A chinese case of prevotella intermedia and streptococcus constellatus intracranial mixed infection

Case report: isolated prevotella intermedia causing intracranial infection detected using metagenomic next generation sequencing

BACKGROUND

Isolated Prevotella intermedia, a rare gram-negative, rod-shaped, anaerobic bacterium, is rarely detected in clinical practice. It has been associated with infections of the oral cavity and female genital tract, but has never been detected in cerebrospinal fluid (CSF) of patients in China. Accurate detection of causative pathogens is still an arduous task owing to the difficult conditions of anaerobic bacterial culture. Isolated Prevotella intermedia can be detected by metagenomic next generation sequencing (mNGS) of the CSF. Correct diagnosis and antibiotic treatment can help patients avoid life-threatening events.

CASE PRESENTATION

Herein, we describe the case of a 64-year-old Chinese woman who presented with typical features of meningoencephalitis. Routine CSF culture failed to identify the causative pathogen. Isolated Prevotella intermedia was detected by mNGS, and the patient was treated with antibacterial agents including ceftriaxone, vancomycin, moxifloxacin, meropenem, metronidazole, and linezolid. The patient underwent surgical treatment for abscess of left frontal parietal lobe, which was observed on magnetic resonance imaging (MRI) and was suspected to be caused by Prevotella intermedia. It was further confirmed that it was a secondary infection from the oral cavity, and the possible etiology might have been dental surgery. Treatment was rendered to the patient based on metagenomic test result, and her condition improved after two months.

CONCLUSIONS

This case highlights the role of mNGS in accurate diagnosis of patients with central nervous system infection. In particular, mNGS can be used to identify rare pathogens and confirm the diagnosis in patients with unknown etiology.

Polymicrobial Bacterial Meningitis in a Patient with Chronic Suppurative Otitis Media: Case Report and Literature Review

Polymicrobial meningitis is a rare entity in the adult population, especially in the antibiotic era. However, disorders such as chronic suppurative otitis media (CSOM) or even poor oral hygiene are considered risk factors for the development of such cerebral infection. We report a case of polymicrobial meningitis associated with oto-mastoiditis in a 64-year-old female patient known to have CSOM. The patient presented atypical symptoms for community-acquired meningitis, showing subacute evolution of headache, without fever or neck stiffness. The aerobe microorganisms Streptococcus anginosus and Corynebacterium spp., sensitive to beta-lactamines, and the anaerobe Prevotella spp., resistant to penicillin and metronidazole, were isolated from CSF specimens, while Proteus mirabilis and Enterococcus faecalis were identified from the ear drainage. The diversity of pathogens identified in our case led us to the hypothesis of two different sources of meningitis: otogenic and/or odontogenic. Favorable evolution was obtained after a multi-disciplinary approach, combining surgery and broad-spectrum antibiotics. In addition, we performed a literature review that highlights the low incidence of polymicrobial mixed aerobe-anaerobe meningitis.

Streptococcus constellatus causing concomitant extra and intracranial abscesses complicated with sagittal sinus thrombosis

Streptococcus constellatus is a gram-positive coccus member of the Streptococcus anginosus group (SAG). It can be found in the oral flora, and may cause abscess more commonly in the gastrointestinal tract, lungs, and heart. Brain abscesses are severe neurological infections with high mortality rates. Streptococcus species other than S. pneumoniae are rare causes of brain abscesses. This case report highlights a severe case of extra and intracranial abscesses due to S. constellatus in an immunocompetent host.

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INTRODUCTION

Prevotella species (i. e. P. intermedia, P. nigrescens, P. pallens, P. oris) are usually responsible for abscesses of head and neck spaces after dental procedures. P. intermedia - related infective endocarditis has never been reported.

CASE REPORT

A 22-year-old man, with a history of aortic valve replacement 6 years ago, presented with fever and persistent retrosternal chest pain. An empirical antibiotic therapy was started on (cefotaxime, 2gx3 - gentamicin, 5mg/kilo). Five blood cultures were positive at Prevotella Intermedia. Metronidazole was introduced (500mg X 3 by day).The oro-pharyngeal spaces were normal. The evolution was marked by a hypotension, a third degree atrio-ventricular block, and a rapidly growing aortic root abscess complicated this case of Prevotella Intermedia infective endocarditis (IE). Aortic valve redux surgery was performed at day 5 of admission. Post-operative course was unremarkable.

CONCLUSION

This first reported case of Prevotella Intermedia IE presented suggestive features of anaerobic IE as the patient developed both aortic-ring abscess, third degree atrio-ventricular block and hypotension.

Inconsistency analysis between metagenomic next-generation sequencing results of cerebrospinal fluid and clinical diagnosis with suspected central nervous system infection

Background

Recently, with the rapid progress of metagenomic next-generation sequencing (mNGS), inconsistency between mNGS results and clinical diagnoses has become more common. There is currently no reasonable explanation for this, and the interpretation of mNGS reports still needs to be standardised.

Methods

A retrospective analysis was conducted on 47 inpatients with suspected central nervous system (CNS) infections, and clinical data were recorded. The final diagnosis was determined by an expert group based on the patient’s clinical manifestation, laboratory examination, and response to treatment. mNGS results were compared with the final diagnosis, and any inconsistencies that occurred were investigated. Finally, the credibility of mNGS results was evaluated using the integral approach, which consists of three parts: typical clinical features, positive results with the traditional method, and cerebrospinal fluid cells ≥ 100 (× 10⁶/L) or protein ≥ 500 mg/L, with one point for each item.

Results

Forty-one patients with suspected CNS infection were assigned to infected (ID, 31/41, 75.61%) and non-infected groups (NID, 10/41, 24.39%) after assessment by a panel of experts according to the composite diagnostic criteria. For mNGS-positive results, 20 of the 24 pathogens were regarded as contaminants when the final score was ≤ 1. The remaining 11 pathogens detected by mNGS were all true positives, which was consistent with the clinical diagnosis when the score was ≥ 2. For mNGS negative results, when the score was ≥ 2, the likelihood of infection may be greater than when the score is ≤ 1.

Conclusion

The integral method is effective for evaluating mNGS results. Regardless of whether the mNGS result was positive or negative, the possibility of infection was greater when the score was ≥ 2. A negative mNGS result does not necessarily indicate that the patient was not clinically infected, and, therefore, clinical features are more important.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07729-0.

Case report: Meningitis and intracranial aneurysm caused by mixed infection of oral microflora dominated by anaerobes

Introduction

Meningitis caused by oral anaerobic bacteria is rare, especially when complicated with an infected intracranial aneurysm. This paper has described an extremely rare case of bacterial meningitis caused by a mixed infection of oral microflora dominated by anaerobes, which developed cerebral infarcts, brain abscess, intracranial aneurysm, and severe hydrocephalus during treatment.

Case report

We describe a 65-year-old male patient who was presented with fever and headache as the initial symptoms and then developed left ophthalmoplegia, right hemiplegia, and disturbance of consciousness. Brain imaging showed that intracranial lesions were increased progressively, and cerebral infarcts, brain abscesses, intracranial aneurysm, and severe hydrocephalus were appeared gradually. Eventually, we diagnosed it as anaerobic meningitis by making deoxyribonucleic acid sequencing from the brain abscess pus. After using an anti-microbial regimen that can sufficiently cover anaerobes, the patient's condition was effectively controlled.

Conclusion

Anaerobic meningitis can cause a series of intracranial complications. Among them, the intracranial aneurysm is extremely rare. When evidence shows that the infection originates from oral flora, physicians should consider the possibility of this type of encephalitis. An early diagnosis and timely treatment are crucial to improving the prognosis.

Expression of the α7 nAChR Subunit Duplicate Form (CHRFAM7A) Was Down-Regulated in Patients with Intracranial Infection and Reduced Inflammation in in vitro Model by p38 MAPK

OBJECTIVE

In this study, we investigated that the effects and possible mechanisms of the α7 nAChR subunit duplicate form (CHRFAM7A) affected inflammation in the model of intracranial infection.

METHODS

Mice of the model group were injected (intracranial injection) with Staphylococcus aureus. Mouse microglial BV2 cell was exposed with 200 ng of LPS for 4 h.

RESULTS

CHRFAM7A mRNA expressions were reduced in patients with intracranial infection. CHRFAM7A mRNA and protein expressions were suppressed in mice with intracranial infection in a time-dependent manner. CHRFAM7A reduced inflammation in mice with intracranial infection. The inhibition of CHRFAM7A reduced inflammation in mice with intracranial infection. CHRFAM7A suppressed p38 MAPK in mice with intracranial infection. The inhibition of p38 MAPK shows the effects of CHRFAM7A in intracranial infection.

CONCLUSION

Our data demonstrate that the expression of the CHRFAM7A was down-regulated in patients with intracranial infection and reduced inflammation in in vitro model by p38 MAPK, which suggests the potential role of CHRFAM7A as a diagnostic biomarker for intracranial infection.

Association between obligatory anaerobes and empyema caused by Streptococcus anginosus group bacteria

Co-infections of Streptococcus anginosus group (SAG) bacteria and obligate anaerobes are observed in patients with empyema; however, their epidemiology and pathology remain unknown. A retrospective study was performed with 44 patients who underwent pleural effusion microbiota evaluation between January 2006 and March 2018, using the clone library method for detecting empyema caused by SAG bacteria. Based on culture analysis of pleural effusion, 12 patients were diagnosed with empyema caused by SAG bacteria. Obligate anaerobe phylotypes were detected in eight patients (66.7%) using the clone library method, whereas anaerobic culture analysis detected anaerobes in only two patients (16.7%). No significant difference was observed between the clinical features of SAG-mediated empyema with and without anaerobes using the clone library method, except for chest computed tomographic data. Co-infection of SAG bacteria and obligate anaerobes may be underestimated if conventional culture methods are used. SAG-mediated empyema with and without anaerobes may present different radiological features; therefore, further studies are required.

Application value analysis of magnetic resonance imaging and computed tomography in the diagnosis of intracranial infection after craniocerebral surgery

BACKGROUND

Intracranial infection is a common clinical disease. Computed tomography (CT) and magnetic resonance imaging (MRI) have certain sensitivity and have good diagnostic efficacy.

AIM

To study the application value of MRI and CT in the diagnosis of intracranial infection after craniocerebral surgery.

METHODS

We selected 82 patients who underwent craniocerebral surgery (including 40 patients with intracranial infection and 42 patients without infection) during the period from April 2016 to June 2019 in our hospital. All 82 patients received CT and MRI examinations, and their clinical data were reviewed. A retrospective analysis was performed, and the coincidence rate of positive diagnosis and the overall diagnosis coincidence rate of different pathogenic infection types were measured with the two examination methods. The diagnostic sensitivity and specificity as well as the positive and negative predictive values of the two examination methods were compared.

RESULTS

For all types of pathogenic infections (Staphylococcus aureus, Staphylococcus hemolyticus, Staphylococcus epidermidis, and others), MRI scans had higher positive diagnostic coincidence rates than CT scans; the overall diagnostic coincidence rate, sensitivity, specificity, positive predictive value, and negative predictive values were significantly higher with MRI examinations than with CT examinations, and the differences were statistically significant (P < 0.05).

CONCLUSION

MRI examination can accurately diagnose intracranial infection after clinical craniocerebral surgery. Compared with CT, MRI had higher diagnostic efficiency. The diagnostic sensitivity and specificity, the diagnostic coincidence rate, and the positive and negative predictive values were significantly higher with MRI than with conventional CT, which can be actively promoted.

First Case of Intracranial Mycotic Aneurysm Caused by Prevotella intermedia Associated with Chronic Sinusitis in a Korean Adult

Intracranial infection caused by anaerobic bacteria is rare, and it is difficult to identify absolute anaerobes in the clinical laboratory, especially when the bacterial load is low. Here, we report the first case of intracranial mycotic aneurysm caused by Prevotella intermedia associated with chronic sinusitis and successful identification of the bacteria by 16S rRNA sequencing from bacterial growth in broth only.