Prosthetic valve endocarditis due to Actinomyces neuii successfully treated with antibiotic therapy

Actinomyces neuii Causing Right-Sided Infective Endocarditis: A Case-Based Literature Review

Actinomyces neuii (also known as Winkia neuii nowadays), quite different from its genus,is a facultatively anaerobic organism that rarely causes human infections.Like the rest of its genus, it usually has a good prognosis. In this case report, we present an interesting case of a middle-aged female who presented to the emergency department (ED) with fever and dyspnea, eventually diagnosed with infective endocarditis (IE) caused by A. neuii. To the best of our knowledge, it is the first reported case of A. neuii causing right-sided infective endocarditis in a middle-aged female with no residual or prosthetic valvular disease.

An unusual case report of transcatheter aortic valve implantation-related actinomycosis endocarditis

BACKGROUND

Actinomycosis is a chronic invasive infection caused by Actinomyces species. Actinomycosis endocarditis has been described, yet considered rare. We present the first reported transcatheter aortic valve implantation (TAVI)-related actinomycosis endocarditis.

CASE SUMMARY

A 70-year-old female patient, presented 4 months after TAVI with malaise and vocal-cord paralysis. She underwent computed tomography angiography which demonstrated a 28 mm pseudoaneurysm of the ascending aorta, which compressed the laryngeal nerves. Her condition rapidly deteriorated with cardiogenic shock and required an emergent surgery, which reviled a tamponade with active bleeding, due to an ascending aortic dissection. She underwent aortic valve and ascending aorta replacement. A 2 cm vegetation was found on the TAVI prosthetic valve and sent for cultures, which later revealed an Actinomyces neuii infection. Long-term intravenous ampicillin treatment was given.

DISCUSSION

This case describes a patient with endocarditis on TAVI prosthetic valve, with an unusual clinical presentation and rapid deterioration to an emergency intervention. This unique presentation of tumour-like tissue invasion is characteristic of actinomycosis, and should be suspected especially following valve replacement.

Four decades of experience of prosthetic valve endocarditis reflect a high variety of diverse pathogens

Prosthetic valve endocarditis (PVE) remains a serious condition with a high mortality rate. Precise identification of the PVE-associated pathogen/s and their virulence is essential for successful therapy, and patient survival. The commonly described PVE-associated pathogens are staphylococci, streptococci and enterococci, with Staphylococcus aureus being the most frequently diagnosed species. Furthermore, multi-drug resistance pathogens are increasing in prevalence, and continue to pose new challenges mandating a personalized approach. Blood cultures in combination with echocardiography are the most common methods to diagnose PVE, often being the only indication, it exists. In many cases, the diagnostic strategy recommended in the clinical guidelines does not identify the precise microbial agent and to frequently, false negative blood cultures are reported. Despite the fact that blood culture findings are not always a good indicator of the actual PVE agent in the valve tissue, only a minority of re-operated prostheses are subjected to microbiological diagnostic evaluation. In this review, we focus on the diversity and the complete spectrum of PVE-associated bacterial, fungal and viral pathogens in blood, and prosthetic heart valve, their possible virulence potential, and their challenges in making a microbial diagnosis. We are curious to understand if the unacceptable high mortality of PVE is associated with the high number of negative microbial findings in connection with a possible PVE. Herein, we discuss the possibilities and limits of the diagnostic methods conventionally used and make recommendations for enhanced pathogen identification. We also show possible virulence factors of the most common PVE-associated pathogens and their clinical effects. Based on blood culture, molecular biological diagnostics, and specific valve examination, better derivations for the antibiotic therapy as well as possible preventive intervention can be established in the future.

Infective endocarditis by Actinomyces species: a systematic review

Actinomycosis, is a slowly progressive infection that may mimic malignancy due to the invasiveness of tissues and the ability to form sinus tracts. Infective Endocarditis (IE) is a rare disease with significant morbidity and mortality. Interestingly, even though there are scarce data of IE by Actinomyces spp. in the literature, a review adequately summarizing all available evidence on the topic in a systematic way is lacking. The aim of this study was to systematically review all cases of IE by Actinomyces spp. in the literature and describe the epidemiology, microbiology, clinical characteristics, treatment and outcomes of this infection. A systematic review of PubMed, Scopus and Cochrane library (through 19 August 2021) for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of IE by Actinomyces spp. was performed. A total of 31 studies providing data for 31 patients were included. A prosthetic valve was present in 12.9%, while the most common microorganism was A. meyeri. Aortic valve was the most commonly infected intracardiac site, followed by the mitral valve. Diagnosis was most commonly performed with transesophageal echocardiography, while the diagnosis was made at autopsy in 16.1%. Penicillin, cephalosporins and aminopenicillins were the most commonly used antimicrobials. Clinical cure was noted in 80.6%, while mortality was 19.4%. Development of heart failure was associated with mortality by IE. This systematic review thoroughly describes IE by Actinomyces and provides information on epidemiology, clinical presentation, treatment and outcomes.

Bacterial Endocarditis Caused by Actinomyces oris: First Reported Case and Literature Review

Actinomyces species are gram-positive, facultative anaerobic bacilli. Infection caused by Actinomyces species is usually limited to cervicofacial, thoracic, and abdominopelvic regions. Infective endocarditis due to Actinomyces species is extremely rare with only 30 reported cases since 1939. We report a case of Actinomyces oris endocarditis in a 14-year-old boy who had a 2-week history of dyspnea on exertion without other constitutional signs. Transthoracic echocardiography was suggestive of perforation of the right coronary cusp of aortic valve. No organisms were isolated from blood cultures. The patient underwent surgical valve repair due to deteriorated cardiac function. Valve tissue culture did not initially identify the organism. However, the terminal subculture in a thioglycolate broth grew gram-positive bacilli. The matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was compatible with Actinomyces oris. After 6 weeks of intravenous ampicillin, the patient remained well with improved cardiac function. We reviewed all reported cases of infective endocarditis caused by Actinomyces species, commenting on clinical characteristics and factors associated with unfavorable outcomes in infective endocarditis due to Actinomyces species. Although infective endocarditis caused by Actinomyces spp is rare, it could be considered in a case of culture-negative endocarditis since the clinical features might be indistinguishable from other bacterial endocarditis. Additionally, MALDI-TOF MS is a useful diagnostic tool for the identification of Actinomyces spp to improve the accuracy of diagnosis.

Implantable cardioverter defibrillator related Actinomyces Odontolyticus endocarditis and bacteremia-First reported case

•

The first case of ICD related Actinomyces endocarditis and bacteremia.

•

Actinomyces Odontolyticus was cultured in 6 blood samples.

•

Chest scan revealed multiple acinar opacities and a cavitation.

•

Transesophageal echocardiogram revealed vegetations on the tricuspid valve and the ICD electrode.

Actinomyces Odontolyticus is a gram-positive bacillus, usually found in the oropharynx, gastrointestinal and urogenital tracts, as commensal flora. Infections caused by this organism are rare but may occur, more commonly in immunocompromised patients. We report a case of a 54-year-old man, who presented to the emergency department (ED), with fever and chills. The patient had undergone an implantable cardioverter defibrillator (ICD) insertion, 5 months prior to his arrival, and was diagnosed with Actinomyces Odontolyticus bacteremia, during the hospitalization. Transesophageal echocardiogram (TEE) revealed vegetations on the tricuspid valve and the ICD electrode. This is the first reported case of ICD related Actinomyces endocarditis and bacteremia based on our literature review. This case emphasizes the importance of probing for the source of actinomyces infection, while considering the indolent properties of the disease.

Percutaneous coronary intervention-associated Actinomyces oris

Coronary artery interventions are safe procedures yet have a risk of stent infection, bacteremia and sepsis, events that are rare but with high morbidity and mortality sequel. A few prior cases had reported post percutaneous coronary intervention (PCI) infections, abscesses and sepsis due to Staphylococcus aureus, followed by Pseudomonas aeruginosa. Cardiac Actinomyces infections are extremely rare. Here we report a case of a 50 year old patient who developed a post intervention Actinomyces oris epicardial abscess occluding right coronary artery with subsequent bacteremia eventually requiring open heart surgery. He was treated during and thereafter with IV penicillin and ceftriaxone for almost 8 weeks. We highlight during this review the available literature regarding risk factors, the possible theories of acquiring such bacterium at this unusual site as well as our patient's course and treatment outcome.

Antimicrobial treatment of Acinetobacter neuii invasive infections: A systematic review

Aims: The objectives of this study were to find out whether and to what extent Actinomyces neuii is pathogenic to humans in terms of causing invasive infections and to ascertain the most appropriate and effective antibiotic therapy against this bacterium. Material and method: This study was designed as a systematic review article. MEDLINE, Google Scholar, SCIndex, Cochrane database of published clinical trials - Central and Clinicaltrials.gov databases were systematically searched for primary case reports or case series describing invasive infection with Actinomyces neuii. Results: A literature search identified 23 studies that met the inclusion criteria, describing cases of patients with an invasive infection caused by Actinomyces neuii. It was found that A. neuii could cause endocarditis, endophthalmitis, osteomyelitis, pleural empyema, soft tissue abscesses, neonatal sepsis, ventriculoperitoneal shunt infections and periprosthetic tissue infections. The most prescribed antibiotics for the treatment of Actinomyces neuii infections were amoxicillin and vancomycin (n = 10; 12.3%), followed by penicillin (n =9; 11.1%), gentamicin (n = 6; 7.4%), ampicillin (n = 5; 6.2%) and ceftazidime (n = 4; 4.9%). Antibiotic treatment of infections caused by A. neuii was followed by clinical improvement or complete cure of all patients, with no recorded deaths. Conclusion: A. neuii has a relevant pathogenic potential to cause invasive infections of various organs and tissues, especially in immunocompromised individuals of any age. For the treatment of mild infections caused by this bacterium, the antibiotics of choice are penicillin or amoxicillin, while vancomycin should be used to treat severe infections caused by Actinomyces neuii.

Actinomyces neuii: a case report of a rare cause of acute infective endocarditis and literature review

BACKGROUND

Infective endocarditis caused by Actinomyces spp. is extremely rare. However, cases by new species of Actinomyces have been increasingly reported due to advances in laboratory techniques, and many of these species do not cause classic presentations of actinomycosis. Actinomyces neuii is reported to have a tendency to cause endovascular infection. The course of infective endocarditis caused by Actinomyces spp. is usually indolent.

CASE PRESENTATION

A 61-year-old man with history of infective endocarditis, end stage renal disease, and monoclonal gammopathy was admitted for an abrupt fever, confusion, dysarthria, and facial droop after hemodialysis. Echocardiogram showed vegetations on both the aortic and mitral valves. Two sets of blood culture grew A. neuii. Brain MRI showed multiple bilateral cerebral infarcts consistent with septic emboli. The patient recovered after valvular surgery and prolonged intravenous and oral antibiotic therapy.

CONCLUSIONS

This case illustrates an unusually acute presentation of A. neuii infective endocarditis. As with other Gram-positive bacilli, Actinomyces spp. isolates are often regarded as a result of contamination. One should keep it in mind as a cause of infective endocarditis in vulnerable patient populations.

Infections Caused by Actinomyces neuii: A Case Series and Review of an Unusual Bacterium

Background. Actinomyces neuii is a Gram-positive bacillus rarely implicated in human infections. However, its occurrence is being increasingly recognized with the use of improved identification systems. Objective. To analyse A. neuii infections in Alberta, Canada, and review the literature regarding this unusual pathogen. Methods. Cases of A. neuii were identified in 2013-2014 in Alberta. Samples were cultured aerobically and anaerobically. A predominant catalase positive Gram-positive coryneform bacillus with no branching was isolated in each case. Testing was initially done with API-CORYNE® (bioMérieux) and isolates were sent to the Provincial Laboratory for Public Health for further testing. Isolates' identities were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry microbial identification system (MALDI-TOF MS MIS; bioMérieux) and/or DNA sequencing. Results. Six cases of A. neuii infection were identified. All patients had soft tissue infections; typically, incision and drainage were done followed by a course of antibiotics. Agents used included cephalexin, ertapenem, ciprofloxacin, and clindamycin. All had favourable outcomes. Conclusions. While A. neuii is infrequently recognized, it can cause a diverse array of infections. Increased use of MALDI-TOF MS MIS is leading to increased detection; thus, understanding the pathogenicity of this bacterium and its typical susceptibility profile will aid clinical decision-making.

Actinomyces naeslundii: An Uncommon Cause of Endocarditis

Actinomyces rarely causes endocarditis with 25 well-described cases reported in the literature in the past 75 years. We present a case of prosthetic valve endocarditis (PVE) caused by Actinomyces naeslundii. To our knowledge, this is the first report in the literature of endocarditis due to this organism and the second report of PVE caused by Actinomyces.

Actinomyces neuii Isolated From a 20-Month-Old Girl With Cervical Lymphadenitis

Actinomycetes are Gram-positive bacteria that can be part of the normal human flora of the gastrointestinal, pulmonary, and genital tract. Infections are rare, slowly progressing and most commonly affect the cervicofacial region. Actinomyces israelii is the most frequently isolated species but a number of other species may cause infection. We report the first postnatally acquired case of an actinomycosis caused by A. neuii in a child. We also provide a systematic review of all published cases of A. neuii infections. In children, there is one case report of a premature infant with perinatally acquired A. neuii sepsis. In adults 21 cases have currently been reported and A. neuii infection was associated with endophthalmitis after eye surgery, foreign material-associated infection and abscess formation in the inguinal, axillary, and mammary area. Our case highlights that a A. neuii infection is also a potential differential diagnosis in children with chronic lymphadenitis.

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.

Actinomycotic endocarditis of the eustachian valve: a rare case and a review of the literature

Eustachian valve endocarditis caused by Actinomyces species is extremely rare. A literature review revealed only one reported case-caused by Actinomyces israelii in an intravenous drug abuser. Our patient, a 30-year-old woman who at first appeared to be in good health, presented with fever, a large mobile mass on the eustachian valve, and extensive intra-abdominal and pelvic masses that looked malignant. Histopathologic examination of tissue found in association with an intrauterine contraceptive device revealed filamentous, branching microorganisms consistent with Actinomyces turicensis. This patient was treated successfully with antibiotic agents. In addition to presenting a new case of a rare condition, we discuss cardiac actinomycotic infections in general and eustachian valve endocarditis in particular: its predisposing factors, clinical course, sequelae, and our approaches to its management.

Postoperative testicular abscess with bacteremia due to Actinomyces neuii

Bacteremia due to Actinomyces neuii has been reported in the literature 14 times. A. neuii is an endogenous organism that has been cultured in clinical specimens of the genitourinary tract; we are reporting a unique case of A. neuii postoperative testicular abscess with bacteremia which was successfully treated with surgery and a short course of parenteral antimicrobials.

Actinomyces neuii: review of an unusual infectious agent

Actinomyces neuii, a species first described in 1994, has proven to be an exception in this genus on account of its aerobic growth, microscopic morphology (no branching), and the types and location of infections. Abscesses and infected atheromas are the most frequent types of infections, followed by infected skin structures, endophthalmitis, and bacteremias, including endocarditis. They are most likely of endogenous origin. To date, approximately 100 cases have been recorded in the literature. Intra-abdominal and intrathoracic infections, however, have not yet been described, and cases of classical actinomycosis seem to be extremely rare. Prognosis has generally been good with antibiotic and/or surgical treatment. Susceptibility to antibiotics has paralleled that of other Actinomyces spp.