A Rare Case of Fusobacterium Necrophorum Liver Abscesses

Cryptogenic pyogenic liver abscess caused by Fusobacterium necrophorum in an immunocompetent patient

Pyogenic liver abscesses are potentially fatal conditions that require prompt treatment with drainage and appropriate antimicrobial therapy. Fusobacterium necrophorum is a gram-negative rod that is found in the oral cavity, gastrointestinal tract and female genital tract. It is an extremely rare cause of liver abscess, particularly in the absence of risk factors or exposures. We describe an unusual case of a cryptogenic F. necrophorum hepatic abscess without a clear source despite extensive investigation in a young, immunocompetent patient without known risk factors or exposures for such an infection.

A case report of liver abscesses caused by Fusobacterium necrophorum in immunocompetent patient and review of the literature

Background

Fusobacterium necrophorum is an anaerobic Gram-negative bacterium that can lead to opportunistic infections, including Lemierre's syndrome and less common presentations of metastatic diseases. However, liver abscesses infected by Fusobacterium necrophorum in clinical settings are rarely reported, particularly in people with normal immune function.

Case presentation

A 35-year-old Chinese man was admitted with hyperthermia and abdominal pain that had persisted for three days. The patient continued to have a fever with a maximum temperature of 39.8 °C during hospitalization. Computed Tomography revealed multiple low-density lesions in the liver, which were diagnosed as liver abscesses caused by Fusobacterium necrophorum infection through blood culture and anaerobic liver abscess fluid culture. After simple local percutaneous abscess drainage and effective anti-infective therapy, the patient achieved complete remission.

Conclusions

Results of our literature search query revealed rare reports of liver abscesses infected by Fusobacterium necrophorum. We recommend that Fusobacterium necrophorum infection be considered in diagnosis special situations of liver abscess.

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.

P. micra and F. necrophorum: Hepatic Abscesses in a Healthy Soldier

Parvimonas micra (P. micra) and Fusobacterium necrophorum (F. necrophorum) are two pathogens known to cause odontogenic and oropharyngeal infections. It is exceedingly rare for these bacteria to cause coinfection and even systemic infection. There is limited literature on liver abscesses and bacteremia involving P. micra. Most cases are found in elderly patients with associated gastrointestinal malignancy (24%) or laryngeal pharynx malignancy (28%). However, a substantial portion of described cases were unable to identify a source (36%). A 36-year-old, otherwise healthy male presented for fevers and chills for 2 weeks. After testing negative for initial infectious workup, including COVID-19 multiple times, he was found to have multiple liver abscesses which grew P. micra and F. necrophorum. This case highlights a rare coinfection of hepatic abscesses in an otherwise healthy young immunocompetent adult with a solitary dental caries, resulting in septic shock.

Are systemic antibiotics indicated in children presenting with an odontogenic abscess in the primary dentition? A systematic review of the literature

OBJECTIVES

This systematic review aimed to assess (1) whether systemic antibiotics are beneficial or harmful in healthy children who present with an odontogenic abscess in the primary dentition with or without systemic involvement and (2) if antibiotics are beneficial, which type, dosage and duration are the most effective.

MATERIALS AND METHODS

Electronic databases (Medline, Embase, and the Cochrane Library) were screened from 1948 up to August 2020. No filters with respect to study design were applied. Outcomes of interest included pain, swelling, pain relief, adverse effects, signs of infection, quality-of-life measurements and medication required for pain relief.

RESULTS

Altogether, 352 titles and abstracts were screened for eligibility; of these, 19 were selected for full text assessment. All were excluded because none of them fulfilled the inclusion criteria and addressed the (adjunctive) use of antibiotics in children who present with an odontogenic abscess in the primary dentition.

CONCLUSIONS

At present, there is no single randomised or non-randomised clinical study evaluating the effectiveness and harms of systemic antibiotics administered in children who present with an odontogenic abscess in the primary dentition.

CLINICAL RELEVANCE

There is no clinical evidence to support nor to refute the use of antibiotics in children who present with an odontogenic abscess in the primary dentition without signs of local spread or systemic involvement. Given this lack of scientific evidence, the use of antibiotics cannot be recommended in these children. Well-designed clinical trials are indicated to fully understand the impact and necessity of antibiotics in these situations.

Fusobacterium nucleatum Secretes Outer Membrane Vesicles and Promotes Intestinal Inflammation

Multiple studies have implicated microbes in the development of inflammation, but the mechanisms remain unknown. Bacteria in the genus Fusobacterium have been identified in the intestinal mucosa of patients with digestive diseases; thus, we hypothesized that Fusobacterium nucleatum promotes intestinal inflammation. The addition of >50 kDa F. nucleatum conditioned media, which contain outer membrane vesicles (OMVs), to colonic epithelial cells stimulated secretion of the proinflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor (TNF). In addition, purified F. nucleatum OMVs, but not compounds <50 kDa, stimulated IL-8 and TNF production; which was decreased by pharmacological inhibition of Toll-like receptor 4 (TLR4). These effects were linked to downstream effectors p-ERK, p-CREB, and NF-κB. F. nucleatum >50-kDa compounds also stimulated TNF secretion, p-ERK, p-CREB, and NF-κB activation in human colonoid monolayers. In mice harboring a human microbiota, pretreatment with antibiotics and a single oral gavage of F. nucleatum resulted in inflammation. Compared to mice receiving vehicle control, mice treated with F. nucleatum showed disruption of the colonic architecture, with increased immune cell infiltration and depleted mucus layers. Analysis of mucosal gene expression revealed increased levels of proinflammatory cytokines (KC, TNF, IL-6, IFN-γ, and MCP-1) at day 3 and day 5 in F. nucleatum-treated mice compared to controls. These proinflammatory effects were absent in mice who received F. nucleatum without pretreatment with antibiotics, suggesting that an intact microbiome is protective against F. nucleatum-mediated immune responses. These data provide evidence that F. nucleatum promotes proinflammatory signaling cascades in the context of a depleted intestinal microbiome.IMPORTANCE Several studies have identified an increased abundance of Fusobacterium in the intestinal tracts of patients with colon cancer, liver cirrhosis, primary sclerosing cholangitis, gastroesophageal reflux disease, HIV infection, and alcoholism. However, the direct mechanism(s) of action of Fusobacterium on pathophysiological within the gastrointestinal tract is unclear. These studies have identified that F. nucleatum subsp. polymorphum releases outer membrane vesicles which activate TLR4 and NF-κB to stimulate proinflammatory signals in vitro Using mice harboring a human microbiome, we demonstrate that F. nucleatum can promote inflammation, an effect which required antibiotic-mediated alterations in the gut microbiome. Collectively, these results suggest a mechanism by which F. nucleatum may contribute to intestinal inflammation.

Some neck swellings are serious; a case of Lemierre's Syndrome

Lemierre's syndrome also termed post-anginal septicemia, is a disease characterized by internal jugular septic thrombophlebitis leading to Fusobacterium septicemia with multiple metastatic foci following an oropharyngeal infection. Diagnosis and management is challenging and can result in fatal consequences due to potential multisystem involvement and multiple complications. We describe here a case of Lemierre's syndrome with multifocal pneumonia, acute renal failure and protracted course of illness over forty days with successful recovery. A brief overview of literature is also presented.