A Case of Streptococcus anginosus Brain Abscess Caused by Contiguous Spread from Sinusitis in an Immunocompetent Patient

Massive bilateral paraclinoidal subdural empyema and parenchymal temporopolar abscess with anatomical infection pathway in a chronic inhaling cocaine-addicted patient: A case report and literature review

Background

Focal suppurative bacterial infections of the central nervous system (CNS), such as subdural empyemas and brain abscesses, can occur when bacteria enter the CNS through sinus fractures, head injuries, surgical treatment, or hematogenous spreading. Chronic cocaine inhalation abuse has been linked to intracranial focal suppurative bacterial infections, which can affect neural and meningeal structures.

Case Description

We present the case of a patient who developed a cocaine-induced midline destructive lesion, a vast bilateral paraclinoidal subdural empyema, and intracerebral right temporopolar abscess due to cocaine inhalation abuse. The infection disseminated from the nasal and paranasal cavities to the intracranial compartment, highlighting a unique anatomical pathway.

Conclusion

The treatment involved an endoscopic endonasal approach, followed by a right frontal-temporal approach to obtain tissue samples for bacterial analysis and surgical debridement of the suppurative process. Targeted antibiotic therapy helped restore the patient's neurological status.

Virulence factors of Streptococcus anginosus - a molecular perspective

Streptococcus anginosus together with S. constellatus and S. intermedius constitute the Streptococcus anginosus group (SAG), until recently considered to be benign commensals of the human mucosa isolated predominantly from oral cavity, but also from upper respiratory, intestinal, and urogenital tracts. For years the virulence potential of SAG was underestimated, mainly due to complications in correct species identification and their assignment to the physiological microbiota. Still, SAG representatives have been associated with purulent infections at oral and non-oral sites resulting in abscesses formation and empyema. Also, life threatening blood infections caused by SAG have been reported. However, the understanding of SAG as potential pathogen is only fragmentary, albeit certain aspects of SAG infection seem sufficiently well described to deserve a systematic overview. In this review we summarize the current state of knowledge of the S. anginosus pathogenicity factors and their mechanisms of action.

Septic shock from multiple intra-abdominal Streptococcus constellatus abscesses unamenable to percutaneous drainage

Streptococcus constellatus are gram-positive cocci belonging to the Streptococcus milleri group that have a propensity to cause bacteremia and abscesses, especially in immunocompromised patients. Here, we report the case of a 39-year-old male who was initially admitted to the hospital for diabetic ketoacidosis. During the hospitalization, he developed sepsis and blood cultures grew Streptococcus constellatus. CT imaging revealed multiple hepatic abscesses. A periapical abscess of the left mandibular central incisor found on CT Scan of face was identified as the likely source of infection. IR-guided drainage was performed however the patient went on to develop septic shock despite attempted source control and IV antibiotic therapy. Repeat imaging showed persistent hepatic abscesses in addition to new intraperitoneal abscesses necessitating exploratory laparotomy, drainage and abdominal washout. Fluid cultures grew Streptococcus constellatus and common enteric flora. Our report highlights the need for high clinical suspicion in cases of Streptococcus constellatus bacteremia to obtain diagnostic imaging for any abscess formation. Prolonged antibiotic therapy is a must and imaging guided or surgical drainage may be needed.

The Clinical View on Streptococcus anginosus Group – Opportunistic Pathogens Coming Out of Hiding

Three distinct streptococcal species: Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus, belonging to the Streptococcus anginosus group (SAG), also known as Streptococcus milleri group, have been attracting clinicians and microbiologists, not only as oral commensals but also as opportunistic pathogens. For years they have been simply classified as so called viridans streptococci, and distinct species were not associated with particular clinical manifestations. Therefore, description of SAG members are clearly underrepresented in the literature, compared to other medically relevant streptococci. However, the increasing number of reports of life-threatening infections caused by SAG indicates their emerging pathogenicity. The improved clinical data generated with the application of modern molecular diagnostic techniques allow for precise identification of individual species belonging to SAG. This review summarizes clinical reports on SAG infections and systematizes data on the occurrence of individual species at the site of infection. We also discuss the issue of proper microbiological diagnostics, which is crucial for further clinical treatment.

Pathologic fracture and hardware failure in Streptococcus anginosus femoral osteomyelitis: Case report

Introduction

Pathologic fracture of the femur due to Streptococcus anginosus osteomyelitis has rarely been described. With limited evidence for treating S. anginosus osteomyelitis, the orthopaedic surgeon is presented with a difficult treatment decision at index presentation. Presented here is a case of failed conservative management, diagnostic dilemma, failed hardware stabilization, and definitive surgical treatment resulting in good clinical outcome.

Case presentation

A 69-year-old male experienced acute right thigh pain, edema, and erythema after dental treatment 17 days prior. He was diagnosed with right femoral diaphyseal osteomyelitis and Brodie's abscess. Blood cultures grew S. anginosus, but all site-specific tissue cultures resulted negative. Initial management consisted of intravenous antibiotic therapy and percutaneous abscess drainage. Months later, the patient sustained a displaced pathologic fracture of the diaphyseal femur and there was concern for neoplasm, but biopsies were negative. Stabilization was attempted with a lateral plate and screws. This hardware catastrophically failed in the setting of an oligotrophic femoral nonunion. Ultimately, the patient was successfully treated with an intramedullary nail coated with antibiotic-impregnated cement. Twelve months later, the patient achieved clinical and radiographic healing with no evidence of relapse of his osteomyelitis.

Clinical discussion

Conservative management of S. anginosus femoral osteomyelitis was inadequate and corroborates the existing literature. S. anginosus osteomyelitis and pyomyositis may be most optimally treated aggressively with early surgical intervention.

Conclusion

Early surgical debridement and stabilization of the compromised bone with an antibiotic coated intramedullary nail following medullary reaming may prevent pathologic fracture, eradicate infection, and achieve predictable outcomes.

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S. anginosus femoral osteomyelitis is rare and difficult to diagnose and treat.

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Conservative measures failed, and pathologic fracture later ensued.

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Although sparse, existing reports suggest early surgical management is indicated.

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This report provides more evidence for early and aggressive surgical management.

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Good outcome was achieved with antibiotic coated intramedullary nailing.

Characterization and spontaneous induction of urinary tract Streptococcus anginosus prophages

Streptococcus anginosus is an often overlooked and understudied emerging pathogen inhabiting many areas of the human body. Through our sequencing of S. anginosus strains isolated from the female bladder microbiota, we detected numerous prophage sequences. Bioinformatic analysis of these sequences identified 17 distinct groups of S. anginosus prophages. The majority of these phages exhibit no sequence homology to previously characterized temperate or virulent phage sequences, indicating an unexplored diversity of Streptococcus phages. By culturing these bacterial isolates, we confirmed that the prophages of five of these groups are capable of induction. One of these putative phages was imaged, the first such evidence of an S. anginosus virus-like particle; it exhibits morphological characteristics of siphoviruses.

β-Hemolytic Streptococcus anginosus subsp. anginosus causes streptolysin S-dependent cytotoxicity to human cell culture lines in vitro

Background: Streptococcus anginosus subsp. anginosus (SAA) is one of the opportunistic pathogens in humans that inhabits the oral cavity. The type strain of SAA, NCTC10713^T, showed clear β-hemolysis on blood agar plates, and the sole β-hemolytic factor revealed two streptolysin S (SLS) molecules. SLS is well known as the peptide hemolysin produced from the human pathogen S. pyogenes and shows not only hemolytic activity on erythrocytes but also cytotoxic activity in cell culture lines in vitro and in vivo, such as in a mouse infection model. However, no cytotoxic activity of SLS produced from β-hemolytic SAA (β-SAA) has been reported so far. Objective and Design: In this study, the SLS-dependent cytotoxicity of the β-SAA strains including the genetically modified strains was investigated in vitro. Results: The SLS-producing β-SAA showed cytotoxicity in human cell culture lines under the co-cultivation condition and it was found that this cytotoxicity was caused by the SLS secreted into the extracellular milieu. Conclusion: The results from this study suggest that the SLS produced from β-SAA might indicate the cytotoxic potential similar to that of the SLS from S. pyogenes and the SLS-producing β-SAA would be recognized as “a wolf in sheep’s clothing” More attention will be paid to the pathogenicity of β-hemolytic Anginosus group streptococci.