Meningitis caused by streptococci other than Streptococcus pneumoniae: a retrospective clinical study

Viridans Group Streptococcus Meningitis in an Immunocompetent Child: A Case Report

Patient: Female, 14-month-old

Final Diagnosis: Viridans group streptococcus meningitis

Symptoms: Fever • irritability • vomiting

Medication: —

Clinical Procedure: —

Specialty: Infectious Diseases

Atypical Streptococcal Meningitis with Fatal Cerebrovascular Complications: A Case Report

Bacterial meningitis is an infectious pathology that remains a public health challenge. The most frequent etiological agent is Streptococcus pneumoniae, which is also associated with higher rates of mortality and sequels. However, less is known about the clinical presentation of atypical non-pneumoniae streptococcal meningitis. Here, we studied a 23-year-old man with no medical background who presented with projectile vomiting, states of consciousness alteration, unilateral cranial nerve palsy, and meningeal signs. Neuroimaging showed tonsillar herniation, regions of empyema, right transverse and sigmoid sinuses thrombosis, and multiple arterial subcortical infarcts. Cerebrospinal fluid suggested bacterial infection; blood and abscess cultures were positive for Streptococcus constellatus. The patient received antibiotics with no clinical improvement. He deteriorated over the following days, the abolishment of brainstem reflexes was observed, and brain death was declared. Streptococcal meningitis produced by atypical species is a potential cause of lethal cerebrovascular complications, even in immunocompetent patients.

Species-Specific Identification of Streptococcus based on DNA Marker in 16S-23S rDNA Internal Transcribed Spacer

Streptococcus is closely correspondent to human. The accurate species-specific identification method of Streptococcus is important for the bacteria clinical diagnosis, molecular epidemiological analysis, and microecological study. In the last decades, DNA markers are widely utilized for identification of prokaryotic species. However, 16S rDNA, the most popular bacterial DNA marker, cannot properly distinguish closely related Streptococcus species. In present study, we employed 16S-23S rRNA gene internal transcribed spacer (ITS) sequence to explore the species-specific DNA marker. We predicted the secondary structure of Streptococcus ITS sequence transcribed products. Then we identified that the specific and consensus sequences in the primary structure can be found occupying an individual subunit in the secondary structure, which explained the foundation of the mosaic-like structure of ITS. We evaluated the specificity of ITS in Streptococcus, and found that the specificity can be detected by a further analysis of a BLAST result. Then, we developed an identification procedure based on the ITS sequence. We verified the procedure by 500 ITS sequence. The accuracy rate of this procedure was 100% for Streptococcus at genus level, and 99.3% at species level. It suggested that ITS can be utilized to accurately identify Streptococcus at the species level. This work suggests that further exploration of ITS could be applied in other bacterial genera for identification and classification, which may be a useful topic for future microbiology studies.

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

Streptococcal Species is increasingly recognized as a potentially preventable emerging infection in human's brain with high prevalence around the world. Streptococcus constellatus is one of the most common pathogens. Meanwhile, anaerobic bacteria are the rare causes for intracranial infection. To date, intracranial mixed infection caused by Prevotella intermedia and Streptococcus constellatus has not been reported. We reported a Chinese case to raise the global awareness of severity of the intracranial mixed infection. Here, we illustrated the epidemiological risk factors, clinical manifestations and outcomes of the patient. For patients who suffer from exacerbated brain infection with fetid cerebrospinal fluid, early repeated imaging is urgently needed and empiric antibiotic therapy should consider anaerobic and aerobic bacteria in these situations.

Acute Bacterial Meningitis and Systemic Abscesses due to Streptococcus dysgalactiae subsp. equisimilis Infection

Disseminated abscesses due to group G β-hemolytic Streptococcus dysgalactiae were observed in a 57-year-old cirrhotic patient with the skin being the putative way of entry for the pathogen. S. dysgalactiae is a rare agent in human infections responsible for acute pyogenic meningitis. The mortality rate associated with S. dysgalactiae bacteraemia and meningitis may be as high as 50%, particularly in the presence of endocarditis or brain abscesses. In our patient, main sites of infections were meningitis and ventriculitis, spondylodiscitis, septic arthritis, and soft-tissue infections. In contrast, no endocarditis was evidenced. Cirrhosis-related immune suppression was considered as a pathophysiological cofactor for the condition. Fortunately, clinical status improved after long-term (3 months) antimicrobial therapy.

Neutrophilic bacterial meningitis: pathology and etiologic diagnosis of fatal cases

The frequency of fatalities due to acute bacterial meningitis has decreased significantly due to vaccinations, early diagnoses, and treatments. We studied brain tissues of patients with fatal neutrophilic meningitis referred to the Centers for Disease Control for etiologic diagnosis from 2000-2009 to highlight aspects of the disease that may be preventable or treatable. Demographic, clinical, and laboratory data were extracted from records. Of 117 cases in the database with a diagnosis of meningitis or meningoencephalitis, 39 had neutrophilic inflammation in the meninges. Inflammatory cells infiltrated the superficial cortex in 16 of 39 (41%) cases. Bacteria were found using Gram and bacterial silver stains in 72% of cases, immunohistochemistry in 69% (including two cases where the meningococcus was found outside the meninges), and PCR in 74%. Streptococcus pneumoniae was the cause of the meningitis in 14 patients and Neisseria meningitidis in 9. In addition, Streptococcus spp. were found to be the cause in six cases, while Staphylococcus aureus, Staphylococcus spp., Enterococcus spp., and Fusobacterium were the cause of one case each. There were six cases in which no specific etiological agent could be determined. The mean age of the patients with S. pneumoniae was 39 years (range 0-65), with N. meningitidis was 19 years (range 7-51), whereas that for all others was 31 years (range 0-68). In summary, our study shows that S. pneumoniae continues to be the most frequent cause of fatal neutrophilic bacterial meningitis followed by N. meningitidis, both vaccine preventable diseases.

Streptococcus australis meningitis

We report a case of meningitis due to Streptococcus australis, a species of oral streptococcus. Accurate identification was performed by various molecular techniques.

Clinical, microbiological and molecular characteristics of six cases of group A streptococcal meningitis in western Norway

Meningitis is a rare clinical manifestation of invasive group A streptococcal (iGAS) disease. Clinical, microbiological and molecular characteristics of 6 consecutive cases of GAS meningitis treated in Haukeland University Hospital in the period 2004-2009 are described. All 6 patients had a primary upper respiratory tract infection, with subsequent mastoiditis in 5, subdural effusions in 2, and cerebral abscess in 1. Five patients needed surgical treatment (myringotomy, craniotomy or mastoidectomy). All patients were treated with a beta-lactam antibiotic in combination with rifampicin. The course was complicated in all cases, and 1 patient died. Three of the bacterial isolates were of the sequence type emm1.0 and they shared the same superantigen gene profile (speA, speG, speJ, smeZ). The remaining 3 isolates belonged to sequence types emm 3.1, emm6.4 and emm12.0. Deletions in emm genes were observed. This report describes the severe and complicated course of GAS meningitis and its management, often requiring surgical intervention.

Identification of clinically relevant nonhemolytic Streptococci on the basis of sequence analysis of 16S-23S intergenic spacer region and partial gdh gene

Nonhemolytic streptococci (NHS) cause serious infections, such as endocarditis and septicemia. Many conventional phenotypic methods are insufficient for the identification of bacteria in this group to the species level. Genetic analysis has revealed that single-gene analysis is insufficient for the identification of all species in this group of bacteria. The aim of the present study was to establish a method based on sequence analysis of the 16S-23S intergenic spacer (ITS) region and the partial gdh gene to identify clinical relevant NHS to the species level. Sequence analysis of the ITS region was performed with 57 NHS reference or clinical strains. Satisfactory identification to the species level was achieved for 14/19 NHS species included in this study on the basis of sequence analysis of the ITS region. Streptococcus salivarius and Streptococcus vestibularis obtained the expected taxon as the best taxon match, but there was a short maximum score distance to the next best match (distance, <10). Streptococcus mitis, Streptococcus oralis, and Streptococcus pneumoniae could not be unambiguously discriminated by sequence analysis of the ITS region, as was also proven by phylogenetic analysis. These five species could be identified to the group level only by ITS sequence analysis. Partial gdh sequence analysis was applied to the 11 S. oralis strains, the 11 S. mitis strains, and the 17 S. pneumoniae strains. All except one strain achieved a satisfactory identification to the species level. A phylogenetic algorithm based on the analysis of partial gdh gene sequences revealed three distinct clusters. We suggest that sequence analysis of the combination of the ITS region and the partial gdh gene can be used in the reference laboratory for the species-level identification of NHS.

Community-acquired Streptococcus mitis meningitis: a case report

BACKGROUND

Streptococcus mitis is prevalent in the normal flora of the oropharynx, the female genital tract, gastrointestinal tract, and skin. Although it is usually considered to have low virulence and pathogenicity, Streptococcus mitis may cause life-threatening infections, particularly endocarditis. Meningitis with S. mitis is rare, but has been described in individuals with previous spinal anesthesia, neurosurgical procedure, malignancy, or neurological complications of endocarditis.

CASE REPORT

A 58-year-old, alcoholic male patient with a high fever, headache, and changes in mental status was admitted to hospital with the diagnosis of meningitis. S. mitis, isolated from cerebrospinal fluid, was sensitive to penicillin. He was given a 14-day course of ampicillin and made a full clinical recovery.

CONCLUSIONS

The purpose of this report is to emphasize the importance of the occurrence of S. mitis meningitis in patients with concomitant factors such as older age (>50 years), alcoholism, poor oral hygiene, and maxillary sinusitis.

Population diversity and dynamics of Streptococcus mitis, Streptococcus oralis, and Streptococcus infantis in the upper respiratory tracts of adults, determined by a nonculture strategy

We reinvestigated the clonal diversity and dynamics of Streptococcus mitis and two other abundant members of the commensal microbiota of the upper respiratory tract, Streptococcus oralis and Streptococcus infantis, to obtain information about the origin of frequently emerging clones in this habitat. A culture-independent method was used, based on cloning and sequencing of PCR amplicons of the housekeeping gene gdh, which shows remarkable, yet species-specific, genetic polymorphism. Samples were collected from all potential ecological niches in the oral cavity and pharynx of two adults on two occasions separated by 2 years. Based on analysis of close to 10,000 sequences, significant diversity was observed in populations of all three species. Fluctuations in the relative proportions of individual clones and species were observed over time. While a few clones dominated, the proportions of most clones were very small. The results show that the frequent turnover of S. mitis, S. oralis, and S. infantis clones observed by cultivation can be explained by fluctuations in the relative proportions of clones, most of which are below the level of detection by the traditional culture technique, possibly combined with loss and acquisition from contacts. These findings provide a platform for understanding the mechanisms that govern the balance within the complex microbiota at mucosal sites and between the microbiota and the mucosal immune system of the host.

Ruptured Mycotic Aneurysm Presenting Initially with Bacterial Meningitis

Infections of the major vessels can result in the formation of mycotic aneurysms, which can ultimately rupture and can be associated with a high mortality rate. Mycotic aneurysms can pose a diagnostic dilemma for the clinicians and successful treatment of this condition often requires a very high index of suspicion. We report an unusual case of a 65-year-old black female who initially presented with bacterial meningitis due to Streptococcus pneumoniae and 1 week later died from a ruptured undetected mycotic aneurysm. A similar case, in which a mycotic aneurysm initially presented with bacterial meningitis, could not be found in the literature.

Report of two cases of aseptic meningitis with persistence of pneumococcal cell wall components in cerebrospinal fluid after Pneumococcal meningitis

We describe two cases of aseptic meningitis occurring some time after pneumococcal meningitis. Both cases may have resulted from an inflammatory response to persistent pneumococcal cell membrane components, as the cerebrospinal fluid samples were positive by the Binax NOW Streptococcus pneumoniae antigen test. Potential mechanisms and diagnostic impact are discussed.

Brainstem infarcts as an early manifestation of Streptococcus anginosus meningitis

BACKGROUND AND PURPOSE

Vasculitis and infarcts are well-established sequelae of bacterial meningitis. However, early large-vessel involvement is rare, particularly within the brainstem. There has been one previous case report of a young male who presented with pontine infarct as an early manifestation of Streptococcus milleri meningitis. We present another case of brainstem infarction associated with meningitis caused by Streptococcus anginosus.

CASE DESCRIPTION

We report a 58-year-old man who developed constitutional symptoms and gait instability, followed by progressive stupor. On examination, he had a Glasgow Coma Scale of 8 with intact brainstem reflexes and no focal findings. Magnetic resonance imaging documented bilateral pontine infarcts. S. anginosus was isolated from cerebrospinal fluid. Despite proper antibiotic treatment, the patient remained comatose and care was withdrawn. Postmortem examination revealed the meningitis was predominantly localized at the base of the brain. In addition, ventriculitis, multiple abscesses, and multiple infarcts in the pons and midbrain were found.

CONCLUSION

S. anginosus, which is part of the normal human flora, causes invasive pyogenic infections and is an uncommon cause of bacterial meningitis. This type of infection is mostly situated at the base of the brain and has a propensity to encase the basilar artery and its perforators, thus causing brainstem stroke early in its course.

Enterococcal meningitis: a clinical study of 39 cases and review of the literature

To describe the clinical features and outcome of enterococcal meningitis, we retrospectively reviewed the charts of 39 cases seen at 2 tertiary hospitals during a 25 years and collected 101 additional, previously reported cases for review. Among these 140 cases, there were 82 cases (59%) of postoperative meningitis and 58 cases (41%) of spontaneous meningitis. Eighty-six patients (61%) were adults and 54 (39%) were children. Patients with spontaneous meningitis had a higher frequency of community-acquired infection (50% versus 18%; p < 0.01), severe underlying diseases (67% versus 22%; p < 0.01), and associated enterococcal infection (29% versus 8%; p < 0.01) than patients with postoperative meningitis. The clinical presentation was similar in both groups, but patients with spontaneous infection had a higher frequency of bacteremia (58% versus 12%; p < 0.01), and a lower frequency of mixed infection (9% versus 29%; p < 0.01). Spontaneous meningitis in children was associated with a significantly lower frequency of fever, altered mental status, headache, and meningeal signs (p < 0.01), probably explained by the high proportion of neonates in this age-group. Most infections were caused by Enterococcus faecalis, which accounted for 76% of the isolates identified at the species level. Fifteen of the 25 cases due to Enterococcus faecium were produced by vancomycin-resistant strains. Most patients were treated with ampicillin, penicillin, or vancomycin, with or without aminoglycosides, for a median period of 18 days (range, 1-85 d). Overall mortality was 21%. The mortality rate was higher in spontaneous than in postoperative meningitis (33% versus 12%; p < 0.01), but was similar in patients treated with beta-lactams (18%), glycopeptides (14%), or other antibiotics (25%), as well as in patients treated with monotherapy (16%) or combination therapy (22%). An adverse outcome correlated significantly with advanced age, the presence of severe underlying diseases, associated enterococcal infection, bacteremia, septic shock, and the absence of fever at presentation. Shunt removal was associated with a lower mortality. Multivariate analysis showed that the presence of severe underlying diseases was the only prognostic factor associated with mortality (odds ratio = 6.8, 95% confidence intervals = 2.7-17.5, p < 0.01).

[Meningitis caused by streptococci other than S. pneumoniae: clinical and microbiological features of 13 cases]

BACKGROUND AND OBJECTIVE

Meningitis caused by streptococci other than S. pneumoniae are uncommon. We present our experience.

PATIENTS AND METHOD

We reviewed the clinical, microbiological, and epidemiological features of all patients with meningitis due to streptococci other than S. pneumoniae diagnosed in the Hospital Universitari Vall d'Hebron during the period 1991-2001.

RESULTS

Main causative agents in 13 studied patients were viridans group streptococci (6 cases) and S. agalactiae (5 cases). There were no differences in the clinical presentation between different streptococci. Bacteremia was common in meningitis due to S. agalactiae (80%). Only one patient died.

CONCLUSIONS

Meningitis caused by streptococci other than S. pneumoniae are often related to a distant focus of infection or to neurosurgical procedures and, in our experience, they seem to have a good outcome.

Delayed diagnosis of meningitis caused by beta-haemolytic group G. Streptococcus in an older woman

A case of meningitis caused by group G beta-hemolytic Streptococcus (dysgalactiae, subspecies equisimilis) is reported in an 83-year-old woman. Streptococci species other than Streptococcus pneumoniae are seldom found in patients with acute bacterial meningitis, therefore, our discussion is focused on this rare organism. The question of the diagnosis of meningitis in the elderly is also addressed.