BACKGROUND: Legionella pneumonia is one of the most severe types of atypical pneumonia, impairing multiple organ systems, posing a threat to life. Diagnosing Legionella pneumonia is challenging due to difficulties in culturing the bacteria and limitations in immunoassay sensitivity and specificity.
METHODS: This paper reports a rare case of sepsis caused by combined infection with Legionella pneumophila and Fusobacterium necrophorum, leading to respiratory failure, acute kidney injury, acute liver injury, myocardial damage, and electrolyte disorders. In addition, we systematically reviewed literature on patients with combined Legionella infections, analyzing their clinical features, laboratory results and diagnosis.
CONCLUSIONS: For pathogens that require prolonged incubation periods and are less sensitive to conventional culturing methods, metagenomic next-generation sequencing (mNGS) can be a powerful supplement to pathogen screening and plays a significant role in the auxiliary diagnosis of complex infectious diseases.

BACKGROUND: Fusobacterium nucleatum (F. nucleatum) belongs to the genus Fusobacterium, which is a gram-negative obligate anaerobic bacterium. Bacteremia associated with F. nucleatum is a serious complication, which is not common in clinic, especially when it is combined with other intracranial pathogenic microorganism infection. We reported for the first time a case of F. nucleatum bacteremia combined with intracranial Porphyromonas gingivalis (P. gingivalis) and herpes simplex virus type 1(HSV-1) infection.
METHODS: A 60-year-old woman was admitted to our hospital with a headache for a week that worsened for 2 days. Combined with history, physical signs and examination, it was characterized as ischemic cerebrovascular disease (ICVD). F. nucleatum was detected in blood by matrix-assisted laser desorption/ionization time-offight mass spectrometry (MALDI-TOF-MS). Meanwhile, P. gingivalis and HSV-1 in cerebrospinal fluid (CSF) were identified by metagenome next generation sequencing (mNGS). After a quick diagnosis and a combination of antibiotics and antiviral treatment, the patient recovered and was discharged.
CONCLUSIONS: To our knowledge, this is the first report of intracranial P. gingivalis and HSV-1 infection combined with F. nucleatum bacteremia.

BACKGROUND: Fusobacterium necrophorum (F. necrophorum)-induced necrotizing pneumonia is a rare but severe pulmonary infection. Insufficient microbiological detection methods can lead to diagnostic difficulties.
METHODS: We report a case of F. necrophorum lung abscess diagnosed by next-generation sequencing (NGS) of bronchoalveolar lavage fluid (BALF).
RESULTS: BALF-NGS detected F. necrophorum, guiding subsequent targeted antibiotic therapy. With active drainage and metronidazole treatment, the patient\'s condition was effectively treated.
CONCLUSIONS: BALF-NGS is a valuable tool for the rapid diagnosis of infections caused by difficult-to-culture bacteria. It played a decisive role in the early identification of F. necrophorum, enabling timely and targeted antibiotic intervention. Early diagnosis and appropriate treatment are crucial for the management of F. necrophorum pneumonia.

Background: Infections caused by anaerobic bacteria occur frequently and can be serious and life-threatening. Anaerobes are a rare cause of community-acquired pneumonia with Streptococcus pneumonia and respiratory viruses being the most frequently detected pathogens. We, herein, report a case of Fusobacterium/Peptostreptococcus parapneumonic effusion with empyema in a patient without risk factors for aspiration pneumonia. This case presents an opportunity to discuss an unusual case of community-acquired empyema secondary to anaerobic infection in a patient without the common risk factors for aspiration.

Case Presentation: A 59-year-old male patient without significant past medical history apart from a twenty-five-year history of smoking presented due to left flank pain and shortness of breath. Findings of a complicated parapneumonic effusion were found on imaging, resulting in surgical decortication and prolonged antibiotic therapy.

Discussion: Parapneumonic effusions and empyema are relatively common complications of pneumonia. It is important to note that the incidence of anaerobic empyema has been on the rise due to more modern culturing techniques.

Conclusion: This case highlights an unusual presentation of community-acquired empyema secondary to anaerobes without any risk factors for aspiration pneumonia. Therefore, clinicians should consider the possibility of anaerobic coverage in the treatment of community-acquired empyema in the appropriate setting.

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This case report illustrates a unique presentation of Lemierre\'s syndrome precipitated by Fusobacterium necrophorum. This case report describes a 20-year-old patient who developed Lemierre\'s syndrome secondary to a shoulder hematoma and neck abscess with multiple systemic complications in the absence of tonsillitis or oropharyngeal infection. Two weeks prior to presentation, the patient sustained a right shoulder injury and contracted COVID-19. Due to his Lemierre\'s syndrome, he developed right internal jugular vein and subclavian vein thrombosis, septic lung emboli, right sided Horner\'s syndrome, disseminated intravascular coagulation, pelvic collection, septic arthritis of pubic symphysis and osteomyelitis of the right pubic bone, and proximal left femoral shaft. The patient received non-operative and operative management to manage his Lemierre\'s syndrome including surgical drainage, antibiotics, and anticoagulation; he was discharged following an extended hospital stay. This case report highlights a rare presentation of Lemierre\'s syndrome secondary to a shoulder hematoma in a COVID-19 positive patient, and its potential systemic and life-threatening complications. Its importance is highly relevant in the context of the COVID-19 pandemic. Further studies are warranted to explore the effect of preceding COVID-19 infections on the microbiological profile in Lemierre\'s syndrome.

BACKGROUND: Fusobacterium nucleatum (F. nucleatum) is a resident anaerobic bacterium, which in rare cases may invade blood from the head and neck or the digestive tract to cause bacteremia and induce venous thrombosis. F. nucleatum is closely related to abdominal tumors, but it has not been reported in relation to renal tumors. We report herein a possible case.
METHODS: This patient had kidney cancer with thrombosis in the right renal vein but had no sign of infection. After radical nephrectomy, thrombi formed in his left renal vein, and when removed, severe sepsis occurred. He did not respond to treatment with antibiotics and died, but the blood culture done confirmed that he had F. nucleatum bacteremia.
CONCLUSIONS: F. nucleatum may also be associated with kidney cancer, and could cause post-operative renal vein thrombosis, and sepsis or septic shock after thrombectomy.

Species (spp.) belonging to the genus Fusobacterium are anaerobic commensals colonizing the upper respiratory tract, the gastrointestinal tract, and the genitals. Infections with Fusobacterium spp. have been reported at many anatomical sites, including pneumonias and pleural empyemas; however, there are very few published cases of Fusobacterium spp. causing spondylodiscitis or fistulas. Bone infections with Fusobacterium can spread directly to surrounding muscular tissue or by hematogenous transmission to any other tissue including pleurae and lungs. Similarly, pleural infections can spread Fusobacterium spp. to any other tissue including fistulas and bone. Concomitant pleural empyema and spondylodiscitis are rare; however, there are a few published cases with concomitant disease, although none caused by Fusobacterium spp. A 77-year-old female patient was assessed using computed tomography (CT) scanning of the thorax and abdomen, as well as analyses of fluid drained from the region affected by the pleural empyema. A diagnosis of Fusobacterium empyema, fistula, bacteremia, and spondylodiscitis was made, and the patient\'s condition improved significantly after drainage of the pleural empyema and relevant long-term antibiotic treatment. We describe the first confirmed case with concomitant infection with Fusobacterium nucleatum as spondylodiscitis and pleural empyema connected by a fistula.

Lemierre syndrome (LS) is an acute oropharyngeal infection with secondary septic thrombophlebitis and distant septic embolisation. A 29-year-old woman with sore throat, dyspnoea and left shoulder pain, who was on levofloxacin for 3 days, presented with worsening symptoms. She was tachycardic, tachypneic and hypoxic on presentation. CT of neck and chest revealed multiple loculated abscesses on her left lower neck and shoulder, right peritonsillar abscess, thrombosis of the right external jugular vein and multiple bilateral septic emboli to the lungs. She was started on clindamycin and ampicillin sulbactam for LS. She developed septic shock and required intubation due to respiratory failure. Drainage of the left shoulder abscess grew Fusobacterium nucleatum After 2 weeks of a complicated intensive care unit stay, her haemodynamic status improved and she was transferred to the floor. LS has variable presentations, but regardless of the presentation, it is a potentially fatal disease-requiring prompt diagnosis and management.

Although Fusobacterium necrophorum is well described as an emerging pathogen of acute mastoiditis in young children, infection with other anaerobes can lead to similar severe sequelae including intracranial and extracranial suppurative thrombophlebitis and sepsis. We describe a patient whose unremarkable exposure history assumed increased significance upon obtaining the results of 16S next generation sequencing from a surgical specimen. The novel pathogen Bacteroides pyogenes is reviewed herein.

Fusobacterium necrophorum is a very rare cause of endocarditis. We herein report a case of F. necrophorum endocarditis with liver abscesses in a 51-year-old woman. This is the first reported case of monomicrobial F. necrophorum endocarditis to present in a patient over 50 years old. We also reviewed 10 reported cases, including the present case. Our review indicated that anaerobic bacteria, including Gram-negative anaerobic bacilli such as F. necrophorum, should be considered in the differential diagnosis of infective endocarditis, especially in patients without preexisting organic heart disease.