Disseminated actinomycosis due to Actinomyces meyeri and Actinobacillus actinomycetemcomitans

Actinomyces meyeri-induced brain abscess in pregnancy: a case report

BACKGROUND

Brain abscesses can occur when suppurative, bacterial or protozoan infections spread to the brain. Here, we report a rare case of Actinomyces meyeri-induced brain abscess in a pregnant woman.

CASE PRESENTATION

We present the case of a 38-years-old primipara admitted to the emergency department at our hospital with a 4-day history of fever and vomiting. The symptoms worsened rapidly during the 8 h prior to admission, and the patient experienced a sudden loss of consciousness 4 h before arrival to the unit. Brain magnetic resonance imaging revealed abnormal signals in the right parietal-temporal lobe, suggesting the possibility of abscess rupture into the ventricle and sulcus. Right lateral ventricle compression and midline structure deviation to the left were noted. A right temporal-occipital mass with midline shift was detected. Emergency procedures were promptly performed, including craniotomy, removal of the right temporal-occipital mass, decompressive craniectomy, implantation of an intracranial pressure monitoring device, and external ventricular drainage. Cerebrospinal fluid culture indicated infection with Actinomyces meyeri. After administration of antibiotics, including linezolid and meropenem injections, along with treatments to decrease intracranial pressure, the patient's vital signs stabilized. However, the patient developed hydrocephalus, requiring placement of a hydrocephalus shunt several months later. Throughout this period, the patient remained in a coma vigil state, and labor was induced for the fetus.

CONCLUSIONS

Although the patient did not present with any apparent predisposing causes for brain abscess, a scout view of CT revealed dental caries. In addition, the occurrence of the brain abscess may have been influenced by the hormonal changes during pregnancy, including increased secretion of estrogen and progesterone, as well as decreased immune function. Early diagnosis and intervention are crucial in such cases. Therefore, it is recommended to seek early medical attention if symptoms such as fever, vomiting, and changes in mental state occur during pregnancy, as the prognosis for both the mother and infant is poor once the abscess ruptures.

Actinomyces meyeri Causing Cerebral Abscess in a Patient on Methotrexate: A Rare Case Report and Systematic Review of the Literature

Central nervous system (CNS) actinomycosis is a rare, serious, life-threatening, suppurative infection caused by Actinomyces species. Actinomyces are anaerobic Gram-positive bacteria, which can be normally isolated from the polymicrobial flora of the gastrointestinal- and genital tracts. They are considered very low virulent bacteria to humans. However, they can lead to several types of local or disseminated infections, if certain pathologic states or immunodeficiency occur. Intracranial abscesses caused by Actinomyces meyeri are rarely reported in adults. In this case report, we describe a 66-year-old woman who presented to the emergency department due to progressive complaints of altered sensorium and low-grade fever, due to an A. meyeri-related brain abscess. The only risk factor was represented by immunodeficiency due to the therapy with Methotrexate and steroids.

Microbial Protein Binding to gC1qR Drives PLA2G1B-Induced CD4 T-Cell Anergy

The origin of the impaired CD4 T-cell response and immunodeficiency of HIV-infected patients is still only partially understood. We recently demonstrated that PLA2G1B phospholipase synergizes with the HIV gp41 envelope protein in HIV viremic plasma to induce large abnormal membrane microdomains (aMMDs) that trap and inactivate physiological receptors, such as those for IL-7. However, the mechanism of regulation of PLA2G1B activity by the cofactor gp41 is not known. Here, we developed an assay to directly follow PLA2G1B enzymatic activity on CD4 T-cell membranes. We demonstrated that gp41 directly binds to PLA2G1B and increases PLA2G1B enzymatic activity on CD4 membrane. Furthermore, we show that the conserved 3S sequence of gp41, known to bind to the innate sensor gC1qR, increases PLA2G1B activity in a gC1qR-dependent manner using gC1qR KO cells. The critical role of the 3S motif and gC1qR in the inhibition of CD4 T-cell function by the PLA2G1B/cofactor system in HIV-infected patients led us to screen additional microbial proteins for 3S-like motifs and to study other proteins known to bind to the gC1qR to further investigate the role of the PLA2G1B/cofactor system in other infectious diseases and carcinogenesis. We have thus extended the PLA2G1B/cofactor system to HCV and Staphylococcus aureus infections and additional pathologies where microbial proteins with 3S-like motifs also increase PLA2G1B enzymatic activity. Notably, the bacteria Porphyromonas gingivalis, which is associated with pancreatic ductal adenocarcinoma (PDAC), encodes such a cofactor protein and increased PLA2G1B activity in PDAC patient plasma inhibits the CD4 response to IL-7. Our findings identify PLA2G1B/cofactor system as a CD4 T-cell inhibitor. It involves the gC1qR and disease-specific cofactors which are gC1qR-binding proteins that can contain 3S-like motifs. This mechanism involved in HIV-1 immunodeficiency could play a role in pancreatic cancer and several other diseases. These observations suggest that the PLA2G1B/cofactor system is a general CD4 T-cell inhibitor and pave the way for further studies to better understand the role of CD4 T-cell anergy in infectious diseases and tumor escape.

Brain Abscess: A Rare Clinical Case with Oral Etiology

Brain abscess is a very rare condition but has a significant mortality rate. The three main routes of inoculation are trauma, contiguous focus, and the hematogenous route. The odontogenic focus is infrequent and is usually a diagnosis of exclusion. This paper presents a brain abscess case proven to be of dental origin, caused by Actinomyces meyeri and Fusobacterium nucleatum. This case highlights the risk underlying untreated dental disease and why oral infectious foci removal and good oral health are essential in primary care.

Multiple Brain Abscesses of Odontogenic Origin. May Oral Microbiota Affect Their Development? A Review of the Current Literature

In the last few years, the role of oral microbiota in the setting of oral diseases such as caries, periodontal disease, oral cancer and systemic infections, including rheumatoid arthritis, cardiovascular disease and brain abscess (BA), has attracted the attention of physicians and researchers. Approximately 5–7% of all BAs have an odontogenic origin, representing an important pathological systemic condition with a high morbidity and mortality. A systematic search of two databases (Pubmed and Ovid EMBASE) was performed for studies published up to 5 January 2021, reporting multiple BAs attributed to an odontogenic origin. According to PRISMA guidelines, we included a total of 16 papers reporting multiple BAs due to odontogenic infections. The aim of this review is to investigate the treatment modality and the clinical outcome of patients with multiple BAs due to odontogenic infections, as well as to identify the most common pathogens involved in this pathological status and their role, in the oral microbiota, in the onset of oral infections. A multidisciplinary approach is essential in the management of multiple BAs. Further studies are required to understand better the role of microbiota in the development of multiple BAs.

[Atypical actinomycosis revealed by distant dermatological disorders: Report of an unusual case and literature review]

INTRODUCTION

Dermatological manifestations of actinomycosis are classical, most often related to Actinomyces israelii. In most of the cases, they occur near to the primary focus, and in the cervicofacial area. Systemic dissemination with cutaneous distant metastasis is rare, most often related to A. israelii, too. We report an original case of upper limb actinomycosis associated with an oral localisation and due to an unusual bacteria.

CASE REPORT

A 49-year-old man was referred to the Department of dermatology for a skin lesion of the left hand and wrist. Biopsies revealed actinomycosis related to A. meyeri. Dental primary focus was identified and treated. Although the patient was lost sight of, dental eradication and prolonged antibiotics therapy allowed cutaneous improvement.

DISCUSSION

We report an atypical case of cutaneous actinomycosis due to an Actinomyces meyeri dental infection occurring in an immunocompetent, smoking adult, with poor oral hygiene. The literature review revealed only 4 well-documented cases of cutaneous A. meyeri infections distant to dental primary focus. All of patients were males, immunocompetent, with a history of poor oral hygiene. The prognosis is favourable with adequate treatment (antibiotic therapy and surgical treatment to eradicate dental infectious entry points).

Emerging role of Actinomyces meyeri in brain abscesses: A case report and literature review

We describe a case of a 29-year-old man from Pakistan who presented with progressive neurologic symptoms over 1 week and was found to have a right parietal cerebral abscess. Neurosurgical drainage cultures showed growth of Actinomyces meyeri, Streptococcus intermedius, and Parvimonas micra. An abscessed molar was identified as the likely port of entry and was extracted. The patient was treated with metronidazole, vancomycin, and doxycycline because of prior anaphylaxis to penicillin. At 6-month follow-up, repeat magnetic resonance imaging showed no signs of residual abscess. Culture-independent identification techniques (e.g., ribosomal sequencing) increasingly identify Actinomyces meyeri as a causative agent and significant pathogen in spontaneous brain abscesses. As understanding about Actinomyces meyeri’s prevalence and pathogenesis improves, questions arise about optimal treatment strategy, which we discuss based on a literature review.

Actinomyces and related organisms in human infections

Actinomyces israelii has long been recognized as a causative agent of actinomycosis. During the past 3 decades, a large number of novel Actinomyces species have been described. Their detection and identification in clinical microbiology laboratories and recognition as pathogens in clinical settings can be challenging. With the introduction of advanced molecular methods, knowledge about their clinical relevance is gradually increasing, and the spectrum of diseases associated with Actinomyces and Actinomyces-like organisms is widening accordingly; for example, Actinomyces meyeri, Actinomyces neuii, and Actinomyces turicensis as well as Actinotignum (formerly Actinobaculum) schaalii are emerging as important causes of specific infections at various body sites. In the present review, we have gathered this information to provide a comprehensive and microbiologically consistent overview of the significance of Actinomyces and some closely related taxa in human infections.

A Case of Disseminated Infection due to Actinomyces meyeri Involving Lung and Brain

Actinomyces meyeri is rarely isolated in cases of actinomycosis. The identification of A. meyeri had historically been difficult and unreliable. With the recent development of 16S ribosomal RNA (16S rRNA) sequencing, Actinomyces species such as A. meyeri can be isolated much more reliably. A. meyeri often causes disseminated disease, which can be secondary to frequent pulmonary infections. A penicillin-based regimen is the mainstay of A. meyeri treatment, with a prolonged course usually required. Here, we report a case of pulmonary actinomycosis with brain abscess caused by A. meyeri that was initially thought to represent lung cancer with brain metastasis.

First reported case of bacterial endocarditis attributable to Actinomyces meyeri

A 48-year-old man presented to the Victoria General Hospital, Halifax, Nova Scotia in severe congestive heart failure. Echocardiographic studies revealed significant aortic valve insufficiency. Two anaerobic blood cultures performed two weeks apart were both positive for Actinomyces meyeri. The patient was treated with high dose intravenous penicillin. Three weeks after antibiotics were begun, he underwent aortic valve replacement. Intraoperative cultures were negative. Histopathological examination revealed findings in keeping with subacute bacterial endocarditis. The patient completed a six-week course of penicillin and was doing well three months after surgery. This is the first case of endocarditis attributable to A meyeri reported in the literature.

Actinomyces meyeri infection: case report and review of the literature

Actinomyces meyeri is an uncommon cause of actinomycosis. We present a patient with pneumonia and empyema due to A. meyeri. The patient underwent open thoracotomy with decortication and was discharged home on a twelve-month course of oral penicillin. Review of the English literature revealed thirty-two cases of infection due to A. meyeri. The majority of patients were male, and a significant number had poor dental hygiene and a history of alcoholism. More than other Actinomyces species, A. meyeri causes pulmonary infection and has a predilection for dissemination. Prognosis is favorable with prolonged penicillin therapy combined with surgical debridement, if needed.

Brain abscess associated with Aggregatibacter actinomycetemcomitans: case report and review of literature

INTRODUCTION

Aggregatibacter actinomycetemcomitans is considered a major pathogen in localized and generalized aggressive periodontitis. A. actinomycetemcomitans has been found in various extra oral infections and most frequently in endocarditis. We report a patient with multiple brain abscesses due to infection with A. actinomycetemcomitans and review the English language literature related to this subject.

CASE REPORT

A 42-year-old patient with no underlying medical conditions presented with multiple brain lesions initially thought to be metastatic lesions of a tumour of unknown origin. Findings during drainage and subsequent histopathological conclusions made infection more likely. Culture of drained material remained negative; however, 16S rDNA polymerase chain reaction and sequence analysis on direct material revealed A. actinomycetemcomitans as the causative agent of the infection. The most likely source of infection was the poor dentition of the patient. After repeated drainage of the lesions and antibiotic treatment the patient gradually improved, although cognitive impairment remained.

CONCLUSIONS

Our report illustrates that a poor dental condition, notably destructive periodontal disease, can be a risk for life-threatening extra oral disease, and thus contributes to the total inflammatory burden of the body.

Focal intracranial infections due to Actinomyces species in immunocompetent patients: diagnostic and therapeutic challenges

OBJECTIVE

Actinomyces spp. are often underestimated as causes of central nervous system infection because they are not looked for routinely and are difficult to detect. We try to determine the optimal management of these problematic intracranial infectious diseases in neurosurgical practice.

METHODS

Five cases of intracranial suppurations due to Actinomyces spp. treated between December 2007 and February 2009 are reported. The relevant clinicobacteriologic features and treatment outcomes are analyzed.

RESULTS

There were two brain abscesses, two subdural empyemas, and one frontal sinus pyomucocele with intracranial extension. Among them, three cases were previously operated and two patients were previously treated for otorhinolaryngeal infection. All cases were immunocompetent. In addition to Actinomyces sp., three patients had coinfectious bacteria (Pseudomonas aeruginosa, Staphylococcus warneri, and Escherichia coli). Complete resolution of the infection was achieved by means of aggressive surgical treatment and relatively short course of antibiotic therapy with a full recovery.

CONCLUSION

Actinomycotic focal cerebral infections may occur with greater frequency than previously recognized. Polymicrobial bacteria may be seen. This rare anaerobic organism should be considered in patients with a history of head trauma, previous surgery, or otorhinolaryngeal infection who present with a long duration of neurologic symptoms with or without an accompanying fever. Patients may be candidates for surgical debridement with relative shorter term of antibiotic therapy (ciprofloxacin).

Mixed infection involving Actinomyces, Aggregatibacter, and Fusobacterium species presenting as perispinal tumor

A representative case in which a polymicrobial infection involving Fusobacterium nucleatum, Actinomyces israelii and Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans was initially diagnosed as malignancy in an edentulous patient. Additional history obtained after the nature of the syndrome was elucidated revealed that he had had his two remaining teeth extracted four months prior to this episode.

Tooth loss, dementia and neuropathology in the Nun study

BACKGROUND

Numerous studies have linked dementia to the subsequent deterioration of oral health. Few investigators, however, have examined oral disease as a potential risk factor in the development of dementia. The authors conducted a study to investigate a potential association between a history of oral disease and the development of dementia.

METHODS

Longitudinal dental records supplemented data collected from 10 annual cognitive assessments of 144 Milwaukee participants in the Nun Study, a longitudinal study of aging and Alzheimer disease, who were 75 to 98 years old. Neuropathologic findings at autopsy were available for 118 participants who died.

RESULTS

A low number of teeth increased the risk of higher prevalence and incidence of dementia.

CONCLUSION

Participants with the fewest teeth had the highest risk of prevalence and incidence of dementia.

CLINICAL IMPLICATIONS

Edentulism or very few (one to nine) teeth may be predictors of dementia late in life.

Brain abscess due to Actinobacillus actinomycetemcomitans. Case report

Actinobacillus actinomycetemcomitans, a constituent of the oral flora, is a rare cause of brain abscesses. We report the case of a 47-year-old male who presented with multiple brain abscesses due to this organism, presumably originating from his poor dentition. Problems met in isolating and identifying A. actinomycetemcomitans suggest that its true rate of isolation from non-oral samples may have been underestimated.

Disseminated Actinomyces meyeri infection resembling lung cancer with brain metastases

Thoracic actinomycosis can resemble bronchogenic carcinoma in its clinical presentation and radiographic appearance. We report a case of pulmonary actinomycosis caused by Actinomyces meyeri in which hematogenous dissemination caused multiple brain abscesses resembling metastatic lung cancer. The correct diagnosis was made by thin-needle aspiration of a pleura-based lung mass. The pathogen isolated was further identified with the use of 16S rDNA sequencing. Antibiotic therapy resulted in rapid improvement of the lung lesion; however, the brain lesions required surgical drainage. Antibiotics were continued for more than a year before magnetic resonance images showed complete resolution of the cerebral abscesses.

Surgical considerations for pulmonary actinomycosis

BACKGROUND

Diagnosis and treatment of pulmonary actinomycosis is difficult without surgical intervention.

METHODS

Thirteen patients (10 men, 3 women; mean age, 62 years) underwent pulmonary resection and were given a pathologic diagnosis of pulmonary actinomycosis at our institution between 1976 and 2001. To clarify when pulmonary actinomycosis should be suspected in patients and the role of surgical intervention, we reviewed preoperative clinical characteristics, computed tomography findings, surgical indication, operative procedure, postoperative clinical course, and outcome.

RESULTS

Ten patients (77%) had poor oral hygiene. Twelve patients (92%) were symptomatic, and 10 patients (77%) had hemoptysis. The mean interval between radiographic identification of the abnormality and surgical intervention was 8 months (interquartile range, 3.25 to 8 months). Computed tomography findings in all cases included radiologic opacity with air bronchogram or a low attenuation area. Lung cancer was diagnosed initially because of computed tomography findings of spiculation or pleural indentation, and operation was required in 8 patients (62%). The others were diagnosed with chronic pneumonia, and surgical intervention became necessary because of recurrent hemoptysis or prolonged illness. Six patients underwent lobectomy; the others underwent partial resection or segmentectomy. Neither complication nor recurrence has occurred.

CONCLUSIONS

When patients, particularly those with poor oral hygiene, show radiologic opacity with an air bronchogram or low attenuation area on the computed tomography scan, pulmonary actinomycosis should be considered and penicillin should be administered as diagnostic therapy. Surgical intervention may be necessary when frequent hemoptysis has no resolution or lung neoplasm cannot be ruled out.

The oral cavity as a reservoir of bacterial pathogens for focal infections

Dental procedures, but more importantly, oral infections and poor oral health can provoke the introduction of oral microorganisms into the bloodstream or the lymphatic system. The subsequent attachment and multiplication of these bacteria on tissues or organs can lead to focal oral infections. Pathogenic agents may also remain at their primary oral site but the toxins liberated can reach an organ or tissue via the bloodstream and cause metastatic injury. Finally, metastatic inflammation may result from an immunological injury caused by oral bacteria or their soluble products that enter the bloodstream and react with circulating specific antibodies to form macromolecular complexes.

Thoracic actinomycosis

OBJECTIVE

Thoracic actinomycosis is a disease that is difficult to diagnose because its appearance varies from similarities with bronchogenic carcinoma to pneumonitis-like tuberculosis infections. Therefore the majority of patients undergo operations for diagnosis. We had seven patients with thoracic actinomycosis which were not diagnosed before operation.

METHODS

Between July 1990 and November 1997, seven patients with thoracic actinomycosis were diagnosed after thoracotomy in our centre. They all had non-specific symptoms and radiographic findings, so we failed to diagnose the disease during preoperative examinations. Therefore they all underwent thoracotomy for diagnosis. Four patients were operated because of suspicion of malignancy, two patients were operated because of pulmonary infiltration and abscess formation and one patient because of undiagnosed pulmonary infiltration. Lobectomy was performed in five of them because of destroyed lobes, and wedge resection was performed in two patients. In two patients the disease was diagnosed by fresh smears obtained from specimens in the course of operation and confirmed histopathologically and in the others histopathologically in the postoperative period.

RESULTS

Three major complications, acute renal failure, empyema and persistent air leakage developed in three cases after the operations. Bronchopleural fistula was found in only one of them and the patient died because of uncontrolled infection and sepsis on the 26th postoperative day. All of the other six cases are still alive. We did not observe any other problem in their long-term follow-up. All patients regularly took 20 million units/day of intravenous crystalline penicillin G when they were in the hospital. After that, antibiotic treatment was completed up to 2 months with procaine penicillin.

CONCLUSIONS

Sometimes diagnosis of the actinomycosis of the lung is very difficult although it is an infection. In that case thoracotomy is needed for the diagnosis and sometimes for the treatment. In some cases because of the irreversible parenchymal change resective surgery may be needed. Actinomyces israelii infections should be suspected of in chronic infiltrative, nodular, cavitary process and tumour-like mass lesions besides other most probable causes. After diagnosed, it is treated using penicillin chemotherapy at least for 2 months.