Fusobacterium nucleatum: a rare cause of pyogenic liver abscess

The Relationship Between the Growth of Fusobacterium nucleatum ATCC 25586 in Glucose-Enriched Media and Protein Activity through Fourier Transform Infrared (FTIR)

Background

Fusobacterium nucleatum (F. nucleatum) is known to increase in number under hyperglycemic conditions, as it is thought to utilize glucose as a nutrient source. The process of glucose utilization in bacteria occurs with the assistance of enzymatic proteins such as glucokinase. This study aims to investigate the glucose utilization by F. nucleatum ATCC 25586 by examining its growth in glucose-enriched media and its relationship with protein activity through FTIR analysis.

Methods

F. nucleatum ATCC 25586 was cultured in media enriched with 2%, 1%, 0.75%, 0.5%, and 0.25% glucose. Its growth was measured using a spectrophotometer, and protein activity was assessed with FTIR at 24 and 48 hours of incubation.

Results

The results showed that F. nucleatum could utilize glucose as a nutrient source, indicated by growth and protein activity. The maximum growth of F. nucleatum occurred at a 0.75% glucose concentration at 24 hours. However, the Kruskal-Wallis test showed no significant differences in the growth and protein activity of F. nucleatum across the five glucose concentrations (growth, p =0.271 and protein, p =0.149). Spearman correlation analysis indicated no correlation between the growth and protein activity of F. nucleatum (p=0.323). The protein activity of F. nucleatum remained stable across various growth levels.

Conclusions

It can be concluded that glucose could influence the growth of F. nucleatum, although the growth and protein activity of the bacteria did not differ significantly based on glucose concentration. F. nucleatum grown in various glucose concentrations exhibits stable protein activity.

Gastrointestinal Variant of Lemierre Syndrome due to Fusobacterium nucleatum: A Case Report

Introduction

Pyogenic liver abscess is a noteworthy health concern in North America, characterized by a mortality rate ranging from 2 to 12%. This condition is often polymicrobial, with Streptococcus species and Escherichia coli as the predominant causal pathogens in Western countries. Fusobacterium species, typically commensals of gastrointestinal, genital, and oral flora, have been implicated in the rare formation of tonsillar abscesses and Lemierre syndrome, including its gastrointestinal variant known as pylephlebitis.

Case Presentation

We present the case of an immunocompetent male with a 2-week history of abdominal distention and pain. Abdominal magnetic resonance imaging revealed multiseptated cystic hepatic masses and portal vein thrombosis. A subsequent liver biopsy confirmed Fusobacterium nucleatum etiology. The patient was initiated on intravenous cefepime and oral metronidazole antibiotics. Unfortunately, the patient succumbed to cardiac arrest before a final diagnosis could be established.

Conclusion

Fusobacterium species-associated liver abscess, coupled with the rare gastrointestinal variant of Lemierre syndrome (pylephlebitis), poses a significant mortality risk. This case underscores the rarity and clinical challenges associated with these conditions. Increased awareness among clinicians is crucial for early diagnosis and prompt intervention, potentially improving outcomes in such cases.

Pyogenic Liver Abscess: A Case of a Fussy Bug Seeking Unlikely Host

Pyogenic liver abscesses (PLAs) represent a rare yet life-threatening condition, and Fusobacterium species are an atypical etiology typically associated with immunocompromised patients or those with recent dental procedures or oro-gingival disease. Nonetheless, it is crucial to maintain a high level of suspicion for Fusobacterium infection in all cases, including immunocompetent individuals without known risk factors. In this case report, we present the clinical scenario of a young male with a history of COVID-19 pneumonia who exhibited subacute fever, abdominal pain, and pleuritic chest pain, leading to sepsis attributed to intraabdominal pathology. Subsequent imaging confirmed the presence of possible liver abscesses, prompting interventional radiology-guided drainage. Cultures obtained from the drained abscesses yielded Fusobacterium species, and significant clinical improvement was observed following the initiation of appropriate antibiotic therapy. This case report underscores the potential for disseminated Fusobacterium infections to occur in immunocompetent individuals without a history of oropharyngeal disease, highlighting the importance of early diagnosis and management to mitigate mortality risk.

Fusobacterium nucleatum promotes the development of acute liver failure by inhibiting the NAD+ salvage metabolic pathway

BACKGROUND

Acute liver failure (ALF) patients are often accompanied by severe energy metabolism abnormalities and intestinal microecological imbalance. The intestinal mucosal barrier is severely damaged. Intestinal endotoxin can induce intestinal endotoxemia through the "Gut-Liver axis". More and more evidence shows that members of the gut microbiota, especially Fusobacterium nucleatum (F. nucleatum), are related to inflammatory bowel disease, but whether F. nucleatum is involved in the development of ALF and whether it affects the liver energy metabolism is unclear.

METHODS

This study first detected the abundance of F. nucleatum and its effect on ALF disease, and explored whether F. nucleatum aggravated liver inflammation in vitro and in vivo.

RESULTS

Our data showed that liver tissues of ALF patients contained different abundances of F. nucleatum, which were related to the degree of liver inflammation. In addition, we found that F. nucleatum infection affected the energy metabolism of the liver during the development of ALF, inhibited the synthesis pathway of nicotinamide adenine dinucleotide (NAD⁺)'s salvage metabolism, and promoted inflammatory damage in the liver. In terms of mechanism, F. nucleatum inhibited NAD⁺ and the NAD⁺-dependent SIRT1/AMPK signaling pathway, and promoted liver damage of ALF.

CONCLUSIONS

Fusobacterium nucleatum coordinates a molecular network including NAD⁺ and SIRT1 to control the progress of ALF. Detection and targeting of F. nucleatum and its related pathways may provide valuable insights for the treatment of ALF.

Liver Abscess Caused by Fusobacterium nucleatum: A Case Report

Introduction: Pyogenic liver abscess (PLA) is a serious infectious disease of the liver. Pyogenic liver abscess caused by Fusobacterium nucleatum is extremely rare. Here we report the first case of liver abscess caused by F. nucleatum in China. Case Presentation: The case was a 34-year-old female patient admitted to the hospital due to high fever. The diagnosis of liver abscess was confirmed by imaging studies and liver puncture. We finally confirmed the pathogen as F. nucleatum by next-generation sequencing (NGS). After the targeted anti-infective treatment, the patient recovered and discharged. Conclusions: As a new microbial detection method, NGS can still help in clinical practice. In addition, to improve the positive rate of anaerobic bacteria culture, we should pay attention to avoid contact with air in the process of specimen collection when the pathogenic bacteria are suspected to be anaerobic bacteria.

Fusobacterium nucleatum causing a pyogenic liver abscess: a rare complication of periodontal disease that occurred during the COVID-19 pandemic

Fusobacterium nucleatum is a periodontal commensal and pathogen. In rare cases, these anaerobic gram-negative bacilli have been reported to cause pyogenic liver abscesses (PLAs). We describe a patient who developed a periodontal abscess during the COVID-19 pandemic and was unable to access the restricted General Dental Services at this time. She subsequently developed a F. nucleatum bacteraemia and liver abscess. The non-specific signs and symptoms experienced meant the patient self-isolated due to suspected COVID-19 infection and presentation to hospital was delayed. We also include the results of a literature search of other cases of PLAs attributed to F. nucleatum PLAs often develop insidiously. They require percutaneous drainage and prolonged antimicrobial therapy. Clinicians should be aware of this rare complication of a dentoalveolar infection in a patient who is systemically unwell.

Characterization of abscesses from liver, pancreas and kidney using deep sequencing of the 16S rRNA gene

To characterize the microbial communities in abscess material from liver, pancreas, and kidneys, we performed deep sequencing of the 16S rRNA gene, in addition to cultivation and Sanger based 16S rRNA gene sequencing directly from the samples. Fifty-nine abscess samples were investigated, 38 from liver, 11 from pancreas, 10 from kidney. Using deep sequencing we made 227 bacterial identifications in 52 specimens, as compared to 69 identifications from the 44 specimens positive by culture. Escherichia coli, Enterococcus sp., Klebsiella sp. and Streptococcus sp. were the most common findings, but various anaerobe bacteria also constituted a large part of the microflora and those were frequently not detected by culture. Culture-independent methods like 16S deep sequencing can significantly improve microbiological diagnostics of clinical specimens. They are particularly valuable for complex purulent infections like abdominal abscesses. Therefore, deep sequencing approaches should be considered as a part of the available repertoire in diagnostic hospital laboratories.

Cryptogenic Pyogenic Liver Abscess Due to Fusobacterium nucleatum in an Immunocompetent Patient

In this case, a 76-year-old female presented with 3-4 days of fever with no other localizing signs. Notably, she had had an untreated Fusobacterium bacteraemia approximately 8 weeks prior to admission. She underwent abdominal imaging which demonstrated a liver abscess and had percutaneous drainage of the same. Blood and pus cultures both grew Fusobacterium nucleatum, which is an unusual organism to be associated with a liver abscess, especially in an immunocompetent host with no risk factors for this condition. Interestingly, this patient did not have any history of dental work, instrumentation, liver function test (LFT) abnormalities and no extrahepatic source for the abscess. This case highlights the importance of having a high index of clinical suspicion for an occult source of infection and emphasizes the importance of following up on cultures even after discharge of a patient, since anaerobic infections such as those caused by Fusobacterium can have a largely indolent course.

LEARNING POINTS

Fever of unknown aetiology with prior bacteraemia merits a thorough work-up for occult sources such as a localized abscess or malignancy, which can cause bacterial translocation.Fusobacterium and other anaerobic infectious agents should be considered in the context of an indolent disease course since they are slow-growing in cultures, and also, if the patient has risk factors such as immunosuppression, diabetes, poor oral hygiene and so on.It is important to have systems in place in hospitals to ensure follow-up for patients who may have a positive culture after discharge from hospital to confirm that the infection is adequately addressed.

A survey of Fusobacterium nucleatum genes modulated by host cell infection

Here, we report comprehensive transcriptomic profiles from Fusobacterium nucleatum under conditions that mimic the first stages of bacterial infection in a highly differentiated adenocarcinoma epithelial cell line. Our transcriptomic in vitro adenocarcinoma approach allows us to measure the expression dynamics and regulation of bacterial virulence and response factors in real time, and is a novel strategy for clarifying the role of F. nucleatum infection in colorectal cancer (CRC) progression. Our data show that: (i) infection alters metabolic and functional pathways in F. nucleatum, allowing the bacterium to adapt to the host-imposed milieu; (ii) infection also stimulates the expression of genes required to help induce and promote a hypoxic and inflammatory microenvironment in the host; and (iii) F. nucleatum invasion occurs by a haematogenous route of infection. Our study identifies novel gene targets from F. nucleatum that are activated during invasion and which may aid in determining how this species invades and promotes disease within the human gastrointestinal tract. These invasion-specific genes may be useful as biomarkers for CRC progression in a host and could also assist in the development of new diagnostic tools and treatments (such as vaccines or small molecule drug targets), which will be able to combat infection and inflammation in the host while circumventing the potential problem of F. nucleatum tolerization.

Concurrent fusobacterial pyogenic liver abscess and empyema

We present a very rare case of concurrent empyema and liver abscess caused by Fusobacterium. Our patient presented with 3-month history of subtle abdominal discomfort and cough leading to eventually presenting with marked chest pain, dyspnoea and septic shock. CT revealed a liver abscess and large right-sided pleural effusion. Drainage of the pleural effusion yielded gross pus with the growth of Fusobacterium varium, while drainage of the liver abscess yielded Fusobacterium nucleatum The patient responded to drainage and antibiotic therapy with resolution of symptoms and decrease in the size of empyema and abscess on follow-up imaging. We also include a review if literature of related fusobacterial infections.

Fusobacterium nucleatum: A cause of subacute liver abscesses with extensive fibrosis crossing the diaphragm, mimicking actinomycosis

Introduction

Fusobacterium nucleatum is a Gram-negative, obligate anaerobic bacterium which predominantly resides within the oral cavity and causes acute abscesses and venous thrombosis, primarily in the head and neck region, but could have unique clinical presentations in different anatomical regions of the body.

Case report

We present a case of subacute liver abscesses extending to the lung. The histopathological examination showed extensive necrosis and fibrosis. The chronic course, extensive fibrosis and extension across the anatomic barriers were suggestive of actinomycosis. two sets of blood cultures grew Fusobacterium nucleatum, only 16s rRNA analysis of the liver tissue and pleural fluid revealed F. nucleatum DNA without other organisms. The clinical and pathological features of our case illustrate that F. nucleatum may mimic actinomycosis.

Conclusions

This case illustrates that F. nucleatum should be considered in patients with subacute infections with extensive fibrosis that crosses anatomic barriers, mimicking actinomycosis.

Denture-Associated Oral Microbiome and Periodontal Disease Causing an Anaerobic Pyogenic Liver Abscess in an Immunocompetent Patient: A Case report and Review of the Literature

Pyogenic liver abscesses (PLA) develop from the spread of infection through the portal circulation, biliary infections or arterial hematogenous seeding in the setting of systemic infections. PLA are often poly-microbial and are uncommonly reported to be due to anaerobic species. We report the case of a previously healthy, immunocompetent 63-year-old man with hepatic abscesses as a result of Fusobacterium nucleatum periodontal disease. In addition, a systemic review of the literature is performed. Fusobacterium is a very rare cause of PLA in immunocompetent hosts with only a handful of cases reported in the literature. Although anaerobic infections such as Fusobacterium most often occur in immunocompromised individuals, clinicians should have a high index of suspicion in immunocompetent patients with periodontal disease or chronic stomatitis.

Septic Shock in the Course of Liver Absces Rescued with Percutaneous Drainage - A Literature Review and Case Report

This study presented a septic shock occurring with striking speed during the percutaneous drainage of a large abscess of the liver in an 18-year-old female patient after an appendectomy performed 3 months earlier using the laparoscopic method because of its phlegmonous and gangraenosus inflammation. The post-operative course was complicated by increased suppuration in places after removal of the trocars. After including the intravenous antibiotic therapy and under the USG control, the percutaneous drainage of the abscess was performed. While withdrawing the guide of the drainage catheter set, the symptoms of septic shock occurred. The pharmacological treatment was applied with continuation of the antibiotic therapy till a negative result of microbiological tests was obtained and the normalization of life parameters. The patient was not qualified for treatment in the ICU. She was discharged in a generally good condition after 24 days of hospitalization. In the case of this patient, the drain covered with the content of the abscess may have contact with the adjacent tiny blood vessels, which may have contributed to the systemic inflammatory response syndrome that was linked with fast-developing sceptic shock.