Human infection with Fusobacterium necrophorum (Necrobacillosis), with a focus on Lemierre's syndrome

Phylogeny and virulence determinant detection of Fusobacterium necrophorum strains isolated at the UK Anaerobe Reference Unit between 1982 and 2019

OBJECTIVES

The study aims to explore the presence, or absence, of virulence genes and the phylogeny of a multidecade United Kingdom collection of clinical and reference Fusobacterium necrophorum isolates.

METHODS

Three hundred and eighty-five F. necrophorum strains (1982-2019) were recovered from storage (-80°C). Illumina whole genome sequencing was undertaken with 374/385 genomes available for examination after quality checking. Sequences were analysed, using BioNumerics (bioMérieux; v 8.1), for the presence of known virulence genes. Strain phylogeny was investigated using a bespoke Fusobacterium spp. whole genome multilocus sequence typing (wgMLST) method and single nucleotide polymorphism (SNP) analysis.

RESULTS

F. necrophorum ssp. necrophorum and F. necrophorum ssp. funduliforme phylogeny showed a clear separation of the two subspecies and clustering of F. necrophorum ssp. funduliforme into three distinct clades. Congruence between SNP and wgMLST analysis was high (99.3%) and indistinguishable clusters were observed with wgMLST (n = 3) and SNP (n = 1) analysis of isolates derived from different students attending the same education setting. There was no grouping of strains by disease state or decade of isolation. No association was demonstrated with specific virulence gene detection although conspicuous virulence gene patterns were seen among the different subspecies and clades.

DISCUSSION

There was no evidence that the pathogenesis of F. necrophorum infection was associated with the presence of the virulence determinants investigated. Host-pathogen interactions should, therefore, be a focus of future research. Person-to-person transmission is a feature of this important pathogen.

Lemierre's Syndrome: An Unlikely Diagnosis in a Patient Presenting with Diarrhoea and Vomiting, or Maybe not?

Lemierre's syndrome is an infectious thrombophlebitis of the internal jugular vein (IJV) where the commonest causative agent is a Fusobacterium from a tonsillar or peritonsillar abscess. This is a case presentation of a patient whose primary complaint was diarrhoea. The blood cultures of this patient grew a Fusobacterium necrophorum which prompted imaging. The imaging demonstrated a right peritonsillar abscess and IJV thrombosis with septic emboli in the lungs. Key points highlighted are: 1) blood cultures remain a key investigation in making a diagnosis in the septic patient; 2) abdominal symptoms can be part of Lemierre's syndrome; 3) abdominal symptoms (abdominal pain, vomiting and diarrhoea) have been characterised as the third, fourth and fifth most common feature after fever and dyspnoea. This case is presented because it shows how Lemierre's syndrome can present with abdominal features, and this may be incongruent with clinicians' understanding and teaching.

LEARNING POINTS

Lemierre's syndrome is an infectious thrombophlebitis of the internal jugular vein most commonly due to Fusobacterium necrophorum originating from a tonsillar or peritonsillar abscess, which may cause septic emboli in the lungs.Gastrointestinal symptoms, including diarrhoea, are commoner than appreciated or classically taught in this syndrome.Blood cultures are a key investigation in the septic patient and in those that grow a Gram-negative rod, Fusobacterium should be considered, and suspicions of Lemierre's syndrome should be raised.

Analysis of the Primary Pathogenic Bacteria in Abscess Disease of Musk Deer Using Metagenomic Approaches

Abscesses are among the diseases affecting the survival of captive musk deer and are difficult to identify in their early stages. In this study, metagenomic sequencing, 16S rRNA sequencing, and paraffin sectioning were used to analyze the microbiota in the abscess musk deer pus group (AMP), abscess musk deer oral group (AMO), and healthy musk deer oral group (HMO) to compare the differences in microbiota in musk deer. By detecting differences in the oral microbiota through throat swabs, we aimed to monitor the early onset of abscess disease to facilitate timely intervention and treatment. The results showed that the alpha diversity of HMO microbiota was significantly higher than that of the AMP and AMO samples. Beta diversity results indicated that there were significant differences in the bacterial communities of HMO and AMO samples, and no significant difference was found between AMO and AMP samples. A taxonomic analysis of the bacterial species indicated that differences between HMO and AMP groups were found in the Fusobacterium and Trueperella species. Fusobacterium and Trueperella were the main pathogenic bacteria responsible for the occurrence of abscess diseases in forest musk deer in this study. Furthermore, the appearance of Fusobacterium and Trueperella in the oral cavity can serve as biomarkers for the early diagnosis of abscess disease in musk deer.

Rare and risky: a unique case of concurrent chronic pulmonary aspergillosis and lemierre syndrome

Lemierre Syndrome is a condition that appears to have been overlooked in recent decades in clinical practice, often resulting in death or long-lasting sequelae when left undetected and untreated. Typically, it occurs following an upper respiratory tract infection, often stemming from tonsillitis, leading to thrombosis of the internal jugular vein and subsequent multiple septic emboli. Here, we present a case a 46-year-old patient with the clinical presentation of pneumogenic sepsis. Remarkably, we were able to diagnose the simultaneous presence of chronic pulmonary aspergillosis and Lemierre syndrome.

Characterizing the prevalence of Fusobacterium necrophorum subsp. necrophorum, Fusobacterium necrophorum subsp. funduliforme, and Fusobacterium varium in bovine and ovine semen, bovine gut, and vagino-uterine and fetal microbiota using targeted culturing and qPCR

Fusobacterium necrophorum is an important pathogen associated with several infectious diseases in cattle. However, recent sequencing-based studies reported that F. necrophorum may be positively associated with pregnancy in beef cows and that Fusobacterium is highly abundant in bull seminal microbiota with potential involvement in reproductive health and fertility. Here, we performed a comprehensive screening to (i) determine the prevalence of Fusobacterium necrophorum (subspecies necrophorum [FNN] and funduliforme [FNF]) and Fusobacterium varium (FV) in the reproductive microbiota of cattle and sheep as well as bovine digestive tract ecosystems, and (ii) explore whether these Fusobacterium spp. colonize calf prenatally. For this, we screened 11 different sample types including bovine and ram semen, bovine vaginal and uterine swabs, and bull fecal samples, as well as samples from 180- and 260-day-old calf fetuses and their respective dams using both quantitative PCR (qPCR; 514 samples) and targeted culturing (499 samples). By qPCR, all the targeted Fusobacterium spp. were detected across all sample types with varying prevalence rates and viability. FNF was highly prevalent in the bull semen (66.7%) and maternal ruminal fluids (87.1%), and its viability was confirmed through culturing. All the targeted Fusobacterium spp. were identified in vaginal and uterine swab samples (3.1%-9.4%), caruncles, fetal fluids, rumen, and meconium samples (2.7%-26.3%) by qPCR but were not isolated by culture method. Overall, our results, for the first time, suggest that F. necrophorum is a commensal member of healthy male reproductive microbiota, and that FNF, FNN, and FV are present in bovine vagino-uterine microbiota and calf intestine prenatally.IMPORTANCERecent sequencing-based studies suggest that Fusobacterium, including F. necrophorum, a known primary etiological agent for several important infectious diseases in cattle, may be non-pathogenic members of the reproductive microbiota with pro-fertility effects. However, further information regarding the absolute abundance, viability, and higher taxonomic resolution of the Fusobacterium species and subspecies which cannot be achievable by the amplicon sequencing approach is needed to confirm the commensal and non-pathogenic status of the Fusobacterium spp. in cattle. Here, we performed a comprehensive screening of F. necrophorum subspecies necrophorum, F. necrophorum subspecies funduliforme, and Fusobacterium varium from over 500 samples from 11 different sample types using targeted culturing and qPCR. Overall, our results provide novel insights into the prevalence and viability of Fusobacterium spp. in bovine male and female reproductive tracts and their presence in calf fetuses, which will serve as the basis for further research into understanding the role of Fusobacterium in cattle fertility.

Microbiological diversity among patients with Lemierre syndrome and clinical implications: an individual patient-level analysis

PURPOSE

Lemierre syndrome is a rare condition traditionally defined by bacterial infection of the head/neck region, local thrombophlebitis, and septic embolism. Although in most cases Fusobacterium necrophorum is isolated, it is questionable whether the presence of this microbe is mandatory for diagnosis. In this study, we investigated microorganisms isolated in cases of Lemierre syndrome and their association with demographical and clinical features.

METHODS

We conducted an analysis of individual patient data from 712 patients diagnosed with Lemierre syndrome. Demographics, clinical presentation, treatment strategies, and outcomes according to different pathogens were evaluated.

RESULTS

Among a total of 712 patients, in 574 cases bacterial growth was detected. In 415 patients Fusobacterium spp. was isolated, in 108 either Streptococcus spp. or Staphylococcus spp., and in 51 other bacteria. Patients with different bacteria differed markedly in age, site of preceding infections, clinical presentation, and treatment. Fusobacterium spp. was typically isolated in younger patients (69% of patients aged 16 to 30 years) while Streptococcus spp. and Staphylococcus spp. were more prevalent in older subjects (30% of patients aged over 45 years). Of all cases with Fusobacterium spp., 63% had a thrombosis of the internal jugular vein and 91% septic embolism, compared with 94% and 69%, respectively, in cases with Streptococcus spp. or Staphylococcus spp.

CONCLUSION

In contrast to the available literature, our study suggests that Lemierre syndrome may be caused by multiple bacterial species, and that the clinical presentation and course may vary according to the specific bacterial species involved.

Lemierre's Syndrome with a Palmar Lesion

Lemierre's syndrome can be fatal if diagnosed late or not treated appropriately. We herein report a 40-year-old woman with a fever and pain with tenderness in her palms after the administration of antibiotics for pharyngotonsillitis. She was diagnosed with Lemierre's syndrome, and her symptoms improved after the administration of intravenous ampicillin-sulbactam. In this case, the palmar lesions indicated septic emboli and were an important finding in recognizing Lemierre's syndrome. Lemierre's syndrome should be considered in the differential diagnosis of patients with a persistent fever following oropharyngeal infection, even if they have received antimicrobial therapy, resolved pharyngeal symptoms, and negative culture results.

Fusobacterium necrophorum septic arthritis of the hip: A case-report and literature review

INTRODUCTION

Fusobacterium necrophorum is a rare but significant cause of septic arthritis, typically following oropharyngeal infections in adolescents. This anaerobic pathogen, commonly associated with Lemierre's syndrome, can lead to joint infections, posing risks for severe morbidity if diagnosis and treatment are delayed. Awareness and timely intervention are essential for preventing long-term joint damage.

CASE REPORT

We report the case of a 19-year-old woman who developed high fever and acute right hip pain one week after a sore throat. Imaging revealed septic arthritis, with F. necrophorum identified in both blood and synovial fluid cultures. She received intravenous piperacillin/tazobactam, followed by outpatient parenteral therapy through an elastomeric pump, achieving full recovery. This case adds to the 42 cases documented in our literature review, reinforcing the need for prompt antimicrobial therapy.

CONCLUSION

Fusobacterium-induced septic arthritis, though uncommon, should be considered in young patients presenting with joint infections post-pharyngitis. Early diagnosis and targeted antimicrobial therapy, particularly with β-lactamase inhibitors, are critical for effective management and preventing joint sequelae.

Risk of mortality in Fusobacterium species bloodstream infection from a large Australian cohort

BACKGROUND

Fusobacterium species are anaerobic Gram-negative bacilli which are uncommon causes of bloodstream infection (BSI). This genus commonly colonises the gastrointestinal tract and can result in significant morbidity.

METHODS

All blood cultures with growth of Fusobacterium species among residents of Queensland, Australia (population ≈ 5 million) were retrospectively identified over a 20-year period. Clinical, microbiological and outcome information was obtained from state-wide databases.

RESULTS

377 incident Fusobacterium species BSI among 375 individuals for an age and sex-standardised incidence of 4.4 per million residents per year. Median age was 47 years (IQR, 24.9-65.8) and 156 (42%) incident episodes were in females. There was a bimodal frequency distribution with respect to age with peaks occurring around 20 and 65 years, respectively. The most identified source of infection was the abdominal (17%), followed by head and neck (12%). 8% of patients had a septic thrombus present, and 4% had an abscess associated with their BSI. Most isolates were F. nucleatum (142, 38%) and F. necrophorum (140, 37%). 9% of isolates were resistant to penicillin. Older age (aHR 1.02, 95% CI 1.01-1.05), healthcare-associated hospital onset (aHR 3.16, 95% CI 1.35-7.40), and Charlson Comorbidity index (aHR 1.20, 95% CI 1.06-1.35) were all associated with 30-day all cause case-fatality. Oropharyngeal source appeared to be a protective factor (P = 0.02).

CONCLUSIONS

Fusobacterium species BSI results in significant morbidity and can cause death in vulnerable patient groups such as the elderly and those with malignancy. An identifiable oropharyngeal source identifies a favourable host.

Lemierre Syndrome: A Rare Complication of Infectious Mononucleosis

Lemierre syndrome is a rare condition that arises from septic thrombophlebitis most commonly in the internal jugular vein. Common precipitating factors include recent oropharyngeal, tonsillar, or dental infection or chronic bacteremia. While modern antibiotic usage has decreased mortality rates, challenges persist in accurately diagnosing the condition at the time of patient presentation due to a lack of awareness of this rare disorder. Here, we present the case of a previously healthy 20-year-old female patient who was diagnosed with infectious mononucleosis approximately two weeks before her hospital admission. She presented with a five-day history of shortness of breath and cough. Diagnostic workup/evaluation revealed pneumonia with bilateral pleural effusions as well as the need for intravenous antibiotics and oxygen via nasal cannula, prompting her admission to the hospital. During her hospitalization, blood cultures showed growth in two out of four test tubes with Streptococcus intermedius, a bacterium commonly associated with abscess formation. This finding led her medical team to conduct a computed tomography scan of her cervical region, revealing significant septic thrombophlebitis within her internal jugular vein.

Lemierre's Syndrome: A Case Report

A 21-year-old woman presented with a sore throat and systemic symptoms, including fever, diarrhea, and chest pain, progressing to sepsis. Imaging revealed a pharyngeal abscess, thrombophlebitis of the left internal jugular vein, and septic emboli. Blood cultures confirmed Fusobacterium necrophorum, and the patient was diagnosed with Lemierre's syndrome. Empirical antibiotics were adjusted to ampicillin-sulbactam based on culture results, leading to a full recovery after a month-long treatment course. This case highlights the diagnostic challenges of Lemierre's syndrome, its severe complications, and the importance of early recognition and targeted antibiotic therapy. Prompt diagnosis and treatment of Lemierre's syndrome are essential to prevent life-threatening complications, underscoring the importance of maintaining a high index of suspicion in patients presenting with systemic symptoms following pharyngitis.

Lemierre syndrome: case presentation of a life-threatening septic pneumonia with complicated parapneumonic effusion: A case report

RATIONALE

Lemierre syndrome is a rare, life-threatening complication of oropharyngeal infections.

PATIENT CONCERNS

A 35-year-old man started with an upper respiratory infection but worsened the clinical course with sepsis and acute respiratory failure with complicated bilateral pleural effusion.

DIAGNOSES

The patient was diagnosed with typical Lemierre syndrome with lung complications.

INTERVENTIONS

Antibiotic therapy with bilateral pleural percutaneous drain with fibrinolysis.

OUTCOMES

The patient improved and was discharged without oxygen therapy after antibiotics were covered and active lung care with complicated parapneumonic effusion. After discharge, lung function showed restrictive lung defect but improved compared to the initial exam.

LESSONS

Lemierre syndrome, which might begin as a mild upper respiratory infection, can progress to a critically ill disease accompanied by sepsis and metastatic septic embolus. The patient suffered septic lung emboli with bilateral complicated parapneumonic effusion but was successfully treated with percutaneous drainage with pleural fibrinolysis, appropriate antibiotics, and anticoagulants. Early suspicion of the disease and active treatment are necessary to treat rare syndromes like Lemierre syndrome.

Lemierre's Syndrome Due to Klebsiella pneumoniae Results in Pulmonary Abscess Complications in a Patient With Diabetes: A Rare Case Report

Background: Lemierre's syndrome (LS), first described by Andre Lemierre in the early 20th century, is a rare but potentially life-threatening condition typically caused by Fusobacterium necrophorum. However, recent literature has reported cases of LS caused by various other bacteria, including Klebsiella pneumoniae. In this report, we present a rare case of LS in a patient with diabetes caused by K. pneumoniae. Case Report: A 62-year-old Vietnamese male with a history of type 2 diabetes mellitus, presented with an 8-day history of progressive left neck swelling, fever, dysphagia, odynophagia, and reduced appetite. Despite initial antibiotic therapy, his condition deteriorated, leading to pulmonary abscesses and septic shock. Abscess content culture revealed K. pneumoniae. The patient required intubation, mechanical ventilation, and surgical drainage of the neck abscess. Treatment with meropenem, along with glycemic control, led to clinical improvement. The patient was subsequently extubated, achieved complete wound healing, and was discharged with normal biochemical parameters. Conclusion: This case highlights that LS can be caused by pathogens not initially outlined by Andre Lemierre, such as K. pneumoniae. Clinicians should consider a broader spectrum of causative organisms when there is a strong clinical suspicion of LS and adjust antimicrobial coverage accordingly. The association between K. pneumoniae-related LS and diabetes mellitus warrants further investigation, as current evidence suggests that diabetes may predispose patients to this particular pathogen.

A Rare Case of Lemierre's Syndrome Caused by Streptococcus pyogenes

Lemierre's syndrome (LS) is a rare condition characterized by septic thrombophlebitis of the internal jugular vein (IJV). Typically, the primary infection originates in the oropharynx, progressing to the lateral pharyngeal space, IJV, and potentially leading to bacteremia. Through septic embolization, these patients can develop severe complications, underscoring the importance of early diagnosis. We present a case of LS in a 33-year-old female who initially presented to the emergency department with odynophagia and was diagnosed with acute tonsillitis. She was discharged with antibiotics. However, one week later, she returned with sudden-onset dyspnea. After a comprehensive workup during her hospital stay, an LS caused by Streptococcus pyogenes was diagnosed. The patient was treated with anticoagulation and antibiotics, resulting in a favorable clinical outcome. This case highlights the importance of maintaining a high level of clinical suspicion for LS in the differential diagnosis of complicated tonsillitis, emphasizing the critical role of early identification and appropriate management. Additionally, we aim to review the pathophysiology, management strategies, and current literature on LS, offering insights into the clinical approach to these rare yet potentially fatal cases.

It all started with a sore throat: Polymicrobial septicaemia, cavitating lung lesions and severe thrombocytopenia

We report a case of a syndrome first described by French bacteriologist André Lemierre nearly 100 years ago. A young woman presented with fever, chest pain and arthralgia. Admission investigations revealed thrombocytopenia, cavitating pneumonia and an internal jugular vein thrombus. Blood cultures were positive for Fusobacterium necrophorum and Streptococcus constellatus. Respiratory failure developed within 48 h and was managed with high-flow nasal oxygen in a critical care setting. The investigation findings leading to diagnosis, as well as the antimicrobial and anticoagulation management strategies, are discussed. Lemierre's syndrome is rarely encountered by non-specialists, but a good outcome can be expected with prompt diagnosis and treatment.

Lemierre's syndrome associated-diabetic ketoacidosis in an elderly female: a case report

BACKGROUND

The co-occurrence of Lemierre's syndrome, primarily triggered by Fusobacterium necrophorum following oropharyngeal infection, with diabetic ketoacidosis (DKA) in diabetes mellitus (DM) patients, underscores a rare but life-threatening clinical scenario. Lemierre's syndrome induced DKA is extremely rare, with only one case report in adult and no case yet reported in elderly.

CASE PRESENTATION

We reported a case of a 69-year-old female who presented with DKA triggered by deep neck space infection (DNSI), leading to rapid clinical deterioration within 6 h that necessitated high flow nasal cannula (HFNC) and antibiotic administration. Laboratory findings included leukocytosis, elevated serum C-reactive protein, hyperglycemia, ketonemia, and severe metabolic acidosis. Culture of the fluid from a neck mass puncture drainage and blood were positive for Klebsiella pneumoniae. The patient was further complicated by thrombosis of the left internal jugular vein with extension to the sigmoid and a neck abscess surrounding the carotid artery sheath, consistent with Lemierre's syndrome. This condition was managed aggressively with fluid resuscitation, insulin therapy, surgical drainage, antibiotics, and anticoagulation led to a significant improvement in her condition. Following a 13-day hospitalization, there was significant clinical improvement, culminating in the patient's discharge.

CONCLUSIONS

The case highlights the need for greater awareness and understanding of the interrelated and mutually promoting conditions of DKA and Lemierre's syndrome among clinicians. Early recognition and treatment are crucial to prevent mortality in such complex cases.

Intelligent method to predict intensive care unit admission after drainage operation in patients with deep neck space abscess: A multicenter retrospective study

BACKGROUNDS

A deep neck space abscess (DNSA) is a critical condition resulting from infection of deep neck fascia and soft issue, leading to high morbidity and mortality. Therefore, intensive care can be very significant for patients with DNSA. This study aimed to develop models to predict the need for postoperative intensive care in patients with DNSA.

METHODS

We retrospectively analyzed the records of 332 patients with DNSA who received drainage operation between 2015 and 2020. Multivariate logistic regression analysis and the eXtrem Gradient Boosting (XGBoost) algorithm were used to develop predictive models.

RESULTS

We developed two predictive models, the nomogram and the XGBoost model. The area under the curve (AUC) of the nomogram was 0.911 and of the XGBoost model was 0.935.

CONCLUSION

We developed two predictive models for guiding clinical decision making for postoperative ICU admission for DNSA patients, which may help improve prognosis and optimize intensive care resource allocation.

Epstein-Barr virus as promoter of Lemierre syndrome: systematic literature review

PURPOSE

To investigate a possible link between acute Epstein-Barr virus infection and Lemierre syndrome, a rare yet life-threatening infection.

METHODS

A systematic review was conducted adhering to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Diagnosis criteria for Lemierre syndrome were established, and data extraction encompassed demographic data, clinical, and laboratory information.

RESULTS

Out of 985 initially identified papers, 132 articles were selected for the final analysis. They reported on 151 cases of Lemierre syndrome (76 female and 75 male patients with a median of 18 years) alongside interpretable results for Epstein-Barr virus serology. Among these, 38 cases (25%) tested positive for acute Epstein-Barr virus serology. There were no differences in terms of age, sex, or Fusobacterium presence between the serologically positive and negative groups. Conversely, instances of cervical thrombophlebitis and pulmonary complications were significantly higher (P = 0.0001) among those testing negative. The disease course was lethal in one case for each of the two groups.

CONCLUSIONS

This analysis provides evidence of an association between acute Epstein-Barr virus infection and Lemierre syndrome. Raising awareness of this link within the medical community is desirable.

Facial vein thrombophlebitis post facial skin infection: a case report and review of the literature

This case report presents a rare instance of facial vein thrombophlebitis, a potentially serious complication, following a facial skin infection. A 33-year-old man known to have cerebral palsy, epilepsy on ventriculoparietal shunt, and kyphoscoliosis presented to the emergency department complaining of small facial wound and swelling for 1 week. The wound failed topical management and fever started to develop. His medications included quetiapine and levetiracetam. Investigations, including computed tomography, were carried out to rule out an extension to deep tissue. Management in the emergency department involved initial resuscitation with 500 mL of 0.9% normal saline and 1 L of lactated ringers, antibiotic coverage with piperacillin/tazobactam and vancomycin was given, and analgesia for pain control. This case highlights the potential for facial vein thrombophlebitis as a complication of facial skin infections. Early diagnosis and prompt initiation of appropriate management are crucial to prevent potentially fatal consequences.

Fusobacterium necrophorum endocarditis with intracranial abscesses: A case report and review of the literature

Fusobacterium species are obligate anaerobic Gram-negative bacilli that are non-spore forming. The two most common species tied to human disease are F. nucleatum and F. necrophorum. They are commensal organisms in the oropharynx, gastrointestinal tract, and genital tract of humans, but can cause invasive infections especially in the head and neck such as periodontal disease and Lemierre's syndrome. F. necrophorum is an uncommon cause of infective endocarditis. We present a case of a previously healthy male who developed F. necrophorum endocarditis with multiple sites of pyogenic abscess formation.

Learning objective

Even among anaerobes, which account for less than 1 % of infective endocarditis (IE) cases, Fusobacterium necrophorum is rare. Specific laboratory conditions are necessary for growth, leading to delays in diagnosis. Severe disease is common given its virulence and predisposition for thrombophlebitis. While uncommon, it is crucial to maintain a degree of suspicion for Fusobacterium IE especially in individuals without prior cardiac disease whose infections were preceded by potential head and neck source.

Association of pathogenic determinants of Fusobacterium necrophorum with bacteremia, and Lemierre's syndrome

Fusobacterium necrophorum is a Gram-negative anaerobic bacterium responsible for localized infections of the oropharynx that can evolve into bacteremia and/or septic thrombophlebitis of the jugular vein or peritonsillar vein, called Lemierre's syndrome. To identify microbial genetic determinants associated with the severity of this life-threatening disease, 70 F. necrophorum strains were collected and grouped into two categories according to the clinical presentation: (i) localized infection, (ii) bacteremia with/without Lemierre's syndrome. Comparative genomic analyses revealed two clades with distinct genetic content, one clade being significantly enriched with isolates from subjects with bacteremia. To identify genetic determinants contributing to F. necrophorum pathogenicity, genomic islands and virulence factor orthogroups (OVFs) were predicted. The presence/absence profiles of OVFs did not group isolates according to their clinical category, but rather according to their phylogeny. However, a variant of lktA, a key virulence factor, with a frameshift deletion that results in two open reading frames, was associated with bacteremia. Moreover, a genome-wide association study identified three orthogroups associated with bacteremic strains: (i) cas8a1, (ii) a sodium/solute symporter, and (iii) a POP1 domain-containing protein. Further studies must be performed to assess the functional impact of lktA mutation and of these orthogroups on the physiopathological mechanisms of F. necrophorum infections.

Case report: The use of metagenomic next-generation sequencing to diagnose Lemierre's syndrome caused by lost root canal fillings in a 33-year-old patient with metabolic syndrome

Background

Lemierre's syndrome is a rare and serious complication of pharyngitis with an estimated annual incidence of 1 in 100,000 people worldwide. It is characterized by septic thrombophlebitis of the internal jugular vein with metastatic infection, usually after oropharyngeal infection. Rare cases of Lemierre's syndrome have been reported to be caused by odontogenic infection.

Case report

A 33-year-old male visited our hospital with symptoms of fever and sore throat for 16 days. The other symptoms included pain in his left neck and shoulder. In addition, metabolic syndrome was diagnosed based on waist circumference, diabetes, and hyperlipidemia. Fusobacterium necrophorum bacteria was detected using the metagenomic next-generation sequencing (mNGS) technique. The enhanced computerized tomography (CT) scan showed thrombosis of the left proximal jugular vein and brachiocephalic vein. Based on these observations, Lemierre's syndrome was diagnosed. The etiology was that the fillings in the root canal tooth were lost with no blood or pain about 2 weeks before the onset. The patient recovered after treatment with antibiotics and blood purification.

Conclusion

Lemierre's syndrome should be evaluated for patients with fever, sore throat, and neck pain. If the loss of fillings from root canal therapy occurs, especially for those with metabolic syndrome, we should be aware of the possibility of this disease. Furthermore, the mNGS test can be used as a crucial supplementary diagnostic tool for patients with undetermined fever.

Lemierre's syndrome complicating multiple organ failure caused by Fusobacterium necrophorum subsp. funduliforme F1260: Case report and review

We described a case of a 24-year-old man with multiple organ failure caused by Fusobacterium necrophorum subsp. funduliforme F1260. This is the first described case of Lemierre's syndrome with multiple organ failure due to F. necrophorum subsp. funduliforme F1260 in an adult in China. Our study highlights that there may be a risk of misdiagnosis based solely on typical manifestations of internal jugular vein thrombophlebitis, metastatic lesions, and F. necrophorum isolated from blood cultures or normally sterile sites. Clinicians should be cognizant of the potential utility of metagenomic next-generation sequencing in facilitating early pathogen detection in severe infections, thus enabling timely and appropriate administration of antibiotics to reduce mortality rates and improve prognosis.

Lemierre's syndrome presenting with arterial and Central nervous system involvement

A 17-year-old male presented with acute onset right-sided facial swelling, trismus, pharyngitis, and sepsis. An initial CT abdomen and pelvis revealed multifocal bilateral nodular cavitary lung lesions. CT soft tissue neck with contrast demonstrated a parapharyngeal abscess and thrombophlebitis of the right internal jugular vein. The patient was subsequently diagnosed with Lemierre's syndrome. On the following day, the patient's neurological status markedly declined. Brain MRI/MRA/MRV showed right internal carotid artery narrowing, multiple areas of acute and subacute infarctions secondary to vasculitis, meningitis, venous sinus thrombosis, and intracerebral abscesses. Workup for primary causes of intracranial vasculitis was negative. Although commonly presented as venous disease, this case highlights a rare presentation of Lemierre's syndrome with arterial involvement and significant intracranial complications. Clinicians should consider vasculitis and central nervous system involvement as potential complications of Lemierre's syndrome rather than searching for separate aetiologies.

Metagenomic next-generation sequencing reveals co-infection with Legionella pneumophila and Fusobacterium necrophorum in a patient with severe pneumonia: a case report

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.

CASE PRESENTATION

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.

A Pediatric Case of Fusobacterium necrophorum Mastoiditis and Meningitis Case Report in a Healthy Child and Review of the Literature

In infants and children, bacterial meningitis caused by anaerobic bacteria is rare. However, a serious infection with the anaerobe Fusobacterium necrophorum can occur in previously healthy children with a peak incidence in preschool children and in adolescents. As the clinical presentation can be very similar to meningitis caused by aerobic bacteria, one should consider Fusobacterium necrophorum as the causative agent when preceded by or associated with otitis media with purulent otorrhea or mastoiditis, in combination with minimal or no improvement on empiric antibiotic treatment. As this pathogen can be difficult to culture, anaerobic cultures should be obtained. Prompt treatment with a third-generation cephalosporin and metronidazole should be initiated once suspected or confirmed. Surgical source control is often necessary, but even with adequate and prompt treatment, the morbidity and mortality in children with a Fusobacterium necrophorum meningitis remains high. In this report, we describe a case of Fusobacterium necrophorum meningitis in a previously healthy child and review the available literature.

The Clinical Value of Cranial CT Venography for Predicting Fusobacterium necrophorum as the Causative Agent in Children with Complicated Acute Mastoiditis

BACKGROUND AND PURPOSE

Fusobacterium necrophorum (F necrophorum) is an anaerobic bacteria that causes invasive head and neck infections in children. Several studies have demonstrated an increasing prevalence of F necrophorum as the causative agent in acute mastoiditis in children, with associated high rates of intracranial complications such as epidural abscess and sinus venous thrombosis, to name a few. F necrophorum requires a treatment protocol that differs from the empiric treatment that is tailored to more common pathogens (eg, group A streptococci, Streptococcus pneumonia), and hence expediting the diagnosis is important. For evaluating complicated acute mastoiditis in children, cranial CT venography remains the imaging study of choice in most medical centers due to its availability in emergency situations. Based on our clinical experience, our hypothesis is that children with F necrophorum-associated complicated acute mastoiditis can be differentiated from those with other etiologies using CT venography.

MATERIALS AND METHODS

CT venography studies of 76 children hospitalized and treated for complicated acute mastoiditis were retrospectively reviewed. Retrieved imaging data included intracranial complications (epidural abscess, sinus venous thrombosis), cranial bone-related complications, and extracranial complications (subperiosteal abscess, temporomandibular joint abscess, and soft-tissue inflammation). The cohort was divided into children with F necrophorum-related disease (study group) and those with non-F necrophorum-related disease (control group).

RESULTS

Thirty-seven children (49%) comprised the study group, and 39 children in whom the causative agents were other bacteria comprised the control group. There were significantly higher rates of complications in the study group: sinus venous thrombosis (P < .001), perisigmoid epidural abscess (P = .036), and extramastoid osteomyelitis (P < .001). Thrombosis in venous sites beyond the sigmoid sinus and jugular foramen (a pattern consistent with an otogenic variant of Lemierre syndrome) and emphysematous osteomyelitis were found only among children in the F necrophorum-related study group (32% and 22% accordingly).

CONCLUSIONS

In children with complicated acute mastoiditis, CT venography findings of emphysematous osteomyelitis and/or thrombosis in venous sites beyond the sigmoid sinus and jugular foramen (a pattern consistent with the otogenic variant of Lemierre syndrome) should lead the radiologist to suggest F necrophorum-related mastoiditis.

Symptoms predictive of Fusobacterium necrophorum pharyngotonsillitis - an observational study of cases presenting to hospitals in Southern Sweden

OBJECTIVES

Fusobacterium necrophorum is a common cause of pharyngotonsillitis. However, no guidelines exist on when to diagnose or treat it. We aimed to investigate associations between clinical criteria and F. necrophorum-positivity in pharyngotonsillitis and assess the predictive potential of a simple scoring system.

METHODS

Pharyngotonsillitis patients who were tested for F. necrophorum (PCR) and presented to hospitals in the Skåne Region, Sweden, between 2013-2020 were eligible. Data were retrieved from electronic chart reviews and registries. By logistic regression we investigated associations between F. necrophorum-positivity and pre-specified criteria: age 13-30 years, symptom duration ≤ 3 days, absence of viral symptoms (e.g. cough, coryza), fever, tonsillar swelling/exudate, lymphadenopathy and CRP ≥ 50 mg/L. In secondary analyses, associated variables were weighted by strength of association into a score and its predictive accuracy of F. necrophorum was assessed.

RESULTS

Among 561 cases included, 184 (33%) had F. necrophorum, which was associated with the following criteria: age 13-30, symptom duration ≤ 3 days, absence of viral symptoms, tonsillar swelling/exudate and CRP ≥ 50 mg/L. Age 13-30 had the strongest association (OR5.7 95%CI 3.7-8.8). After weighting, these five variables had a sensitivity and specificity of 68% and 71% respectively to predict F. necrophorum-positivity at the proposed cut-off.

CONCLUSION

Our results suggest that F. necrophorum cases presenting to hospitals might be better distinguished from other pharyngotonsillitis cases by a simple scoring system presented, with age 13-30 being the strongest predictor for F. necrophorum. Prospective studies, involving primary care settings, are needed to evaluate generalisability of findings beyond cases presenting to hospitals.

Surgical intervention of Lemierre's syndrome: a case report and review of the literature

BACKGROUND

Lemierre's syndrome is a fatal and rare disease that is typically characterized by oropharyngeal infection and internal jugular vein thrombosis. Timely institution of appropriate antibiotics is the standard treatment.

CASE PRESENTATION

The authors report a case of Lemierre's syndrome. A 67-year-old male patient of Han ethnicity in China suffered from a large inflammatory neck mass involving left internal jugular vein thrombosis diagnosed as Lemierre's syndrome and finally cured by surgical treatment. In addition, a literature review was carried out through PubMed using the terms "Lemierre's syndrome/disease and review, meta-analysis or retrospective study" and "Lemierre's syndrome/disease and internal jugular vein". This search yielded six articles that recorded surgical methods such as drainage, craniotomy, tooth extraction, and ligation of the occluded vein to give clinicians more ideas about the treatment of the Lemierre's syndrome.

CONCLUSION

This is the first review to summarize the conditions under which surgical treatment are conducted. Additionally, this is the first report of such a large inflammatory neck mass that was completely cured by surgical resection and internal jugular vein ligation. The authors also offer several conclusions regarding surgical intervention in Lemierre's syndrome for the first time.

Proteomic Characterization of Plasma in Lemierre's Syndrome

BACKGROUND

 The underlying mechanisms of thrombosis in Lemierre's syndrome and other septic thrombophlebitis are incompletely understood. Therefore, in this case control study we aimed to generate hypotheses on its pathogenesis by studying the plasma proteome in patients with these conditions.

METHODS

 All patients with Lemierre's syndrome in the Skåne Region, Sweden, were enrolled prospectively during 2017 to 2021 as cases. Age-matched patients with other severe infections were enrolled as controls. Patient plasma samples were analyzed using label-free data-independent acquisition liquid chromatography tandem mass spectrometry. Differentially expressed proteins in Lemierre's syndrome versus other severe infections were highlighted. Functions of differentially expressed proteins were defined based on a literature search focused on previous associations with thrombosis.

RESULTS

 Eight patients with Lemierre's syndrome and 15 with other severe infections were compared. Here, 20/449 identified proteins were differentially expressed between the groups. Of these, 14/20 had functions previously associated with thrombosis. Twelve of 14 had a suggested prothrombotic effect in Lemierre's syndrome, whereas 2/14 had a suggested antithrombotic effect.

CONCLUSION

 Proteins involved in several thrombogenic pathways were differentially expressed in Lemierre's syndrome compared to other severe infections. Among identified proteins, several were associated with endothelial damage, platelet activation, and degranulation, and warrant further targeted studies.

Diagnostic and Therapeutic Challenges in Lemierre Syndrome: A Case Report Using Metagenomic Next Generation Sequencing

Lemierre syndrome (LS) is a rare and life-threatening condition predominantly caused by Fusobacterium necrophorum. Currently, there are no standardized clinical guidelines for LS management. Here, we describe the case of a 40-year-old male with fever, productive cough, and dyspnea but no sore throat. Diagnostic radiological examinations revealed multiple pulmonary cavitary nodules and an internal jugular vein occlusion. Metagenomic Next-Generation Sequencing (mNGS) of the alveolar lavage fluid identified Fusobacterium necrophorum, thereby confirming the diagnosis of LS. Intriguingly, the patient exhibited a delayed clinical response despite receiving the appropriate antibiotic. After integrating tigecycline into the treatment to address potential co-infecting bacteria, we observed a marked improvement in his clinical symptoms. Subsequent follow-up over 12 weeks post-discharge revealed complete alleviation of symptoms, and a chest CT scan showed marked regression of the lung lesions.

Atypical presentation of Lemierre's syndrome caused by penicillin-susceptible Staphylococcus aureus in a patient with chronic stomatitis and COVID-19

A healthy man in his late 20s was admitted to the emergency department due to a flare-up in his severe chronic stomatitis, along with flu-like symptoms. CXR showed multiple bilateral consolidations and subsequent CT revealed thrombosis of the left facial and internal jugular vein, together with septic embolism in both lungs. Blood cultures showed penicillin-susceptible Staphylococcus aureus The patient was diagnosed with Lemierre's syndrome, despite atypical bacteria and clinical presentation. During hospitalisation, he developed pulmonary empyema as a complication and was admitted for 4 weeks. During hospitalisation and after discharge, the patient was examined for multiple rheumatic, immunological and dermatological diseases, but no underlying cause for Lemierre's syndrome has been found. We present this case due to the rarity of its nature, with atypical clinical presentation and pathogen for Lemierre's syndrome, but with classic radiological findings.

Lemierre syndrome with pulmonary empyema caused by Prevotella intermedia

Lemierre syndrome is a rare disease that is most often caused by Fusobacterium necrophorum We present a case caused by Prevotella intermedia in a young, healthy man, complicated by multiple cavitary lung lesions, loculated pleural effusions requiring chest tube placement and trapezius abscess. Our case highlights (a) P. intermedia as a rare cause of Lemierre syndrome and (b) clinical response to appropriate antimicrobial therapy may be protracted.

Gastrointestinal Variant of Lemierre's Syndrome: A Systematic Review and Comprehensive Analysis of 36 Case Reports

Background

A gastrointestinal (GI) variant of Lemierre's syndrome (LS) involving Fusobacterium species causing pylephlebitis and possibly liver abscesses was recently identified. This systematic review aims to summarize the literature on this variant.

Methods

PubMed, Embase, Scopus, and Cochrane databases were searched up to November, 2nd, 2023 for case reports or case series detailing the GI variant of LS. Data regarding demographics, clinical features, and management were extracted. Descriptive statistics were used for analysis, including means, standard deviations, and percentages.

Results

The cohort included 36 patients (mean age 50.8 years; predominantly men 72%). Positive blood cultures were detected in 88.8% of cases, primarily growing Fusobacterium nucleatum (47.2%) and Fusobacterium necrophorum (33.3%). The GI tract was the primary infection source (58.3%), mostly related to diverticular disease (25%). Common manifestations were fever (86.1%), abdominal pain (72.2%), and leukocytosis (86.1%). Thrombosis involved the portal vein in 77.7%, with isolated portal vein thrombosis (PVT) (44.4%) and PVT extending to the superior mesenteric vein (30.5%). Liver abscesses were detected in 50% of cases, with positive aspirate cultures in 92.3%. Treatment included penicillin/penicillin-lactamase inhibitors alone (17%) and ertapenem alone (17%). Abscess drainage (13/18) resulted in complete/near-complete resolution in 83%. Long-term anticoagulation therapy was given in 75% of cases, commonly using vitamin K antagonists (59.2%). No deaths occurred.

Conclusion

The GI variant of LS should be considered in patients with abdominal pain, fever, leukocytosis, and portal/superior mesenteric vein thrombosis. Identifying Fusobacterium species in blood cultures and liver abscesses further supports the diagnosis. Management involves antibiotic therapy, abscess drainage, and long-term anticoagulation.

Case Report on Mycobacterium tuberculosis Presenting As Lemierre's Syndrome: A Reemerging Catastrophe

Lemierre's syndrome is characterized by internal jugular vein thrombophlebitis and bacteremia, primarily from anaerobic organisms. The condition usually arises after a recent oropharyngeal infection. Young, healthy people with prolonged pharyngitis that progresses into septicemia, pneumonia, or lateral neck stiffness should be suspected of having Lemierre's syndrome. Identifying internal jugular vein thrombophlebitis and developing anaerobic bacterial growth on blood culture are frequently used to confirm the diagnosis. Treatment consists of long-term antibiotic treatment, sometimes in conjunction with anticoagulant medication. In this case report, we describe the unique case of a 29-year-old male with Mycobacterium tuberculosis with pulmonary tuberculosis, tubercular meningitis, tuberculosis-related acute ischemic stroke with septic thrombophlebitis. The patient presented with sudden onset altered sensorium for 4 hours. Magnetic resonance imaging of the brain was done, which suggested obstructive hydrocephalus with periventricular ooze. The patient was started on antibacillary treatment, antibiotics, anticoagulants, and systemic steroids. The patient was vitally stable when he was discharged. Therefore, it is crucial to consider the likelihood of such atypical tuberculosis presentations while providing a prompt and relevant diagnosis and recommending the right course of therapy.

Case report: Metagenomics next-generation sequencing in the diagnosis of septic shock due to Fusobacterium necrophorum in a 6-year-old child

Fusobacterium necrophorum (F. necrophorum) infection is rare in pediatrics. In addition, the detection time of F. necrophorum by blood culture is long, and the positive rate is low. Infection with F. necrophorum bacilli usually follows rapid disease progression, resulting in high mortality. In previous reports of F. necrophorum-related cases, the most dangerous moment of the disease occurred after the appearance of Lemierre's syndrome. We report an atypical case of a 6-year-old female patient who developed septic shock within 24 h of admission due to F. necrophorum infection in the absence of Lemierre's syndrome. F. necrophorum was identified in a blood sample by metagenomics next-generation sequencing (mNGS) but not by standard blood culture. The patient was finally cured and discharged after receiving timely and effective targeted anti-infection treatment. In the present case study, it was observed that the heightened virulence and invasiveness of F. necrophorum contribute significantly to its role as a primary pathogen in pediatric septic shock. This can precipitate hemodynamic instability and multiple organ failure, even in the absence of Lemierre's syndrome. The use of mNGS can deeply and rapidly identify infectious pathogens, guide the use of targeted antibiotics, and greatly improve the survival rate of patients.

Lemierre Syndrome: Report of a Case with an Innovative Diagnostic Method and Literature Review

Objective

To understand the clinical features, diagnosis and treatment of Lemierre syndrome (LS), a high-risk and low-prevalence infectious disease.

Methods

We present the severe LS case that was diagnosed using metagenomic next-generation sequencing (mNGS) in our hospital, and systematically summarized the diagnosis and treatment strategies of patients that reported LS from 2006 to 2022.

Results

The 24-year-old patient in our hospital suffered from cranial nerve paralysis, a neurological complication rarely seen in LS cases. The causative agent (Fusobacterium necrophorum, Fn) of this patient was only detected by mNGS tests, and the reads number of Fn detected by plasma mNGS tests was decrease as the patients gradually improved, indicating plasma mNGS is valuable in monitoring treatment efficacy. Although most of the cases retrieved from the literature showed typical symptoms, such as a history of sore throat, septic emboli, and internal jugular vein thrombosis, clinical manifestations were still relatively heterogeneous (eg, diversity of predisposing factors and pathogens, differences in pulmonary imaging features).

Conclusion

We summarized the clinical presentation, diagnosis, treatment, and regression of 17 symptomatic cases reported LS to provide clinicians with knowledge about this rare but fatal disease. mNGS assays should be considered as early as possible to identify the responsible pathogens for acute and critically ill patients with suspected infections in order to implement accurate and effective treatment.

Lemierre syndrome complicated by bronchopleural fistula

We present a 19-year-old woman, a case of Lemierre syndrome, who presented with fever, sore throat, and left shoulder pain. Imaging revealed a thrombus in the right internal jugular vein, multiple nodular shadows below both pleura with some cavitations, right lung necrotizing pneumonia, pyothorax, abscess in the infraspinatus muscle, and multiloculated fluid collections in the left hip joint. After inserting a chest tube and administering urokinase for the pyothorax, a bronchopleural fistula was suspected. The fistula was identified based on clinical symptoms and computed tomography scan findings. If a bronchopleural fistula is present, thoracic lavage should not be performed as it may cause complications such as contralateral pneumonia due to reflux.

A case of Lemierre's syndrome causing panhypopituitarism, cavernous sinus thrombosis, ischaemic stroke and pulmonary embolism

Infection is a rare cause of panhypopituitarism and has not been reported in the context of Lemierre's syndrome. We present the case of a previously well 19-year-old man, who presented acutely unwell with meningitis and sepsis. Fusobacterium necrophorum was isolated from peripheral blood cultures and identified on cerebrospinal fluid with 16S rDNA Polymerase Chain Reaction (PCR). Imaging demonstrated internal jugular vein thrombosis with subsequent cavernous venous sinus thrombosis. Pituitary function tests were suggestive of panhypopituitarism. The patient was diagnosed with Lemierre's syndrome complicated by meningitis, cavernous sinus thrombosis, base of skull osteomyelitis, ischaemic stroke and panhypopituitarism. He was treated with 13 weeks of intravenous antibiotics followed by 3 weeks of oral amoxicillin, and anticoagulated with dalteparin then apixaban. His panhypopituitarism was managed with hydrocortisone, levothyroxine and desmopressin.

Atypical thrombophlebitis patterns in head and neck infections

Thrombophlebitis is a known complication of head and neck infection, which can result in propagation of infected thrombi and associated complications. While antegrade/downstream propagation of thrombus is well described-the Lemierre syndrome-thrombophlebitis can spread in atypical patterns which has specific diagnostic and treatment considerations. In this series, we highlight 6 cases of atypical thrombophlebitis patterns complicating head and neck infection, 5 of which extend intracranially. Through these pathways, head and neck infections such as oral cavity, oropharynx, or skin can be the culprit of remote, including intracranial, complications, which may be overlooked. Furthermore, understanding pathways of venous drainage and communication can help accurately diagnose thrombophlebitis patterns and associated complications.

Delayed diagnosis of Lemierre's syndrome in a patient with severe coronavirus disease 2019: importance of comprehensive oral and neck examination - a case report

BACKGROUND

Given the widespread prevalence of the coronavirus disease 2019 (COVID-19), oral and neck examinations tend to be avoided in patients with suspected or confirmed COVID-19. This might delay the diagnosis of conditions such as Lemierre's syndrome, which involves symptoms resembling COVID-19-related throat manifestations.

CASE PRESENTATION

A 24-year-old man without any underlying conditions was diagnosed with COVID-19 7 days before presentation. He was admitted to another hospital 1 day before presentation with severe COVID-19 and suspected bacterial pneumonia; accordingly, he was started on treatment with remdesivir and meropenem. Owing to bacteremic complications, the patient was transferred to our hospital for intensive care. On the sixth day, the patient experienced hemoptysis; further, a computed tomography (CT) scan revealed new pulmonary artery pseudoaneurysms. Successful embolization was performed to achieve hemostasis. In blood cultures conducted at the previous hospital, Fusobacterium nucleatum was isolated, suggesting a cervical origin of the infection. A neck CT scan confirmed a peritonsillar abscess and left internal jugular vein thrombus; accordingly, he was diagnosed with Lemierre's syndrome. The treatment was switched to ampicillin/sulbactam, based on the drug susceptibility results. After 6 weeks of treatment, the patient completely recovered without complications.

CONCLUSION

This case highlights the significance of thorough oral and neck examinations in patients with suspected or diagnosed COVID-19 for the detection of throat and neck symptoms caused by other conditions.

Common laboratory tests and their correlation with the clinical presentation and prognosis of Lemierre syndrome

INTRODUCTION

Lemierre syndrome is a thromboembolic complication following an acute bacterial infection of the head/neck area, often due to anaerobes. Data on the prognostic role of laboratory parameters is lacking.

METHODS

We analyzed individual-patient level data from a multinational cohort of patients with Lemierre-syndrome. Patients had an infection in the head/neck area, and contiguous vein thrombosis or septic embolism, irrespective of the causal pathogen. We studied the patterns of white blood cell count, platelet count, and C-reactive protein concentration investigating their association with baseline characteristics and in-hospital clinical outcomes (septic embolism, major bleeding, all-cause death).

RESULTS

A total of 447 (63%) patients had complete data for analysis. White blood cells were elevated across all subgroups (median 17 × 103/μL; Q1-Q3:12-21). Median platelet count was 61 × 103/μL (Q1-Q3:30-108) with decreasing levels with increasing age. Males, patients with renal failure or cardiopulmonary impairment, and those with typical Lemierre syndrome (tonsillitis, septic thromboembolism, positivity for Fusobacterium spp.) had the lowest platelet count. Median C-reactive protein was 122 (Q1-Q3:27-248) mg/L with higher values in patients who also had more severe thrombocytopenia. The overall risk of complications was similar across subgroups of patients stratified according to white blood cell and C-reactive protein levels. Patients in the lowest third of platelet count (<42 × 103/μL) had the highest rate of complications (26%), as opposed to those in the highest third (11%), notably septic embolic events.

CONCLUSIONS

Common laboratory tests correlate with the clinical presentation of Lemierre syndrome. However, extreme values did not appear to be prognostically relevant for in-hospital complications and potentially able to improve clinical management.

Invasive Sinusitis With Arcanobacterium haemolyticum and Fusobacterium necrophorum Complicated by Subdural Empyema in an Immunocompetent Adolescent Patient

We are reporting a very rare case of an invasive infection with Arcanobacterium haemolyticum and Fusobacterium necrophorum that resulted in meningitis, cerebral edema, and subdural empyema secondary to upper respiratory infection (URI) and sinusitis in an immunocompetent adolescent patient. Our patient is a 17-year-old male with no significant medical history who presented to his pediatrician with a fever for three days, was diagnosed with a viral URI, and instructed to continue symptomatic care. Seven days later, the patient developed a headache, left-sided weakness, and continued to spike fever. The patient presented to the Emergency Center due to altered mental status, worsening left-sided weakness, and difficulty speaking. Head computed tomography (CT) scan showed small right-sided fluid collection with right-to-left midline shift and marked opacification of paranasal sinuses with air-fluid levels in frontal sinuses. The patient underwent an emergent craniotomy that revealed subdural empyema under high pressure and was started on vancomycin, cefepime, metronidazole, and levetiracetam. Six hours after his craniotomy, the patient developed fixed dilatation of his right-side pupil and a head CT scan showed developing ischemic changes and increased in his midline shift which prompted to emergent right decompressive craniectomy. The following day of his surgery, magnetic resonance imaging of the brain showed large acute infarctions of the right hemisphere, edema, and subfalcine herniation. Two brain death exams - 12 hours apart - were performed in which criteria for brain death were met. The patient's subdural empyema culture grew Fusobacterium necrophorum and Arcanobacterium haemolyticum.

Outer-Membrane Vesicles of Fusobacterium necrophorum: A Proteomic, Lipidomic, and Functional Characterization

Outer-membrane vesicles (OMVs) are extruded nanostructures shed by Gram-negative bacteria, containing periplasmic contents, and often including virulence factors with immunogenic properties. To assess their potential for use in vaccine development, we purified OMVs from the Fusobacterium necrophorum subspecies necrophorum, an opportunistic necrotic infection-causing pathogen, and characterized these structures using proteomics, lipid-profiling analyses, and cytotoxicity assays. A proteomic analysis of density-gradient-purified F. necrophorum OMVs identified 342 proteins, a large proportion of which were outer-membrane proteins (OMPs), followed by cytoplasmic proteins, based on a subcellular-localization-prediction analysis. The OMPs and toxins were among the proteins with the highest intensity identified, including the 43-kDa-OMP-, OmpA-, and OmpH-family proteins, the cell-surface protein, the FadA adhesin protein, the leukotoxin-LktA-family filamentous adhesin, the N-terminal domain of hemagglutinin, and the OMP transport protein and assembly factor. A Western blot analysis confirmed the presence of several OMPs and toxins in the F. necrophorum OMVs. The lipid-profiling analysis revealed phospholipids, sphingolipids, and acetylcarnitine as the main lipid contents of OMVs. The lactate-dehydrogenase-cytotoxicity assays showed that the OMVs had a high degree of cytotoxicity against a bovine B-lymphocyte cell line (BL-3 cells). Thus, our data suggest the need for further studies to evaluate the ability of OMVs to induce immune responses and assess their vaccine potential in vivo.

Lung abscess as a complication of Lemierre Syndrome in adolescents: a single center case reports and review of the literature

BACKGROUND

Fusobacterium necrophorum is an anaerobic, gram-negative, non-motile, filamentous, non-spore forming bacillus found in the oral cavity, gastrointestinal tract, and female genital tract, responsible of a rare disease named Lemierre Syndrome, characterized by septic thrombophlebitis of the internal jugular vein, which mainly affects previously healthy adolescents and young adults; some risk factors are reported, as smoking or primary viral or bacterial infection leading to the disruption of mucosa. The syndrome originates commonly from an upper respiratory infection such as pharyngotonsillitis, acute otitis media, cervical lymphadenitis, sinusitis, or odontogenic abscess, and may result in multiorgan metastasis, more frequently leading to pulmonary complications, especially lung abscesses.

CASE PRESENTATION

We describe two cases of adolescents with atypical Lemierre Syndrome evaluated in a tertiary care center, one with a confirmed infection by Fusobacterium necrophorum and one with a presumptive diagnosis based on clinical features, who developed lung abscesses needing a prolonged antibiotic course and hospitalization. Of interest, both were user of electronic cigarette, configuring a possible new risk factor. The proper diagnosis of Lemierre Syndrome is often difficult to establish, so a high degree of suspicion is needed, especially in the case of lung abscesses in otherwise healthy adolescents.

CONCLUSION

The current study will contribute to providing insight into Lemierre Syndrome clinical presentation and management in adolescents, promoting awareness for a rare but potentially fatal disease. Moreover, it suggests a possible relationship between Lemierre syndrome and the use of electronic cigarette, that should be investigated by future studies.

Lemierre's Syndrome Caused by Klebsiella pneumoniae: A Case Report and Literature Review

Lemierre's syndrome is a rare condition that involves anaerobic sepsis following pharyngitis and is characterized by a high mortality rate. It often manifests as a septic embolism within the internal jugular vein due to oropharyngeal infections, leading to vein wall inflammation. Despite modern antibiotics, Lemierre's syndrome remains underdiagnosed and poses a significant threat. We report the case of a 43-year-old man who has alcoholic liver cirrhosis and diabetes mellitus. Symptoms included chest pain, back pain, and neck swelling, with Klebsiella pneumoniae leading to the diagnosis of K. pneumoniae-associated Lemierre's syndrome. Furthermore, K. pneumoniae-associated Lemierre's syndrome is linked to diabetes mellitus and the elderly population. Notably, it showed a tendency for distant metastases, particularly in the lungs and brain. Additionally, central nervous system and renal involvement were observed in a smaller subset of cases.

Lemierre's Syndrome in the 21st Century: A Literature Review

Lemierre's syndrome is a rare, life-threatening complication of an acute oropharyngeal infection. It is generally characterised by pharyngitis secondary to Fusobacterium necrophorum, causing thrombophlebitis of the internal jugular vein and sepsis, with subsequent formation of septic emboli that can rapidly spread to different organ sites. The condition is associated with high mortality if treatment with antibiotics is delayed, and recent evidence suggests that patients are at significant risk of in-hospital morbidity and long-term neurological sequelae. Although it is agreed that antibiotics are the mainstay of treatment, there is currently no consensus on the use of anticoagulation in the condition. This review article aims to summarise our current understanding of Lemierre's syndrome with regard to its definition, epidemiology, microbiology, presentation, diagnosis, and treatment.