[Skin abscess caused by Actinomyces radingae]

We report a 77-year-old man with a skin abscess caused by Actinomyces radingae. Targeted antibiotic therapy with amoxicillin/clavulanic acid for 6 weeks resulted in clearing of the infection. A. radingae is a rare pathogenic agent of skin and soft tissue infections. As with other Actinomyces infections, the early identification of the pathogen and specific antibiotic therapy is crucial for successful resolution of the infection because of the chronic course and the long treatment time needed. Usually, A. radingae is sensitive to β‑lactam antibiotics.

Actinomycosis presenting as a nasopharyngeal mass: A case report

Actinomycetes are predominantly pathogenic bacteria that lack aerial hyphae and do not form spores. They are generally anaerobic or facultative anaerobic Gram-positive bacteria, belonging to the prokaryotic group. Actinomycetes are widely distributed in nature, similar to other bacteria, and are mostly saprophytic, with a few being parasitic. They are named as such due to their colony's radial form. The symptoms and signs of actinomycosis are atypical and rarely manifest in the nasopharynx. Consequently, it can be challenging to distinguish actinomycosis from nasopharyngeal carcinoma, making diagnosis difficult. Histopathology is usually relied upon for diagnosis, although culture may pose challenges. Fortunately, actinomycetes are highly sensitive to penicillin. Therefore, timely treatment with high doses of penicillin is crucial for successful recovery. In this case study, we present the details of a 53-year-old female patient with no history of mucosal damage or tooth decay but with a previous partial thyroidectomy. The patient experienced recurring neck pain accompanied by progressive limitation of neck movement. Nasopharyngoscopy revealed the presence of a smooth-surfaced mass. Subsequent biopsy, clinical imaging, microbiological analysis, and histological findings confirmed the diagnosis of actinomycosis.Following a comprehensive treatment plan involving a combination of penicillin and doxycycline for a duration of two months, the disease was successfully eradicated.

Appendecular actinomycosis: A case series of 14 patients

OBJECTIVE

This study aims to assess the clinical, radiological, and histological characteristics of Actinomyces infection identified in appendectomy specimens.

MATERIAL AND METHODS

Between January 2013 and November 2023, 5834 patients underwent appendectomy in our clinic, and their pathology reports were retrospectively reviewed.

RESULTS

Actinomyces appendicites were reported in 14 specimens (0.23%). It was determined that appendectomy was performed in only 10 patients (71.4%), ileocecal resection was performed in two patients (14.2%) and right hemicolectomy in two patients (14.2%). The operations on five patients were performed by laparoscopy, and the operations on the other nine patients were performed by open surgery. Laparoscopy was started in three patients and converted to open surgery due to suspicion of an ileocecal mass and cecal perforation. It was found that the white blood cell count of three patients was within the normal range of reference (8-9.77mg/dL); leukocytosis was detected in other patients (10.2-18.7mg/dL). C-reactive protein was normal in one patient and high in the rest of the patients. While the first-hour erythrocyte sedimentation rate was normal in five patients, it was found to be high in the other patients. Findings on radiological imaging were reported as acute appendicitis, appendicular plastron, and ileocecal mass. As a result of the pathology findings, the patients were given oral penicillin or semi-synthetic penicillin derivatives during one month.

CONCLUSION

Ileocecal and appendecular actinomycosis are rare, and preoperative diagnosis is difficult. A definitive diagnosis is usually made after a histopathological examination. After surgery, long-term antimicrobial treatment of the patient is possible with penicillin.

Successful Antimicrobial Therapy of Esophageal Stenosis Because of Actinomycosis

Esophageal stenosis can cause vomiting or dysphagia in children and is commonly treated with esophageal balloon dilation. However, surgery may be required if the stenosis does not respond to dilation. Although esophageal actinomycosis can cause severe esophageal strictures and be refractory to balloon dilation, it has been reported to respond effectively to antimicrobial therapy in adults. However, the course of the disease and appropriate treatment strategies in children are not well understood. We present a case of a previously healthy 2-year-old boy diagnosed with esophageal stenosis because of actinomycosis. The patient was treated with intravenous penicillin G, followed by oral amoxicillin for 8 weeks and 6 months, respectively. After completion of the antimicrobial treatment, the patient showed improvement in symptoms and endoscopic findings. At the 1-year follow-up, the patient showed consistent weight gain and normal growth without further intervention. This case highlights the importance of considering esophageal actinomycosis as a potential cause of esophageal stenosis in children and the potential effectiveness of antimicrobial therapy in avoiding surgical intervention.

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.

Mediastinal Mass, Cancer, or Infection, Atypical Paraesophageal Actinomycosis Infection, Clinical and Surgical Approach

Actinomyces israelii (AI) is a Gram-positive, rod-shaped bacterium that lives commensally on and within humans as a typical colonizer within the gastrointestinal tract, including the mouth. As an opportunistic pathogen, infection often results from tissue injury or breach of the mucosal barrier (ie, during various dental or GI procedures, aspiration, or specific pathologies such as diverticulitis). Symptoms generally present slowly as a non-tender, indurated mass that evolves into multiple abscesses, fistulae, or draining sinus tracts without regard for anatomical barriers, including fascial planes or lymphatic drainage. However, it may also present as an acute suppurative infection with pain and rapid progression to abscess formation.

Actinomycotic osteomyelitis of the maxilla in a female patient: A rare case report with the review of the literature

Actinomycotic osteomyelitis is a rare chronic suppurative, granulomatous, fibrosing saprophytic infection. It is an endogenous infection caused by the Actinomyces species, which are part of the normal oral microflora. There is a male predilection for this type of infection, with the male to female ratio of 4:1. Though the etiopathogenesis of the infection is unclear, it is mostly attributed to the disruption of the normal oral microflora and the invasion of the microorganism into deeper tissues through a break in the mucosal barrier due to damage from trauma, extraction or previous injury. The portal of entry can be through the pulpal, periodontal or mucosal route, causing the purulent and necrotic infection of soft tissue, bone, or both. The diagnosis is usually considered when there is a persistent infection without the presence of regional lymphadenopathy and is usually confirmed through the histopathological depiction of the bacterial colonies - 'ray fungus' - as obtaining the positive culture of the causative microorganisms is difficult and is reported to be effective in less than 50%. Patients with such infections are managed with surgical debridement, followed by antibiotic therapy for a longer time period. Recent advances have been emphasized for an early diagnosis and a better prognosis of the therapy. Therefore, this paper aimed to present a rare case of actinomycotic osteomyelitis of the maxilla in a 45-year-old female patient, and also to review the literature on this rare infection.

Regular resident becomes aggressive enemy: Diagnosed on cytology

Actinomycosis, an oral cavity commensal, causes cervicofacial infection in patients associated with an immunosuppression state and local mucosal injuries. Bone involvement by this commensal is rare. In the present case, we report a case of left peri mandibular soft tissue, soft to firm, tender swelling in a 39-year-old immunocompetent male diagnosed as Actinomycosis infection on fine needle aspiration cytology (FNAC) and cell block preparation.

Brain abscess caused by Actinomyces turicensis in a non-immunocompromised adult patient: a case report and systematic review of the literature

BACKGROUND

Actinomyces turicensis is rarely responsible of clinically relevant infections in human. Infection is often misdiagnosed as malignancy, tuberculosis, or nocardiosis, therefore delaying the correct identification and treatment. Here we report a case of a 55-year-old immunocompetent adult with brain abscess caused by A. turicensis. A systematic review of A. turicensis infections was performed.

METHODS

A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The databases MEDLINE, Embase, Web of Science, CINAHL, Clinicaltrials.gov and Canadian Agency for Drugs and Technology in Health (CADTH) were searched for all relevant literature.

RESULTS

Search identified 47 eligible records, for a total of 67 patients. A. turicensis infection was most frequently reported in the anogenital area (n = 21), causing acute bacterial skin and skin structure infections (ABSSSI) including Fournier's gangrene (n = 12), pulmonary infections (n = 8), gynecological infections (n = 6), cervicofacial district infections (n = 5), intrabdominal or breast infections (n = 8), urinary tract infections (n = 3), vertebral column infections (n = 2) central nervous system infections (n = 2), endocarditis (n = 1). Infections were mostly presenting as abscesses (n = 36), with or without concomitant bacteremia (n = 7). Fever and local signs of inflammation were present in over 60% of the cases. Treatment usually involved surgical drainage followed by antibiotic therapy (n = 51). Antimicrobial treatments most frequently included amoxicillin (+clavulanate), ampicillin/sulbactam, metronidazole or cephalosporins. Eighty-nine percent of the patients underwent a full recovery. Two fatal cases were reported.

CONCLUSIONS

To the best of our knowledge, we hereby present the first case of a brain abscess caused by A. turicensis and P. mirabilis. Brain involvement by A. turicensis is rare and may result from hematogenous spread or by dissemination of a contiguous infection. The infection might be difficult to diagnose and therefore treatment may be delayed. Nevertheless, the pathogen is often readily treatable. Diagnosis of actinomycosis is challenging and requires prompt microbiological identification. Surgical excision and drainage and antibiotic treatment usually allow for full recovery.

Actinomycosis with Fusobacterium empyema

Actinomyces, are gram-positive, non-spore forming anaerobic or microaerophilic species. Empyema due to actinomycosis is relatively rare and can be difficult to diagnose as the presenting symptoms may be indolent and the micro-organism may be difficult to culture. This case report describes a patient presenting with dyspnoea, weight loss and lethargy. The chest radiograph, CT and thoracic ultrasound revealed a left-sided pleural effusion. A chest drain was inserted under ultrasound guidance. The pleural fluid was macroscopically consistent with pus and microbiology showed growth of gram-positive bacilli, Actinomyces meyeri as well as the Fusobacterium species. The patient was treated with a drainage of the pleural fluid, a prolonged course of antibiotics and made a good recovery. The awareness that the Actinomyces species and the Fusobacterium species through their synergistic interaction may cause empyema, may lead to a timely diagnosis and treatment.

The role of Actinomyces spp. and related organisms in cervicofacial infections: Pathomechanism, diagnosis and therapeutic aspects

Members of the Actinomyces genus and Actinomyces-like organisms (ALOs; namely Actinotignum, Arcanobacterium, Schaalia and Varibaculum) are Gram-positive, non-spore-forming rods that are commensal members of the human oral cavity, gastrointestinal tract, female genital tract and skin microbiota. Cervicofacial actinomycosis or "lumpy jaw syndrome" - the chronic, suppurative granulomatous disease caused by Actinomyces spp. And ALOs - is characterized by an initially slow and unspecific disease-presentation, which often mimics other pathologies, followed by the formation of painful abscesses and severe tissue destruction. Actinomycosis has been described as a rare disease, however, reliable epidemiological data are lacking. In addition, there is increasing awareness regarding the role of Actinomyces spp. in the development of osteoradionecrosis and medication-related osteonecrosis of the jaw. The aim of this narrative review is to succinctly summarize the current advances regarding the microbiological, clinical, diagnostic and therapeutic aspects of cervicofacial actinomycosis, in addition to the roles of Actinomyces species and ALOs as members of the oral microbiota and in dental biofilm, in other dental infections (caries, root canal infection, periapical infection, periodontitis) and osteonecrosis of the jaw, in the context of recent taxonomic changes affecting the genus. Our paper aims to be a blueprint for dentists, other physicians, microbiologists and researchers regarding the multifaceted field of cervicofacial actinomycosis.

Unmasked immune reconstitution inflammatory syndrome towards B-cell non-Hodgkin lymphoma during treatment of esophageal actinomycosis in a patient with advanced HIV: a case report

BACKGROUND

Actinomycosis is an unusual chronic bacterial infection, even rarer in people living with HIV. It is not considered an AIDS-defining disease. However, the role in co-presentation or overlap with other opportunistic conditions of advanced HIV is unknown.

CASE PRESENTATION

A 49-year-old Peruvian male presented with a 4-month history of dysphagia, odynophagia, hyporexia and wasting. He underwent an upper digestive endoscopy, in which ulcers with a necrotic center were observed, therefore, the initial diagnostic assumption was esophageal cancer. Subsequent pathology report excluded neoplasms and confirmed the diagnosis of actinomycosis. Serology for human immunodeficiency virus was requested, yielding a positive result. Antimicrobial treatment with amoxicillin and antiretroviral therapy were indicated, with slow clinical improvement. After 4 months, epigastric discomfort presented, for which a new upper digestive endoscopy was performed, revealing a deep gastric ulcer, which was compatible with diffuse large B-cell non-Hodgkin lymphoma.

CONCLUSION

Esophageal actinomycosis in people living with HIV is very rare. We suggest HIV-associated immunosuppression is not enough to allow for actinomycosis to develop, and masked underlying entities should be sought. The existence of such entities in people living with HIV should raise awareness of the possibility of unmasked immune reconstitution inflammatory syndrome once treatment has started.

Incidental histopathological diagnosis of tonsilar actinomycosis: A report of four cases

Actinomycosis of the tonsils is uncommon even though the causative organisms are normal commensal of the oropharyngeal tract that may colonise the tonsillar crypts with resultant infection in apparently healthy individuals. Diagnosis is often incidental in tonsillectomy specimens sent to the pathology laboratory for varied diseases. This is a 10-year study of tonsillectomy specimens diagnosed with actinomycosis. Specimens were formalin-fixed and paraffin processed and stained with haematoxylin and eosin, gromott methenamine silver and periodic acid-Schiff. Four cases of tonsillar actinomycosis were diagnosed from a total of 772 tonsillectomy specimens. Histologically, characteristic oeosinophilic granules with peripheral radial protuberances surrounded by microabscesses were seen. Tonsillar actinomycosis is often an incidental diagnosis; however, a high index of suspicion should be entertained in patients with recurrent tonsillitis and/or tonsillar hypertrophy of unknown cause.

Persistent Multispecies Actinomyces Mastitis Treated With Repeated Aspiration and Long-Term Oral Antibiotics

Actinomycosis is an infection characterized by abscess formation, draining sinuses, and tissue fibrosis. The causative bacterium is a Gram-positive facultative anaerobe from the genus Actinomyces. Infections classically affect the cervicofacial, thoracic, or pelvic region and often require prolonged antibiotic therapy. Actinomycosis of the breast is a rare condition that may present as a recurrent breast abscess. We present a 33-year-old female with a recurrent breast abscess which grew A. radingae and A. israeli on aspirated fluid cultures. Treatment with surgical aspiration and a 6-week course of oral amoxicillin/clavulanic acid 875 mg twice daily resulted in clinical improvement. Our case demonstrates how recurrent breast abscesses caused by Actinomyces can be difficult to manage. Long-term antibiotic therapy with surgical aspiration and regular follow-up offer the best chance of clinical resolution.

Pseudo tumor pelvic actinomycosis revealed by colonic obstruction with hydronephrosis: Can extensive surgery be avoided? A case report

Pelvic actinomycosis with an intrauterine device accounts for approximately 3% of all actinomycoses. It is a chronic infectious disease characterized by infiltrative, suppurative, or granulomatous inflammation, sinus fistula formation, and extensive fibrosis, and caused by filamentous, gram-positive, anaerobic bacteria called Actinomyces israelii. The slow and silent progression favors pseudo tumor pelvic extension and exposes the patient to acute life-threatening complications, namely colonic occlusion with hydronephrosis. Preoperative diagnosis is often difficult due to the absence of specific symptomatology and pathognomonic radiological signs simulating pelvic cancer. We discuss the case of a 67-year-old woman who complained of pelvic pain, constipation, and weight loss for 4 months, and who presented to the emergency department with a picture of colonic obstruction and a biological inflammatory syndrome. The computed tomography scan revealed a suspicious heterogeneous pelvic mass infiltrating the uterus with an intrauterine device, the sigmoid with extensive upstream colonic distension, and right hydronephrosis. The patient underwent emergency surgery with segmental colonic resection and temporary colostomy, followed by antibiotic therapy. The favorable clinical and radiological evolution under prolonged antibiotic therapy with the almost total disappearance of the pelvic pseudo tumor infiltration confirms the diagnosis of pelvic actinomycosis and thus makes it possible to avoid an extensive and mutilating surgery with important morbidity.

Pediatric appendicular actinomycosis: a case report and literature review

BACKGROUND

Actinomycosis (ACM) is a rare infectious granulomatous disease caused by Actinomyces, a Grampositive, filamentous, saprophytic bacteria. There are several types of pediatric ACM, such as orocervicofacial (55%) and other less common forms: abdominopelvic and thoracic. We report a case of a 16-year-old who presented with abdominal ACM in the setting of acute appendicitis. After the case report, we provide a short literature review of pediatric appendicular ACM cases published.

CASE

A 16-year-old boy presented with nausea, vomiting, pain in the upper part of the abdomen and fever (37.5°C) lasting for 24 hours. On physical examination, the patient`s epigastrium and lower right abdominal quadrant were tender. White cell count and C-reactive protein (CRP) were elevated at 16,300/μL and 48.6mg/L respectively. Ultrasonography (US) showed appendicolith and edema of the appendiceal wall, focally with stratification as well as periappendiceal inflammation. The patient underwent a classic appendectomy, and the postoperative course was without complications. Histopathological analysis showed diffuse transmural neutrophilic infiltration of the appendix, focally with areas of necrosis and abscesses. There were numerous brightly eosinophilic colonies made of filamentous bacteria, located predominantly in submucosa. Special stains Grocott-Gomori`s Methenamine Silver and Gram were positive and a diagnosis of ACM was made.

CONCLUSIONS

Although appendicitis is very common in the general population, appendicitis associated with ACM is very rare, accounting for 0.02% - 0.06%, especially in the pediatric population. Diagnosis can be very challenging because they usually present with non-specific symptoms, and can form masses that mimic malignancies. Although rare, clinicians and pathologists should be aware of this entity. Satisfactory results and complete cure are achieved with adequate antibiotic therapy and surgery. In most cases, if there are no associated diseases, early and accurate diagnosis ensure an excellent prognosis.

Actinomycotic Sinomaxillary Infection in a COVID-19 Patient: A Case Report and Review of the Literature

Individuals with COVID-19 are prone to a variety of infections due to immune dysregulation. The present report presents a case of actinomycotic infection in the maxillary bone and sinus region in a patient with a history of COVID-19. This case report highlights the importance of considering bacterial infections including actinomycosis when encountering destructive lesions resembling more prevalent fungal infections due to different therapeutic medication protocols. In addition, a literature review of the existing reports of similar post-COVID-19 actinomycotic infection is presented.

Urinary Actinomyces infection with a urachal remnant

Urinary Gram staining is helpful in patients with complicated urinary retention, such as prolonged urinary retention and coexisting ureteral retention disease. If gram-positive rods are observed on urine Gram staining in a patient with urinary tract infection, an anaerobic culture of the urine may be helpful for early diagnosis and treatment of Actinomyces infection.

[Clinical presentation and short-term treatment of pulmonary actinomycosis]

Actinomycosis is an uncommon disease caused by Actinomyces, a commensal of the oropharyngeal, digestive, and genital tract. Commonly, it manifests as cervicofacial infection and is often related to poor oral health, smoking, chronic alcoholism or immune deficiency. Pulmonary actinomycosis is a rare disease, characterized by unspecific clinical, biological, and radiological manifestations that may be confused with other diseases. It should always be considered in patients suspected of having tuberculosis, lung abscess or pulmonary neoplasia. We describe a case of pulmonary actinomycosis treated successfully with short-term antibiotic therapy of three months, with a short review of the literature.