Challenges and Insights in Aggregatibacter aphrophilus endocarditis: a review of literature.

Infective endocarditis is a serious disease associated with high mortality despite recent advances in diagnosis and treatment. Aggregatibacter aphrophilus is a fastidious Gram-negative member of the HACEK organisms (Haemophilus spp., Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae). A. aphrophilus is associated with dental infections but has also been implicated in cases of infective endocarditis. We highlight the importance of a high index of suspicion in symptomatic patients with an initial negative blood culture, particularly in high-risk groups such as patients with congenital valve disease and prosthetic valve. The knowledge of this rare entity may lead to early diagnosis and appropriate management. We review the main characteristics of Aggregatibacter aphrophilus endocarditis reported in the medical literature.

La endocarditis infecciosa es una enfermedad grave que está asociada con una alta mortalidad a pesar de los avances recientes en el diagnóstico y tratamiento. Aggregatibacter aphrophilus es un miembro Gram-negativo de los organismos HACEK (Haemophilus spp., Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens y Kingella kingae). A. aphrophilus está relacionado con infecciones dentales, pero también ha estado implicado en casos de endocarditis infecciosa. Se destaca la importancia de tener un alto índice de sospecha en pacientes sintomáticos con un cultivo sanguíneo inicial negativo, especialmente en grupos de alto riesgo como pacientes con enfermedad valvular congénita y válvula protésica. El conocimiento de esta entidad poco común puede llevar a un diagnóstico temprano y un manejo adecuado. Revisamos las principales características de la endocarditis por Aggregatibacter aphrophilus reportadas en la literatura médica.

Case Report: The First Case of Bloodstream Infection Complicated with Psoas Abscess and Pulmonary Infection Caused by Aggregatibacter aphrophilus in China.

Aggregatibacter aphrophilus is part of the normal flora in the oropharynx and upper respiratory tract, which causes invasive bacteremia in rare cases. However, the culture and identification of Aggregatibacter aphrophilus are challenging, hence easily misdiagnosed or undetected in clinical practice. In this case, a 73-year-old male patient was admitted to the hospital with a fever and right hip pain. Routine blood and C-reactive protein tests showed abnormal inflammatory markers. Positive blood culture revealed the presence of Aggregatibacter aphrophilus through mass spectrometry. The computed tomography examination further revealed the presence of psoas abscess, pulmonary infection, and pleural effusion, which was relieved by ceftriaxone combined with levofloxacin therapy, the drainage of psoas abscess and pleural effusion. Therefore, since multiple anatomic sites infection, including bloodstream, psoas abscess and pulmonary infection caused by Aggregatibacter aphrophilus, is rare, sufficient attention should be paid to its clinical diagnosis and treatment.

Brain abscess due to Aggregatibacter aphrophilus in association with atrial septal defect：Case report and literature review.

BACKGROUND: Aggregatibacter aphrophilus（A. aphrophilus）is one of the organisms of the HACEK group. Previously reported cases of brain abscesses caused by A. aphrophilus infection have occurred in children with a basis for congenital heart disease, or in adults with a basis for dental disease. Rare cases of brain abscess caused by A. aphrophilus have been reported in adults with congenital heart disease or in patients without dental disease history. Herein we present a rare case of brain abscess caused by A. aphrophilus, who was in association with atrial septal defect for more than 20 years, and had no dental disease and did not develop infective endocarditis. CASE PRESENTATION: A 51-year-old female was admitted due to progressively worsening headache and left limb weakness for more than 10 days. She denied the history of chronic diseases such as hypertension and diabetes, and no periodontal disease. While she had a history of atrial septal defect, a form of congenital heart disease with severe pulmonary hypertension for more than 20 years. After admission, echocardiographic illustrated congenital heart disease with severe pulmonary hypertension. CT and MRI showed brain abscess. Cerebrospinal fluid (CSF) results also confirmed the presence of intracranial infection. Empirical therapy with vancomycin 1.0 g i.v q12h and meropenem 2.0 g i.v q8h was initiated from the day of admission. On the fourth day after admission, brain abscess resection and decompressive craniectomy were performed, and the pus drained on operation were cultured and Gram-negative bacilli grew, which was identified as A.aphrophilus. Vancomycin was discontinued and meropenem was continued（2.0 g i.v q8h）for 5 weeks, followed by oral levofloxacin 0.5 qd for 4 weeks of out-patient antibiotics. The patient recovered fully within 9 weeks of treatment. CONCLUSIONS: This is the first case of A. aphrophilus to cause brain abscess in adult with a history of congenital heart disease for more than 20 years, who had no dental disease and did not develop infective endocarditis. We also highlight the value of bacterial 16 S rDNA PCR amplification and sequencing in identifying bacteria in abscesses which are culture-negative, and prompt surgical treatment，choosing effective antibiotics and appropriate course of treatment will get better clinical effect.

Invasive Aggregatibacter infection: shedding light on a rare pathogen in a retrospective cohort analysis.

Introduction. Aggregatibacter are Gram-negative, facultatively anaerobic rods or coccobacilli that are infrequently encountered as pathogens causing infection.Hypothesis/Gap Statement. The range of invasive infection that Aggregatibacter cause is poorly described. The pathogenicity of species such as Aggregatibacter segnis is debated.Aim. To identify invasive infection due to Aggregatibacter species in a large healthcare organization and to characterize clinical syndromes, co-morbidities and risk factors.Methodology. All microbiological samples positive for Aggregatibacter species were identified by conventional culture or 16S rRNA PCR between October 2017 and March 2021. Electronic records for all patients with positive samples were reviewed and the infection syndrome classified for patients with invasive disease.Results. Twenty-seven patients with invasive infection were identified, with a statistically significant difference in species-specific patterns of invasive infection (P=0.02) and a statistically significant association with residence in the 30 % most deprived households in the UK by postcode (P<0.01). The three most common co-morbidities were periodontitis or recent dental work (29.6%), cardiovascular disease (25.9%) and diabetes (18.5 %).Conclusion. We describe a novel association of Aggregatibacter segnis with skin and soft tissue infection. The propensity of the Aggregatibacter species to cause invasive infection at different body sites and be associated with deprivation is reported. Aggregatibacter actinomycetemcomitans bacteraemia was associated with infective endocarditis, and Aggregatibacter aphrophilus was implicated in severe appendicitis and noted to cause brain abscess. Areas warranting future research include exploring the risk-factors required for invasive infection and those that may determine the species-specific differences in patterns of invasive disease.

Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus in a Kenyan Maasai Adolescent Population and Inhibition of Leukotoxic Activity by Herbal Plants Used as Part of Oral Hygiene Procedures.

BACKGROUND: A virulent genotype (JP2) of the periodonto-pathogen, Aggregatibacter actinomycetemcomitans (Aa), is widespread in North and West Africa, while its presence in East Africa has not been thoroughly investigated. This JP2 genotype is associated with periodontitis in adolescents and has a high leukotoxicity. The aim of the study was to examine the prevalence of Aa and its JP2 genotype, the prevalence of the oral, commensal Aggregatibacter aphrophilus in a Maasai adolescent population, and the effect of herbal plants for inhibition of leukotoxicity. METHODS: A total of 284 adolescents from Maasai Mara, Kenya, underwent an oral examination and microbial sampling. The presence of Aa and A. aphrophilus was analyzed by quantitative PCR and cultivation (the 58 samples collected at the last day of field study). The collected Aa strains were characterized and leukotoxin promoter typed. Additionally, herbal plants commonly used for oral hygiene were assessed for the inhibition of leukotoxicity. RESULTS AND CONCLUSIONS: The prevalence of Aa in stimulated whole saliva was high (71.8%), with the JP2 genotype detected in one individual, and A. aphrophilus in 99% of the sampled individuals. The commonly used herbal plant, Warburgia ugandensis, inactivated Aa leukotoxicity. The Aa virulence might be reduced through use of W. ugandensis and the high levels of A. aphrophilus.

A rare case of voluminous brain abscess due to Actinomyces meyeri and Aggregatibacter aphrophilus: is there any evidence for a prolonged antibiotic oral relay?

We present the case of a patient with a voluminous cerebral abscess caused by Aggregatibacter aphrophilus and Actinomyces meyeri occurring a week post dental scaling. Both these bacteria are rarely involved in brain abscesses, and so far, cases of cerebral actinomyces have mostly been treated surgically and with intravenous (IV) antibiotics for 3-4 months, then put on oral antibiotic therapy with penicillin or amoxicillin for a further 3-12 months. Our patient underwent drainage through craniotomy and was subsequently put on intravenous ceftriaxone for 3 months accompanied by brain imaging control at the end of this period which showed complete regression of the abscess. Following parenteral treatment, no oral antibiotics were given since pharmacokinetic properties do not allow to attain high tissue concentration in the brain. This treatment gave excellent results.

An unusual case of multiple hepatic and pulmonary abscesses caused by Aggregatibacter aphrophilus in a young man: a case report.

BACKGROUND: Aggregatibacter aphrophilus, formerly known as Haemophilus aphrophilus, belongs to the HACEK organisms, a group of pathogens classically associated with infectious endocarditis. A. aphrophilus is a rarely found pathogen, though abscess formation in various organs has been described, typically due to spread from an infected heart valve. Here we describe the unusual case of multiple hepatic abscesses caused by A. aphrophilus. CASE PRESENTATION: A 33-year-old Caucasian man presented at our hospital with fever and malaise, elevated inflammatory markers, and liver enzymes. Imaging was compatible with multiple liver and pulmonary abscesses, without evidence of endocarditis. Cultures of blood and liver abscess material remained without growth. Polymerase chain reaction finally revealed Aggregatibacter aphrophilus in the liver tissue. The patient recovered fully within 6 weeks of doxycycline treatment. CONCLUSIONS: There are only a few case descriptions of liver abscesses caused by A. aphrophilus. As a ubiquitous organism in the gastrointestinal tract, A. aphrophilus may reach the liver via the portal venous system, as well as through hematogenous spread from the oropharynx. HACEK organisms are notoriously difficult to grow on culture, which highlights the diagnostic importance of eubacterial PCR.

The First Known Case of Liver Abscess Caused by Aggregatibacter aphrophilus in Japan.

A 48-year-old man presented with a sustained fever. Abdominal computed tomography revealed multilocular liver abscesses. He underwent percutaneous needle aspiration, yielding straw-colored pus. Gram staining revealed Gram-negative coccobacilli. The organism grew only on chocolate II agar in a 7% carbon dioxide atmosphere. Identification of Aggregatibacter aphrophilus was confirmed using mass spectrometry and 16S rRNA gene sequencing. He was successfully treated with antibiotics. Liver abscess caused by A. aphrophilus is extremely rare. We herein report the first such case in Japan. Even fastidious organisms, such as A. aphrophilus, should be correctly identified using mass spectrometry or 16S rRNA gene sequencing for adequate treatment.

Polymicrobial Cerebral Abscess in a Child with Uncorrected Tetralogy of Fallot.

Aggregatibacter aphrophilus and Beta haemolytic Streptococci Lancefield group F are part of the normal oral flora and are known to cause endocarditis, sinusitis, empyema, meningitis and septic arthritis. They are now emerging as a cause of brain abscess particularly in patients with congenital heart diseases. We report a case of a 10-year-old boy with Tetralogy of Fallot (TOF), who presented with fever, headache and drowsiness. Culture yielded the growth of Aggregatibacter aphrophilus and Beta hemolytic streptococci Lancefield group F. He became clinically stable after treatment with ceftriaxone.

[Septic arthritis byAggregatibacteraphrophilus: Case report] / Artritis séptica por Aggregatibacter aphrophilus.

Introduction: Septic arthritis by Aggregatibacter aphrophilus is an uncommon entity, so it's important to diagnose it early, to avoid serious consequences. In adults, the knee is the most affected site. Methods: We present a case of a 17-year-old boy, with pain in the left knee since one month ago. It shows an increase in local temperature, erythema and movement inability. A nuclear magnetic resonance (NMR) was performed and empirical treatment was given with cephalothin and clindamycin. A knee arthrotomy was realized, and intramedullary secretion and bone tissue was sent to study. Results: the NMR images were suggestive of an infectious process. In the culture gram-negative coccobacilli were isolated, later identified like as Aggregatibacter aphrophilus. According to this diagnostic, the treatment was changed to ceftriaxone The main conclusions: the rapidity and certainty in the choice of antimicrobial therapy is the most important step for a well evolution of this infection, therefore is very important to emphasize the importance of a correct identification of these rare microorganisms

Introducción: Aunque la artritis séptica es una entidad poco común, es importante debido a las graves consecuencias de un diagnóstico tardío o un incorrecto tratamiento. En adultos, la rodilla es el sitio más afectado. El objetivo de este trabajo es presentar un caso clínico de artritis séptica por Aggregatibacter aphrophilus en rodilla en un paciente joven, inmunocompetente, sin antecedentes patológicos. Materiales y métodos: Se estudia el caso de un joven de 17 años, tabaquista, con un cuadro de 1 mes de evolución caracterizado por gonalgia izquierda, aumento de la temperatura local, eritema e impotencia funcional. Se realizan análisis de sangre, una ecografía,y resonancia magnética (RMN).Se solicitan hemocultivos y cultivos de líquido intrarticular de rodilla. En la RMN se observa una lesión expansiva en la región femoral, sugestiva de un proceso infeccioso. Se comienza tratamiento empírico con cefalotina y clindamicina. Se realiza una artrotomia de rodilla enviándose para su estudio secreción endomedular, tejido óseo y endomedular. Resultados: Los hemocultivos y el cultivo del líquido intraarticular fueron negativos, pero los materiales obtenidos por técnica quirúrgica fueron positivos para el cultivo, aislándose cocobacilos gram negativos, posteriormente identificados como Aggregatibacter aphrophilus Se realizó el diagnóstico de artritis séptica por Aggregatibacter aphrophilus y se roto el tratamiento antimicrobiano a ceftriaxona. Conclusión: La rapidez y la certeza en la elección de la terapia antimicrobiana son un paso decisivo para la evolución de la enfermedad, por lo tanto se remarca la importancia de una correcta identificación de estos microorganismos poco frecuentes.

Isolation of Aggregatibacter aphrophilus from bronchoalveolar lavage in a paediatric patient presenting with haemoptysis.

We report a rare case of non-cystic fibrosis bronchiectasis accompanied by protracted infection with Aggregatibacter aphrophilus in a 12-year-old boy with haemoptysis.

Role of OmpA1 and OmpA2 in Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus serum resistance.

Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus belong to the HACEK group of fastidious Gram-negative organisms, a recognized cause of infective endocarditis. A. actinomycetemcomitans is also implicated in aggressive forms of periodontitis. We demonstrated that A. aphrophilus strains, as A. actinomycetemcomitans are ubiquitously serum resistant. Both species encode two Outer membrane protein A paralogues, here denoted OmpA1 and OmpA2. As their respective pangenomes contain several OmpA1 and OmpA2 alleles, they represent potential genotypic markers. A naturally competent strain of A. actinomycetemcomitans and A. aphrophilus, respectively were used to elucidate if OmpA1 and OmpA2 contribute to serum resistance. Whereas OmpA1 was critical for survival of A. actinomycetemcomitans D7SS in 50% normal human serum (NHS), serum resistant ompA1 mutants were fortuitously obtained, expressing enhanced levels of OmpA2. Similarly, OmpA1 rather than OmpA2 was a major contributor to serum resistance of A. aphrophilus HK83. Far-Western blot revealed that OmpA1AA, OmpA2AA, and OmpA1AP can bind to C4-binding protein, an inhibitor of classical and mannose-binding lectin (MBL) complement activation. Indeed, ompA1 mutants were susceptible to these pathways, but also to alternative complement activation. This may at least partly reflect a compromised outer membrane integrity but is also consistent with alternative mechanisms involved in OmpA-mediated serum resistance.

Craniectomía descompresiva para empiema por Aggregatibacter aphrophilus: revisión de la literatura y presentación de caso / Decompressive Craniectomy for Empyema by Aggregatibacter aphrophilus: Literature Review and Case Report

El empiema subdural es una patología rara que ocurre secundaria a otra infección en el complejo craneofacial; puede ser por una otitis media o por sinusitis en la mayoría de los casos. Por esto, normalmente, los gérmenes asociados con esta patología son los mismos encontrados en el oído medio y en los senos paranasales. A veces, un microrganismo raro causa el absceso, caso de este paciente, quien ingresó al hospital con dolor ocular y rápidamente progresó a un déficit neurológico causado por la bacteria Aggregatibacter aphrophilus. El caso tuvo una rápida intervención de todos los servicios involucrados. Neurocirugía drenó el empiema mediante trepano; posteriormente, el paciente requirió ventriculostomía y craniectomía descompresiva. El objetivo de esta revisión de la literatura es determinar qué dice la evidencia acerca del drenaje de empiemas mediante trepano o el uso temprano de craniectomía en este tipo de pacientes.

The subdural empyema is a rare pathology that normally occurs secondary' to another infection in the skull-facial complex, could be medial otitis or sinusitis in most of the cases, that's why the germs associated with this pathology' are normally the same found in the middle ear and paranasal sinuses. Eventually a rare microorganism causes an abscess, this is the case of this patient, who arrived to the hospital with ocular pain and rapidly progress with neurological déficit cause by' a bacteria called Aggregatibacter aphrophilus. The case had a fast intervention of all the Services involved, neurosurgery made an empyema drainage by burr hole, after that the patient required ventriculostomy and finally decompressive craniectomy. The objective of this review of the literature is to determine what does the evidence say about the empyema drainage by' burr hole or the early use of craniectomy in this kind of patients.

Exceptional association of two species of bacteria causing mediastinitis: Haemophilus influenzae (H. influenzae) and Aggregatibacter aphrophilus (A. aphrophilus).

BACKGROUND: Post cardiac surgery mediastinitis is the major infectious complication, despite the development of surgical techniques and the application of strict preventive measures. The Haemophilus influenzae mediastinitis is very rare. The mediastinitis caused by the association between Haemophilus influenzae and Aggregatibacter aphrophilus has never been described to our knowledge. CASE PRESENTATION: We report the case of an exceptional combination of Haemophilus influenzae and Aggregatibacter aphrophilus in a patient operated for single bypass which is complicated by mediastinitis the 10th day after the surgical act. CONCLUSION: The conclusion to be drawn from this work is to think in unusual seeds in case of mediastinitis post cardiac surgery for the elaboration of recommendations for antibiotic prophylaxis.

N-Glycosyltransferase from Aggregatibacter aphrophilus synthesizes glycopeptides with relaxed nucleotide-activated sugar donor selectivity.

N-Glycosyltransferase (NGT) is an inverting glycosyltransferase for an unusual pathway of N-linked protein glycosylation and glycosylates polypeptides in the consensus sequon (N-(X≠P)-T/S) with hexose monosaccharides. Here, we expressed and characterized a novel N-glycosyltransferase from Aggregatibacter aphrophilus (named AaNGT). RP-HPLC and Mass Spectrometry were used to assay and quantify glycopeptide formation by AaNGT and determine its substrate specificities. AaNGT could utilize a variety of nucleotide-activated sugar donors, including UDP-Glc, UDP-Gal, UDP-Xyl, GDP-Glc, dGDP-Glc and UDP-GlcN, to glycosylate the tested peptides. To the best of our knowledge, AaNGT was the first identified natural glycosyltransferase able to transfer GlcN moiety onto asparagine residues. AaNGT also exhibited a different position-specific residue preference of substrate peptides from the NGT of Actinobacillus pleuropneumoniae (ApNGT). In vitro assays with diverse synthesized peptides revealed that AaNGT preferred different peptide substrates from ApNGT. The efficient glycosylation of natural short peptides by AaNGT showed its potential to modify important therapeutic mammalian N-glycoproteins.

An unusual case of aggregatibacter aphrophilus liver abscess.

Liver abscess of oropharyngeal origin in an immunocompetent patient is a rare condition. Furthermore, microbiologic diagnosis of liver abscess can be challenging due to the tremendous diversity of the microorganisms implicated and culture difficulties under laboratory conditions. We report a case of a previously healthy 23-year-old male, who presented multiple liver abscesses, attributed to aggregatibacter aphrophilus, an obligatory oral gram-negative microorganism, that normally is a component of the commensal oral microbiota and non-virulent. The etiopathogenic microorganism was identified after needle aspiration of a liver abscess cavity. Treatment with broad-spectrum antimicrobials and percutaneous catheter drainage under computed tomography guidance of both abscesses, resulted in full recovery. A. aphrophilus represents a rare entity of liver abscess in healthy individuals and suggests that a pathogen of oropharyngeal origin should be suspected when an overt source of infection cannot be documented.

Solitary Aggregatibacter aphrophilus tectal abscess in an immunocompetent patient.

BACKGROUND: A solitary abscess involving the tectum, specifically by Aggregatibacter aphrophilus, is an extremely rare condition with no known reported cases to date. CASE DESCRIPTION: Here, we present a case of isolated solitary midbrain tectum abscess in an immunocompetent 28-year-old male who was empirically diagnosed as a primary tectal tumor at an outside hospital where he also underwent placement of a ventriculoperitoneal shunt (VPS) for obstructive hydrocephalus. Eight weeks later he was readmitted with a VPS infection. He was transferred to our institution where the VPS was removed and he was started on broad-spectrum antibiotics. Cerebrospinal fluid (CSF) culture revealed A. aphrophilus. All other workup was negative for infectious etiologies. The tectal lesion completely resolved after 15 weeks of intravenous ceftriaxone without surgical aspiration. CONCLUSION: We suggest that an empiric diagnosis of tectal glioma should be made with caution for a ring-enhancing mass. CSF should be routinely cultured at the time of operative diversion if abscess is a possibility.

Prosthetic Valve Endocarditis caused by HACEK Organisms: a Case Reports and Systematic Review of the Literature.

HACEK is a rare cause of prosthetic valve endocarditis (PVE). We describe 42-year-old male patient who presented with Aggregatibacter aphrophilus PVE and cerebral infarct. A. aphrophilus was isolated from his blood cultures as the sole pathogen, which was confirmed by subsequent 16S rRNA sequencing. He was treated with valve replacement surgery and an 8 week course of pathogen-directed antibiotic therapy and followed for 20 months without recurrence.

Aggregatibacter aphrophilus aortic valve infective endocarditis / Endocarditis infecciosa en válvula aórtica por Aggregatibacter aphrophilus

Nowadays, infective endocarditis remains a major cause of morbidity and mortality worldwide and there are concerns related to the increased number of infections associated with virulent agents and medical procedures. We present a case of a homeless man with unknown medical history, admitted for lumbar pain who became confused, hypotensive and tachy cardic, evolving to severe sepsis. His initial investigation was also suggestive of acute myocardial infarction but the transthoracic echocardiogram revealed massive aortic valve vegetation with perivalvular abscess leading to severe aortic regurgitation. The patient died with the final diagnosis of infective endocarditis. Later on the blood cultures was identified Aggregatibacter aphrophilus, an HACEK group agent. This case confirms that, albeit the general favorable outcomes, there are cases of serious infections, especially if the diagnosis and treatment were late.

Hoy día, la endocarditis infecciosa continúa siendo una causa importante de mor-bimortalidad en todo el mundo y es preocupante el aumento del número de infecciones asociadas con agentes virulentos y procedimientos médicos. Presentamos el caso de un indigente con antecedentes médicos desconocidos, ingresado por dolor lumbar, que comenzó a sentirse confuso, hipotenso y taquicárdico. Poco después de su ingreso su estado evolucionó a septicemia grave. Los resultados de las pruebas iniciales también eran indicativos de infarto agudo de miocardio, pero el ecocardiograma transtorácico reveló una vegetación masiva en la válvula aórtica con absceso perivalvular condicionando regurgitación aórtica grave. El paciente murió, con el diagnóstico definitivo de endocarditis infecciosa. Más tarde, en los hemocultivos se identificó Aggregatibacter aphrophilus, un microorganismo del grupo HACEK. Este caso confirma que, a pesar de los resultados favorables en general, hay casos de infecciones graves, sobre todo si el diagnóstico y el tratamiento fueron tardíos.

Aggregatibacter aphrophilus infective endocarditis confirmed by broad-range PCR diagnosis: A case report.

INTRODUCTION: Aggregatibacter aphrophilus is a rare cause of infective endocarditis. This pathogen is difficult to identify with common culture methods, which can lead to incorrect diagnosis and treatment. PRESENTATION OF CASE: A 72-year-old woman was admitted to a community hospital with a persistent high fever and deteriorating renal function. Based on negative blood culture and positive serum proteinase 3 anti-neutrophil cytoplasmic antibody (PR3-ANCA), acute renal failure associated with ANCA-rerated vasculitis was initially suspected. However, the patient developed heart failure soon afterward; echocardiography showed mitral insufficiency with mobile vegetation attached to the mitral valve, indicating infective endocarditis. After transfer to our hospital, the patient underwent mitral valve repair. Broad-range polymerase chain reaction (br-PCR) and sequencing identified Aggregatibacter aphrophilus in the excised vegetation. The patient had a good postoperative course, with recovery of renal function. CONCLUSION: A rare disease, Aggregatibacter aphrophilus infective endocarditis was successfully treated with surgical repair and appropriate antibiotic therapy. To avoid misdiagnosis, br-PCR testing should be performed in patients with blood culture-negative endocarditis.