges on the protonated g-C3N4 facilitate the physical disruption of cell walls for further promoting oxidative damage. Protonated C3N4 demonstrated superior bactericidal performance than that of pristine g-C3N4, effectively eliminating Escherichia coli within 40 minutes under irradiation. This work highlights the significance of incorporating physical and chemical synergies in photocatalyst design to enhance the disinfection efficiency of photocatalysis.

Unraveling the interplay between meningitis and mitochondria: Etiology, pathogenesis, and therapeutic insights

Meningitis, characterized by an inflammatory response affecting the membranes surrounding the brain and spinal cord, poses a formidable challenge to global public health. Its etiology spans a spectrum of infectious agents, ranging from bacteria, to viruses, fungi, and parasites. Concurrently, mitochondria-traditionally known as 'cellular powerhouses'-have emerged as critical players in various essential biological functions, including but not limited to, energy production, metabolic regulation, and cell fate determination. Emerging evidence suggests that mitochondria may play vital roles in the pathogenesis of meningitis. In this review, we delineated the definition, classification, etiology, pathogenesis, and clinical manifestations of meningitis, and elucidated the structure, dynamics and functions of mitochondria. We subsequently delved into the intricate interplay between meningitis and mitochondria, identifying potential therapeutic interventions targeting mitochondria for the first time. With clinical trials on the horizon, our review lays the foundation for a transformative era in meningitis therapeutics, where unraveling the intricate interplay between meningitis and mitochondria offers promise for mitigating neuroinflammation and improving patient outcomes.

Pediatric bacterial meningitis in southern China: analysis of 838 cases

Objective

This work aims to study the clinical features and risk factors of children with bacterial meningitis (BM) in southern China.

Methods

Clinical data of children with BM between 2012 and 2018 from one national center were analyzed retrospectively.

Results

A total of 838 patients (male/female = 1.8:1) were enrolled, with 90.6% under 1 year old. Common symptoms included fever, seizure, lethargy, vomiting, anorexia, poor feeding, and irritability. Most patients initially exhibited typical cerebrospinal fluid (CSF) changes of BM, including elevated white blood cell count, increased protein levels, and decreased glucose concentration. Some initially atypical cases showed typical changes after about 1 week. Furthermore, 38.7% of the patients had positive bacterial cultures of blood or CSF, with Streptococcus agalactiae, Escherichia coli, and Streptococcus pneumoniae commonly seen. Moreover, 92.0% of the patients were graded five Glasgow outcome scale (GOS) points at discharge. Differences in symptoms, pathogens, CSF results, brain MRI, and GOS points were observed across age groups (neonate [29 days, 12 months) and aged ≥12 months). Fatality rate was 1.9%, and 10.7% of survivors had neurological sequelae. Recurrent BM was rare (1.6%) but notable in patients with CSF fistula or immunodeficiency. Risk factors for intensive care unit admission, brain parenchymal involvement, subdural effusion, and hearing impairment were identified.

Conclusion

Most pediatric BM patients in southern China were under 1 year old, with more distribution in male patients and some age-related differences in clinical features and outcomes. Recurrent BM is rare but more likely in patients with conditions such as CSF fistula or immunodeficiency. Most patients have favorable outcomes, with a low fatality rate and around 10% of the survivors experiencing neurological sequelae. Several clinical risk factors were identified.

Comparison of positive BioFire FilmArray meningitis/encephalitis (ME) panels, CSF cultures, CSF parameters, clinical presentation and in-patient mortality among patients with bacterial and fungal meningitis

The BioFire FilmArray meningitis/encephalitis panel (MEP) was brought to the University of Kentucky in 2016 to aid in the identification of community-acquired meningitis and encephalitis (ME). This panel has shown variable performance with some institutions showing high sensitivity and specificity for many pathogens but others seeing false positives during clinical use. We evaluated the panel's performance using retrospective chart review of patients at the University of Kentucky from October 2016 to September 2022, including 7,551 MEP results. Cerebrospinal fluid (CSF) samples with positive results for bacterial and fungal pathogens were compared with CSF and blood cultures, other laboratory parameters, and clinical presentations, to classify MEP results as true positive (TP), likely TP, or false positive (FP). Of 132 patients with positive bacterial or fungal MEP results, 48.9% of bacterial and 88.9% of cryptococcal analytes were classified as TP. The positive predictive value (PPV) varied by organism, with the highest being Listeria monocytogenes and Neisseria meningitidis. One-third of the FP results were Streptococcus agalactiae. Among patients with likely TP, 75.7% (28 out of 37) received oral or IV antibiotics before blood or CSF culture. MEP was 100% specific compared to culture. The PPV based on pathogen ranged from 78.6% to 100%. Interestingly, 27.4% (29 out of 106) cases (excluding FPs) would have no pathogen definitively identified if MEP had not been used. This study highlights the utility of MEP in rapidly diagnosing ME, particularly in patients pretreated with antibiotics. It also emphasizes the importance of correlating MEP results with clinical assessments and other diagnostic tests to assure accuracy.

IMPORTANCE

This study compares the performance of the meningitis/encephalitis panel (MEP) in detecting bacterial and fungal pathogens with cerebrospinal fluid cultures and other parameters. Almost half of bacterial analytes of MEP had positive cerebrospinal fluid (CSF) or blood cultures; the remaining 42% of bacterial analytes were correlated with clinical presentation and other CSF parameters. 27.4% (29 out of 106) cases would not have had a pathogen definitively identified if the MEP had not been used. This study highlights the importance of using MEP as a diagnostic tool, especially in patients who have already received antibiotics, where traditional culture-based methods may not be diagnostic. This research underscores the use of MEP in improving the speed of diagnosing meningitis. However, it emphasizes that MEP can produce false positive results in some patients. It is therefore necessary to interpret MEP results together with clinical assessments and other diagnostic tests to ensure the most accurate diagnosis.

Triple threat: Sequential meningitis infections in an immunosuppressed patient with Morganella morganii, Acinetobacter baumannii, and vancomycin-resistant Enterococcus faecium

Gram-negative bacilli and vancomycin-resistant enterococci (VRE) are rare causative agents in the etiology of bacterial meningitis and can lead to significant mortality due to the difficulty of treatment. This article reports three successive cases of different meningitis clinical presentations in an immunosuppressed patient diagnosed with diffuse large B-cell lymphoma. A 65-year-old male patient was initially followed with Morganella morganii meningitis. Later, the patient was diagnosed with Acinetobacter meningitis and VRE meningitis. Clinical and microbiological success was achieved following a prolonged hospital stay and antibiotic therapy.

Streptococcus agalactiae Meningitis in an Adult: A Case Report

Streptococcus agalactiae meningitis is usually observed among neonates. We present a rare case of Streptococcus agalactiae meningitis in a 33-year-old immunocompromised male patient with Burkitt lymphoma. Initially, the patient exhibited nonspecific symptoms, including postprandial vomiting, blurred vision, and episodic memory loss. Cerebrospinal fluid (CSF) analysis and imaging revealed meningitis. Empiric antibiotic therapy with ceftriaxone and vancomycin, followed by targeted ampicillin treatment, resulted in complete resolution. This case highlights the importance of considering unusual pathogens in immunocompromised patients with nonspecific symptoms and underscores the need for prompt diagnosis and targeted antibiotic therapy.

Factors Associated with In-Hospital Mortality in Adult Patients with Bacterial Meningitis

Background/Objectives: The aim of this study was to evaluate the association between various clinical and laboratory findings and in-hospital mortality in community-acquired bacterial meningitis (BM). Methods: We retrospectively analyzed 339 adult (≥18 years old) patients with bacterial meningitis who were admitted to the Hospital for Infectious Diseases in Warsaw between January 2010 and December 2017. Results: Altogether, 56 patients (16.5%) died during hospitalization. On admission, the non-survivors scored lower on the Glasgow Coma Scale (GCS) (median 7 vs. 13, p < 0.001) and higher on the Sequential Organ Failure Assessment (SOFA) score (median 6 vs. 2, p < 0.001) and were less likely to complain about headaches (18.75% vs. 54.21%, p < 0.001) and nausea and/or vomiting (1.89% vs. 36.2%, p < 0.001), but were more likely to manifest peripheral nerve palsies (21.43% vs. 9.61%, p = 0.02). The patients who died were also more likely to be immunocompromised (53.57% vs. 34.28%, p = 0.01), have Streptococcus pneumoniae etiology (35.71% vs. 16.25%, p = 0.001), higher concentrations of procalcitonin (median 5.035 ng/mL vs. 2.245 ng/mL, p = 0.003) and urea (median 10.7 mmol/L vs. 5.865 mmol/L, p < 0.001) in the blood and higher protein (median 4.57 g/L vs. 2.605 g/L, p = 0.014) and lower glucose levels (median 0.765 mmol/L vs. 1.89 mmol/L, p = 0.006) in the cerebrospinal fluid (CSF). In a multiple logistic regression analysis, which was conducted separately for the GCS and SOFA, both scoring systems (OR = 0.67, OR 95% CI 0.59-0.75, p < 0.001 for GCS and OR = 1.42, OR 95% CI 1.29-1.60, p < 0.001 for SOFA) as well as an age over 70 years (OR = 3.99, OR 95% CI 1.39-12.93, p = 0.014) and Streptococcus pneumoniae etiology (OR = 2.38, OR 95% CI 1.12-4.99, p = 0.022) were associated with in-hospital deaths. Conclusions: The survivors and non-survivors with BM differed with respect to a number of signs and symptoms, etiology, the results of blood and CSF laboratory tests, and the immune deficiency status, as well as the GCS and SOFA scores. In the multiple logistic regression analysis, both of the GCS and SOFA scoring systems, age and Streptococcus pneumoniae etiology showed high associations with the in-hospital deaths.

Molecular diagnostics in cerebrospinal fluid for the diagnosis of central nervous system infections

SUMMARYCentral nervous system (CNS) infections can be caused by various pathogens, including bacteria, viruses, fungi, and parasites. Molecular diagnostic methods are pivotal for identifying the different causative pathogens of these infections in clinical settings. The efficacy and specificity of these methods can vary per pathogen involved, and in a substantial part of patients, no pathogen is identified in the cerebrospinal fluid (CSF). Over recent decades, various molecular methodologies have been developed and applied to patients with CNS infections. This review provides an overview of the accuracy of nucleic acid amplification methods in CSF for a diverse range of pathogens, examines the potential value of multiplex PCR panels, and explores the broad-range bacterial and fungal PCR/sequencing panels. In addition, it evaluates innovative molecular approaches to enhance the diagnosis of CNS infections.

Bacterial Meningitis in Infants Under 90 Days of Age: A Retrospective Single-Center Study

BACKGROUND

Bacterial meningitis (BM) in infants is a serious condition that can lead to significant complications. Lumbar puncture (LP) is essential to provide diagnoses, however false negatives may result if LP is performed after the starting of antibiotic therapy.

METHODS

We conducted a retrospective analysis of infants of any gestational age with BM within their first 90 days of life and admitted to the Neonatal Intensive Care Unit of Modena Policlinico between 1 January 2011, and 31 December 2023.

RESULTS

A total of 44 episodes of meningitis were confirmed in 40 infants, diagnosed by positive cerebrospinal fluid cultures (n = 37), polymerase chain reaction testing (n = 4), or both methods (n = 3). Three out of forty infants (8%) experienced a relapse of meningitis. Most episodes (31/44, 70%) occurred in preterm infants. The incidence of early-onset meningitis was lower than that of late-onset (0.18 vs. 0.94 cases per 1000 births, respectively), with Gram-positive accounting for most cases (27/44, 61%). LP was performed prior to antibiotic administration in most episodes (30/44, 68%). Two preterm infants (5%) died from meningitis-related complications. Forty-two episodes occurred among thirty-eight surviving infants; brain lesions were detected through brain ultrasound or MRI in nine out of forty-two episodes (21%).

CONCLUSIONS

Preterm infants have higher rates of BM, brain lesions or case fatalities. Early diagnosis and prompt antibiotic treatment are critical to improve outcomes.

Bacterial Meningoencephalitis in Newborns

Bacterial meningoencephalitis in newborns is a severe and life-threatening pathology, which results from meningeal infection and the subsequent involvement of the brain parenchyma. The severity of the acute onset of symptoms and the risk of neurodevelopmental adverse sequelae in children strongly depend on the timing of the infection, the immunological protection transmitted by the mother to the fetus during pregnancy, and the neonate's inflammatory and immune system response after birth. Although the incidence of neonatal meningitis and meningoencephalitis and related mortality declined in the past twenty years with the improvement of prenatal care and with the introduction of intrapartum antibiotic prophylaxis against Streptococcus beta Hemolyticus group B (Streptococcus Agalactiae) in the 1990s, bacterial meningitis remains the most common form of cerebrospinal fluid infection in pediatric patients. To date, the rate of unfavorable neurological outcomes is still from 20% to 60%, and the possibility of containing its rate strongly depends on early diagnosis, therapy, and a multidisciplinary approach, which involves neonatologists, neurologists, neuroradiologists, and physiotherapists. Neonatal meningitis remains difficult to diagnose because the responsible bacteria vary with gestational age at birth, age at presentation, and environmental context. The clinical presentation, especially in the newborn, is very ambiguous. From a clinical point of view, the definitive test for diagnosis is lumbar puncture in patients with symptoms suggestive of neurological involvement. Therefore, neuroimaging is key for raising clinical suspicion of meningitis or corroborating the diagnosis based on clinical and laboratory data. Our pictorial review offers a practical approach to neonatal meningoencephalitis by describing the epidemiology, the pathophysiology of bacterial meningoencephalitis, defining the indications and suggesting optimized protocols for neuroimaging techniques, and showing the main neuroimaging findings to reach the diagnosis and offering proper follow-up of bacterial meningitis. Moreover, we tried identifying some peculiar MRI patterns related to some bacteria.

Pneumolysin contributes to dysfunction of nasal epithelial barrier for promotion of pneumococcal dissemination into brain tissue

Streptococcus pneumoniae is one of the major pathogens responsible for bacterial meningitis and neurological sequelae. The present study was conducted to identify a non-hematogenous route used by S. pneumoniae to gain access to brain tissue without causing bacteremia or pneumonia, as well as bacterial and host factors involved in this process. To investigate the molecular mechanisms and dissemination pathways of pneumococcal infection in brain tissue, mice were intranasally inoculated with S. pneumoniae strain EF3030, a clinical isolate from a patient with otitis media. Pneumococci were isolated from the frontal olfactory bulb, caudal cerebrum, and cerebellum, with neither bacteremia nor pneumonia observed in the present model. Immunostaining imaging revealed the presence of S. pneumoniae organisms in olfactory nerve fibers. Knockout of the ply gene encoding pneumolysin (PLY) markedly compromised the ability of the bacterial organisms to disseminate into brain tissue, whereas the dissemination efficiency of the complemented strain was restored to nearly the same level as the wild type. Notably, distinct upregulation of Gli1 and Snail1, which are involved in the transcriptional repression of junctional proteins, along with downregulation of E-cadherin, was detected in nasal lavage samples from mice infected with the wild-type or complemented strain, but not in those from mice infected with the ply mutant. Taken together, the present findings indicate that PLY induces Gli1-Snail1-dependent dysfunction of the nasal epithelial barrier, thus allowing pneumococcal dissemination to brain tissue that occurs in a non-hematogenous manner.IMPORTANCEBacterial meningitis, considered to be caused by bacteremia, can lead to blood-brain barrier disruption and bacterial dissemination into the central nervous system. Despite the availability of intravenously administered antibiotics with cerebrospinal fluid transferability, bacterial meningitis remains associated with high rates of morbidity and mortality. Here, we utilized Streptococcus pneumoniae strain EF3030, clinically isolated from otitis media, for the construction of a murine infection model to investigate the molecular mechanisms by which nasally colonized pneumococci disseminate into brain tissue. The obtained findings indicate that pneumolysin (PLY) induces Gli1-Snail1-dependent dysfunction of the nasal epithelial barrier, which facilitates pneumococcal dissemination to brain tissue in a non-hematogenous manner. Our results support the existence of an alternative route by which S. pneumoniae can reach the central nervous system and indicate the need for the development of novel therapeutic strategies, which would be an important contribution to the clinical management of bacterial meningitis.

Demographic and pathogen characteristics of incident bacterial meningitis in infants in South Africa: A cohort study

INTRODUCTION

Bacterial meningitis is a major cause of death, with an approximate case fatality rate of 37% across all age groups in South Africa. This study aimed to describe the demographic and pathogen characteristics of incident meningitis in children aged <1 year in South Africa from 2014 through 2018, during a period when Haemophilus influenzae type b vaccine and pneumococcal conjugate vaccines (PCV) were both included in the expanded program on immunization (EPI).

METHODS

We conducted a cohort study of routine laboratory data in the National Health Laboratory Service Corporate Data Warehouse, which covers approximately 80% of the South African population. We defined a case of laboratory-confirmed bacterial meningitis as any person aged <1 year with meningitis diagnosed by culture and identification of a pathogen documented as being a common cause of meningitis in CSF. The cause-specific incidence risks were calculated by dividing the number of positive specimens in each age group and year by the corresponding mid-year population for children under 1 year old and those in the post-neonatal period (≥ 28 days to 365 days old). For children under 28 days old, the annual numbers of registered livebirths were used. We used Poisson regression to compare the incidence of meningitis by year.

RESULTS

We identified 3575 (1.5%) cases of culture-confirmed bacterial meningitis from the 232,016 cerebrospinal fluid (CSF) specimens tested from 2014-2018. The highest number of cases were recorded in children aged <28 days (1873, 52.4%), male children (1800, 50.4%) as well as in the Gauteng Province (2014, 56.3%). Acinetobacter baumannii (14.9%), followed by Klebsiella pneumoniae (13.5%), and group B streptococcus (GBS) (10.7%), were the most common pathogens detected. Overall, A. baumannii had the highest incidence risk, occurring at 9.8 per 100,000 persons in children aged <1 year in 2018. Among neonates, A. baumannii peaked at 14.9 per 100,000 livebirths in 2018, while Streptococcus pneumoniae was most common in the post-neonatal period (≥ 28 days to 365 days old), peaking at 9.8 per 100,000 persons in 2014. There was an increase in the annual incidence of most pathogens over the study period.

CONCLUSION

There was an increasing trend in the annual incidence of bacterial meningitis in infants caused by most pathogens, particularly A. baumannii, K. pneumoniae and GBS. In addition to increased uptake of vaccination, prevention measures to reduce nosocomial and mother-to-child transmission of bacteria could include antenatal screening for GBS in pregnant women, rigorous hygiene in the hospital environment as well as rational antibiotic use.

Relationship between serum prealbumin level and prognosis of community-acquired bacterial meningitis in adults: a retrospective cohort study

Background

Low serum prealbumin levels have been identified as a predictor of infectious complication in critically ill patients. However, the association in patients with Community-acquired bacterial meningitis (CABM) remains unclear. The aim of this study is to investigate the relationship of prealbumin and the poor outcome of CABM through a retrospective cohort study.

Methods

A total of 77 patients of CABM were enrolled. They were divided into good outcome group (GOS: 5) and a bad outcome group (GOS: 1-4). Serum prealbumin and other clinical records were measured within 24 h after admission.

Results

Among the included patients, 38(65.52%) had a bad outcome (the GOS score between 1 and 4). The mean age of the overall cohort was 45.3 ± 15.9 years, and 58.6% of patients were male. The mean prealbumin level in the bad outcome group was 115.4 ± 49.4 mmol/L, while the mean level in the good outcome group was 199.1 ± 49.3 mmol/L (p < 0.001). Individuals with plasma prealbumin level ≤180 mmol/L had a 3.32-fold higher risk of CABM than those with normal plasma prealbumin level [OR = 4.32 (1.02 ~ 18.24), p < 0.05].

Conclusion

Reduced plasma prealbumin level is independently associated with the poor outcome of CABM. Plasma prealbumin level might help to identify patients at high risk of bad outcome.

Neurological Symptoms and Cause of Death Among Young Children in Low- and Middle-Income Countries

Importance

The emergence of acute neurological symptoms in children necessitates immediate intervention. Although low- and middle-income countries (LMICs) bear the highest burden of neurological diseases, there is a scarcity of diagnostic and therapeutic resources. Therefore, current understanding of the etiology of neurological emergencies in LMICs relies mainly on clinical diagnoses and verbal autopsies.

Objective

To characterize the association of premortem neurological symptoms and their management with postmortem-confirmed cause of death among children aged younger than 5 years in LMICs and to identify current gaps and improve strategies to enhance child survival.

Design, Setting, and Participants

This cross-sectional study was conducted between December 3, 2016, and July 22, 2022, at the 7 participating sites in the Child Health and Mortality Prevention Surveillance (CHAMPS) network (Bangladesh, Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, and South Africa). Minimally invasive tissue sampling was performed at the CHAMPS sites with specimens from deceased children aged younger than 5 years. This study included deceased children who underwent a premortem neurological evaluation and had a postmortem-confirmed cause of death. Data analysis was performed between July 22, 2022, and January 15, 2023.

Main Outcomes and Measures

Descriptive analysis was performed using neurological evaluations from premortem clinical records and from postmortem determination of cause of death (based on histopathology, microbiological testing, clinical records, and verbal autopsies).

Results

Of the 2127 deaths of children codified during the study period, 1330 (62.5%) had neurological evaluations recorded and were included in this analysis. The 1330 children had a median age of 11 (IQR, 2-324) days; 745 (56.0%) were male and 727 (54.7%) presented with neurological symptoms during illness before death. The most common postmortem-confirmed neurological diagnoses related to death were hypoxic events (308 [23.2%]), meningoencephalitis (135 [10.2%]), and cerebral malaria (68 [5.1%]). There were 12 neonates with overlapping hypoxic events and meningoencephalitis, but there were no patients with overlapping meningoencephalitis and cerebral malaria. Neurological symptoms were similar among diagnoses, and no combination of symptoms was accurate in differentiating them without complementary tools. However, only 25 children (18.5%) with meningitis had a lumbar puncture performed before death. Nearly 90% of deaths (442 of 511 [86.5%]) with neurological diagnoses in the chain of events leading to death were considered preventable.

Conclusions and Relevance

In this cross-sectional study of children aged younger than 5 years, neurological symptoms were frequent before death. However, clinical phenotypes were insufficient to differentiate the most common underlying neurological diagnoses. The low rate of lumbar punctures performed was especially worrying, suggesting a challenge in quality of care of children presenting with neurological symptoms. Improved diagnostic management of neurological emergencies is necessary to ultimately reduce mortality in this vulnerable population.

Optimization of the Diagnosis of Central Nervous System Infections in Vietnamese Hospitals: Results From a Retrospective Multicenter Study

Introduction

Central nervous system infections pose significant health challenges, particularly in low- and middle-income countries, because of high morbidity and mortality rates. Rapid and accurate diagnosis is essential for effective treatment to prevent adverse outcomes. Traditional culture-based diagnostics are often slow and lack specificity. This study evaluates the BioFire FilmArray Meningitis/Encephalitis (FAME) Panel against standard diagnostics in Vietnam to assess its clinical impact and suitability for local epidemiology.

Methods

We conducted a prospective study involving 330 patients with suspected central nervous system infections at 4 hospitals in northern Vietnam from July 2022 to April 2023. Cerebrospinal fluid samples were analyzed using routine culture methods and FAME. We compared pathogen detection rates and assessed the potential clinical impact of FAME results on patient management.

Results

Of the 330 cerebrospinal fluid specimens, 64 (19%) were positive by either conventional diagnostics (n = 48) and/or FAME (n = 33). The agreement between FAME and conventional diagnostics was 87%. Key pathogens Mycobacterium tuberculosis (n = 7), Klebsiella pneumoniae (n = 5), Streptococcus suis (n = 5), Epstein-Barr virus (n = 3), Acinetobacter baumannii (n = 1), and Trichosporon asahii (n = 1) were not detected by FAME. Classical meningitis parameter clinical symptoms, altered glucose, protein, and pleocytosis were good predictors of FAME positivity, indicating their utility in optimizing local diagnostic algorithms.

Conclusions

FAME complements traditional diagnostics by offering rapid and broad pathogen detection, crucial for timely and appropriate therapy. However, its effectiveness varies with local epidemiology, and it should not replace conventional methods entirely. Tailoring diagnostic panels to regional pathogen prevalence is recommended to enhance diagnostic accuracy and clinical outcomes in low- and middle-income countries.

Development and Validation of a Predictive Model for Postoperative Intracranial Infections in Neurosurgery with Risk Factor Analysis

BACKGROUND

Currently, the diagnosis of postneurosurgical intracranial infection is mainly dependent on cerebrospinal fluid (CSF) bacterial culture, which has the disadvantages of being time-consuming, having a low detection rate, and being easily affected by other factors. These disadvantages bring some difficulties to early diagnosis. Therefore, it is very important to construct a nomogram model to predict the risk of infection and provide a basis for early diagnosis and treatment.

METHODS

This retrospective study analyzed postneurosurgical patient data from the Fourth Affiliated Hospital of Harbin Medical University between January 2019 and September 2023. The patients were randomly assigned in an 8:2 ratio into the training cohort and the internal validation cohort. In the training cohort, initial screening of relevant indices was conducted via univariate analysis. Subsequently, the least absolute shrinkage and selection operator logistic regression identified significant potential risk factors for inclusion in the nomogram model. The model's discriminative ability was assessed using the area under the receiver operating characteristic curve, and its calibration was evaluated through calibration plots. The clinical utility of the model was determined using decision curve analysis and further validated by the internal validation cohort.

RESULTS

Multivariate logistic regression analysis of the training cohort identified 7 independent risk factors for postoperative intracranial infection: duration of postoperative external drainage (odds ratio [OR] 1.19, P = 0.005), continued fever (OR 2.11, P = 0.036), CSF turbidity (OR 2.73, P = 0.014), CSF pressure (OR 1.01, P = 0.018), CSF total protein level (OR 1.26, P = 0.026), CSF glucose concentration (OR 0.74, P = 0.029), and postoperative serum albumin level (OR 0.84, P < 0.001). Using these variables to construct the final model. The area under the receiver operating characteristic curve value of the model was 0.868 in the training cohort and 0.900 in the internal validation cohort. Calibration and the decision curve analysis indicated high accuracy and clinical benefit of the nomogram, findings that were corroborated in the validation cohort.

CONCLUSIONS

This study successfully developed a novel nomogram for predicting postoperative intracranial infection, demonstrating excellent predictive performance. It offers a pragmatic tool for the early diagnosis of intracranial infection.

Cochlear Implantation in Post-Meningitis Deafness: Audiological, Imaging, and Postoperative Outcomes: A Systematic Review With Qualitative Synthesis

INTRODUCTION

Post-meningitis deafness (PMD) is a potentially devastating cause of hearing loss among pediatric and adult patients, for which hearing rehabilitation with cochlear implants (CIs) remains the standard of care. To date, there have been limited systematic studies on the impact of cochlear ossification (CO) and time-to-implantation (TTI) on audiological outcomes.

METHODS

An online database search was performed on the PubMed, Embase, and Scopus databases for articles within the past 20 years pertaining to audiological outcomes among pediatric and adult patients with PMD. Information on study characteristics, patient demographics, clinical outcomes, and postoperative complications was collected and analyzed.

RESULTS

From 8,325 articles generated in the original search, 11 were included in the final analysis, representing 376 patients in total. Of the articles discussing TTI, the majority (3 of 4) found that a shorter TTI of 6 months on average led to improved audiological outcomes compared with control groups with a longer TTI. Of the articles that discussed the impact of preoperative CO, the majority (4 of 6) found that the presence of CO had a detrimental effect on postoperative audiological outcomes after CI. Finally, of the articles that discussed long-term audiological outcomes for PMD compared with the non-PMD control group after CI, the majority (4 of 7) found that PMD patients had inferior long-term outcomes.

CONCLUSION

CI is a safe and effective treatment modality for PMD, with the majority of literature demonstrating improved long-term outcomes for patients without CO and a reduced TTI.

Acute infections of the central nervous system in children and adults: diagnosis and management

Central nervous system infections are due to different microorganisms such as viruses, bacteria, mycobacteria, fungi, amoebas, and other parasites. The etiology depends on multiple risk factors, and it defines the infection location because some microorganisms prefer meninges, brain tissue, cerebellum, brain stem or spinal cord. The microorganisms induce diseases in the nervous system through direct invasion, neurotoxin production, and the triggered immune response. To determine the infection etiology, there are several diagnostic tests which may be conducted with cerebrospinal fluid, blood, respiratory and stool samples. These tests include but are not limited to direct microscopic examination of the sample, stains, cultures, antigenic tests, nucleic acid amplification tests, metagenomic next-generation sequencing, immunologic biomarker and neuroimaging, especially contrast-enhanced magnetic resonance imaging. The treatment may consist of specific antimicrobial treatment and supportive standard care. Since viruses have no specific antiviral treatment, antimicrobial treatment is mainly targeted at non-viral infections. This article will focus on diagnosis and treatment of acute acquired infections of the central nervous system beyond the neonatal period. The discussion defines the disease, provides the clinical presentation, explains the etiology and risk factors, and briefly mentions potential complications. This updated review aims to provide the reader with all the elements needed to adequately approach a patient with a central nervous system infection. Mycobacterium tuberculosis infection, Cryptococcus spp. infection and vaccines are not within the scope of this article.

Performance Characteristics of a Real-Time PCR Assay for Direct Detection of Streptococcus pneumoniae in Clinical Specimens

Community-acquired pneumonia and complications, such as bacteremia and meningitis due to Streptococcus pneumoniae infection, still occur in at-risk populations, despite the availability of effective vaccines. Laboratory confirmation of S. pneumoniae remains challenging despite advances in blood culture techniques and the availability of nucleic acid-amplification tests. The goal of this study was to determine the performance characteristics of a molecular assay designed as a diagnostic test using primary clinical specimens for invasive pneumococcal disease. The molecular assay adapted for the Luminex Aries instrument targets an S. pneumoniae-specific gene (autolysin, lytA) in clinical specimens. Using real-time PCR MultiCode technology, four different clinical specimen types were evaluated. Specimen types included bronchoalveolar lavage, whole blood, cerebrospinal fluid, and urine to cover the various presentations and appropriate specimen types for invasive pneumococcal infections. The lower limit of detection in urine was 10 colony forming units (CFU)/mL, while in bronchoalveolar lavage, cerebrospinal fluid, and whole blood, it was 100 CFU/mL. Accuracy and specificity were both 100%, and all specimen types were stable for 8 days at 4°C. Finally, 38 clinical specimens were tested to further evaluate the assay. The performance characteristics met Clinical Laboratory Improvement Amendments standards for a clinical diagnostic assay, and the assay offers a sensitive and specific real-time PCR test for direct detection of S. pneumoniae in relevant clinical specimens.

Epidemiology and antimicrobial resistance patterns of bacterial meningitis among hospitalized patients at a tertiary care hospital in Saudi Arabia: a six-year retrospective study

INTRODUCTION

Bacterial meningitis poses significant medical challenges due to its acute inflammatory nature and potential for severe neurological complications, emphasizing the need for prompt diagnosis and treatment. Limited data exists on its epidemiology and antimicrobial resistance trends among hospitalized patients in Saudi Arabia. This study aimed to investigate these factors at a tertiary care hospital over six years.

METHODS

A retrospective analysis was conducted on cerebrospinal fluid samples results from 222 bacterial meningitis cases among hospitalized patients between 2018 and 2023. Demographic, clinical, microbiological data, and antibiotic susceptibility patterns were collected and analyzed.

RESULTS

Pseudomonas aeruginosa (43%) was the predominant pathogen isolated. Neonates (16%) and children (47%) were most affected population. Nosocomial meningitis accounted for 92% of cases, mainly in the intensive care settings (50.45%). Extended-spectrum beta-lactamase was the leading resistance pattern (12.2%). Seasonal variation was observed, with a peak incidence in October-November.

CONCLUSION

The study highlights the substantial burden of bacterial meningitis among hospitalized patients, especially among high-risk groups. Emerging antimicrobial resistance emphasizes the need for optimized surveillance and stewardship. Future prospective research employing molecular techniques across multiple centers in the country is warranted to enhance understanding and guide public health strategies in Saudi Arabia.

Recurrent community-acquired pneumococcal meningitis in adults with and without identified predisposing factors

Bacterial meningitis is still a significant public health concern, with high morbidity and mortality rates. Despite this, it is still a rare event that requires the bacterial invasion of the meninges. However, some predisposing factors can trigger recurrent episodes of meningitis. This study is aimed at determining the clinical characteristics and the molecular epidemiology of episodes of recurrent community-acquired meningitis with and without predisposing factors. For this purpose, we performed a retrospective study of our laboratory database during the period of 2010 to 2020. Additionally, using molecular tools developed in our previous works, the epidemiology of the pathogens causing these episodes was analyzed using cerebrospinal fluid samples, especially in the absence of isolated strains. We observed a total of 1,779 meningitis cases and 230 were caused by Streptococcus pneumoniae. Of those, 16 were recurrent meningitis episodes (16/1,779; 0.9%) from seven patients. Pneumococcus was the main agent responsible in these recurrent episodes and only two episodes were caused by Haemophilus influenzae. The mean age of these patients was 20 years old and three had predisposing factors which could have led to contracting meningitis. The samples presented different pneumococcal serotypes. Most of them were non-vaccine-covered serotypes and antibiotic susceptible strains. Therefore, it was demonstrated how the practical employment of molecular tools, developed for research, when applied in the routine of diagnosis, can provide important information for epidemiological surveillance. Furthermore, it was shown how pneumococcus was the leading cause of recurrent community-acquired meningitis without predisposing factors, suggesting that pneumococcal vaccination may be necessary, even in those groups of individuals considered to be less susceptible.

Detection of intrathecal IgG antibody for varicella and measles diagnosis by evaluation and comparison of a commercial IgG chemiluminescent immunoassay with two ELISAs

OBJECTIVES

Analyse alternative methods of intrathecal antibody detection by comparing chemiluminescent immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA) techniques to determine if CLIA can replace ELISA in the diagnosis of CNS infections.

METHODS

A panel of 280 paired samples-cerebrospinal fluid (CSF) and serum-with known antibody reactivities (Varicella, n = 60; Measles, n = 120) and negative samples (n = 100) were used to evaluate the performance of six serological test kits (Enzygnost, VirClia®, and Serion ELISA (Measles and Variella).

RESULTS

For Measles virus IgG, the VirClia® IgG monotest revealed 97% and 94% positive and negative agreement to the Enzygnost as reference test, respectively. In contrast, Serion ELISA kits yielded values of 18% and 90%. For the Varicella Zoster virus (VZV) IgG, the VirClia® IgG monotest showed 97% and 90% positive and negative agreement compared to Enzygnost. The Serion ELISA kits showed values of 55% and 86%, respectively. ROC analysis revealed that the areas under the curve for Measles and VZV IgGs were 0.7 and 0.852, respectively, using the Serion kit, and 0.963 and 0.955, for Vircell S.L CLIA technique. VirClia® monotest values were calculated using an antibody index cut-off of 1.3.

CONCLUSION

The findings indicate that CLIA testing can improve antibody detection in CSF samples, aiding the diagnosis of infectious neurological impairments.

Streptococcus suis meningoencephalitis diagnosed with metagenomic next-generation sequencing: A case report with literature review

Streptococcus suis is a pathogen of emerging zoonotic diseases and meningoencephalitis is the most frequent clinical symptom of S. suis infection in humans. Rapid diagnosis of S. suis meningoencephalitis is critical for the treatment of the disease. While the current routine microbiological tests including bacterial culture and gram staining are poorly sensitive, diagnosis of S. suis meningoencephalitis by metagenomic next-generation sequencing (mNGS) has been rarely reported. Here, we report a 52-year-old female pork food producer with a broken finger developed S. suis meningoencephalitis. After her admission, no pathogenic bacteria were detected through bacterial culture and Gram staining microscopy in the cerebrospinal fluid obtained via lumbar puncture. However, mNGS identified the presence of S. suis in the sample. mNGS is a promising diagnostic tool for rapid diagnosis of rare infectious diseases in the central nervous system.

Bacterial etiologies, antimicrobial susceptibility pattern and associated factors among patients suspected sterile body site infections at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia

Background

Sterile body locations are usually associated with clinical urgency and life-threatening illnesses, and they are typically contaminated with diverse bacterial etiologies. If the bacteria acquire resistance to antimicrobial drugs, the public health crisis will only worsen. In developing countries, drug-resistant bacteria are common because of poor surveillance, diagnostic capacity, and control measures. Early diagnosis, and assessing the drug resistance and factors associated with infection are important to combat the drug resistance and treatment. This study aimed to assess the bacterial etiologies, antimicrobial susceptibility pattern, and possible associated factors among patients suspected of sterile body sites.

Methods

A hospital-based cross-sectional study was conducted from June 2022 to August 2022 at Debre Markos Comprehensive Specialized Hospital in Amhara regional state, Ethiopia. One hundred seven study participants were selected using consecutive convenient sampling techniques. A structured questionnaire was used to collect socio-demographic and clinical data. Gram stain was done for a preliminary report and inoculated into blood agar, MacConkey agar, and chocolate agar and incubated aerobically and micro aerobically at 37°C for 24 h. Antimicrobial susceptibility testing was done by the modified Kirby Bauer's disk diffusion method. Data were analyzed using bivariate and multivariate logistic regression was used. A p-value less than 0.05 is considered as statistically significant.

Results

The overall magnitude of sterile body site infection among study participants was 7.5% (14/187). The majority of the isolates were Gram-negative bacteria with the predominant species Enterobacter cloacae accounting for 28.57% (4/14). Among isolates 78.57%(11/14) of them were multidrug-resistant isolates. Being inpatient, co-morbidity, and alcohol consumption were significantly associated with sterile body site infection.

Conclusion

In our study, Gram-negative bacteria were the predominant bacteria that infects sterile body fluid. The prevalence of multi-drug resistance bacteria isolates was significantly high. Therefore, before prescribing an empirical treatment, a medical professional should identify the bacterial etiology of sterile body fluids and the susceptibility of microbes to the drug.

Streptococcus agalactiae Meningitis in an Immunocompetent Adult: A Case Report and Literature Review

Streptococcus agalactiae is a rare cause of meningitis in healthy adults. We herein report a case of culture-negative Streptococcus agalactiae meningitis in a healthy adult which was diagnosed using the FilmArray Meningitis and Encephalitis Panel. A healthy 22-year-old man presented with a fever, headache, and neck stiffness. Despite negative results from blood and cerebrospinal fluid cultures, the diagnosis was confirmed using the FilmArray Meningitis and Encephalitis Panel. The patient was treated with dexamethasone, vancomycin, and ceftriaxone, and thereafter recovered completely. This report highlights the importance of being aware that Streptococcus agalactiae meningitis can occur in healthy individuals, and summarizes these features.

Changing Landscape of Haemophilus influenzae Meningitis and Implication on Public Health

Haemophilus influenzae (H. influenzae) has evolved as a prominent pathogen, with nontypeable strains (NTHi) emerging as a leading cause of invasive disease, particularly among the elderly. Since the introduction of Haemophilus influenzae B (Hib) vaccine, invasive infection has shifted from children with Hib to the elderly with NTHi. NTHi affects those primarily with predisposing factors such as an immunocompromised state, CSF leakage, or ENT infections. We present two cases that emphasize the shift of invasive infection, risk factors, and elevated intracranial pressure (ICP) as a complication. Case 1. A 75-year-old female with a sudden onset of weakness and respiratory symptoms deteriorated rapidly. Imaging revealed mastoid effusion and ventriculitis, likely originating from otomastoiditis. Lumber puncture confirmed NTHi. ICU course complicated by elevated ICP prompted repeat lumbar puncture. The patient recovered after 8 days but not near baseline. Case 2. A 50-year-old female with altered mental status, headache, and ear pain exhibited signs of pansinusitis and pseudotumor cerebri. Elevated ICP was evident upon lumbar puncture, and NTHi was isolated in CSF and blood cultures. MRI of the brain showed prominent optic nerve sheaths and transverse sinus arachnoid granulations' concern for underlying pseudotumor cerebri. Repeat lumbar puncture or ventricular drainage was deferred after discussion with neurosurgery. Diabetes was identified as a comorbidity. The patient's condition improved after 14 days of antibiotics and dexamethasone. These cases emphasize the shifting landscape of H. influenzae meningitis, primarily driven by NTHi, especially among the elderly. Although NTHi infections were considered less invasive, recent epidemiology review indicated it as the leading cause of H. influenzae meningitis. With the increasing prevalence of NTHi and its increase in invasive patterns, it is crucial to implement vaccination strategies and develop new vaccines targeting NTHi.

CCR2+ monocytes replenish border-associated macrophages in the diseased mouse brain

Border-associated macrophages (BAMs) are tissue-resident macrophages that reside at the border of the central nervous system (CNS). Since BAMs originate from yolk sac progenitors that do not persist after birth, the means by which this population of cells is maintained is not well understood. Using two-photon microscopy and multiple lineage-tracing strategies, we determine that CCR2+ monocytes are significant contributors to BAM populations following disruptions of CNS homeostasis in adult mice. After BAM depletion, while the residual BAMs possess partial self-repopulation capability, the CCR2+ monocytes are a critical source of the repopulated BAMs. In addition, we demonstrate the existence of CCR2+ monocyte-derived long-lived BAMs in a brain compression model and in a sepsis model after the initial disruption of homeostasis. Our study reveals that the short-lived CCR2+ monocytes transform into long-lived BAM-like cells at the CNS border and subsequently contribute to BAM populations.

Adjunctive treatments for pneumococcal meningitis: a systematic review of experimental animal models

New treatments are needed to improve the prognosis of pneumococcal meningitis. We performed a systematic review on adjunctive treatments in animal models of pneumococcal meningitis in order to identify treatments with the most potential to progress to clinical trials. Studies testing therapy adjunctive to antibiotics in animal models of pneumococcal meningitis were included. A literature search was performed using Medline, Embase and Scopus for studies published from 1990 up to 17 February 2023. Two investigators screened studies for inclusion and independently extracted data. Treatment effect was assessed on the clinical parameters disease severity, hearing loss and cognitive impairment and the biological parameters inflammation, brain injury and bacterial load. Adjunctive treatments were evaluated by their effect on these outcomes and the quality, number and size of studies that investigated the treatments. Risk of bias was assessed with the SYRCLE risk of bias tool. A total of 58 of 2462 identified studies were included, which used 2703 experimental animals. Disease modelling was performed in rats (29 studies), rabbits (13 studies), mice (12 studies), gerbils (3 studies) or both rats and mice (1 study). Meningitis was induced by injection of Streptococcus pneumoniae into the subarachnoid space. Randomization of experimental groups was performed in 37 of 58 studies (64%) and 12 studies (12%) were investigator-blinded. Overall, 54 treatment regimens using 46 adjunctive drugs were evaluated: most commonly dexamethasone (16 studies), daptomycin (5 studies), complement component 5 (C5; 3 studies) antibody and Mn(III)tetrakis(4-benzoicacid)porphyrin chloride (MnTBAP; 3 studies). The most frequently evaluated outcome parameters were inflammation [32 studies (55%)] and brain injury [32 studies (55%)], followed by disease severity [30 studies (52%)], hearing loss [24 studies (41%)], bacterial load [18 studies (31%)] and cognitive impairment [9 studies (16%)]. Adjunctive therapy that improved clinical outcomes in multiple studies was dexamethasone (6 studies), C5 antibodies (3 studies) and daptomycin (3 studies). HMGB1 inhibitors, matrix metalloproteinase inhibitors, neurotrophins, antioxidants and paquinimod also improved clinical parameters but only in single or small studies. Evaluating the treatment effect of adjunctive therapy was complicated by study heterogeneity regarding the animal models used and outcomes reported. In conclusion, 24 of 54 treatment regimens (44%) tested improved clinically relevant outcomes in experimental pneumococcal meningitis but few were tested in multiple well-designed studies. The most promising new adjunctive treatments are with C5 antibodies or daptomycin, suggesting that these drugs could be tested in clinical trials.

Hydrogen peroxide is responsible for the cytotoxic effects of Streptococcus pneumoniae on primary microglia in the absence of pneumolysin

INTRODUCTION

Streptococcus pneumoniae is the most common cause of bacterial meningitis and meningoencephalitis in humans. The bacterium produces numerous virulence determinants, among them hydrogen peroxide (H2O2) and pneumolysin (Ply), which contribute to bacterial cytotoxicity. Microglia, the resident phagocytes in the brain, are distinct from other macrophages, and we thus compared their susceptibility to pneumococcal toxicity and their ability to phagocytose pneumococci with those of bone marrow-derived macrophages (BMDM).

METHODS

Microglia and BMDM were co-incubated with S. pneumoniae D39 to analyze survival of phagocytes by fluorescence microscopy, bacterial growth by quantitative plating, and phagocytosis by an antibiotic protection assay. Ply was detected by hemolysis assay and Western blot analysis.

RESULTS

We found that microglia were killed during pneumococcal infection with a wild-type and an isogenic ply-deficient mutant, whereas viability of BMDM was not affected by pneumococci. Treatment with recombinant Ply showed a dose-dependent cytotoxic effect on microglia and BMDM. However, high concentrations of recombinant Ply were required and under the chosen experimental conditions, Ply was not detectable in the supernatant during infection of microglia. Inactivation of H2O2 by exogenously added catalase abolished its cytotoxic effect. Consequently, infection of microglia with pneumococci deficient for the pyruvate oxidase SpxB, primarily producing H2O2, resulted in reduced killing of microglia.

CONCLUSION

Taken together, in the absence of Ply, H2O2 caused cell death in primary phagocytes in concentrations produced by pneumococci.

Pneumococcal Meningitis Induces Hearing Loss and Cochlear Ossification Modulated by Chemokine Receptors CX3CR1 and CCR2

PURPOSE

Pneumococcal meningitis is a major cause of hearing loss and permanent neurological impairment despite widely available antimicrobial therapies to control infection. Methods to improve hearing outcomes for those who survive bacterial meningitis remains elusive. We used a mouse model of pneumococcal meningitis to evaluate the impact of mononuclear phagocytes on hearing outcomes and cochlear ossification by altering the expression of CX3CR1 and CCR2 in these infected mice.

METHODS

We induced pneumococcal meningitis in approximately 500 C57Bl6 adult mice using live Streptococcus pneumoniae (serotype 3, 1 × 105 colony forming units (cfu) in 10 µl) injected directly into the cisterna magna of anesthetized mice and treated these mice with ceftriaxone daily until recovered. We evaluated hearing thresholds over time, characterized the cochlear inflammatory response, and quantified the amount of new bone formation during meningitis recovery. We used microcomputed tomography (microCT) scans to quantify cochlear volume loss caused by neo-ossification. We also performed perilymph sampling in live mice to assess the integrity of the blood-perilymph barrier during various time intervals after meningitis. We then evaluated the effect of CX3CR1 or CCR2 deletion in meningitis symptoms, hearing loss, macrophage/monocyte recruitment, neo-ossification, and blood labyrinth barrier function.

RESULTS

Sixty percent of mice with pneumococcal meningitis developed hearing loss. Cochlear fibrosis could be detected within 4 days of infection, and neo-ossification by 14 days. Loss of spiral ganglion neurons was common, and inner ear anatomy was distorted by scarring caused by new soft tissue and bone deposited within the scalae. The blood-perilymph barrier was disrupted at 3 days post infection (DPI) and was restored by seven DPI. Both CCR2 and CX3CR1 monocytes and macrophages were present in the cochlea in large numbers after infection. Neither chemokine receptor was necessary for the induction of hearing loss, cochlear fibrosis, ossification, or disruption of the blood-perilymph barrier. CCR2 knockout (KO) mice suffered the most severe hearing loss. CX3CR1 KO mice demonstrated an intermediate phenotype with greater susceptibility to hearing loss compared to control mice. Elimination of CX3CR1 mononuclear phagocytes during the first 2 weeks after meningitis in CX3CR1-DTR transgenic mice did not protect mice from any of the systemic or hearing sequelae of pneumococcal meningitis.

CONCLUSIONS

Pneumococcal meningitis can have devastating effects on cochlear structure and function, although not all mice experienced hearing loss or cochlear damage. Meningitis can result in rapid progression of hearing loss with fibrosis starting at four DPI and ossification within 2 weeks of infection detectable by light microscopy. The inflammatory response to bacterial meningitis is robust and can affect all three scalae. Our results suggest that CCR2 may assist in controlling infection and maintaining cochlear patency, as CCR2 knockout mice experienced more severe disease, more rapid hearing loss, and more advanced cochlear ossification after pneumococcal meningitis. CX3CR1 also may play an important role in the maintenance of cochlear patency.

An unusual imaging presentation of pediatric bacterial meningoencephalitis: a case-report study

Background

Bacterial meningoencephalitis is a serious infection affecting the brain and its surrounding membranes. While imaging studies play a crucial role in diagnosing this condition, the typical radiological findings are well-documented. However, this case report describes an unusual imaging presentation that deviates from the expected patterns, emphasizing the need for awareness of such variations.

Case presentation

A 7-year-old female with no prior medical history was referred to our hospital with fever, seizure, and loss of Consciousness. She had mild flu a week before admission. The duration of seizure episodes were 2-3 min, with tonic-clonic uncontrollable jerky movements. Brudzinski and Kernig signs were positive and plantar reflex was upward bilaterally in the physical examination. The computed tomography (CT) scan showed brain ventriculomegaly/hydrocephalus, and MRI findings indicated multiple foci located at cerebellum, basal ganglia, and thalamus alongside intensely restricted diffusion of the layering debris, suggesting pyogenic ventriculitis. Cerebrospinal fluid (CSF) analysis showed severe hypoglycorrhachia, despite non-significant increase of protein. The patient was undergone antibiotic therapy with ceftriaxone, vancomycin and rifampin, resulting in normalization of CSF values.

Conclusion

This case report highlights the importance of recognizing and interpreting unusual imaging presentations of bacterial meningoencephalitis in paediatric patients. It emphasizes the need for a comprehensive diagnostic approach, including clinical evaluation, laboratory tests, and imaging studies, to ensure accurate diagnosis and appropriate management of this potentially life-threatening condition. Further research and awareness of atypical imaging findings are warranted to enhance our understanding and improve patient outcomes.

Audit of adherence to international guidelines (IDSA) in the treatment of infectious meningitis in pediatric patients in Jordan

OBJECTIVE

This study aims to audit the adherence of Jordanian medical care staff to the guidelines provided by the Infectious Disease Society of America (IDSA) for managing pediatric patients admitted with suspected cases of meningitis.

METHODS

A retrospective observational study was conducted at Jordan University Hospital (JUH). All pediatric patients admitted to JUH with suspected meningitis between January 1, 2019, and September 30, 2022, who underwent Cerebrospinal Fluid (CSF) and blood culture tests were recruited in this study unless there was a reason for exclusion. The study collected data on the empiric antibiotics prescribed prior to diagnostic cultures and susceptibility results. Additionally, the length of hospital stay and all-cause mortality were observed. The appropriateness of antibiotics prescription before culture results was compared to IDSA guidelines, and an overall adherence rate was calculated.

RESULTS

A total of 332 pediatric patients were included in this study, of whom 12.3% (n = 41) were diagnosed with bacterial meningitis. Among the enrolled pediatric patients, only 27 patients (8.1%) received appropriate treatment adhering to the IDSA guidelines. The remaining 91.9% (n = 305) showed various forms of non-adherence to recommendations. The highest adherence rate was observed for performing CSF culture (n = 330, 99.4%), while the lowest adherence rate was found in selecting the appropriate dose and duration for empiric antibiotics (n = 107, 41.3% and n = 133, 51.0%, respectively).

CONCLUSION

This study revealed a low overall adherence in the management of pediatric patients with meningitis in Jordan. Establishing an antimicrobial stewardship program may improve the outcomes of meningitis infections found in Jordan, and prevent dangerous adverse effects and bacterial resistance.

Distinguishing community-acquired bacterial and viral meningitis: Microbes and biomarkers

Diagnostic tools to differentiate between community-acquired bacterial and viral meningitis are essential to target the potentially lifesaving antibiotic treatment to those at greatest risk and concurrently spare patients with viral meningitis from the disadvantages of antibiotics. In addition, excluding bacterial meningitis and thus decreasing antibiotic consumption would be important to help reduce antimicrobial resistance and healthcare expenses. The available diagnostic laboratory tests for differentiating bacterial and viral meningitis can be divided microbiological pathogen-focussed methods and biomarkers of the host response. Bacterial culture-independent microbiological methods, such as highly multiplexed nucleic acid amplification tests, are rapidly making their way into the clinical practice. At the same time, more conventional host protein biomarkers, such as procalcitonin and C-reactive protein, are supplemented by newer proteomic and transcriptomic signatures. This review aims to summarise the current state and the recent advances in diagnostic methods to differentiate bacterial from viral meningitis.

Clinical characteristics and outcomes of acute bacterial meningitis in adults at a tertiary university hospital in Thailand

The epidemiology of acute bacterial meningitis varies among settings, areas, and times. This study aimed to determine the clinical characteristics, the causative organisms and their antibiotic susceptibility, and the outcomes of patients with acute bacterial meningitis in Thai adults. This retrospective study included hospitalized patients aged ≥18 years diagnosed with acute bacterial meningitis at Siriraj Hospital during January 2002-December 2016. Of 390 patients, the median age was 48 years, 51% were male, and 80% had at least 1 underlying illness. Over half (54%) of patients had community-acquired bacterial meningitis (CBM), and 46% had nosocomial bacterial meningitis (NBM). The triad of acute bacterial meningitis (fever, headache, and neck stiffness) was found in 46% of CBM and 15% of NBM (P < .001). The causative organisms were identified in about half (53%) of patients. Most study patients (73%) received antibiotic treatment before the CSF collection. Causative organisms were identified more frequently in CBM (P < .001). Gram-positive cocci were more prevalent in CBM (P < .001), whereas Gram-negative bacilli were more common in NBM (P < .001). Streptococcus agalactiae (29%), Streptococcus pneumoniae (12%), and Streptococcus suis (11%) were most common in CBM, and all of them were sensitive to third-generation cephalosporins. Acinetobacter baumannii (19%), Klebsiella pneumoniae (16%), and Staphylococcus aureus (11%) were the most common organisms in NBM, and antibiotic-resistant isolates were frequently found among these organisms. Ceftriaxone monotherapy and meropenem plus vancomycin were the most common empiric antibiotic in CBM and NBM, respectively. Mortality was 19% among CBM and 23% among NBM (P = .338). HIV infection, alcoholism, pneumonia, shock, and disseminated intravascular coagulation were independent predictors of mortality. Mortality remains high among adults with acute bacterial meningitis in Thailand. A clinical practice guideline for acute bacterial meningitis should be developed that is based on local epidemiology and microbiology data.

Pro-inflammatory cerebrospinal fluid profile of neonates with intraventricular hemorrhage: clinical relevance and contrast with CNS infection

BACKGROUND

Interpretation of cerebrospinal fluid (CSF) studies can be challenging in preterm infants. We hypothesized that intraventricular hemorrhage (IVH), post-hemorrhagic hydrocephalus (PHH), and infection (meningitis) promote pro-inflammatory CSF conditions reflected in CSF parameters.

METHODS

Biochemical and cytological profiles of lumbar CSF and peripheral blood samples were analyzed for 81 control, 29 IVH grade 1/2 (IVH1/2), 13 IVH grade 3/4 (IVH3/4), 15 PHH, 20 culture-confirmed bacterial meningitis (BM), and 27 viral meningitis (VM) infants at 36.5 ± 4 weeks estimated gestational age.

RESULTS

PHH infants had higher (p < 0.02) CSF total cell and red blood cell (RBC) counts compared to control, IVH1/2, BM, and VM infants. No differences in white blood cell (WBC) count were found between IVH3/4, PHH, BM, and VM infants. CSF neutrophil counts increased (p ≤ 0.03) for all groups compared to controls except IVH1/2. CSF protein levels were higher (p ≤ 0.02) and CSF glucose levels were lower (p ≤ 0.003) for PHH infants compared to all other groups. In peripheral blood, PHH infants had higher (p ≤ 0.001) WBC counts and lower (p ≤ 0.03) hemoglobin and hematocrit than all groups except for IVH3/4.

CONCLUSIONS

Similarities in CSF parameters may reflect common pathological processes in the inflammatory response and show the complexity associated with interpreting CSF profiles, especially in PHH and meningitis/ventriculitis.

Headache Disorders: Differentiating Primary and Secondary Etiologies

In the initial assessment of a headache patient, several dangerous secondary etiologies must be considered. A thorough history and physical examination, along with a comprehensive differential diagnosis may alert a physician to the diagnosis of a secondary headache particularly when it is accompanied by certain clinical features. Evaluation and workup include a complete neurological examination, consideration of neuroimaging, and serum/spinal fluid analysis if indicated. Careful attention to the patients' history and physical examination will guide the diagnostic work-up and management. In this review, we summarize the diagnostic workup of various primary and secondary headache etiologies. Although most headaches are primary in nature, it is essential to screen for headache "red flags", as they can suggest life threatening secondary etiologies. When secondary causes are suspected, appropriate neuroimaging can further differentiate the underlying cause. The appropriate imaging is dependent on the most likely secondary etiology, which is deduced from history and physical examination. When no red flags are present, primary headaches are more likely. These can be differentiated by frequency, location, duration, triggers, and presence of aura. The different clinical presentations for secondary headaches, as well as the distinguishing features for primary headaches are outlined in this review.

RNA sequencing reveals differential long noncoding RNA expression profiles in bacterial and viral meningitis in children

BACKGROUND

We aimed to investigate the involvement of long non-coding RNA (lncRNA) in bacterial and viral meningitis in children.

METHODS

The peripheral blood of five bacterial meningitis patients, five viral meningitis samples, and five healthy individuals were collected for RNA sequencing. Then, the differentially expressed lncRNA and mRNA were detected in bacterial meningitis vs. controls, viral meningitis vs. healthy samples, and bacterial vs. viral meningitis patients. Besides, co-expression and the competing endogenous RNA (ceRNA) networks were constructed. Receiver operating characteristic curve (ROC) analysis was performed.

RESULTS

Compared with the control group, 2 lncRNAs and 32 mRNAs were identified in bacterial meningitis patients, and 115 lncRNAs and 54 mRNAs were detected in viral meningitis. Compared with bacterial meningitis, 165 lncRNAs and 765 mRNAs were identified in viral meningitis. 2 lncRNAs and 31 mRNAs were specific to bacterial meningitis, and 115 lncRNAs and 53 mRNAs were specific to viral meningitis. The function enrichment results indicated that these mRNAs were involved in innate immune response, inflammatory response, and immune system process. A total of 8 and 1401 co-expression relationships were respectively found in bacterial and viral meningitis groups. The ceRNA networks contained 1 lncRNA-mRNA pair and 4 miRNA-mRNA pairs in viral meningitis group. GPR68 and KIF5C, identified in bacterial meningitis co-expression analysis, had an area under the curve (AUC) of 1.00, while the AUC of OR52K2 and CCR5 is 0.883 and 0.698, respectively.

CONCLUSIONS

Our research is the first to profile the lncRNAs in bacterial and viral meningitis in children and may provide new insight into understanding meningitis regulatory mechanisms.

Multiplex real-time PCR FilmArray performance in the diagnosis of meningoencephalitis: lights and shadows

PURPOSE

We aimed to evaluate the performance of the FilmArray (FA) meningitis/encephalitis (ME) panel. Secondarily, we analyzed the false positive (FP) and false negative (FN) results, as well as the predictive values of the technique, regarding the cerebrospinal fluid (CSF) characteristics.

METHODS

FA is a multiplex real-time PCR detecting 14 of the most common ME pathogens in CSF. All FA performed at our hospital (2018-2022) were retrospectively reviewed. FA was compared to conventional techniques and its performance was assessed based on the final diagnosis of the episode.

RESULTS

FA was performed in 313 patients with suspicion of ME. Most patients had altered mental status (65.2%) and fever (61%). Regarding CSF characteristics, 49.8% and 53.7% presented high CSF proteins and pleocytosis, respectively. There were 84 (26.8%) positive FA results, mainly for HSV-1 (10.9%), VZV (5.1%), Enterovirus (2.6%), and S. pneumoniae (1.9%). In the 136 cases where both FA and routine methods were performed, there was a 25.7% lack of agreement. We identified 6.6% FN results, but 28.6% FP, mainly due to HSV-1. This resulted in a high negative predictive value (NPV) of 93.4%, but a positive predictive value (PPV) of 73%. Remarkably, PPV as low as 36.9%, and 70.2%, were found in cases without pleocytosis, or lack of high CSF protein levels, respectively.

CONCLUSION

FA was associated with high NPV, but frequent FP results and low PPV, particularly for HSV-1, and especially in patients without high CSF protein levels or pleocytosis.

Clinical Characteristics, Treatment, and Outcomes of Veterans with Cerebrospinal Fluid Culture Positive for Gram-Negative Rod Bacteria: A Retrospective Analysis over 18 Years in 125 Veterans Health Administration Hospitals

Optimal management for patients with bacterial ventriculitis/meningitis due to Gram-negative rods (GNRs) has yet to be well investigated. We assessed the clinical characteristics, treatment, and outcomes of patients with a positive cerebrospinal fluid (CSF) culture for GNRs. We conducted a retrospective cohort study of all patients with a positive CSF culture within the Veterans Health Administration (VHA) system during 2003-2020. Clinical and microbiological characteristics between the true meningitis and contamination groups were compared. Of the 5919 patients with positive CSF cultures among 125 nationwide VHA acute-care hospitals, 297 (5.0%) were positive for GNRs. Among 262 patients analyzed, 156 (59.5%) were assessed as patients with true meningitis, and 106 (40.5%) were assessed as patients with contaminated CSF cultures. Patients with true meningitis had a significantly higher CSF protein (median 168 vs 57 mg/dL, p < 0.001), CSF white blood cell count (median 525 vs 3/µL, p = 0.008) and percentage of neutrophils in CSF (median 88 vs 4%, p < 0.001). Enterobacterales were more common in the true meningitis group, while unidentified GNR or polymicrobial CSF cultures were more common in the contamination group. The all-cause 90-day mortality was 25.0% (39/156) in patients with true meningitis and 10.4% (11/106) in those with contaminated CSF cultures. None of the 11 patients with contaminated CSF cultures who died were considered due to missed meningitis. More than 40% of patients with a positive CSF culture with GNR did not receive treatment without negative consequences. Careful clinical judgment is required to decide whether to treat such patients.

A Rare Case of Meningitis Caused by Streptococcus gallolyticus subsp. pasteurianus in an Immunocompetent Young Adult

Bacterial meningitis is a life-threatening condition that is mainly caused by Streptococcus pneumoniae and Neisseria meningitis. Although Streptococcus gallolyticus subsp. pasteurianus (Sgp) is also known to cause meningitis, its frequency is quite low, especially in adults. We herein report the first immunocompetent Japanese adult patient (20-year-old woman) with bacterial meningitis caused by Sgp. The patient showed dramatic improvement after antibiotic treatment. Although previous reports have described an association between Sgp infection and an immunosuppressive status, bowel and hepatobiliary diseases, or strongyloidiasis, our case did not demonstrate any of these conditions, suggesting that Sgp can cause meningitis even in young immunocompetent adults.