Hepatic Actinomycosis

Granulomatous liver diseases

A granuloma is a discrete collection of activated macrophages and other inflammatory cells. Hepatic granulomas can be a manifestation of localized liver disease or be a part of a systemic process, usually infectious or autoimmune. A liver biopsy is required for the detection and evaluation of granulomatous liver diseases. The prevalence of granulomas on liver biopsy varies from 1% to 15%. They may be an incidental finding in an asymptomatic individual, or they may represent granulomatous hepatitis with potential to progress to liver failure, or in chronic disease, to cirrhosis. This review focuses on pathogenesis, histological features of granulomatous liver diseases, and most common etiologies, knowledge that is essential for timely diagnosis and intervention.

Case report of actinomycotic liver abscess following COVID-19 infection

Introduction and importance

In the last few years, the novel coronavirus, named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), generated a large health care problem worldwide. Due to the immunomodulation effect of the virus the number of opportunistic infections has also increased.

Case presentation

We present the unique case of a patient who was diagnosed with an actinomycotic liver abscess after coronavirus disease 2019 (COVID-19) without the presence of any chronic disease or mucosal injury.

Clinical discussion

According to the results of the computer tomography (CT scan) and the liver biopsy, the patient was treated with antibiotics and ultrasound-guided drainage.

Conclusion

With this case we would like to draw attention to the possible occurrence of liver abscesses caused by an opportunistic pathogen following COVID-19.

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SARS-CoV-2 is an acute respiratory infection, that could result immune dysregulation.

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Immunocompromised patients have a higher risk for opportunistic infections (e.g. actinomycosis).

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Actinomycosis could result in liver abscess, which is a rare type of the liver abscesses.

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Actinomycosis followed by COVID-19 infection disease could be a post-COVID syndrome.

Early prediction of incident liver disease using conventional risk factors and gut-microbiome-augmented gradient boosting

The gut microbiome has shown promise as a predictive biomarker for various diseases. However, the potential of gut microbiota for prospective risk prediction of liver disease has not been assessed. Here, we utilized shallow shotgun metagenomic sequencing of a large population-based cohort (N > 7,000) with ∼15 years of follow-up in combination with machine learning to investigate the predictive capacity of gut microbial predictors individually and in conjunction with conventional risk factors for incident liver disease. Separately, conventional and microbial factors showed comparable predictive capacity. However, microbiome augmentation of conventional risk factors using machine learning significantly improved the performance. Similarly, disease-free survival analysis showed significantly improved stratification using microbiome-augmented models. Investigation of predictive microbial signatures revealed previously unknown taxa for liver disease, as well as those previously associated with hepatic function and disease. This study supports the potential clinical validity of gut metagenomic sequencing to complement conventional risk factors for prediction of liver diseases.

Actinomyces in Forensic Practice

ABSTRACT

A 19-year-old woman in septic shock with recent computed tomography findings of a loculated hepatic abscess was transferred to an intensive care unit where she went into asystolic cardiac arrest. After resuscitation, surgical exploration revealed a purulent pericardial effusion with tamponade and a liver abscess. Microbiological analyses from both sites were negative. Shortly after surgical exploration, she developed multiorgan failure and died. At autopsy, pus was observed both within the pericardial cavity and around the left lobe of the liver. Green "sulfur granules" suggestive of infection with Actinomyces spp. were able to be extruded from the liver during the postmortem examination and cultures returned positive for Actinomyces israelii. This case is a rare example of primary hepatic actinomycosis infection that resulted in the death of a young woman. Nonspecific clinical manifestations may delay diagnosis; however, the finding of "sulfur granules" in areas of abscess formation at autopsy should be taken as an indication of possible underlying Actinomyces infection.

A systematic review of case reports of hepatic actinomycosis

Background

Hepatic Actinomycosis (HA) is one of the infections that causes disorders in patients when diagnosed untimely and inappropriately.

Methods

Case reports on HA in patients published between 2000 and April 2020 were gathered by carrying out a structured search through PubMed/Medline.

Results

Through a survey of the Medline database, 130 studies were identified and then, 64 cases with HA were included in the final analysis. Asia had the largest share of cases with 37.5% (24 reports), followed by Europe and the Americas. Affected patients were predominantly males (64%) and the overall mortality rate was 1% with only one male patient in his 50 s dying. Nearly all patients (92%) were immunocompetent. However, in four patients, the use of immunosuppressive medication led to depression of the immune system. Most of the patients (80%) experienced complications. In terms of the complications, the most frequent ones were previous history of abdominal surgery (32%) and foreign bodies in the abdominopelvic region (20%). Actinomyces israelii was the most common pathogen isolated from patients. Abdominal pain (66%), fever (62%), weight loss (48%), night sweat, malaise, and anorexia (14%) over about 3.1 months were the most frequently reported clinical symptoms. Extension to one or more surrounding organs was evident in 18 patients (28%). Histopathologic examination confirmed infection in 67% of the patients and samples obtained from liver puncture biopsy (32%) were most frequently used in diagnosis. Surgery or puncture drainage + anti-infection was the most common method to treat patients and penicillin, Amoxicillin, Doxycycline, and ampicillin were the most frequently used drugs to control infection.

Conclusion

HA should be considered in patients with a subacute or chronic inflammatory process of the liver. With accurate and timely diagnosis of infection, extensive surgery can be prevented.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01821-5.

Oral, Cloacal, and Hemipenal Actinomycosis in Captive Ball Pythons (Python regius)

Ball pythons (Python regius) are one of the most commonly kept and bred reptiles in captivity. In a large ball python breeding colony, a unique syndrome characterized by granulomatous inflammation of the cloaca and hemipenes (phalli) was observed in 140 of 481 (29.1%) breeding males, but only one of 1,446 breeding females. Lesions were absent in virgin males (n = 201) and virgin females (n = 293). On postmortem examination (n = 13, 12 males, 1 female), numerous well-defined mucosal and submucosal granulomas were present in the hemipenes (males) and cloaca (males and female). Extension into the coelomic cavity and liver was noted in a subset of these animals. An additional small subset of breeder animals (6/2027; 0.3%) presented with oral and mandibular swellings. Postmortem examination (n = 4, all female) showed oral lesions histologically indistinguishable from the cloacal/hemipenal lesions. Aerobic bacterial culture of a hepatic granuloma of one snake resulted in the isolation of filamentous, Gram-positive bacilli; amplification, and sequencing of the 16S rRNA gene and subsequent phylogenetic analysis of the isolate identified the bacterium as a novel species of Actinomyces. Screening of cloacal and oral granulomas using a specific, heminested 16S rRNA PCR assay confirmed the presence of the agent in all 17 snakes, as well as in cloacal swabs taken at the time of necropsy in 11/13 snakes. The Actinomyces sp. was also identified by PCR of cloacal swabs of unaffected snakes (n = 94) from the affected colony and two unrelated, grossly unaffected breeding colonies. In the affected colony, 65.5% of breeding animals (n = 23) but only 11.9% of virgin animals (n = 42) tested PCR positive, with breeding status being a significant predictor of bacterium presence (P < 0.00001). This study characterizes a granulomatous mucosal disease syndrome of breeding male ball pythons associated with a novel Actinomyces. In stark contrast to male snakes, the presence of the bacterium in both breeding and virgin females was very rarely associated with clinical disease. Though additional studies are necessary, these data suggest a role for the novel bacterium in the disease process, a predilection for clinical disease in male snakes, and the potential for sexual transmission of the disease.

Hepatic Actinomycosis in a Patient With Retained Common Bile Duct Stent

Primary hepatic actinomycosis is rare, with less than 100 cases reported in English literature. Most of these cases are cryptogenic. We describe a 35-year-old woman who presented with a retained common bile duct stent for 6 years and found to have a hepatic mass with altered perfusion and enhancement, and minimal degree of washout on enhanced cross-sectional imaging. Fine-needle aspiration revealed presence of filamentous bacteria morphologically consistent with Actinomyces species. This report is a demonstration of a rare instance in which a retained biliary stent led to primary hepatic actinomycosis.