The changing pattern of Fusobacterium infections in humans: recent experience with Fusobacterium bacteraemia

Epidemiology and Clinical Outcomes of Fusobacterium Infections: A Six-Year Retrospective Study

Background and Objectives: Anaerobic bacteria like Fusobacterium can lead to severe and life-threatening infections. The inherent complexities in the isolation of these bacteria may result in diagnostic and therapeutic delays, thereby escalating both morbidity and mortality rates. We aimed to examine data from patients with infections due to Fusobacterium to gain insights into the epidemiology and clinical outcomes of patients with these infections. Methods and Results: We conducted a retrospective analysis of clinical data from a cohort of patients with cultures positive for Fusobacterium species at a tertiary care medical center in the United States. Between 2009 and 2015, we identified 96 patients with cultures positive for Fusobacterium. Patients could be categorized into three groups based on the site of primary infection. Patients with head and neck infections constituted 37% (n 36). Patients with infections of other soft tissue sites accounted for 38.5% (n 37). Patients with anaerobic bacteremia due to Fusobacterium formed 24% (n 23) of the cohort. Surgical intervention coupled with antibiotic therapy emerged as cornerstones of management for patients with head and neck or other soft tissue infections, who generally exhibited more favorable outcomes. Patients with bacteremia were older, more likely to have malignancy, and had a high mortality rate. When speciation was available, Fusobacterium necrophorum was the most frequently isolated species. Conclusions: Our retrospective analysis of epidemiology and clinical outcomes of Fusobacterium infections revealed three distinct cohorts. Patients with head, neck, or soft tissue infections had better outcomes than those with bacteremia. Our findings highlight the importance of employing management strategies based on infection site and underlying comorbidities in patients with Fusobacterium infections. Further research is needed to investigate the optimal therapeutic strategies and identify prognostic indicators to improve clinical outcomes for these complex infections.

Clinical Differences in Patients Infected with Fusobacterium and Antimicrobial Susceptibility of Fusobacterium Isolates Recovered at a Tertiary-Care Hospital in Korea

Background

Fusobacterium species are obligately anaerobic, gram-negative bacilli. Especially, F. nucleatum and F. necrophorum are highly relevant human pathogens. We investigated clinical differences in patients infected with Fusobacterium spp. and determined the antimicrobial susceptibility of Fusobacterium isolates.

Methods

We collected clinical data of 86 patients from whom Fusobacterium spp. were isolated from clinical specimens at a tertiary-care hospital in Korea between 2003 and 2020. In total, 76 non-duplicated Fusobacterium isolates were selected for antimicrobial susceptibility testing by the agar dilution method, according to the Clinical and Laboratory Standards Institute guidelines (M11-A9).

Results

F. nucleatum was most frequently isolated from blood cultures and was associated with hematologic malignancy, whereas F. necrophorum was mostly prevalent in head and neck infections. Anti-anaerobic agents were more commonly used to treat F. nucleatum and F. varium infections than to treat F. necrophorum infections. We observed no significant difference in mortality between patients infected with these species. All F. nucleatum and F. necrophorum isolates were susceptible to the antimicrobial agents tested. F. varium was resistant to clindamycin (48%) and moxifloxacin (24%), and F. mortiferum was resistant to penicillin G (22%) and ceftriaxone (67%). β-Lactamase activity was not detected.

Conclusions

Despite the clinical differences among patients with clinically important Fusobacterium infections, there was no significant difference in the mortality rates. Some Fusobacterium spp. were resistant to penicillin G, ceftriaxone, clindamycin, or moxifloxacin. This study may provide clinically relevant data for implementing empirical treatment against Fusobacterium infections.

Unusual case of necrotizing pneumonia caused by Fusobacterium nucleatum complicating influenza a virus infection

We report a rare case of Fusobacterium nucleatum necrotizing pneumonia following an influenza viral infection. This rare bacterial lung infection can have severe complications such as respiratory failure and septic shock, so early recognition and treatment are necessary.

Correlation of gut microbial compositions to the development of Kawasaki disease vasculitis in children

Aim: Here, we hypothesize that dysbiotic gut microbiota might contribute to the development of Kawasaki disease (KD), a pediatric disease with unknown etiology. This is the second report on gut microbiota composition in KD patients. Materials & results: 16S amplicon sequencing was performed on fecal DNA samples and revealed predominance of bacterial pathogens, such as Fusobacterium, Neisseria, Shigella and Streptococcus, in the gut of KD patients, but absent or suppressed after immunoglobulin/antibiotics therapy. In addition, beneficial bacteria propagated after the therapy. Conclusion: We conclude that prevalence of Fusobacteria, Shigella and Streptococcus might contribute to KD pathogenesis.

Fusobacterium necrophorum sepsis after tonsillitis/pharyngitis

Fusobacterium necrophorum is a rare infection most notable for causing Lemierre's syndrome. This consists of a primary oropharyngeal infection and septic thrombophlebitis, and one or more metastatic focus. Prior to the widespread use of antibiotics, Lemierre's syndrome commonly followed a rapidly progressing course, with a high mortality. We describe a case of a previously well 18-month-old boy who presented to the emergency department with a 3-week history of progressive, right-sided, painful neck swelling and systemic sepsis. He was initially treated conservatively with intravenous antibiotics, but ultimately required surgical drainage. Lemierre's syndrome is a rare condition with increasing incidence which can have significant adverse outcomes including death. Early recognition and treatment are essential, but identifying Lemierre's disease is challenging.

Bad news itself or just the messenger? The high mortality of Fusobacterium spp. infections is related to disseminated malignancy and other comorbidities

BACKGROUND

Fusobacterium species are pleomorphic, obligate anaerobic gram-negative bacilli. They are difficult to culture and grow slowly. If antibiotic treatment is initiated prior to blood cultures, the bacteria might evade detection. This is a comprehensive report on mortality in non-bacteraemia fusobacterial infection.

METHODS

Data were collected retrospectively in adults having a positive culture with Fusobacterium spp. admitted during 2000-2012 at the medical department. Data on culture specimens, number of cultures, admission and culture dates, patient age, gender, clinical disease, Charlson's index of co-morbidity, CRP level and survival were obtained. For comparison, we traced 60 consecutive, similarly obtained cultures from 2009 to 2010 containing Staphylococcus aureus.

RESULTS

Within a 12-year period, we identified 28 patients with a positive culture of Fusobacterium spp. in a medical ward serving a population of 220,000. Only a minority (39%) had a positive blood culture, and 54% had focus in respiratory tract or pleura. Overall 6-month mortality was 32%, and unrelated to subspecies, treatment or anatomic location but significantly related to age >60 years, admission for severe, acute illness, and comorbidity, especially metastatic malignancy. Comparison between infection with Fusobacterium spp. and S. aureus showed that Fusobacterium spp. infections were predominantly community acquired, while S. aureus were both community and hospital acquired. Overall mortality for both bacterial infections increased significantly with age and current malignant disease. S. aureus-infected patients carried a significantly higher mortality.

CONCLUSION

Our data support that Fusobacterium spp. infection is a marker for significant, chronic disease rather than carrying a poor prognosis per se.

Lemierre's Syndrome: Recognising a Typical Presentation of a Rare Condition

Lemierre's syndrome is a rare complication following an acute oropharyngeal infection. The aetiological agent is typically anaerobic bacteria of the genus Fusobacterium. The syndrome is characterised by a primary oropharyngeal infection followed by metastatic spread and suppurative thrombophlebitis of the internal jugular vein. If left untreated, Lemierre's syndrome carries a mortality rate of over 90%. Whilst relatively common in the preantibiotic era, the number of cases of Lemierre's syndrome subsequently declined with the introduction of antibiotics. With the increase of antibiotic resistance and a greater reluctance to prescribe antibiotics for minor conditions such as tonsillitis, there are now concerns developing about the reemergence of the condition. This increasing prevalence in the face of an unfamiliarity of clinicians with the classical features of this “forgotten disease” may result in the misdiagnosis or delay in diagnosis of this potentially fatal illness. This case report illustrates the delay in diagnosis of probable Lemierre's syndrome in a 17-year-old female, its diagnosis, and successful treatment which included the use of anticoagulation therapy. Whilst there was a positive outcome, the case highlights the need for a suspicion of this rare condition when presented with distinctive signs and symptoms.

Epidemiology and clinical outcomes of patients with Fusobacterium bacteraemia

This 10-year retrospective study assessed the epidemiology and outcomes of patients with Fusobacterium bacteraemia (FB) at a tertiary-care hospital in the USA - this is the second study focusing on FB in adults to be conducted in the USA in 30 years. Demographic, clinical, laboratory, treatment, and outcome data were collected and statistically analysed. Nineteen patients with FB were identified, representing 0·11% of bacteraemia cases. Mean age was 58·6 years with equal gender distribution. Common comorbidities included cardiovascular disease (CVD) and immunosuppression. Thirty-day mortality was 21·1%, and 68·4% of FB patients required intensive care unit (ICU) admission. Elevated creatinine levels and mental status changes were associated with higher mortality (P = 0·0181 and 0·0374, respectively). CVD, diabetes, and ICU admission were associated with increased length of hospital stay (P = 0·0017, 0·0010, and 0·0379, respectively). The prevalence of FB at our hospital was very low, with poor outcomes associated with increased creatinine level, mental status changes, CVD, diabetes and ICU admission.

A case of craniocervical abscess with sinus thrombosis in Lemierre's syndrome

A 74-year old gentleman with a cranio-cervical abscess failed to improve after incision and drainage and standard intravenous antibiotic therapy. Imaging demonstrated thrombosis of the internal jugular vein, sigmoid sinus and transverse sinus; and microbiological analysis isolated Fusobacterium nucleatum. The diagnosis of Lemierre's syndrome was confirmed, and he was effectively treated with appropriate antibiotics and anti-coagulation.

Clinical spectrum of bacteraemic Fusobacterium infections: from septic shock to nosocomial bacteraemia

BACKGROUND

Fusobacterium species are anaerobic bacteria that relatively rarely cause sepsis with a variable clinical presentation.

METHODS

We reviewed the records of 52 consecutive patients who had Fusobacterium bacteraemia over a 10-y period.

RESULTS

The clinical pictures could be classified into 4 groups: (1) patients who had Lemierre's syndrome with Fusobacterium necrophorum sepsis and internal jugular vein thrombosis, n = 5 (10%); (2) previously healthy patients who had F. necrophorum sepsis without any signs of macroscopic vascular thrombosis (but 5 of them had abscesses), n = 14 (27%); (3) women who had puerperal infections, n = 6 (12%); and (4) patients who were on average older than the patients in the previous groups, who had cardiovascular, pulmonary, neoplastic, or other underlying diseases, n = 27 (52%). Of these latter 27 patients, 23 had nosocomial Fusobacterium nucleatum bacteraemia presenting as a febrile illness associated with chemotherapy or instrumentation.

CONCLUSIONS

Patients with chronic underlying diseases are more likely to be infected with F. nucleatum than F. necrophorum. F. nucleatum bacteraemia may present as a febrile illness without severe symptoms. F. necrophorum caused sepsis mainly in previously healthy individuals. These infections may be accompanied with a jugular vein thrombosis characteristic of Lemierre's syndrome and septic shock. However, F. necrophorum infections present more frequently without any apparent venous thrombosis and may be accompanied by abscesses.

An unusual case of Lemierre's syndrome presenting as pyomyositis

Fusobacteria are most often associated with the classic presentation of Lemierre's syndrome consisting of a sore throat, internal jugular vein thrombophlebitis, and septic emboli to the lungs. Unusual presentations due to the causative organism, F. necrophorum, may occur. We present such a case involving a 17-year-old male patient with pyomyositis and fasciitis due to necrobacillosis. Fusobacterium spp. should be considered in the differential diagnosis of cases involving sepsis syndrome and pyomyositis.

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

Human infection with Fusobacterium necrophorum usually involves F. necrophorum subsp. funduliforme rather than F. necrophorum subsp. necrophorum, which is a common pathogen in animals. Lemierre's syndrome, or postanginal sepsis, is the most common life-threatening manifestation. Tonsillitis is followed by septic thrombophlebitis of the internal jugular vein and then a septicemia with septic emboli in lungs and other sites. Recent evidence suggests that F. necrophorum can be limited to the throat and cause persistent or recurrent tonsillitis. F. necrophorum is unique among non-spore-forming anaerobes, first for its virulence and association with Lemierre's syndrome as a monomicrobial infection and second because it seems probable that it is an exogenously acquired infection. The source of infection is unclear; suggestions include acquisition from animals or human-to-human transmission. Approximately 10% of published cases are associated with infectious mononucleosis, which may facilitate invasion. Recent work suggests that underlying thrombophilia may predispose to internal jugular vein thrombophlebitis. Lemierre's syndrome was relatively common in the preantibiotic era but seemed to virtually disappear with widespread use of antibiotics for upper respiratory tract infection. In the last 15 years there has been a rise in incidence, possibly related to restriction in antibiotic use for sore throat.