Spinal sepsis due to Streptococcus milleri: two cases and review

Central Nervous System Infections Due to Streptococcus anginosus Group: A Single-Center Case Series

BACKGROUND

The Streptococcus anginosus group is known for its pathogenicity and tendency for abscess formation. The S anginosus group also causes brain abscesses, yet few studies describe this presentation in the pediatric neurology literature. We describe 5 patients with central nervous system infection due to S anginosus group evaluated by child neurologists at the University of Iowa from 2014 to 2020.

METHODS

We performed a retrospective case series review of electronic medical records detailing the clinical presentation and course of pediatric patients with S anginosus group-associated central nervous system infection.

RESULTS

We identified 4 males and 1 female (8, 11, 14, 16, and 21 years). Brain imaging showed abscesses in 4 cases and empyema in 1. All underwent neurosurgical intervention and antibiotic treatment. Cultures obtained during the neurosurgical procedure grew S anginosus group (4 cases with Streptococcus intermedius and 1 with Streptococcus constellatus). An 8-year-old boy with a delayed diagnosis died from brain herniation.

CONCLUSIONS

Central nervous system infections due to the S anginosus group can be life-threatening. Neuroimaging plays a key role in the early identification of abscesses. Prompt surgical intervention and timely initiation of antibiotics are critical for optimal outcomes.

Spinal Subdural Abscess Following Laminectomy for Symptomatic Stenosis: A Report of 2 Cases and Review of the Literature

BACKGROUND Spinal subdural abscesses, also known as empyemas, are rare infectious lesions, the exact incidence of which is unknown. Presentation is typically dramatic, with back pain, fever, motor, and sensory deficits. Rapid identification and surgical intervention with laminectomy, durotomy, and washout provides the best outcomes. While hematogenous spread of an extra-spinal infection is the most common cause of this condition, a significant number of cases result from iatrogenic mechanisms, including lumbar punctures, epidural injections, and surgery. CASE REPORT Here we present 2 cases: 1) an 87-year-old man with type 2 diabetes, schizophrenia, mild cognitive impairment, and symptomatic lumbar spinal stenosis and 2) a 62-year-old man with a prior L3-4 spinal fusion with symptomatic lumbar spinal stenosis. In both cases, patients underwent laminectomy for spinal stenosis and developed epidural abscess. Following successful drainage of the epidural abscess, they continued to be symptomatic, and repeat imaging revealed the presence of a subdural abscess that was subsequently evacuated. Case 1 had significant improvement with residual lower-extremity weakness, while Case 2 made a complete neurological recovery. CONCLUSIONS These cases illustrate patients at increased risk for developing this rare spinal infection, and demonstrate that rapid recognition and surgical treatment is key to cure and recovery. Review of the literature highlights pertinent risk factors and demonstrates nearly one-third of reported cases have an iatrogenic etiology. The cases presented here demonstrate that a subdural process should be suspected in any patient with intractable pain following treatment of an epidural abscess.

Spinal subdural abscess: a rare complication of decubitus ulcer

Spinal subdural abscess (SSA) is an uncommon entity. The exact incidence is unknown, with very few cases reported in the literature. This condition may result in spinal cord compression, thus constituting a medical and neurosurgical emergency. The pathogenesis of SSA is not well-described, and the available knowledge is based on case observations only. There is only one case report that describes direct seeding from decubitus ulcers as a possible mechanism for development of SSA. We report a case of subacute onset of quadriplegia in a male patient, age 55 years, due to spinal cord compression from SSA and superimposed spinal subdural hematoma. The direct seeding from decubitus ulcers is thought to be the cause of infection in our patient. We present this case of SSA to elucidate and review the predisposing factors, pathogenesis, clinical presentation, diagnostic modalities, and treatment regarding management of this rare disorder.

Infections of the spinal subdural space in children: a series of 11 contemporary cases and review of all published reports. A multinational collaborative effort

INTRODUCTION

Positioned anatomically between the spinal epidural space and the intramedullary compartment, the spinal subdural space remains the least common area of localized infection in the central nervous system. Infectious processes of the subdural spinal space include subdural spinal empyema, subdural spinal abscess, infected spinal subdural cyst, and infectious spinal subdural cyst. To date, there has been no systematic review of these entities in children, with the cumulative knowledge of the pathophysiologic, microbiologic, and demographic characteristics of these infections relegated solely to few small series and case reports.

METHODS

A series of 11 recent cases culled from the collaboration of international authors are presented. In addition, an exhaustive MEDLINE search and manual review of the international literature was performed, identifying a total of 73 cases of spinal subdural infections in patients under the age of 21. Data of interest include the age, sex, signs, and symptoms at presentation, spinal location of infection, presence of spinal dysraphism, and other comorbidities, offending organism, treatment, outcome, and follow-up.

RESULTS

Patients ages ranged from 4 weeks to 20 years (mean, 6.5 years). Males outnumbered females by a ratio of 2:1. Over half (53 %) of spinal subdural infections in children were associated with spinal dysraphism or other congenital abnormalities of the spine. The commonest organism to infect the spinal subdural space in children is mycobacterium tuberculosis and the thoracic spinal region was most commonly infected.

CONCLUSIONS

The disease is usually treated surgically, although a more expectant approach consisting of antibiotics and observation has also been proposed.

Development of real-time PCR assays for detection of the Streptococcus milleri group from cystic fibrosis clinical specimens by targeting the cpn60 and 16S rRNA genes

Cystic fibrosis (CF) is a multiorgan disease, with the majority of mortalities resulting from pulmonary failure due to repeated pulmonary exacerbations. Recently, members of the Streptococcus anginosus group (S. anginosus, S. constellatus, and S. intermedius), herein referred to as the "Streptococcus milleri group" (SMG) have been implicated as important etiological pathogens contributing to pulmonary exacerbations in CF patients. This is partly due to better microbiological detection of the SMG species through the development of a novel specific medium termed "McKay agar." McKay agar demonstrated that SMG has been an underreported respiratory pathogen contributing to lung exacerbations. Our aim was to develop a real-time PCR assay to expedite the detection of SMG within diagnostic samples. The cpn60 gene was chosen as a target, with all three members amplified using a single hybridization probe set. SMG strain analysis showed that speciation based on melting curve analysis allowed for the majority of the S. constellatus (96%), S. intermedius (94%), and S. anginosus (60%) strains to be correctly identified. To increase specificity for S. anginosus, two 16S rRNA real-time PCR assays were developed targeting the 16S rRNA gene. The 16s_SA assay is specific for S. anginosus (100%), while the 16s_SCI assay is specific for S. constellatus and S. intermedius (100%). These assays can detect <10 genome equivalents in pure culture and >10(4) genome equivalents in sputum samples, making this a great tool for assessment of the presence of SMG in complex polymicrobial samples. Novel molecular methods were developed providing detection ability for SMG, an emerging opportunistic pathogen.

Spinal Subdural Staphylococcus Aureus Abscess: case report and review of the literature

Background

Only 65 cases (including our case) of spinal subdural abscesses have been reported to the literature, mostly to the lumbar spine. Staphylococcus aureus is the most common bacterial. The symptoms are not caracteristic and contrast – enhanced magnetic resonance imaging scan (MRI) is the imaging method of choice. The early diagnosis is crucial for the prognosis of the patient.

Case presentation

We present a patient 75 years old who had a history of diabetes and suffered acute low back pain in the region of the lumbar spine for the last 4 days before his admission to the hospital. He also experienced lower leg weakness, fever and neck stiffness. After having a brain CT scan and a lumbar puncture the patient hospitalized with the diagnosis of meningitis. Five days after his admission the diagnosis of subdural abscess secured with contrast – enhanced MRI but meanwhile the condition of the patient impaired with respiratory failure and quadriplegia and he was admitted to the ICU. A laminectomy was performed eight days after his admission into the hospital but unfortunately the patient died.

Conclusion

Early diagnosis and treatment are very important for the good outcome in patients with subdural abscess. Although morbidity and mortality are very high, surgical and antibiotic treatment should be established as soon as possible after the diagnosis has secured.

Infectious Diseases of the Nervous System

In this chapter infectious diseases of the nervous system are discussed. These include bacterial, viral, fungal, spirochetal, and parasitic infections. Although the central nervous system (CNS) is protected from bacterial invasion by the intact blood-brain barrier, bacterial invasion is enhanced by the special surface properties of bacteria as well as host immune deficiencies. Similar to any type of infection of the nervous system, bacteria may involve any of the nervous system compartments: the epidural space (epidural abscess); the dura (pachymeningitis); the subdural space (subdural empyema); the leptomeninges and the subarachnoid space containing cerebrospinal fluid (meningitis or leptomeningitis); and the brain parenchyma (brain abscess). The clinical manifestations, pathogenesis, pathology, etiology, epidemiology, diagnosis, differential diagnosis, and treatment of these syndromes are presented.

Epidural abscess caused by Streptococcus milleri in a pregnant woman

BACKGROUND

Bacteria in the Streptococcus milleri group (S. anginosus, S. constellatus, and S. intermedius) are associated with bacteremia and abscess formation. While most reports of Streptococcus milleri group (SMG) infection occur in patients with underlying medical conditions, SMG infections during pregnancy have been documented. However, SMG infections in pregnant women are associated with either neonatal or maternal puerperal sepsis. Albeit rare, S. milleri spinal-epidural abscess in pregnancy has been reported, always as a complication of spinal-epidural anesthesia. We report a case of spinal-epidural abscess caused by SMG in a young, pregnant woman without an antecedent history of spinal epidural anesthesia and without any underlying risk factors for invasive streptococcal disease.

CASE PRESENTATION

A 25 year old pregnant woman developed neurological symptoms consistent with spinal cord compression at 20 weeks gestation. She underwent emergency laminectomy for decompression and was treated with ceftriaxone 2 gm IV daily for 28 days. She was ambulatory at the time of discharge from the inpatient rehabilitation unit with residual lower extremity weakness.

CONCLUSION

To our knowledge, this is the first reported case of a Streptococcus milleri epidural abscess in a healthy, pregnant woman with no history of epidural anesthesia or invasive procedures. This report adds to the body of literature on SMG invasive infections. Treatment of SMG spinal-epidural abscess with neurologic manifestations should include prompt and aggressive surgical decompression coupled with targeted anti-infective therapy.

Spinal subdural Staphylococcus aureus abscess: case report and review of the literature

Spinal subdural abscesses (SSA) are rare and to date only 57 cases have been reported. The exact incidence of the SSA is unknown. The most affected region is the thoraco-lumbar spine and the most common bacterial source is Staphylococcus aureus. The timing for magnetic resonance imaging is very important in these patients. Because early diagnosis and emergent treatment is vital to prevent the formation or progression of neurologic deficits.

Clinically significant concentrations of local anesthetics inhibit Staphylococcus aureus in vitro

This study explores which concentrations of local anesthetics might be expected to inhibit the growth of Staphylococcus aureus. Serial dilutions were made of 0.5% and 0.75% bupivacaine, 2% and 5% lidocaine, 2% and 3% chloroprocaine, and 0.2% and 1% ropivacaine. To each concentration of local anesthetic solution, Mueller Hinton broth medium and Staphylococcus aureus were added. The resulting solutions were incubated and then observed for growth 24 and 48 h later. The minimum concentrations of the local anesthetics that could inhibit growth of Staphylococcus aureus were 0.25% bupivacaine, 1.25% lidocaine and 0.75% chloroprocaine. The inhibitory concentration of ropivacaine could not be determined because the more concentrated solutions precipitated in the Mueller Hinton broth. Local anesthetics may help protect against epidural abscess formation if they are used in sufficiently high concentrations. This effect may help explain the very low reported incidence of epidural abscess.

Spinal epidural abscess: the importance of early diagnosis and treatment

OBJECTIVES

To remind clinicians of the dangers of delayed diagnosis and the importance of early treatment of spinal epidural abscess.

METHODS

A review of the literature on spinal epidural abscess and a comparison of the published literature with local experience.

RESULTS

Imaging with MRI or CT enables early diagnosis of spinal epidural abcess and optimal therapy is surgical evacuation combined with 6-12 weeks (median 8 weeks) of antimicrobial chemotherapy. Clinical features are fever, pain, and focal neurological signs and may be associated with preceding and pre-existing bone or joint disease. The commonest aetiological organism is S aureus.

CONCLUSION

Early diagnosis and appropriate early antimicrobial chemotherapy with surgery is associated with an excellent prognosis.

Subdural empyema of the cervical spine: clinicopathological correlates and magnetic resonance imaging. Report of three cases

A paucity of formally described information is available in the scientific literature regarding spinal subdural empyema. Patients presenting with neurological deterioration associated with subdural empyema are rarely identified, and treatment is often based upon anecdotal cases. The authors contribute three cases of primary cervical spinal subdural empyema and review the seven found in the literature. All patients had clinical evidence of neurological compromise, cervical tenderness, cervical pain, and leukocytosis upon admission. Cervical involvement ranged from C-2 to C-7. All patients underwent laminectomy with durotomy and drainage. The authors recommend prompt surgical decompressive laminectomy, copious irrigation, and drainage, followed with appropriate adjunctive antibiotic therapy for treatment of these patients.

Streptococcus milleri group: renewed interest in an elusive pathogen

The following review examines the bacteriological characteristics, epidemiology, pathogenicity and antimicrobial susceptibility of the "Streptococcus milleri group". "Streptococcus milleri group" is a term for a large group of streptococci which includes Streptococcus intermedius, Streptococcus constellatus and Streptococcus anginosus. Usually considered commensals, these organisms are often associated with various pyogenic infections including cardiac, abdominal, skin and central nervous system infections. Organisms of the "Streptococcus milleri group" are often unrecognized pathogens due to the lack of uniformity in classifications and difficulties in microbiological identification. Penicillin G, cephalosporins, clindamycin and vancomycin all possess activity against these streptococci. Use of agents with poor activity may promote infections with "Streptococcus milleri group" and allow it to exhibit its pathogenicity. An understanding of these organisms may aid in their recognition and proper treatment.