Mixed Actinomyces israelii and Aggregatibacter actinomycetemcomitans infection causing empyema necessitatis and multiple skin abscesses in an immunocompetent patient

Empyema Caused by Mixed Infection with Streptococcus intermedius and Streptococcus constellatus in a Patient with Previous Surgery for Oral Carcinoma: A Case Report

Background

The incidence of community-acquired empyema caused by the Streptococcus anginosus group (SAG) has been on the rise in the 2020s. To the best of our knowledge, while empyema caused individually by either strain has been reported, there are no reports on empyema caused by concurrent infection with these two strains. Here, we report for the first time empyema caused by concurrent infection with Streptococcus intermedius and Streptococcus constellatus (both SAG species) in a postoperative patient who had been treated for floor of the mouth carcinoma.

Case Presentation

A 61-year-old male patient who had undergone surgical treatment for floor of the mouth carcinoma 2 year earlier suddenly presented with left-sided chest pain. Chest computed tomography (CT) revealed encapsulated pleural effusion on the left side, which was diagnosed as empyema. Metagenomic next-generation sequencing(mNGS) of the pleural fluid sample indicated mixed infection caused by Streptococcus intermedius and Streptococcus constellatus. The patient's condition improved about 5 weeks after treatment with thoracic fluid drainage and cephalosporin antibiotics.

Conclusion

This case highlights the possibility of concurrent infection with two SAG strains in patients with empyema. Currently, it is unclear whether there is a definitive relationship between a surgical history of carcinoma of the floor of the mouth and empyema caused by infection with SAG strains. This case could, perhaps, serve as a reference for future related research on the topic.

Causes, management and treatment of empyema

Infections in the pleural space have been a significant problem since ancient times and continue to be so today, with an incidence of 52% in patients with post-pneumonia syndrome. Typically, these effusions require a combination of medical treatment and surgical drainage, including debridement and decortication. Researchers have been studying the use of intrapleural fibrinolytics in managing complicated pleural effusions and empyema, but there is still ongoing debate and controversy among clinicians. Empyema has traditionally been considered a surgical disease, with antibiotics and chest tube drainage being the initial treatment modality. However, with advances in minimally invasive procedures such as video-assisted thoracoscopic surgery (VATS) and the use of intrapleural fibrinolytics, medical management is now preferred over surgery for many cases of empyema. Surgical options, such as open thoracotomy, are reserved for patients who fail conservative management and have complicated or chronic empyema. This comprehensive review aims to explore the evolution of various management strategies for pleural space infections from ancient times to the present day and how the shift from treating empyema as a surgical condition to a medical disease continues.

Case Report: Pericardial Actinomycosis in a 79-Year-Old Man with Poor Dental Hygiene

Actinomycosis is an uncommon infection caused by Actinomyces species, and the diagnosis is often challenging owing to low prevalence and diverse clinical manifestations. Pericardial involvement of actinomycosis is particularly rare. Here, we present a case of a 79-year-old man who initially complained of exertional dyspnea, orthopnea, and decreased urine amount. There was no fever, chest pain, or productive cough. Physical examination was remarkable for decreased breath sounds at the left lower lung field. Poor dental hygiene and a firm, well-defined mass without discharge over the hard palate were noted. Echocardiography revealed reduced ejection fraction of the left ventricle, global hypokinesia, and thickened pericardium (> 5 mm) with a small amount of pericardial effusion. On admission, the patient underwent diagnostic thoracentesis, and the results suggested an exudate. However, bacterial and fungal cultures were all negative. There was no malignant cell by cytology. Computed tomography revealed contrast-enhanced pericardial nodular masses. Video-assisted thoracoscopic pericardial biopsy was performed. Histopathology confirmed actinomycosis with chronic abscess formation, and a tissue culture yielded Aggregatibacter actinomycetemcomitans. The symptoms resolved with administration of clindamycin for 6 months. This case highlights the challenge in the diagnosis of cardiac actinomycosis, the potential role of concomitant microorganisms as diagnostic clues, and the favorable clinical response achieved with appropriate antibiotic treatment.

Pulmonary Aggregatibacter actinomycetemcomitans infection masquerades as malignancy in a patient with periodontitis

A 49-year-old man with a 37.5 pack-year smoking history presented with a suspected neoplasm of the right lung following the discovery of a metabolically active mass on positron emission tomography-CT imaging. The patient, who demonstrated poor oral hygiene, had a history of irregular problem-oriented dental visitation. Having excluded malignancy through histologic investigations, Aggregatibacter actinomycetemcomitans-a well-established periodontal pathogen-was subsequently cultured from his pulmonary aspirate. The patient was therefore managed with systemic antimicrobials and adjunctive dental extractions to eliminate the likely source of infection, whereafter the mass resolved without complication. This case corroborates previous reports of extraoral isolation of A. actinomycetemcomitans, which may mimic cancer clinically and radiographically. While a definitive causative link between untreated periodontitis and systemic infection remains to be elucidated, such cases present a compelling argument in favour of promoting oral health to prevent systemic disease.

Aggregatibacter actinomycetemcomitans Causing Empyema Necessitans and Pyomyositis in an Immunocompetent Patient

Empyema necessitans is a relatively rare clinical entity in which the empyema extends through the parietal pleura into the adjacent soft tissue and musculature of the chest wall. It usually occurs due to inadequate treatment of a primary lung infection. Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans is a facultative anaerobic gram-negative coccobacillus that is part of the normal oral flora. Infections due to this organism usually result from aspiration in conjunction with dental disease or trauma to the oral mucosa resulting in pneumonia or empyema. It often coinfects with Actinomyces and is known to cause empyema necessitans. Cases of monomicrobial empyema necessitans due to Aggregatibacter actinomycetemcomitans in adults have rarely been reported with four such publications found on review of the literature. We present a patient with severe periodontitis who developed empyema necessitans due to Aggregatibacter actinomycetemcomitans likely from aspiration complicated by pyomyositis of the right triceps brachii and a left posterior thigh abscess.

Diaphragmatic mass caused by Aggregatibacter actinomycetemcomitams

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actinomycetemcomitans causes periodontitis, endocarditis and soft tissue abscess.

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First case of A. actinomycetemcomitans diaphragmatic infection without lung injury.

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Hematogenous spread of A. actinomycetemcomitans from oral mucosa to thorax.

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Color is not necessary for the figure.

A 52-year-old man was evaluated in our outpatient facility because of a thoracic mass for one month. A needle biopsy of the chest mass was performed and microbiological culture showed growth of Aggregatibacter actinomycetemcomitans. Three months after starting antimicrobial therapy, acute phase reactants normalized, and chest CT showed a progressive reduction in the size of the phlegmon. To our knowledge, we report the first case of A. actinomycetemcomitans diaphragmatic and chest wall infection without pulmonary involvement. This supports the theory of hematogenous spread of the germ from oral mucosa to produce thoracic lesions.

MALDI-TOF vs. VITEK 2 for identification of Aggregatibacter actinomycetemcomitans chest wall abscess

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A 56-year-old male patient has a chest wall abscess with intercostal muscle involvement.

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Aggregatibacter actinomycetemcomitans was misidentified as Pasturella canis or Pasturella multocida by the automated VITEK 2 system.

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The study re-enforces the importance of an accurate and rapid diagnosis to assist patient management.

Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) is a facultative anaerobic Gram-negative coccobacillus that is associated with a variety of diseases in humans. In the present study, the isolate finally identified as A. actinomycetemcomitans by MALDI-TOF was misidentified as Pasturella canis or Pasturella multocida by the automated VITEK 2 system. The findings re-enforce the importance of an accurate and rapid diagnosis to assist patient management.